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1
Handayani, Tri, and Kazuo Watanabe. "The combination of drought and heat stress has a greater effect on potato plants than single stresses." Plant, Soil and Environment 66, No. 4 (April 30, 2020): 175–82. http://dx.doi.org/10.17221/126/2020-pse.
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Several research groups have examined the effects of drought stress and heat stress on potato, but few investigations of the effects of combined drought-heat stress have been reported. Using five potato lines, the potato plants’ responses to drought stress, heat stress, as well as combined drought-heat stress were studied, to get the insight in phenotypic shift due to abiotic stresses. The experiment was conducted as a growth room experimental under non-stress and abiotic stresses (drought, heat, and combined drought-heat) conditions. The results demonstrated that potato plants responded to the abiotic stresses by decreasing their plant height, leaf size, cell membrane stability, and relative water content (RWC). However, increasing their leaf chlorophyll content under drought and combined drought-heat stresses. Generally, the combined drought-heat stress had a greater effect on the tested traits. The potato line L1 (84.194.30) showed the lowest level of wilting in all three types of abiotic stress, supported by a small RWC change compared to the control condition; L1 is thus considered relatively tolerant to abiotic stress. The potato lines’ different responses to each type of abiotic stress indicate that the potato lines have different levels of sensitivity to each abiotic stress.
2
Kaňová, D., and E. Kula. "The effect of stress factors on birch Betula pendula Roth." Journal of Forest Science 50, No. 9 (January 11, 2012): 399–404. http://dx.doi.org/10.17221/4636-jfs.
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In a controlled pot trial, plants of birch (Betula pendula Roth) were treated in six variants: acid watering (pH 3), acid watering with spraying, drought, ammonium sulphate fertilisation, ammonium sulphate fertilisation in combination with drought, and control. The response to the treatment with ammonium sulphate in terms of the increment was discordant as it increased the sensitivity of birch to frost. Drought had a negative effect on increments. A combination of ammonium sulphate and drought; drought; ammonium sulphate and sprayed acid watering delayed the shedding of leaves; this was due to a longer vegetation period, significantly higher nitrogen content in these variants, with the exception of drought.
3
Zhu, X. C., F. B. Song, S. Q. Liu, T. D. Liu, and X. Zhou. " Arbuscular mycorrhizae improves photosynthesis and water status of Zea mays L. under drought stress." Plant, Soil and Environment 58, No. 4 (April 19, 2012): 186–91. http://dx.doi.org/10.17221/23/2011-pse.
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The influences of arbuscular mycorrhizal (AM) fungus on growth, gas exchange, chlorophyll concentration, chlorophyll fluorescence and water status of maize (Zea mays L.) plants were studied in pot culture under well-watered and drought stress conditions. The maize plants were grown in a sand and black soil mixture for 4 weeks, and then exposed to drought stress for 4 weeks. Drought stress significantly decreased AM colonization and total dry weight. AM symbioses notably enhanced net photosynthetic rate and transpiration rate, but decreased intercellular CO<sub>2</sub> concentration of maize plants regardless of water treatments. Mycorrhizal plants had higher stomatal conductance than non-mycorrhizal plants under drought stress. The concentrations of chlorophyll were higher in mycorrhizal than non-mycorrhizal plants under drought stress. AM colonization significantly increased maximal fluorescence, maximum quantum efficiency of PSII photochemistry and potential photochemical efficiency, but decreased primary fluorescence under well-watered and droughted conditions. Mycorrhizal maize plants had higher relative water content and water use efficiency under drought stress compared with non-mycorrhizal plants. The results indicated that AM symbiosis alleviates the toxic effect of drought stress via improving photosynthesis and water status of maize plants.
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Mudge, Kenneth W., Kent S. Diebolt, and Thomas H. Whitlow. "Ectomycorrhizal Effect on Host Plant Response to Drought Stress." Journal of Environmental Horticulture 5, no. 4 (December 1, 1987): 183–87. http://dx.doi.org/10.24266/0738-2898-5.4.183.
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Ectomycorrhizal symbiosis affects the water relations and drought resistance of woody landscape trees and shrubs in the families Pinaceae, Fagaceae, Betulaceae, and others. It has frequently been observed that host plants mycorrhizal with drought-adapted fungi exhibit improved growth and survival during drought and more rapid recovery after rewatering than non-mycorrhizal plants or plants mycorrhizal with fungi not adapted to dry sites. Relatively few studies have addressed the effect of mycorrhizae on the physiological response of host plants to drought stress. It is suggested that some fungi confer drought tolerance to their host, while others confer drought avoidance. Possible mechanisms by which mycorrhizae influence host water relations are discussed.
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Toscano, Stefania, Antonio Ferrante, and Daniela Romano. "Response of Mediterranean Ornamental Plants to Drought Stress." Horticulturae 5, no. 1 (January 14, 2019): 6. http://dx.doi.org/10.3390/horticulturae5010006.
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Ornamental plants use unique adaptive mechanisms to overcome the negative effects of drought stress. A large number of species grown in the Mediterranean area offer the opportunity to select some for ornamental purposes with the ability to adapt to drought conditions. The plants tolerant to drought stress show different adaptation mechanisms to overcome drought stress, including morphological, physiological, and biochemical modifications. These responses include increasing root/shoot ratio, growth reduction, leaf anatomy change, and reduction of leaf size and total leaf area to limit water loss and guarantee photosynthesis. In this review, the effect of drought stress on photosynthesis and chlorophyll a fluorescence is discussed. Recent information on the mechanisms of signal transduction and the development of drought tolerance in ornamental plants is provided. Finally, drought-induced oxidative stress is analyzed and discussed. The purpose of this review is to deepen our knowledge of how drought may modify the morphological and physiological characteristics of plants and reduce their aesthetic value—that is, the key parameter of assessment of ornamental plants.
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Krček, M., P. Slamka, K. Olšovská, M. Brestič, and M. Benčíková. "Reduction of drought stress effect in spring barley (Hordeum vulgare L.) by nitrogen fertilization." Plant, Soil and Environment 54, No. 1 (January 14, 2008): 7–13. http://dx.doi.org/10.17221/2781-pse.
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An effect of nitrogen rates (0.0 g, 1.0 g, 2.0 g N per pot) on NRA (nitrate reductase activity) in leaves of spring barley (cultivar Kompakt) was investigated in a pot experiment. Plants were grown under optimum moisture regime and drought stress was induced during the growth stages of tillering, shooting and earing. Before and after respective stress period plants were grown under optimal water regime. In all the fertilized and unfertilized treatments, NRA was significantly higher under optimal water regime than in drought stress conditions. Nitrogen fertilization alleviated adverse effects of drought stress on the yields of grain; the rate of 1 g N per pot increased the grain yield of plants stressed during tillering 3.73 times compared to unfertilized and stressed treatment. When the stress was induced during shooting or earing grain yields declined by over 50% compared to optimal water regime; when compared with stressed and unfertilized treatment, the rate of 1 g N however increased yield by 29% (stress at shooting) and 55% (stress at earing). NRA values were significantly higher when plants were grown under optimum water regime than under stress conditions as well as when fertilized with nitrogen compared to unfertilized control both under optimum water regime and drought stress.
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Lee, Jin Wook, Kenneth W. Mudge, and Joseph Lardner. "Effect of Drought Stress on Growth and Ginsenoside Content of American Ginseng." HortScience 40, no. 4 (July 2005): 1116A—1116. http://dx.doi.org/10.21273/hortsci.40.4.1116a.
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American ginseng (Panax quinquefolium L.) contains pharmacologically active secondary compounds known as ginsenosides, which have been shown to be affected by both genetic and environmental factors. In this greenhouse experiment, we tested the hypothesis that ginsenosides would behave as “stress metabolites” and be associated with osmoregulation in response to drought stress. Two year-old seedlings, grown in 5-inch pots, were well watered for 40 days prior to the initiation of treatments. Plants in the drought stress treatment were watered every 20 days while the controls were watered every 10 days, and the experiment was terminated after 4 and 8 dry down cycles (80 days), respectively. Predawn leaf water potential and relative water content (RWC) of drought-stressed plants during a typical dry down cycle were lower than control plants. The diameter and weight of primary storage roots were decreased in the stressed treatment. The length of the main storage root and the longest secondary (fibrous) root were significantly increased by the drought stress treatment. Leaf chlorophyll content of drought-stressed plants was lower than controls. The osmotic potential of the drought-stressed ginseng was not lower than the control, indicating that ginsenoside is not involved in osmoregulation in response to drought stress. Furthermore, ginsenosides Rb1 and Rd, and total ginsenosides were significantly lower in primary roots of drought-stressed plants compared to control plants.
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Fathi, Amin, and Davood Barari Tari. "Effect of Drought Stress and its Mechanism in Plants." International Journal of Life Sciences 10, no. 1 (February 10, 2016): 1–6. http://dx.doi.org/10.3126/ijls.v10i1.14509.
