Academic literature on the topic 'Idioblasts'

In leaves of the periwinkle plant (Catharanthus roseus (L.) G. Don) idioblasts are randomly distributed in the mesophyll. They are distinguishable from ordinary palisade and spongy parenchyma cells as large, refractile, and autofluorescent cells. Density gradient centrifugation of protoplasts derived from leaves resulted in fractions enriched in idioblast protoplasts. Analysis of indole alkaloid composition by high pressure liquid chromatography has shown that idioblasts are enriched in vindoline and catharanthine relative to other mesophyll cells. The significance of these observations for attempts to produce specific indole alkaloids in cell cultures is discussed.

Histological analysis of Ruta graveolens L. roots and in vitro grown cell suspensions revealed idioblasts with vacuoles containing clusters of droplets thought to be the storage compartment of acridone alkaloids. These idioblasts contained numerous vacuoles of varying sizes rather than the large, single, central vacuole characteristic of most adjacent parenchyma cells. The structure of idioblasts in roots and suspension cultures was identical. Treatment of suspension cultures with fungal elicitors known to increase alkaloid accumulation greatly did not affect the structure of idioblasts.

Several specimens of Lauraceae fossil wood from the Cenozoic of Greece (southern part of Lesbos), the Czech Republic (Kadaň-Zadní Vrch Hill and Jáchymov), and Hungary (Ipolytarnóc) were studied. When considering whether they belonged to the speciose fossil wood genus Laurinoxylon, we reviewed the literature and data from InsideWood on fossil and modern woods. As a result, we propose criteria for excluding a fossil Lauraceae wood from Laurinoxylon and list the species that should be excluded from this genus. The criteria (filters) proposed to exclude a genus from having relationships with Laurinoxylon are: A. Axial parenchyma features: A1. Marginal axial parenchyma, A2. Aliform to aliform-confluent paratracheal parenchyma. B. Ray features: B1. Rays higher than 1 mm, B2. Exclusively homocellular rays, B3. Rays more than 5 cells wide, B4. Rays storied. C. Porosity features: Ring-porous. D. Idioblasts: Absence of idioblasts. Based on the distribution of idioblasts, we recognize four groups in Laurinoxylon (Type 1 - with idioblasts associated only with ray parenchyma cells, Type 2a - with idioblasts associated with both ray and axial parenchyma, Type 2b - with idioblasts associated both with rays and present among the fibres, and Type 3 - with idioblasts associated with ray and axial parenchyma and also among the fibres) and list the extant genera with features of those groups. Such grouping helps with interpreting the relationships of fossil lauraceous woods with extant genera. We discuss the Oligocene–Miocene European species that belong to these Laurinoxylon groups, noting that some warrant reassignment to different genera or even families. Future studies are needed to determine whether new genera should be established to accommodate these species. We propose the new combination Cinnamomoxylon variabile (Privé-Gill & Pelletier) Mantzouka, Karakitsios, Sakala & Wheeler.

X-ray microprobe analysis of freeze-fractured Lemna fronds has shown that zinc (Zn) and cadmium (Cd) are not incorporated into oxalate crystals in idioblasts, whereas strontium (Sr) is readily incorporated as an alternative to calcium (Ca). Ca and Sr are uniformly distributed throughout the crystal bundle when both elements are present in the nutrient solution. However, in neighbouring, non-idioblast cells Sr (but not Ca) may also be incorporated into globular deposits of less than 1 �m diameter. These globules contain the mineral elements potassium and phosphorus and their composition appears to be identical to that of phytate globules which contain Zn or Cd under conditions of Zn or Cd toxicity.

In developing leaflets of Stylosanthes guianensis (Aubl.) Sw., twin prismatic calcium oxalate crystals form in adaxial and abaxial epidermal crystal idioblasts. These cells eventually die and collapse, leaving the crystals embedded in a matrix of cutin and cell-wall materials. Adaxial crystal idioblasts develop above large conical cells that, in turn, are interspersed among smaller, multiple-layered palisade parenchyma. Abaxial crystal idioblasts develop beneath a uniseriate layer of large horizontally branched cells abutting the abaxial epidermis. Spongy parenchyma occupies the middle mesophyll above the layer of branched cells. The abaxial crystals and the branched cells of the lowermost mesophyll develop simultaneously. Adaxial crystals and the conical cells develop later and in conjunction with each other. In mature leaflets, the adaxial and abaxial crystals and their associated collapsed crystal idioblasts form networks, the interstices of which are occupied by either single stomates and accompanying epidermal cells (adaxial) or clusters of stomates and accompanying epidermal cells (abaxial). Epidermal crystals are known from other Leguminosae; however, to our knowledge this is the first report where epidermal crystal development involving cell death and collapse is correlated with two types of specialized mesophyll cells.

