Academic literature on the topic 'Clinostat. Plants'

Gravity variation effects on plants provide definite changes. Normal Earth gravity (1G) and microgravity (µg) are possible variations for experimental purposes. On-board spaceflight microgravity experiments are rare and expensive, as the microgravity environment is an outstanding platform for research, application and education. A Clinostat was used for ground-based experiments to investigate the shoot morphology of maize plants at the Space Agency of Nigeria—National Space Research and Development Agency (NASRDA). A Clinostat device uses rotation to negate gravitational pull effects on plant growth and development. Maize was selected for this experiment because of its nutritional and economic importance, and its usability on the Clinostat. Plant shoot morphology is important for gravi-responses. Shoot curvature and shoot growth rate analyses were conducted on the shoots of a provitamin variety of maize. The seeds were planted into three Petri dishes (in parallel) in a wet chamber using a plant substrate—agar-agar. The experimental conditions were subject to relative humidity, temperature and light conditions. After 3 days of germination under 1G, two of the Petri dishes were left under 1G, serving as controls for shoot curvature and shoot growth rate analyses. The clinorotated sample was mounted on the Clinostat under: a fast rotation speed of 80 rpm, a horizontal rotation position and a clockwise rotation direction. The images of the samples were taken at a 30 min interval for 4 h. After observations, the shoot morphology of the seedlings was studied using ImageJ software. The grand average shoot angles and shoot lengths of all the seedlings were calculated following the experimental period to provide the shoot curvatures and shoot growth rates, respectively. The results show that the clinorotated sample had a reduced response to gravity, with 50.77°/h for the shoot curvature, while the 90°-turned sample had 55.49°/h. The shoot growth rate for the 1G sample was 1.25 cm/h, while that for the clinorotated sample was 1.26 cm/h. The clinorotated sample had an increased growth rate per hour compared to the counterpart 1G sample. These analytical results serve as preparation for future real-space experiments on maize and could be beneficial to the agriculture sector.

Rice (Oryza sativa L.) is a staple food in many Asian countries with an ever increasing demand. However, the production of high quality rice seeds is insufficient to meet this demand. Research on plant growth in space related to the exposure of a microgravity environment are rare, costly and time-limited. Similar experiments can be conducted on the ground to simulate the microgravity condition using a 2-D clinostat which compensates for the unilateral influence of gravity. This study was conducted to establish a simple and cost effective technique to enhance the quality of the Malaysian rice seed variety MR 219 by using a 2-D clinostat and to determine the effects of simulated microgravity on the growth and yield of the rice seeds. The experiments were performed at different rotation speeds (2 rpm and 10 rpm) for 10 days at room temperature. The rice growth and yield parameters were measured every 2 weeks and at harvest time (day 110), respectively. The data were analysed using the MINITAB statistical software package. The mean value estimates of the parameters obtained under different conditions were compared using analysis of variance (ANOVA) with the Tukey test for multiple comparisons using a 0.05 significance level. Significant differences in the number of tiller, stem width , chlorophyll content , weight of grains and panicles and total grain weight per plant were identified at rotation speed 10 rpm when compared to rotation speed 2 rpm and control. The highest means were mainly obtained under 10 rpm clinorotated rice seeds. In general, plants grown from 10 rpm clinorotated seeds are also more resistant to rice diseases (rice blast disease, rice tungro disease and hopper burn). These results suggest that simulated microgravity using a 2-D clinostat affected several rice (MR219) growth and yield parameters significantly.

In the present study, Hibiscus sagittifolius Kurz. seeds were used as the plant materials for studying on the effects of simulated microgravity (on a 2D clinostat) on seed germination, shoot multiplication, growth, development and secondary metabolite accumulation. After surface sterilization, seeds were cultured on MS medium supplemeted with 30 g/l sucrose and 9 g/l agar in Petri dishes (9 seeds per dish, the seed to seed distance of 1.5 cm and kept in the same direction), and maintained in a Clinostat (2 rpm). The results showed that simulated microgravity inhibited the growth and development of Hibiscus sagittifolius roots with root length of 11.83 cm, fresh and dry weight of 58.28 and 5.23 mg, respectively but it made an increase in germination rate (87%) and accumulation of secondary metabolites (the total saponins content of 53.00 mg/g and the total coumarin content of 25.67 mg/g) after 3 weeks of culture. In addition, the simulated microgravity also resulted in positive shoot multiplication (shoot height of 3.07 cm, 6.33 nodes per shoot, 3.33 shoots per explant, and the fresh and dry weight of 401.33 and 37.00 mg, respectively), and growth and development of Hibiscus sagittifolius shoots (plant height of 12.17 cm with 5.67 leaves per shoot together with the average root length of 1.77 cm, and the fresh and dry weight of 419.00 and 36.00 mg) after 4 weeks of culture. The results from this study could be attributed to future perspectives in research on plant breeding and accumulation of secondary metabolites in medicinal plants.

AbstractClinorotation used to simulate microgravity effects in ground-based experiments is considered as a mild stress factor for plants. We have assumed that it might influence the plant tolerance to other stressful factors. To test this, Arabidopsis thaliana seedlings were grown on a horizontal clinostat (2 rpm) or under stationary conditions (control), and then were subjected to heat treatment. The kinetics of gene expression of cytosolic HSP70s and HSP90s during exposure to 37°C for 0.5-2 h was examined by RT-qPCR to estimate level of the heat shock reaction. It was shown that clinorotation caused the minor increase in transcript abundance of five AtHSP70s and AtHSP90-1 under normal temperature, as well as a faster onset and enhancement of their induction during heat shock. The heat tolerance was evaluated as a function of seedling survival after exposure to 45°C for 45 min. Seedlings grown under clinorotation were determined to withstand heat treatment better than seedlings grown under stationary conditions. The obtained data support the assumption that clinorotation may provide cross-protection of plants against fluctuations in environmental conditions.