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Drought is the most important abiotic factor limiting growth, adversely affect growth and crop production. Stresses, resulting in the non-normal physiological processes that influence one or a combination of biological and environmental factors. Stress can damage which has occurred as a result of an abnormal metabolism and may reduce growth, plant death or the death of the plant develops. Production is limited by environmental stresses, according to different scholars estimates, only 10 percent of the world's arable land is free from Stress, in general, a major factor in the difference between yield and potential performance, environmental stresses. Drought and stress is the most common environmental stresses that almost 25 percent of agricultural lands for agricultural farm products in the world is limited. Drought risk to successful production of crops worldwide and occurs when a combination of physical and environmental factors causing stress in plants and thus reduce production.International Journal of Life Sciences 10 (1) : 2016; 1-6
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Vandegeer, Rebecca, Rebecca E. Miller, Melissa Bain, Roslyn M. Gleadow, and Timothy R. Cavagnaro. "Drought adversely affects tuber development and nutritional quality of the staple crop cassava (Manihot esculenta Crantz)." Functional Plant Biology 40, no. 2 (2013): 195. http://dx.doi.org/10.1071/fp12179.
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Cassava (Manihot esculenta Crantz) is the staple food source for over 850 million people worldwide. Cassava contains cyanogenic glucosides and can be toxic to humans, causing paralysing diseases such as konzo, and even death if not properly processed. Konzo epidemics are often associated with times of drought. This may be due to a greater reliance on cassava as it is drought tolerant, but it may also be due to an increase in cyanogenic glucosides. Episodic droughts are forecast to become more common in many cassava-growing regions. We therefore sought to quantify the effect of water-stress on both yield and cyanogenic glucoside concentration (CNc) in the developing tubers of cassava. Five-month-old plants were grown in a glasshouse and either well watered or droughted for 28 days. A subset of droughted plants was re-watered half way through the experiment. Droughted plants had 45% fewer leaves and lower tuber yield, by 83%, compared with well-watered plants. CNc was 2.9-fold higher in the young leaves of droughted plants, whereas CNc in tubers from droughted plants was 4-fold greater than in tubers from well-watered plants. Re-watered plants had a similar biomass to control plants, and lower CNc than droughted plants. These findings highlight the important link between food quality and episodic drought.
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Aras, Servet, and Hakan Keles. "Responses of Apple Plants to Drought Stress." Journal of Agricultural Studies 7, no. 2 (August 14, 2019): 153. http://dx.doi.org/10.5296/jas.v7i3.15271.
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In order to screen apple rootstocks for drought tolerance, two different drought levels moderate and severe stress, and a control were applied to apple cultivar Red Chief grafted onto M9 and MM106 rootstocks. Apple plants were subjected to drought stress by withholding water for 15 and 19 days in the greenhouse conditions, while the control treatment was continued watering. Data were recorded 15 (moderate drought stress) and 19 days (severe drought stress) after application of drought stress. At the end of the experiment, both rootstocks were significantly affected under drought conditions. Severe drought stress caused decrease in SPAD value in Red Chief grafted onto M9 and MM106 by 15.7 % and 11.1 %, respectively. Severe drought stress declined anthocyanin content in M9 and MM106 by 7.8 % and 28.4 %, respectively. Stomatal conductance was remarkably affected by drought stress. Effects of drought stress on plants depended on rootstocks, severity and duration of drought stress. As a result, the more invigorating rootstock MM106 was found more drought-tolerant when compared to M9 that is needed to be evaluated with more parameters.
11
Kokorev, O. I., and M. A. Shkliarevskyi. "Stress-protective effect of putrescine and spermine on wheat plants during soil drought." Vìsnik Harkìvsʹkogo nacìonalʹnogo agrarnogo unìversitetu. Serìâ Bìologiâ 2020, no. 3 (October 30, 2020): 58–70. http://dx.doi.org/10.35550/vbio2020.03.058.
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Polyamines are considered multifunctional stress metabolites in plants. The ability of exogenous polyamines to increase plant resistance to adverse factors of various nature is well-known. At the same time, the stress-protective effects of polyamines at the level of whole plants under conditions of dehydration close to natural have not been sufficiently studied. The aim of this work was to study the effect of foliar treatment of wheat plants with solutions of putrescine and spermine on the functioning of their protective systems during drought under laboratory soil culture conditions. In the experiments, we used young wheat plants (Triticum aestivum L.), which were subjected to a 4-day drought with a gradual decrease in the water content in the soil to 25% of the total moisture capacity. Spraying plants with putrescine in a concentration range of 0,25-5 mM significantly reduced the growth-inhibiting effect of drought; the effect of spermine was less effective, but also significant at P ≤ 0,05. Putrescine significantly reduced the manifestation of water deficit caused by drought. Under the action of spermine, only a tendency towards a decrease in the water deficit of the leaves was noted. Drought caused the effect of oxidative stress, which was manifested in an increase in the content of malondialdehyde (MDA) in leaves. During the pretreatment of plants with spermine, the increase in the MDA content was partially leveled, and under the action of putrescine it was leveled almost completely. Treatment of plants with both polyamines at concentrations of 1 and 5 mM promoted preservation of the pool of chlorophylls and carotenoids in leaves under stress conditions. Moreover, when plants were treated with putrescine and spermine under drought conditions, a close to usual ratio of chlorophylls a/b was maintained. The proline content in leaves increased significantly under the influence of drought. Pretreatment with 1 and 5 mM putrescine, and 5 mM spermine reduced effect of proline content growth in leaves, caused by drought. At the same time, the treatment of plants with both polyamines caused the accumulation of sugars in the leaves. Under the influence of drought, the content of anthocyanins and flavonoids absorbing in the UV-B region significantly decreased in the leaves. Pretreatment with spermine somewhat mitigated the negative effect of drought on the anthocyanin content. Under the action of both putrescine and spermine, the content of flavonoids absorbing in UV-B stabilized in leaves. It was concluded that the protective effect of polyamines on wheat plants under drought conditions is primarily due to the regulation of water metabolism and the prevention of oxidative damage.
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Yang, Xinyi, Meiqi Lu, Yufei Wang, Yiran Wang, Zhijie Liu, and Su Chen. "Response Mechanism of Plants to Drought Stress." Horticulturae 7, no. 3 (March 13, 2021): 50. http://dx.doi.org/10.3390/horticulturae7030050.
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With the global climate anomalies and the destruction of ecological balance, the water shortage has become a serious ecological problem facing all mankind, and drought has become a key factor restricting the development of agricultural production. Therefore, it is essential to study the drought tolerance of crops. Based on previous studies, we reviewed the effects of drought stress on plant morphology and physiology, including the changes of external morphology and internal structure of root, stem, and leaf, the effects of drought stress on osmotic regulation substances, drought-induced proteins, and active oxygen metabolism of plants. In this paper, the main drought stress signals and signal transduction pathways in plants are described, and the functional genes and regulatory genes related to drought stress are listed, respectively. We summarize the above aspects to provide valuable background knowledge and theoretical basis for future agriculture, forestry breeding, and cultivation.
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Lukács, A., G. Pártay, T. Németh, S. Csorba, and C. Farkas. "Drought stress tolerance of two wheat genotypes." Soil and Water Research 3, Special Issue No. 1 (June 30, 2008): S95—S104. http://dx.doi.org/10.17221/10/2008-swr.
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Biotic and abiotic stress effects can limit the productivity of plants to great extent. In Hungary, drought is one of the most important constrains of biomass production, even at the present climatic conditions. The climate change scenarios, developed for the Carpathian basin for the nearest future predict further decrease in surface water resources. Consequently, it is essential to develop drought stress tolerant wheat genotypes to ensure sustainable and productive wheat production under changed climate conditions. The aim of the present study was to compare the stress tolerance of two winter wheat genotypes at two different scales. Soil water regime and development of plants, grown in a pot experiment and in large undisturbed soil columns were evaluated. The pot experiments were carried out in a climatic room in three replicates. GK Élet wheat genotype was planted in six, and Mv Emese in other six pots. Two pots were left without plant for evaporation studies. Based on the mass of the soil columns without plant the evaporation from the bare soil surface was calculated in order to distinguish the evaporation and the transpiration with appropriate precision. A complex stress diagnosis system was developed to monitor the water balance elements. ECH<sub>2</sub>O type capacitive soil moisture probes were installed in each of the pots to perform soil water content measurements four times a day. The irrigation demand was determined according to the hydrolimits, derived from soil hydrophysical properties. In case of both genotypes three plants were provided with the optimum water supply, while the other three ones were drought-stressed. In the undisturbed soil columns, the same wheat genotypes were sawn in one replicate. Similar watering strategy was applied. TDR soil moisture probes were installed in the soil at various depths to monitor changes in soil water content. In order to study the drought stress reaction of the wheat plants, microsensors of 1.6 mm diameter were implanted into the stems and connected to a quadrupole mass spectrometer for gas analysis. The stress status was indicated in the plants grown on partly non-irrigated soil columns by the lower CO<sub>2</sub> level at both genotypes. It was concluded that the developed stress diagnosis system could be used for soil water balance elements calculations. This enables more precise estimation of plant water consumption in order to evaluate the drought sensitivity of different wheat genotypes.
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Rezazadeh, Amir, Richard L. Harkess, and Guihong Bi. "Effects of Paclobutrazol and Flurprimidol on Water Stress Amelioration in Potted Red Firespike." HortTechnology 26, no. 1 (February 2016): 26–29. http://dx.doi.org/10.21273/horttech.26.1.26.