Tissue-culturedexplantsofDieffenbachiamaculate`Exotic Perfection', D.`Snow Flake', and D. × `Tropic Breeze' were grown on ebb-and-flow trays subirrigated with nitrogen (N) at 50, 200, or 800 mg·L-1 using a water-soluble fertilizer 17N–2.1P–15.7K for 10 weeks in a shaded greenhouse under a maximum photosynthetic photon flux density of 285 μmol·m-2·s-1. Plants were then transferred to interior rooms under a light level of 8 μmol·m-2·s-1. Samples of the midrib were taken from the first mature leaf of plants before being placed indoors and also from the first mature leaf of plants 8 months after growing indoors. Counts of calcium oxalate crystal idioblasts in cross-sections of the basal midrib using polarized light microscopy showed that the number of crystal idioblasts was higher in all three cultivars fertigated with 200 mg·L-1 N than those fertigated with either 50 or 800 mg·L-1 N. The number of crystal idioblasts in each cultivar grown under 8 μmol·m-2·s-1 was about 50% of the number detected when plants were grown under 285 μmol·m-2·s-1. `Snow Flake' had the highest number of crystal idioblasts with counts up to 60 per cross-section, whereas `Exotic Perfection' had the lowest with only 30 per cross-section. This study shows that in addition to cultivar differences, light intensity and N can significantly affect calcium crystal formation, and the highest number of crystal idioblasts occurred when Dieffenbachia cultivars were grown under optimum conditions.

Two legume trees largely known as tannin producers — Dimorphandra mollis Benth. (Caesalpinioideae) and Stryphnodendron adstringens (Mart.) Coville (Mimosoideae) — were used as models to elucidate the morphology and ontogeny of tannin cells. Vegetative parts of plants were processed for observation using light and electron microscopy (scanning and transmission). Idioblasts, found even in young plants of both species, and secretory trichomes, observed in vegetative buds of mature plants of S. adstringens, are responsible for tannin production. The tanniniferous idioblasts originate from protoderm and also from ground meristem cells. The ground meristem proved to be the best place to study the development of tanniniferous idioblasts at different stages of development, which allowed us to monitor the production and accumulation of tannins in the same tissue. Our data indicate that there is a relationship between the production of tannins and the process of vacuolation of tanniniferous cells. The results also indicate the probable performance of rough endoplasmic reticulum (RER) and plastids in the production of tannins.

ABSTRACT The growing of Piper aduncum for essential oil extraction has increased, but there is a lack of basic information about its management and cultivation, which allows the productivity and quality of the oil, in order to attend the market demands. This study aimed to evaluate the relation between the production of essential oils from P. aduncum and soil water pressure heads (20 kPa, 40 kPa, 60 kPa, 100 kPa and non-irrigated). The assessment comprised the quantification of idioblasts and the production of essential oil extracted from leaves of cultivated plants. The variation in the soil water pressure head alters the amount of idioblasts in P. aduncum leaves, with impacts on the essential oil production. A soil water pressure head range of 20-60 kPa is sufficient for this species to express the highest amount of idioblasts and the highest level of essential oil production. The species adapts itself to different water availability conditions in the soil. Under stress conditions, due to water deficit or excess, the production of essential oil is reduced.

Duas espécies de Barbatimão, da família Leguminosae, foram utilizadas como modelo neste trabalho para elucidar as vias ontogenéticas de produção de taninos: Dimorphandra mollis Benth. (Caesalpinioideae) e Stryphnodendron adstringens (Mart.) Coville (Mimosoideae). Apesar de inseridas em grupos distantes de Leguminosae, as duas espécies são grandes produtoras de taninos, geralmente concentrados na casca, o que confere a elas uma grande procura para uso na medicina popular. Partes vegetativas de Indivíduos jovens e adultos foram processadas para observações em microscopia de luz e eletrônica (varredura e transmissão). Dois tipos de estruturas secretoras são responsáveis pela produção e acúmulo de taninos: idioblastos, encontrados já em indivíduos jovens de ambas espécies; e tricomas secretores, encontrados em gemas vegetativas de indivíduos adultos de S. adstringens. O processo de produção de taninos nas duas espécies é semelhante, com alguma diferença nas etapas de acúmulo. Plastídios e RER parecem ser as organelas associadas à produção de taninos nessas espécies. Destaca-se ainda o relato inédito da ocorrência de coléteres de origem protodérmica em D. mollis. Considerando a problemática referente à classificação de estruturas secretoras, pretende-se utilizar os resultados obtidos para reflexão sobre o tema
In this study, two species of Leguminosae, popularly known as Barbatimão, were used as a model to elucidate the ontogenetic process of tannin production: Dimorphandra mollis Benth. (Caesalpinioideae) and Stryphnodendron adstringens (Mart.) Coville (Mimosoideae). Although inserted in non-related groups of Leguminosae, the two species are largely known as tannin producers, a metabolite often concentrated in the bark, which makes them highly sought after for use in folk medicine. Vegetative parts of young and adult plants were processed for observation using light and electron microscopy (scanning and transmission). Two types of secretory structures are responsible for tannin production and accumulation: idioblasts, found even in young plants of both species, and secretory trichomes, observed in vegetative buds of mature plants of S.adstringens. Tannin production is similar in both species, although some differences in the stages of accumulation occur. Plastids and RER organelles appear to be associated with the production of tannins in these species. This study also provides the first report of colleters in D. mollis, which originate from protodermal cells. Considering the controversies regarding the classification and nomenclature of secretory structures, our results can be used to help clarify some issues regarding secretory structures, especially colleters

Glucosinolates are natural plant products known as flavor compounds, cancerpreventing agents, and biopesticides. There is a strong interest in controlling the level of glucosinolates to improve flavor and nutritional qualities of food crops and to study the physiological role of glucosinolates in plants. The role of the myrosinaseglucosinolate system in plant defense-related reactions of Cruciferae is accepted. As metabolism of glucosinolates in healthy intact plants has been reported, this indicates that products produced by hydrolysis of glucosinolates may also be important in the growth and development of the plant.