Study on the effect of various disturbances on the cayenne pepper seeds (Capsicum Frutescens L.) to the content of chlorophyll a, chlorophyll b, carotenoids, and biomass of the plants in the germination period have been done. The disturbances given include UV-C irradiation for 1 hour (S1), microgravity for 12 hours (S2), for 24 hours (S3), and for 48 hours (S4), as well as combined disturbances that are UV-C irradiation for 1 hour followed by microgravity for 12 hours (S5), for 24 hours (S6), and for 48 hours (S7). As comparison, it has been used seeds without treatment called control (S0). The microgravity environment was created using a 2-D clinostat with a rotational speed of 2.7 rpm (1.2 x 10-4 g). All samples were grown in normal gravity (1 g) environment. Observations were made during the vegetative phase until the plant was 40 days old. Measurements of chlorophyll a, chlorophyll b, carotenoids, and biomass were performed at the plants were 10, 20, and 40 days old. The results showed that disturbances which given on the seeds gave positive effects on the content of chlorophyll a, chlorophyll b, carotenoids, and biomass of the plants. The impacts depend on the duration of the disturbances given.

Aim. The main aim of the study was to analyze the effect of microgravity on the growth and development of Arabidopsis thaliana seedlings at different time intervals of cultivation (4–10 days) and to investigate the development of autophagy induced by the conditions of microgravity in seedlings root cells. Methods. Microscopic methods as well as in vitro propagation method were used. To simulate of microgravity conditions plants were placed in clinostat machine. Results. In the course of experiments, the peaks of the formation of autophagosome were recorded: in the cells of the root cap zone of at 9th day and in the cells of the root zone extension on the 10th day of clinical establishment. Conclusions. It can be concluded that microgravity is capable to induce the development of autophagy in the roots of A. thaliana seedlings. Cells with signs of autophagy were revealed on the 9th and 10th day of cultivation of seedlings under microgravity conditions. Keywords: Arabidopsis thaliana, autophagy, microgravity.

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The gravity is a force present in entire world and acted during the evolutionary process of the all species. Every biological structure present on Earth is adapted to this force. The growing of the plants is guided by gravity. The root cells knows that they have to grown on direction of this force and the stem cells knows that they have to grown on the opposite direction. This tropism caused by gravity is not effective in microgravity environments. Studies with microgravity equipment, as The 3D Clinostat improved in this work, show similar results as obtained in spaceships. These equipments are, for the science, very important. They help to develop microgravity experiments in the surface of the Earth, with low price and many possibilities of customization. The prime objective of this work is to improve a 3D Clinostat prototype. New motors and a microcontroller was added to improve robustness, confiability and compatibility to new features and designs. To evaluate the equipment modification, an experiment was made using seeds of maize. The seeds were put into equipment for two periods of time, 8 and 22 hours. After, the seeds were cultivated and the data was analyzed. The data shows significant statistical difference between the plants provided by the equipment seeds and the others, in both periods of time (p<0.01 and p<0,0001). The equipment was validated by the experiment. The results shown difference in grown level. More studies are necessary to explain why microgravity change the maize seeds grown speed.
A gravidade ? uma for?a presente em todo o planeta e atuou durante a evolu??o de esp?cies animais e vegetais. Todas as estruturas hoje existentes s?o adaptadas ? essa for?a. O crescimento das plantas ? guiado pela gravidade, direcionando o desenvolvimento da raiz a favor desta for?a e o caule contra. Esse tropismo causado pela gravidade n?o se mostrou presente em experimentos onde esta atuava com menor intensidade. Em experi?ncias fora do planeta Terra, as plantas apresentaram um crescimento diferente, levando a crer que a gravidade ? um fator que deve ser considerado para e desenvolvimento de esp?cies vegetais. Estudos utilizando equipamentos simuladores de Microgravidade, como o clinostato 3D aprimorado no presente trabalho, tamb?m apresentaram resultados an?malos no crescimento de plantas, muito similar aos resultados obtidos em estudos realizados no interior de esta??es espaciais. Uma vez que simuladores de Microgravidade s?o para a ci?ncia equipamentos tecnol?gicos de ponta e que auxiliam nos estudos dos efeitos causados pela gravidade, este trabalho tem como principal objetivo o aprimoramento de um clinostato 3D. Os aprimoramentos consistiram na adi??o de motores de passo de alta precis?o, microcontrolador Ardu?no e controle de velocidade dos motores digital e unilateral. Essas adi??es colaboraram para que o equipamento opere com maior robustez, confiabilidade e compatibilidade para inclus?o de outros componentes e uso em pesquisas. Para valida??o do equipamento, um experimento foi realizado com sementes da esp?cie Zea mays L., popularmente conhecido como milho. As sementes foram submetidas ao equipamento por dois per?odos de tempo diferentes: 8 e 22 horas. Ap?s, foram plantadas e cultivadas fora do clinostato por 25 dias. No estudo de valida??o, houve diferen?a significativa no crescimento nas plantas que sofreram a??o da microgravidade para o primeiro tempo (p<0,01) e tamb?m para o segundo (p<0,0001), considerando na an?lise outros dois grupos de controle. Os resultados obtidos validaram a efic?cia do aprimoramento do clinostato 3D, uma vez que as sementes que passaram pelo equipamento geraram plantas que apresentaram crescimento superior. Mais estudos para explicar as raz?es fisiol?gicas que levaram as plantas a crescer mais precisam ser realizados.