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This study evaluated the effects of paclobutrazol (PBZ) and flurprimidol on the morphological and physiological characteristics of potted red firespike (Odontonema strictum) under drought stress. PBZ and flurprimidol were applied as a soil drench at 0.24 mg/pot. Untreated plants acted as a control. The plants were exposed to drought stress 2 weeks after plant growth regulator (PGR) application. Another group of plants treated with PGRs was watered regularly. A reduction in plant height, plant diameter, and growth index (GI) was observed in plants treated with PGRs and drought stress 5 weeks after beginning the study. Drought stress reduced plant height by 45% compared with control. Flurprimidol under drought stress decreased plant diameter and GI by 36% and 76%, respectively, compared with the control. The least leaf area and plant dry weight were observed in plants drenched with flurprimidol and grown under drought stress. Drought stress also delayed flowering and the number of plants flowering. Plants treated with PBZ had the highest photosynthesis rate, 54% more than untreated plants under drought stress alone. The lowest stomatal conductance (gS) was measured in plants under drought stress alone or drought plus PBZ. Application of PBZ-enhanced red firespike drought tolerance reducing adverse effects of water stress on photosynthesis during the experiment.
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Augé, Robert, Keunho Cho, Jean Stutz, and Heather Toler. "(319) Mycorrhizal Symbiosis and Response of Sorghum Plants to Combined Drought and Salt Stresses." HortScience 40, no. 4 (July 2005): 1037C—1037. http://dx.doi.org/10.21273/hortsci.40.4.1037c.
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Colonization of roots by arbuscular mycorrhizal (AM) fungi can increase host resistance to drought stress, although the effect is unpredictable. Since AM symbiosis also frequently increases host resistance to salt stress, and since drought and salt stress are often linked in drying soils, we speculated that the AM influence on plant drought response may be linked to AM influence on salt stress. We tested the hypothesis that AM-induced effects on drought responses would be more pronounced when plants of comparable size are exposed to drought in salinized soils. In two greenhouse experiments, several water relations characteristics were measured in sorghum plants colonized by Glomus intraradices, Gigaspora margarita, or a mixture of AM species during a sustained drought following exposure to salt treatments (NaCl stress, osmotic stress, or soil leaching). The presence of excess salt in soils widened the difference in drought responses between AM and non-AM plants in just two instances: days needed for plants to reach stomatal closure, and promotion of stomatal conductance. In other instances, the addition of salt tended to nullify an AM-induced change in drought response; e.g., an AM effect on the decline in leaf or soil water potential required to cause stomatal closure disappeared when soils were salinized. Our findings confirm that AM fungi can alter host response to drought but do not lend much support to the idea that AM-induced salt resistance might help explain why AM plants can be more resilient to drought stress than their non-AM counterparts.
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Li, Biao, Jing Ni, Jin Hua Wang, Zhi Xiong, Juan Wang, Li Li Zhu, and Shao Xiong Liu. "Effect of Water-Retaining Agent on Growth and Development of Three Local Legumes on Lead-Zinc Tailings of Lanping." Advanced Materials Research 518-523 (May 2012): 1744–48. http://dx.doi.org/10.4028/www.scientific.net/amr.518-523.1744.
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Effect of water-retaining agent on growth and development of three local legumes were studied, in order to provide science basis for revegetation of lead-zinc tailings in Lanping. Testing survival numbers and moisture and proline content in plants, aim at revealing effect of water-retaining agent on plants under drought stress. The results show that water-retaining agent can prolong survival time of plants and keep stability of moisture and proline content in plants under drought stress. Survival numbers and moisture content of plants leafs decrease with prolonging drought stress time, and proline content of plants leafs increase with prolonging drought stress time. There was no significant difference of survival numbers and moisture and proline content in plants on tailings soil with 0.3% and 0.4% water-retaining agent, so 0.3% water-retaining agent was best dosage in tailings soil for revegetation of lead-zinc tailings in Lanping.
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Ruppenthal, Viviane, Tiago Zoz, Fábio Steiner, Maria Do Carmo Lana, and Deise Dalazen Castagnara. "Silicon does not alleviate the adverse effects of drought stress in soybean plants." Semina: Ciências Agrárias 37, no. 6 (December 14, 2016): 3941. http://dx.doi.org/10.5433/1679-0359.2016v37n6p3941.
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Beneficial effects of silicon (Si) in the plants growth under conditions of drought stress have been associated with to uptake and accumulation ability of element by different species. However, the effects of Si on soybean under water stress are still incipient and inconclusive. This study investigated the effect of Si application as a way to confer greater soybean tolerance to drought stress. The experiment was carried out in 20-L pots under greenhouse conditions. Treatments were arranged in a randomized block design in a 2 × 4 factorial: two water regimes (no stress or water stress) and four Si rates (0, 50, 100 and 200 mg kg–1). Soybean plants were grown until beginning flowering (R1) growth stage with soil moisture content near at the field capacity, and then it started the differentiation of treatments under drought by the suspension of water supply. Changes in relative water content (RWC) in leaf, electrolyte leakage from cells, peroxidase activity, plant nutrition and growth were measured after 7 days of drought stress and 3 days recovery. The RWC in soybean leaves decreased with Si rates in the soil. Silicon supply in soil with average content of this element, reduced dry matter production of soybean under well-irrigated conditions and caused no effect on dry matter under drought stress. The nitrogen uptake by soybean plants is reduced with the Si application under drought stress. The results indicated that the Si application stimulated the defense mechanisms of soybean plants, but was not sufficient to mitigate the negative effects of drought stress on the RWC and dry matter production.
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Sharif, Asim, and Utsab Thapa. "Effect of Water Stress in Soil Nitrogen Dynamics under Intercropping System with Maize and Sorghum." Forestry: Journal of Institute of Forestry, Nepal 15 (July 31, 2018): 1–12. http://dx.doi.org/10.3126/forestry.v15i0.24916.
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Global warming, one of the most persistent threats to nature, is expected to result in severe droughts in many parts of the world. Droughts are supposed to effect individual plants and/or plant communities by changing their a/ biotic interactions. The objective of this study was to elucidate drought effects on soil nitrogen allocation in different aggregate sizes. This was done by growing Zea mays and Sorghum bicolor in monoculture and mixture. Nitrogen allocation under drought stress was traced using nitrogen stable isotope 15N. Drought disintegrated soil aggregates into finer aggregates for sorghum monoculture and decreased the aggregate proportion in small macro-aggregate fraction for maize monoculture. For plant mixture, drought increased total nitrogen content in micro-aggregate fraction and uptake of added 15N in bulk soil. Hence, the study showed that mix planting maize and sorghum offer better resistance against changes in plant biomass and nitrogen content which suggests its effectiveness in nitrogen conservation during water stress. Moreover, intergrowing maize and sorghum under agroforestry systems also produce advantageous results.
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KIRAN, Sevinç. "Effects of Vermicompost on Some Morphological, Physiological and Biochemical Parameters of Lettuce (Lactuca sativa var. crispa) under Drought Stress." Notulae Botanicae Horti Agrobotanici Cluj-Napoca 47, no. 2 (December 21, 2018): 352–58. http://dx.doi.org/10.15835/nbha47111260.
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Vermicompost can play an effective and important role in plant growth and development and also in reducing harmful effects of various environmental stresses on plants. The vermicompost fertilizer application was evaluated for the growth, physiological and biochemical parameters of lettuce (Lactuca sativa var. crispa) plants under drought stress conditions. Tests were carried out at different levels of vermicompost (0, 2.5 and 5%) and drought stress [no stress, moderate drought, and severe drought at 100, 50 and 25% of field capacity]. In comparison to control (vermicompost at 0%), lettuce plants treated with vermicompost at 2.5 or 5% had higher shoot height, shoot fresh weight, relative water content, stomatal conductance, chlorophyll a, chlorophyll b , total chlorophyll and carotenoid contents under moderate and severe drought stress conditions. Malondialdehyde (MDA) content and superoxide dismutase (SOD) and catalase (CAT) activities increased while plants under drought stress conditions. Application of vermicompost caused higher SOD and CAT enzyme activities and lower MDA content under drought stress. Enhancement in antioxidant enzyme activities as a result of vermicompost destroyed reactive oxygen species. Therefore, application of vermicompost under moderate and severe drought stress decreased MDA content in lettuce plant cells. Data indicated a positive effect of the vermicompost on the growth of lettuce under drought stress conditions.
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Veatch-Blohm, Maren E., and Dennis T. Ray. "(453) Effect of Drought Stress on Growth and Secondary Compound Production in Greenhouse-grown Guayule." HortScience 40, no. 4 (July 2005): 1036B—1036. http://dx.doi.org/10.21273/hortsci.40.4.1036b.
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As a native of the Chihuahuan desert, guayule (Partheniumargentatum Gray) has a history of dealing with low water availability. Agronomic studies have shown that increasing irrigation increases overall rubber yields, but decreases rubber concentration per plant. As water availability is an important factor in agricultural production, this study was conducted to examine how drought affects plant growth and secondary compound distribution throughout the plant. One-year-old guayule plants were subjected to water stress from June through August, in 2003 and 2004. The well-watered treatment was irrigated daily, and the drought-stressed plants were irrigated when the soil water potential reached 6 (0.6) or 3 (0.3) bars (megapascals) in 2003 and 2004, respectively. Plant growth was monitored by measuring height, width, and stem diameter. Fresh weight of shoots and roots was recorded at harvest, and a subset of plants were defoliated and used to determine leaf weight and area. Resin and rubber were extracted from dried and ground plant samples. Growth, leaf weight, and leaf to stem ratio were decreased in the drought-stressed plants compared to the well-watered plants. Rubber concentration, but not resin concentration, was higher in the drought-stressed plants. There were no significant differences in resin and rubber concentration in the leaves and roots of the different treatments; however, they were both higher in the stems of the drought-stressed plants. In guayule, rubber is deposited mainly in the bark parenchyma of the stems. The drought-stressed plants had a greater contribution of stem biomass to overall biomass and a reduced stem diameter with higher bark to wood ratio, which could account for the higher rubber concentration in the drought-stressed plants.
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Habibi, Ghader, and Roghieh Hajiboland. "Alleviation of drought stress by silicon supplementation in pistachio (Pistacia vera L.) plants." Folia Horticulturae 25, no. 1 (June 1, 2013): 21–29. http://dx.doi.org/10.2478/fhort-2013-0003.
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ABSTRACT The effect of silicon (Si) supplementation (0.35 g Na2SiO3 kg-1 soil, 2.73 mmol Si kg-1 soil) was studied in drought-stressed pistachio (Pistacia vera L. ‘Ahmadaghaii’) plants under field conditions. Silicon treatment significantly increased plant dry weight and relative water content under drought stress. The application of Si for drought-stressed plants improved the maximum quantum yield of PSII. A reduction in the net assimilation rate due to drought stress was alleviated by Si application, accompanied by an increase in stomatal conductance. Silicon treatment resulted in higher catalase and superoxide dismutase activities and lower lipid peroxidation in the leaves of drought-stressed plants. The results suggest that supplementation of water-deficient pistachio plants with Si alleviates the adverse effects of drought due to its enhancement of photochemical efficiency and photosynthetic gas exchange, as well as an activation of the antioxidant defence capacity in this species.
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Kim, Tae Yoon, Sang-Hyo Lee, Hara Ku, and Seung-Yop Lee. "Enhancement of Drought Tolerance in Cucumber Plants by Natural Carbon Materials." Plants 8, no. 11 (October 24, 2019): 446. http://dx.doi.org/10.3390/plants8110446.
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Stress induced by climate change is a widespread and global phenomenon. Unexpected drought stress has a substantial effect on the growth and productivity of valuable crops. The effects of carbon materials on living organisms in response to abiotic stresses remain poorly understood. In this study, we proposed a new method for enhancing drought tolerance in cucumber (Cucumis sativus L.) using carbon nanotubes and natural carbon materials called shungite, which can be easily mixed into any soil. We analyzed the phenotype and physiological changes in cucumber plants grown under conditions of drought stress. Shungite-treated cucumber plants were healthier, with dark green leaves, than control plants when watering was withheld for 21 days. Furthermore, compared with the control cucumber group, in the shungite-treated plants, the monodehydroascorbate content of the leaf, which is a representative marker of oxidative damage, was 66% lower. In addition, major scavenger units of reactive oxygen species and related drought stress marker genes were significantly upregulated. These results indicate that successive pretreatment of soil with low-cost natural carbon material improved the tolerance of cucumber plants to drought stress.
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Ogneva, Zlata V., Andrey R. Suprun, Alexandra S. Dubrovina, and Konstantin V. Kiselev. "Effect of 5-azacytidine induced DNA demethylation on abiotic stress tolerance in Arabidopsis thaliana." Plant Protection Science 55, No. 2 (February 17, 2019): 73–80. http://dx.doi.org/10.17221/94/2018-pps.
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The effect of 5-azacytidine (5A)-induced DNA hypomethylation on the growth and abiotic stress tolerance of Arabidopsis thaliana were analysed. Growth analysis revealed that aqueous solutions of 5A added to the soil did not affect the fresh and dry biomass accumulation but led to a higher percentage of flowering A. thaliana plants after four weeks of cultivation. The 5A treatment considerably lowered survival rates of Arabidopsis plants under high soil salinity, heat stress, and drought, while it did not affect the survival rates after freezing stress. 5A eliminated the stimulatory effect of the heat and drought stresses on the transcriptional levels of a number of stress-inducible genes, such as DREB1, LEA, SOS1, or RD29A. A less clear but similar trend has been detected for the effect of 5A on expression of the stress-inducible genes under salt and cold stresses. The data indicate that DNA methylation is an important mechanism regulating plant abiotic stress resistance.
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Cohen, Ana C., Claudia N. Travaglia, Rubén Bottini, and Patricia N. Piccoli. "Participation of abscisic acid and gibberellins produced by endophytic Azospirillum in the alleviation of drought effects in maize." Botany 87, no. 5 (May 2009): 455–62. http://dx.doi.org/10.1139/b09-023.
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Azospirillum spp. are plant growth promoting bacteria (PGPB) that enhance growth by several mechanisms, including the production of phytohormones such as abscisic acid (ABA), indole-3-acetic acid (IAA), and gibberellins (GAs). Their presence may also alleviate plant water stress. In the present paper, the effects of Azospirillum lipoferum in maize ( Zea mays L.) plants treated with inhibitors of ABA and GA synthesis, fluridone (F) and prohexadione-Ca (P), respectively, and either submitted to drought stress or provided sufficient water, were analysed. Fluridone diminished the growth of plants that had been well watered, in a manner similar to drought, but inoculation with Azospirillum completely reversed this effect. The relative water content of the F-treated and drought-stressed plants was significantly lower (even though drought-stressed plants had been allowed to recover for one week), and this effect was completely neutralized by Azospirillum. These results were correlated with ABA levels assessed by GC-EIMS. Growth was diminished in drought-submitted plants treated with P, alone or combined with F, even though ABA levels were enhanced, suggesting that GAs produced by the bacterium are also important in stress alleviation. The results suggest that both ABA and GAs contribute to water-stress alleviation of plants by Azospirillum.
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Umami, Mashlahatul, Linda M. Parker, and Stefan K. Arndt. "The Impacts of Drought Stress and Phytophthora cinnamomi Infection on Short-Term Water Relations in Two Year-Old Eucalyptus obliqua." Forests 12, no. 2 (January 20, 2021): 109. http://dx.doi.org/10.3390/f12020109.
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The effects of drought stress, Phytophthora cinnamomi infection and their interaction on water relations and growth were examined for 28 days on two year-old potted trees of Eucalyptus obliqua (L’Hér.). There were significant effects of drought stress on plant photosynthesis, stomatal conductance, biomass accumulation, plant water potential at turgor loss point and the bulk modulus of elasticity. E. obliqua was successfully infected but the trees showed only mild symptoms. Infection with P. cinnamomi led to a significant reduction in the root biomass and root-to-shoot ratio in well-watered and droughted plants but did not impact water relations. There was no observable cumulative effect of drought and P. cinnamomi infection. There are multiple potential reasons why P. cinnamomi infection did not lead to drought-like symptoms in E. obliqua, including short experimental duration, delayed infection symptoms, potential resistance of E. obliqua and a possible lower aggressiveness of the P. cinnamomi strain. Hence, our results indicate that P. cinnamomi infection will not always lead to immediate short-term symptoms, and that plants that are mildly symptomatic respond very similar to drought stress compared to non-infected trees.
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Heidari, M., N. Amirfazli, H. Ghorbani, and F. Zafarian. "Calcium Chloride and Drought Stress Changed Grain Yield and Physiological Traits in Sesame (Sesamum indicum L.)." Scientia Agriculturae Bohemica 50, no. 4 (December 1, 2019): 211–18. http://dx.doi.org/10.2478/sab-2019-0029.
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Abstract Water deficit or drought stress is one of the most significant abiotic stresses that induce reduction in plant growth and crops yield. Calcium chloride has been shown to ameliorate the adverse effects of drought stress on many plants. Therefore, this study aimed to investigate the role of calcium chloride in drought resistance and its effect on some physiological characteristics in sesame. Calcium is essential for good growth and structure of plants. In sesame (Sesamum indicum L.), the foliar application of calcium chloride (C1=0 (control), C2=5, C3=10 and C4=15 mM concentration) significantly affected on grain yield under drought stress (W1= 7 (control, no drought stress-plants irrigation at a 7-day interval), W2= 12 (severe drought and plants irrigation at a 12- day interval) and W3= 17 (the most severe drought and plants irrigation at a 17-day interval). Drought stress reduced grain yield and 1000 seed weight, but these were enhanced by foliar application of calcium chloride when drought levels increased from W1 to W3. Although the increasing calcium chloride concentration reduced the content of photosynthesis pigments in leaves, the drought treatment until W2 increased the content of photosynthetic pigments (chlorophyll “a” and carotenoids) in leaves. The foliar application of calcium chloride increased the seed weight in plant, the number of capsules per plant, plant height, and the concentration of potassium and phosphorus in leaves and seeds. The greatest amount of potassium in leaves and seeds were measured under the W1C3 treatment. Sesame plants under W3C3 and W2C3 had the highest amount of phosphorus in leaves and seeds, respectively. Overall, although drought stress reduced the growth and grain yield in sesame, the foliar application of calcium chloride at the concentration of 10 mM, prevented the drought-stressed sesame plants from damage by improving their physiological parameters.
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Thakur, Jaya, and Bharat Shinde. "Effect of water stress and AM fungi on the growth performance of pea." International Journal of Applied Biology 4, no. 1 (June 29, 2020): 36–43. http://dx.doi.org/10.20956/ijab.v4i1.9446.
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The study was conducted to determine the effect of arbuscular mycorrhizal (AM) fungi inoculation on growth of pea grown under water stressed pot culture conditions. Water stress was given to the pea plants after 30 days at the interval of 4, 8 and 12 days. The data was collected at an interval of 15 days. Three replicates of each set were maintained. . The mixture of AM fungi used for current experiment included the species of Acaulospora denticulata, A. gerdemannii, Glomus macrocarpum, G. maculosum, G. fasciculatum and Scutellospora minuta. The mycorrhizal plants have shown more shoot and root length as compared to the control plants. The height of shoot and root was significantly decreased with the increase in drought stress. Mycorrhizal plants with low water stress showed enhanced shoot and root length than high water stress. The mycorrhizal plants have shown more number of leaves than control plants during drought stress. The number of leaves significantly reduced with the increase in drought stress. The leaves produced by the control plants were comparatively smaller than those of mycorrhizal plants. The dry weight of root and shoot of both control and mycorrhizal plants decreased with the increase in water stress. Mycorrhizal plants showed more dry weight of shoot and root as compared to control plants. Plants inoculated with AM fungi produce more dry weight than the control plants. The fresh weight of both control and mycorrhizal plants has been decreased with the increase in water stress interval and also the fresh weight of root and shoot was observed higher in mycorrhizal plants as compared to those of control plants.
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Hasan, Md Mahadi, Nadiyah M. Alabdallah, Basmah M. Alharbi, Muhammad Waseem, Guangqian Yao, Xu-Dong Liu, Hany G. Abd El-Gawad, et al. "GABA: A Key Player in Drought Stress Resistance in Plants." International Journal of Molecular Sciences 22, no. 18 (September 20, 2021): 10136. http://dx.doi.org/10.3390/ijms221810136.
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γ-aminobutyric acid (GABA) is a non-protein amino acid involved in various physiological processes; it aids in the protection of plants against abiotic stresses, such as drought, heavy metals, and salinity. GABA tends to have a protective effect against drought stress in plants by increasing osmolytes and leaf turgor and reducing oxidative damage via antioxidant regulation. Guard cell GABA production is essential, as it may provide the benefits of reducing stomatal opening and transpiration and controlling the release of tonoplast-localized anion transporter, thus resulting in increased water-use efficiency and drought tolerance. We summarized a number of scientific reports on the role and mechanism of GABA-induced drought tolerance in plants. We also discussed existing insights regarding GABA’s metabolic and signaling functions used to increase plant tolerance to drought stress.
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Singh*, Neelima, and B. P. Shinde. "Efficacy of AM fungi against drought stress on sweet corn cultivars with special reference to biochemical contents." International Journal of Bioassays 6, no. 06 (June 1, 2017): 5399. http://dx.doi.org/10.21746/ijbio.2017.06.004.
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This study was carried out to investigate the effect of drought stress on biochemical contents of sweet corn cultivars. The plants of sweet corn were grown in pots without mycorrhiza and with mycorrhiza i.e. control and experimental. The pots were placed under shade net and watered with normal water for one month at an interval of 4 days. The water stress treatment was started after one month at an interval of 4, 8 and 12 days. The biochemical analysis was carried out from leaves and kernels of sweet corn plants. The amount of chlorophyll, protein and starch has been decreased significantly due to increase in drought stress. The amount of proline and carbohydrates has been increased significantly with the increase in drought stress. However, these contents were more in mycorrhizal plants as compared to control plants. The results indicated that AM symbiosis alleviates the toxic effect of drought stress via improving water status of plants.
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Tale Ahmad, S., and R. Haddad. "Study of silicon effects on antioxidant enzyme activities and osmotic adjustment of wheat under drought stress." Czech Journal of Genetics and Plant Breeding 47, No. 1 (March 18, 2011): 17–27. http://dx.doi.org/10.17221/92/2010-cjgpb.
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The effect of silicon (Si) was investigated on the major antioxidant enzyme activities including superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), peroxidase (POD), relative water content (RWC), chlorophyll and soluble protein contents, proline (Pro) and glycine betaine (GB) accumulation in three different growth stages (2<sup>nd</sup>, 4<sup>th</sup> leaf and tillering stages) of wheat (Triticum aestivum L.) plants under drought stress. The experiment was performed in a completely randomized design for three treatments including control, drought and Si-drought (2mM silicate sodium/kg) with three replications in a greenhouse. The results indicated that Si partially offset the negative impacts of drought stress increasing the tolerance of wheat by rising Pro and GB accumulation and soluble protein content. Compared with the plants treated with drought, applied Si significantly enhanced the activities of SOD, CAT, APX and POD. In contrast, drought stress caused a considerable decrease in RWC, chlorophyll and soluble protein contents. This Si effect was time-dependent and became stronger in the tillering stage. The results of the present experiment coincided with the conclusion that Si alleviates water deficit of wheat by preventing the oxidative membrane damage and may be associated with plant osmotic adjustment.
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Clemente, Hiphil S., and Thomas E. Marler. "245 Growth of Papaya Seedlings under Wind Load and Drought Stress." HortScience 34, no. 3 (June 1999): 484D—484. http://dx.doi.org/10.21273/hortsci.34.3.484d.
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Two studies were conducted with `Known You 1' and `Sunrise' papaya seedlings to determine the combined influence of wind and drought stress on growth. For each study, 4-week-old nursery plants were transplanted into 2.6-L containers and placed in a protected site with rain exclusion provided by polypropylene cover. Industrial fans were used to provide unidirectional wind of ≈2 m/s for 12 hours per day to half of the plants; the remaining half of the plants received no wind. One half of the plants for each cultivar and wind combination were designated as well-watered and received daily irrigation. The remaining half of the plants were designated as drought-stressed and received 25% to 50% of the water applied to the well-watered plants. Plants were grown for 3 weeks under these experimental conditions. There were no interactions between the drought and wind main effects. The reduction in height, trunk cross-sectional area, total plant dry weight, and relative growth rate below that for control plants was similar for drought stress or wind stress. Wind stress reduced growth of `Sunrise' plants more than `Known You 1' plants in both studies. Although the main effects did not interact, the combination of drought and wind stress reduced growth of papaya seedlings more than did either main effect alone. The greatest wind load from trade winds occurs on Guam during the annual dry season. These data indicate that chronic wind stress during the dry season may be more detrimental to growth of papaya seedlings than during the rainy season or under sufficient irrigation practices.
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Gujjar, Ranjit Singh, Pennapa Banyen, Wannisa Chuekong, Phapawee Worakan, Sittiruk Roytrakul, and Kanyaratt Supaibulwatana. "A Synthetic Cytokinin Improves Photosynthesis in Rice under Drought Stress by Modulating the Abundance of Proteins Related to Stomatal Conductance, Chlorophyll Contents, and Rubisco Activity." Plants 9, no. 9 (August 27, 2020): 1106. http://dx.doi.org/10.3390/plants9091106.
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Drought susceptible rice cultivar PTT1 (Pathumthani1) was treated with drought (−72 kPa) and CPPU (N-2-(chloro-4-pyridyl)-N-phenyl urea) @ 5 mg/L at tillering and grain-filling stages. Plants were tested for the effect of synthetic cytokinin on the parameters influencing the process of photosynthesis. Exogenous spray of CPPU improved the stomatal conductance of rice leaves, which was severely reduced by drought. The abundance intensities of proteins, associated with the stomatal conductance (ZEP, NCED4, PYL9, PYL10, ABI5, SnRK4, Phot1, and Phot2), were also in agreement with the positive impact of CPPU on the stomatal conductance under drought stress. Among the photosynthetic pigments, Chl b contents were significantly reduced by drought stress, whereas CPPU treated plants retained the normal contents of Chl b under drought stress. Subsequently, we examined the abundance intensities of chlorophyll synthase and HCR proteins, implicated in the biosynthesis of chlorophyll pigments and the conversion of Chl b to Chl a, respectively. The results indicated a drought-mediated suppression of chlorophyll synthase. However, CPPU treated plants retained normal levels of chlorophyll synthase under drought stress. In addition, drought stress induced HCR proteins, which might be the cause for reduced Chl b contents in drought stressed plants. Further, CPPU treatment helped the plants sustain photosynthesis at a normal rate under drought stress, which was comparable with well-watered plants. The results were further confirmed by examining the abundance intensities of two key proteins, RAF1 and Rubisco activase, implicated in the assembly and activation of Rubisco, respectively. CPPU treatment reversed the drought mediated suppression of these proteins at both of the growth stages of rice under drought stress. Based on the results, it can be suggested that synthetic cytokinins help the plants sustain photosynthesis at a normal rate under drought stress by positively influencing the determinants of photosynthesis at a molecular level.
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Paric, Adisa, and Erna Karalija. "The Effect of Salicylic Acid on Response to Water Deficit in Basil." Genetics & Applications 2, no. 1 (June 21, 2018): 42. http://dx.doi.org/10.31383/ga.vol2iss1pp42-48.
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Drought-induced stress is the main limiting factor that affects growth and development in plants. In this study, the effect of exogenous application of salicylic acid (SA) on drought tolerance in basil was investigated. The analysis showed that application of SA under drought stress had significant effects on physiological and biochemical parameters, such as photosynthetic pigments content, total phenolics, flavonoids, flavanols and protein content and peroxidise activity, but had no significant effects on the morphological parameters, such as stem length, length and areaof leaves . In drought conditions, total phenolics and peroxidase activity reduced significantly, but all photosynthetic pigments, total flavonoids, flavanols and proteins increased significantly. Application of SA displayed some alleviating effects against drought induced stress through increase of plant growth, total flavonoids content and peroxidase activity
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Alhaithloul, Haifa Abdulaziz S. "Impact of Combined Heat and Drought Stress on the Potential Growth Responses of the Desert Grass Artemisia sieberi alba: Relation to Biochemical and Molecular Adaptation." Plants 8, no. 10 (October 15, 2019): 416. http://dx.doi.org/10.3390/plants8100416.
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Artemisia sieberi alba is one of the important plants frequently encountered by the combined effect of drought and heat stress. In the present study, we investigated the individual and combined effect of drought and heat stress on growth, photosynthesis, oxidative damage, and gene expression in A. sieberi alba. Drought and heat stress triggered oxidative damage by increasing the accumulation of hydrogen peroxide, and therefore electrolyte leakage. The accumulation of secondary metabolites, such as phenol and flavonoids, and proline, mannitol, inositol, and sorbitol, was increased due to drought and heat stress exposure. Photosynthetic attributes including chlorophyll synthesis, stomatal conductance, transpiration rate, photosynthetic efficiency, and chlorophyll fluorescence parameters were drastically reduced due to drought and heat stress exposure. Relative water content declined significantly in stressed plants, which was evident by the reduced leaf water potential and the water use efficiency, therefore, affecting the overall growth performance. Relative expression of aquaporin (AQP), dehydrin (DHN1), late embryogenesis abundant (LEA), osmotin (OSM-34), and heat shock proteins (HSP70) were significantly higher in stressed plants. Drought triggered the expression of AQP, DHN1, LEA, and OSM-34 more than heat, which improved the HSP70 transcript levels. A. sieberi alba responded to drought and heat stress by initiating key physio-biochemical and molecular responses, which were distinct in plants exposed to a combination of drought and heat stress.
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Sianturi, Eva Proditus, Budiman Budiman, and Moh Ega Elman Miska. "Respon Pertumbuhan Tanaman Iler (Coleus scutellarioides (L.) Benth) pada Kondisi Cekaman Kekeringan terhadap Inokulasi Fungi Mikoriza Arbuskular (FMA)." Journal of Tropical Silviculture 12, no. 1 (April 15, 2021): 17–22. http://dx.doi.org/10.29244/j-siltrop.12.1.17-22.
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Iler plant (Coleus artopurporeus L benth) is a plant that was originally cultivated as an ornamental plant and then developed as a medicinal plant because it contains flavonoids and anthocyanins. Drought stress is a major environmental problem that causes various changes in plant morphological, metabolic and physiological functions. Utilization of Arbuscular Mycorrhizal Fungi (AMF) is an effort to support the growth and development of iler plants in drought stress conditions. This study aims to determine the effect of AMF inoculation on the growth of iler plants under drought stress conditions, determine the optimal level of drought stress for ilher plant growth, and determine the best interaction between AMF inoculation and the level of drought stress on the growth of iler plants. The design used in this study was a completely randomized factorial 2-factor design. The first factor is AMF inoculation consisting of 2 levels, namely, without administration of AMF inoculum and AMF inoculum administration. The second factor is drought stress consists of 3 levels namely, 100% field capacity, 90% drought stress, and 45% drought stress. The results showed the effectiveness of the AMF inoculum test was able to increase the growth of iler plants based on parameters plant height, number of leaves, number of branches, leaf area, root length, root volume, root dry weight, number of spores and root infection. The optimal level of drought stress for iler plant growth is 90% drought stress, it is based on the parameters of plant height, number of leaves, number of branches, leaf area, root length, number of spores and root infection. There is the best interaction between AMF inoculation and 90% drought stress level on the growth of iler plants. These interactions can increase plant height, leaf area, number of spores and root infection.
Keywords: arbuscular mycorrhizal fungi (FMA), drought stress, iler plants
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Bayat, Hassan, and Mohammad Hossein Aminifard. "Seed priming with selenium improves growth, water relation and antioxidant activity of pot marigold (Calendula officinalis L.) under drought conditions." Acta Scientiarum Polonorum Hortorum Cultus 20, no. 1 (February 26, 2021): 27–36. http://dx.doi.org/10.24326/asphc.2021.1.3.
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Selenium (Se) seed priming is an effective method for enhancing seed performance and improving tolerance of crops to abiotic stresses particularly drought. A pot experiment was conducted to determine the effect of seed priming of pot marigold (Calendula officinalis L.) with Se on growth, physiology and antioxidant activity grown under both control and drought stress conditions. Treatments included 6 levels of seed priming with Se (0 (control), 0.5, 1, 1.5, 2 and 4 mg. L–1) and 2 levels of water stress (well-watered and drought conditions). The results showed that supplemental Se at lower concentrations improved growth parameters like total leaf area, root length and total biomass of control and drought-stressed plants. In addition, relative water content and chlorophyll content of the drought-stressed plants increased with the application of Se at lower concentrations. Treatment with Se mitigated adverse effects of drought stress through enhancement of photosynthetic pigments, improvement of water relations, accumulation of soluble sugars and increased antioxidant activity. Seed priming with Se also increased total phenols, flavonoids and free radical scavenging activity of pot marigold plants both under well-watered and water stress conditions. It was found that seed priming with Se at lower concentrations (especially 1.5 mg. L–1) can mitigate the adverse effects of drought stress and improved antioxidant system of pot marigold plants.
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Sharma and Zheng. "Melatonin Mediated Regulation of Drought Stress: Physiological and Molecular Aspects." Plants 8, no. 7 (June 26, 2019): 190. http://dx.doi.org/10.3390/plants8070190.
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Drought stress adversely effects physiological and biochemical processes of plants, leading to a reduction in plant productivity. Plants try to protect themselves via activation of their internal defense system, but severe drought causes dysfunction of this defense system. The imbalance between generation and scavenging of reactive oxygen species (ROS) leads to oxidative stress. Melatonin, a multifunctional molecule, has the potential to protect plants from the adverse effects of drought stress by enhancing the ROS scavenging efficiency. It helps in protection of photosynthetic apparatus and reduction of drought induced oxidative stress. Melatonin regulates plant processes at a molecular level, which results in providing better resistance against drought stress. In this review, the authors have discussed various physiological and molecular aspects regulated by melatonin in plants under drought conditions, along with their underlying mechanisms.
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Choudhary, Minakshi, Jayanand Manjhi, and Anvesha Sinha. "Effect of Drought Stress in Various Enzymes of Pennisetum glaucum." International Journal of Applied Sciences and Biotechnology 3, no. 1 (March 25, 2015): 134–38. http://dx.doi.org/10.3126/ijasbt.v3i1.12278.
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Introduction: Pearl millet (Pennisetum glaucum) is an important cereal of traditional farming systems that has the natural ability to withstandvarious abiotic stresses such as drought, which is one of the most important manifestations of abiotic stress in plants. These plants havehowever evolved mechanisms that allow them to adapt and survive prolonged periods of water deficit at some level or form of plant structure,if not at the whole plant level. The hostile conditions augment the formation of reactive oxygen species (ROS) during physiological stresses inplants which are combated by various enzymatic and non-enzymatic mechanisms. The present study aims at examining the role of fourimportant enzymes namely Ascorbic peroxidase (APX), Peroxidase (POX), Catalase (CAT) and Superoxide Dismutase(SOD) expressed duringdrought stress in pearl millet (Pennisetum glaucum). Method: 12 and 22 days old seedlings of Pennisetum cultivar HHB-68 were subjectedto drought stress by treatment of 30% Polyethylene glycol for different time periods 30min (T1), 2hr (T2), 4hr (T3), 8hr (T4), 16hr (T5), 24hr(T6) and 48hr (T7) respectively, monitored by examining RWC of seedlings. The treatment seedlings were then used for investigating thelevels of enzymes activity in response to prolonged dehydration periods of 22 days. The enzyme activity of POX, APX, CAT and SOD wereassayed. Result: Enzymes expression was assayed for each treatment sets at both time intervals. Drought stress was observed to causeremarkable increase in POX, APX and SOD activity while incidence of CAT enzyme decreased with the increasing period of water deficit.Conclusion: Prolonged periods of water deficiency causes significant variations in expression of various enzymes in Pennisetum glaucum,known to be involved in ROS scavenging and drought stress management. The study provides a sturdy validation of the role of these enzymesas potent mechanisms undertaken by drought resistant plants for successful management of drought stress, which can be used for thedevelopment of more efficient and economic drought resistant cultivars.DOI: http://dx.doi.org/10.3126/ijasbt.v3i1.12278 Int J Appl Sci Biotechnol, Vol. 3(1): 134-138
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Adebusola, Adewole, Odjegba Victor, Iwuala Emmanuel, and Afroz Alam. "Effect of nitrogen application on the phytochemical production in Jatropha curcas L. (Angiosperms: Euphorbiaceae) during drought conditions." Plant Science Today 6, no. 2 (April 28, 2019): 183–89. http://dx.doi.org/10.14719/pst.2019.6.2.523.
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Nitrogen is an important nutrient for the successful metabolism of plants, but its occurrence in soil is always very limited. This nutrient has a significant role to preserve plants during various stress conditions by altering the production rate of phytochemicals as defense weapons. Hence, this study was carried out to analyze the effect of nitrogen supply on the phytochemical composition and relative water content in Jatropha curcas L. under a simulated drought condition. The selected seedlings were grown from stem cuttings and categorized into different treated three groups along with the control. After the completion of the experiment, the growth pattern and phytochemical production were investigated. An increased malondialdehyde activity (MDA) was reported with a reduction in relative water content (RWC) of the leaf and in the biomass of seedlings under drought stress. A significant decrease in the levels of alkaloids, phenol, flavonoids and tannins with an increase in saponins and terpenoids was also observed in only simulated drought stressed plants. While a significant increase in the levels of total alkaloid, tannins, flavonoids and phenols was observed in those plants where exogenous nitrogen was supplied before the start of drought periods, unlike in treated and control plants. Therefore, it was revealed that application of Nitrogen enabled the plants to possess protective mechanism through the production of phytochemicals that facilitate the cell membrane to reduce the detrimental effects caused by drought stress.
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Awasthi, Rashmi, Neeru Kaushal, Vincent Vadez, Neil C. Turner, Jens Berger, Kadambot H. M. Siddique, and Harsh Nayyar. "Individual and combined effects of transient drought and heat stress on carbon assimilation and seed filling in chickpea." Functional Plant Biology 41, no. 11 (2014): 1148. http://dx.doi.org/10.1071/fp13340.
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High temperatures and decreased rainfall are detrimental to yield in chickpea (Cicer arietinum L.), particularly during grain filling. This study aimed to (i) assess the individual and combined effects of drought and heat stress on biochemical seed-filling processes, (ii) determine genotypic differences in heat and drought tolerance, and (iii) determine any cross-tolerance. Plants were grown outdoors in the normal growing season when temperatures during seed filling were <32−20°C or were planted late (temperatures >32−20°C; heat stress). Half of the pots were kept adequately watered throughout, but water was withheld from the others from the initiation of seed filling until the relative leaf water content reached 50% of the irrigated plants (drought stress); all plants were rewatered thereafter until seed maturit. Water was withheld for 13 days (normal sowing) and 7 days (late sowing), so soil moisture decreased by 54–57%. Tests on leaves and seeds were performed after the stress. Individual and combined stress damaged membranes, and decreased cellular oxidising ability, stomatal conductance, PSII function and leaf chlorophyll content; damage was greater under combined stress. Leaf Rubisco activity increased with heat stress, decreased with drought stress and decreased severely with combined stress. Sucrose and starch concentrations decreased in all seeds through reductions in biosynthetic enzymes; reductions were greater under combined stress. These effects were more severe in heat- and drought-sensitive genotypes compared with drought-tolerant genotypes. Drought stress had a greater effect than heat stress on yield and the biochemical seed-filling mechanisms. Drought- and heat-tolerant genotypes showed partial cross-tolerance.
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Nguy, Tuan Minh, Thang Thanh Tran, and Huong Thanh Tran. "Effects of drought stress on shoot development of tomato (Solanum lycopersicum L.)." Science and Technology Development Journal - Natural Sciences 5, no. 2 (May 3, 2021): 1208–15. http://dx.doi.org/10.32508/stdjns.v5i2.1049.
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In recent years, drought stress was strongly affected on the development and yield of tomatoes. There are increasing interests in the study of physiological transformations in adaption to stress in plants In this study, effects of drought stress (mannitol at different concentration) on the development of tomato shoot were studied. Morphological and physiological changes during the development of shoot under drought stress conditions were analyzed. Based on the analysis results, the combination of cytokinin and gibberellin was treated to increase the drought stress tolerance of plants. Results showed that mannitol at 20 g/L induced tomato drought stress. Shoot height, number of leaves, leaf area, and the number of roots significantly decreased in the drought stress condition compared to the control. The formation superoxide (O2-) and hydrogen peroxide (H2O2) occurred in the meristem, elongation region and cap of the roots in the drought stress condition instead of only cap root in the control. In the drought stress condition, there was an increase in respiration intensity, proline and carotenoid content, and abscisic acid activity. In contrast, the content of chlorophyll, photosynthesis intensity, cytokinin and gibberellin activity decreased in comparison with the control. The combination treatment of zeatin 0.5 mg/L and GA3 0.5 mg/L improved the drought stress tolerance of plants. The shoot height, number of leaves, leaf area and number of roots of the treated plants were higher than those of the control plants.
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Zhou, Rong, Hongjian Wan, Fangling Jiang, Xiangnan Li, Xiaqing Yu, Eva Rosenqvist, and Carl-Otto Ottosen. "The Alleviation of Photosynthetic Damage in Tomato under Drought and Cold Stress by High CO2 and Melatonin." International Journal of Molecular Sciences 21, no. 15 (August 4, 2020): 5587. http://dx.doi.org/10.3390/ijms21155587.
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The atmospheric CO2 concentration (a[CO2]) is increasing at an unprecedented pace. Exogenous melatonin plays positive roles in the response of plants to abiotic stresses, including drought and cold. The effect of elevated CO2 concentration (e[CO2]) accompanied by exogenous melatonin on plants under drought and cold stresses remains unknown. Here, tomato plants were grown under a[CO2] and e[CO2], with half of the plants pre-treated with melatonin. The plants were subsequently treated with drought stress followed by cold stress. The results showed that a decreased net photosynthetic rate (PN) was aggravated by a prolonged water deficit. The PN was partially restored after recovery from drought but stayed low under a successive cold stress. Starch content was downregulated by drought but upregulated by cold. The e[CO2] enhanced PN of the plants under non-stressed conditions, and moderate drought and recovery but not severe drought. Stomatal conductance (gs) and the transpiration rate (E) was less inhibited by drought under e[CO2] than under a[CO2]. Tomato grown under e[CO2] had better leaf cooling than under a[CO2] when subjected to drought. Moreover, melatonin enhanced PN during recovery from drought and cold stress, and enhanced biomass accumulation in tomato under e[CO2]. The chlorophyll a content in plants treated with melatonin was higher than in non-treated plants under e[CO2] during cold stress. Our findings will improve the knowledge on plant responses to abiotic stresses in a future [CO2]-rich environment accompanied by exogenous melatonin.
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Berumen, Salvador, and Norman K. Lownds. "Ethylene Production as a Drought Stress Response in Cassia corymbosa." HortScience 31, no. 4 (August 1996): 649b—649. http://dx.doi.org/10.21273/hortsci.31.4.649b.
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Landscapes in the desert Southwest must be water efficient and utilize drought tolerant plants. Therefore, plants with landscape potential must be evaluated for their level of drought tolerance and drought tolerance mechanisms. Drought tolerance, for some plant species, may be related to the plants ability to produce ethylene as a mechanism for defoliation, thus reducing water use. Cassia corymbosa has potential as a woody shrub for southwestern landscapes because of its dark green foliage and bright yellow flowers. Studies were conducted to determine the effect of leaf dehydration and drought stress on ethylene production in Cassia. Leaf dehydration was examined by excising leaves and placing them at 20, 25, or 30 °C. The time course of ethylene production depended on the temperature (rate of dehydration), but the peak occurred at 18% to 25% fresh weight loss, regardless of dehydration temperature. The effect of irrigation rate was determined by supplying plants with 0%, 40%, 60% and 100% of the daily water consumption (WC) based on pot capacity. Ethylene production depended on irrigation rate. Plants irrigated at 100% of daily WC were not stressed and did not produce ethylene. Irrigation at 60% of daily WC induced peak ethylene production 72 hours after treatment with decreased production as at longer times. Irrigation at 40% or 0% of the daily WC did not induce ethylene production because of the rapid dehydration. Drought-induced ethylene production in Cassia corymbosa appears to be closely related to the rate of dehydration and may provide a drought tolerance mechanism.
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Arivalagan, Maruthaiya, and Ramamurthy Somasundaram. "Alteration of photosynthetic pigments and antioxidant systems in tomato under drought with Tebuconazole and Hexaconazole applications." Journal of Scientific Agriculture 1 (June 13, 2017): 146. http://dx.doi.org/10.25081/jsa.2017.v1.52.
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Present investigation was focused on the response and regulation of the antioxidant defense system and photosynthetic pigment variation effect of two important fungicides or plant growth regulators Hexaconazole (HEX) and Tebuconazole (TBZ) on drought stressed tomato (Lycopersicon esculentum Mill.) plants. Drought stress was imposed for 30 Days after sowing (DAS) of tomato plant. The water was irrigated by 4 Days Interval Drought (DID) and the control plants were regularly irrigated. Triazole treatment like HEX at 15 mg L-1 and TBZ at 10 mg L-1 imposed on 30, 40 and 50 DAS. The plant samples were collected on 40, 50 and 60 DAS. The photosynthetic pigments like chlorophyll – a, chlorophyll – b and total chlorophyll were estimated. The drought stress reduced the photosynthetic pigments and increased the antioxidant contents and antioxidant enzymes activities. The combined drought stress with triazole treatments increased the photosynthetic pigments then reduced the ascorbic acid (AA), α-tocopherol, catalase (CAT), peroxidase (POX) and superoxide dismutase (SOD) activities, when compared to drought stressed plants. It can be concluded that the triazole treatment partially mitigated the adverse effects of drought stress in L. esculentum.
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Arivalagan, Maruthaiya, and Ramamurthy Somasundaram. "Induction of drought stress tolerance by Propiconazole and Salicylic acid in Sorghum bicolor is mediated by enhanced osmoregulation, compatible solutes and biochemical accumulation." Journal of Applied and Advanced Research 1, no. 2 (August 26, 2016): 41. http://dx.doi.org/10.21839/jaar.2016.v1i2.25.
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A pot-culture experiment was carried out to estimate the ameliorating effect of Propiconazole (PCZ) and Salicylic acid (SA) on drought stressed Sorghum bicolor. The plants were subjected to 3, 6 and 9 Day Interval Drought (DID) and drought with PCZ 1 mM and SA 1 mM alone from 30, 40 and 50 Days After Sowing (DAS). One day interval irrigation was kept as control. The plant samples were collected on 60, 70 and 80 DAS then separated into root and shoots for estimate the protein, proline, amino acid (AA), glycine betaine (GB) and total sugar content. Drought stress inhibited protein content then the proline, AA, GB and total sugar contents were increased when compared to control. Plants were treated drought with PCZ and SA these parameters to a larger extent when compared to drought stressed plants. The PCZ and SA treatments increased the protein content, but decreased the proline, AA, GB and total sugar contents when compared to drought stressed plants. From the results of this investigation, it can be concluded that the application of PCZ and SA caused a partial amelioration of the adverse effects of drought stress in sorghum plants.
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Arivalagan, Maruthaiya, and Ramamurthy Somasundaram. "Propiconazole and Salicylic acid alleviate effect of drought stress in sorghum (Sorghum bicolor L. Moench) through biochemical and some physiological characters." Journal of Applied and Advanced Research 1, no. 3 (October 8, 2016): 1. http://dx.doi.org/10.21839/jaar.2016.v1i3.26.
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In this study, the protective role of propiconazole (PCZ) and salicylic acid (SA) in relation to biochemical content and some physiological parameters were investigated in drought stressed Sorghum bicolor plants. The pot culture experiment was carried out on Botanical garden, Deportment of Botany, Annamalai University. A 30 Days After Sowing (DAS) plants were subjected to 3, 6, and 9 Days Interval Drought (DID) stress and drought with PCZ at 1 mM and drought with SA at 1 mM at 30, 40, and 50 DAS. The plants irrigated regularly in alternate day interval were kept as control. The plant samples were collected on 60, 70, and 80 DAS from all the treatments. The biochemical contents like starch and sucrose, then physiological parameter like Relative Water Content (RWC) and Electrolyte Leakage (EL) were analysed. Under the drought stress reduced starch and RWC was observed then, sucrose and EL content were increased. The drought with growth regulator treated plants starch and RWC was reduced then, sucrose and EL was increased but it was lower than that of control. Together, our findings demonstrate that, PCZ and SA is an efficient growth regulator with diversified roles that contribute to its potential alleviating effect against drought stress.
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Irawan, Wiski, and Eka Tarwaca Susila Putra. "The Effect of Potassium Addition on Oil Palm (Elaeis guineensis Jacq.) Roots Anatomic Properties under Drought Stress." Caraka Tani: Journal of Sustainable Agriculture 35, no. 1 (January 6, 2020): 54. http://dx.doi.org/10.20961/carakatani.v35i1.32578.
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The availability of water is one of the main limiting factors for oil palm growth and production. Potassium (K) is an essential nutrient for plants because of its role in controlling metabolic and physiological activities. This study aimed to examine the effect of different K fertilizer doses on root anatomic properties under drought stress. The experiment was arranged in factorial Randomized Complete Block Design (RCBD) with two factors. The first factor was drought stress, consisting of three levels of fractions of transpirable soil water (FTSW) (FTSW 1 (control: field capacity); FTSW 0.35 (moderate drought); FTSW 0.15 (severe drought)) and the second factor was K dose (sourced from KCl), consisting of five levels (K0: 0%; K1: 50%; K2: 100%; K3: 150%; K4: 200%). The results showed that there was an interaction between the addition of K doses and the tolerance level of oil palm plants to drought stress. The addition of 100% K gave higher results in the parameters of xylem diameter, phloem diameter and cortex cell width compared to the plants without K. The results disclosed that 200% K application on moderate drought stress and severe drought stress in oil palm seedlings could widen xylem diameter, phloem diameters, strengthen cell such as epidermal cells, cortex cells, thickness of endodermic cells, thickness of sclerenchyma cells and increase hardness of cell compared to field capacity. As for the parameters of thick endodermic cells, stele diameter and sclerenchyma diameter, an addition of 50% K could give higher results.
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Tufail, Muhammad Aammar, María Touceda-González, Ilaria Pertot, and Ralf-Udo Ehlers. "Gluconacetobacter diazotrophicus Pal5 Enhances Plant Robustness Status under the Combination of Moderate Drought and Low Nitrogen Stress in Zea mays L." Microorganisms 9, no. 4 (April 17, 2021): 870. http://dx.doi.org/10.3390/microorganisms9040870.
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Plant growth promoting endophytic bacteria, which can fix nitrogen, plays a vital role in plant growth promotion. Previous authors have evaluated the effect of Gluconacetobacter diazotrophicus Pal5 inoculation on plants subjected to different sources of abiotic stress on an individual basis. The present study aimed to appraise the effect of G. diazotrophicus inoculation on the amelioration of the individual and combined effects of drought and nitrogen stress in maize plants (Zea mays L.). A pot experiment was conducted whereby treatments consisted of maize plants cultivated under drought stress, in soil with a low nitrogen concentration and these two stress sources combined, with and without G. diazotrophicus seed inoculation. The inoculated plants showed increased plant biomass, chlorophyll content, plant nitrogen uptake, and water use efficiency. A general increase in copy numbers of G. diazotrophicus, based on 16S rRNA gene quantification, was detected under combined moderate stress, in addition to an increase in the abundance of genes involved in N fixation (nifH). Endophytic colonization of bacteria was negatively affected by severe stress treatments. Overall, G. diazotrophicus Pal5 can be considered as an effective tool to increase maize crop production under drought conditions with low application of nitrogen fertilizer.
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Wang, Zhaolong, Bingru Huang, and Qingzhang Xu. "Effects of Abscisic Acid on Drought Responses of Kentucky Bluegrass." Journal of the American Society for Horticultural Science 128, no. 1 (January 2003): 36–41. http://dx.doi.org/10.21273/jashs.128.1.0036.
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Abscisic acid (ABA) is an important hormone regulating plant response to drought stress. The objective of this study was to investigate effects of exogenous ABA application on turf performance and physiological activities of kentucky bluegrass (Poa pratensis L.) in response to drought stress. Plants of two kentucky bluegrass cultivars, `Brilliant' (drought susceptible) and `Midnight' (drought tolerant), were treated with ABA (100 μm) or water by foliar application and then grown under drought stress (no irrigation) or well-watered (irrigation on alternate days) conditions in a growth chamber. The two cultivars responded similarly to ABA application under both watering regimes. Foliar application of ABA had no effects on turf quality or physiological parameters under well-watered conditions. ABA application, however, helped maintain higher turf quality and delayed the quality decline during drought stress, compared to the untreated control. ABA-treated plants exposed to drought stress had higher cell membrane stability, as indicated by less electrolyte leakage of leaves, and higher photochemical efficiency, expressed as Fv/Fm, compared to untreated plants. Leaf water potential was not significantly affected, whereas leaf turgor pressure increased with ABA application after 9 and 12 d of drought. Osmotic adjustment increased with ABA application, and was sustained for a longer period of drought in `Midnight' than in `Brilliant'. The results suggested that exogenous ABA application improved turf performance during drought in both drought-sensitive and tolerant cultivars of kentucky bluegrass. This positive effect of ABA could be related to increased osmotic adjustment, cell turgor maintenance, and reduced damage to cell membranes and the photosynthetic system.
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Virgona, JM, and EWR Barlow. "Drought Stress Induces Changes in the Non-Structural Carbohydrate Composition of Wheat Stems." Functional Plant Biology 18, no. 3 (1991): 239. http://dx.doi.org/10.1071/pp9910239.
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The effect of drought stress on the non-structural carbohydrate (NSC) composition and water relations of the wheat (Triticum aestivum L.) stem has been investigated. Five separate parts of the stem were sampled: the unsheathed portion of the peduncle (Stem 1a), the sheathed portion of the peduncle (Stem 1b), the penultimate internode (Stem 2), the lower internodes (Stem 3+4) and the flag-leaf-pulvinus (pulvinus). The NSC was analysed as two fractions, an ethanol-soluble carbohydrate (ESC) fraction containing mono- and di-saccharides and some low molecular weight oligosaccharides, and a water-soluble carbohydrate (WSC) fraction containing mostly fructans and some high molecular weight oligosaccharides. In Stems 1b, 2 and 3 +4, the imposition of drought midway through grain filling resulted in a shift in soluble carbohydrate from the WSC to the ESC fraction indicating hydrolysis of fructans. In Stem 2 on day 29 of grain filling, the WSC/ESC ratio was 7.6 � 1.5 in well watered plants in contrast to 0.5 � 0.1 in droughted plants on day 30, even though NSC concentration did not differ. The NSC content of Stem la and the pulvinus increased threefold under drought, although levels were significantly lower than in the rest of the stem. The WSC/ESC ratio in these tissues was low com- pared to the rest of the stem but still declined noticeably under drought stress. Turgor (P) was fully maintained in Stem 2 and the pulvinus of droughted plants. Under drought, P in the pulvinus was maintained at higher levels (1.9-2.4 MPa) than in Stem 2 (0.8-1.2 MPa).