The main focus in this thesis has been to study the effect of preventing glucosinolate hydrolysis by removal of the hydrolyzing enzyme, myrosinase. By the use of the Myr1.Bn1 promoter, we have made myrosinase free seeds of Brassica napus by controlled cell death (genetic ablation) of myrosin cells. The glucosinolate substrates were mainly unaffected by this ablation supporting their localization in non-myrosin cells and a cellular separation of enzyme and substrate. GC and GC-MS analysis confirmed that seeds with ablated myrosin cells had lost the ability to produce isothiocyanates. The effects of genetically ablating myrosin cells were tested for two other components in this complex enzyme system. The epithiospecifier protein (ESP) had lost the expression of one of its isoforms (39 kDa ESP) by the ablation indicating a cellular co-localization with myrosinase in myrosin cells for this specific isoform.

The expression of myrosinase binding proteins (MBPs) was not severely affected supporting localization to non-myrosin cells in the B. napus seed. Plants grown from seeds with ablated myrosin cells (MINELESS) showed a bushy phenotype and morphological abnormalities in flower and silique. Seed maturation was delayed and seed production reduced. Parallel experiments performed in our lab with Arabidopsis thaliana produced similar results. The tissues affected were consistent with the expression pattern directed by the myrosinase gene promoter used.

Ablating myrosinase proteins affected the behavior of the specialist cabbage aphid Brevicoryne brassicae and the generalist peach potato aphid Myzus persicae. When seedlings of MINELESS and wild type were challenged by these aphid species, a difference in preference was observed. B. brassicae preferred wild type seedlings with high levels of myrosinase proteins, while M. persicae preferred MINELESS seedlings with a reduced level of myrosinase compared to wild type. Statistical analysis revealed that the MINELESS seedlings were more susceptible to attacks by aphids, regardless of aphid species. Furthermore, the number of aphids established on the seedling influenced the myrosinase activity and the height of the plant. Thus, by ablating myrosinase proteins, new insights into the functions of the myrosinase-glucosinolate system have been elucidated. This complex system seems important not only in the defense against pests, but also show potential to influence the growth and development of the plant.

Orientador: Silvia Rodrigues Machado
Resumo: Leguminosae é a terceira maior família dentre as Angiospermas, é cosmopolita, podendo ocorrer em florestas tropicais úmidas, florestas secas, savanas, regiões mediterrâneas e desérticas. Papilionoideae, subfamília com maior riqueza de espécies de Leguminosae, apresenta Phaseoleae como uma de suas tribos de maior importância econômica e alto número de espécies. Cajaninae, por sua vez, é a maior subtribo de Phaseoleae, destacando-se por apresentar aproximadamente 490 espécies distribuídas em 10 gêneros. Os representantes desta subtribo possuem distribuição pantropical, com apenas Rhynchosia e Eriosema ocorrendo nos neotrópicos. De modo geral, as espécies desta subtribo ocorrem em campos graminosos, florestas tropicais secas, regiões semiáridas, áreas degradadas e ambientes propensos à passagem do fogo. A ocorrência das espécies de Cajaninae nestes diferentes ambientes pode estar relacionada à presença de estruturas secretoras, como glândulas vesiculares e tricomas de base bulbosa. Apesar do conhecimento sobre a existência destas estruturas peculiares neste grupo desde o século 19, nenhum estudo detalhado de anatomia, ultraestrutura ou estudos com enfoque evolutivo haviam sido realizados. A subtribo tem sido considerada monofilética, porém os poucos trabalhos filogenéticos existentes abordam Phaseoleae como um todo, possuindo uma amostragem muito baixa dos representantes de Cajaninae, o que não esclarece sua monofilia. Considerando o pouco conhecimento sobre as relações filogené... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Leguminosae is the third largest family among Angiosperms, is cosmopolitan, occurring in humid tropical forests, dry forests, savannas, Mediterranean and desert regions. Papilionoideae, a subfamily with the highest species richness of Leguminosae, presents Phaseoleae as one of its tribes of major economic importance and high number of species. Cajaninae, in turn, is the largest subtribe of Phaseoleae, standing out to present approximately 490 species distributed in 10 genera. The representatives of this subtribe have pantropical distribution, with only Rhynchosia and Eriosema occurring in the neotropics. The species of this subtribe occur in greenfields, dry tropical forests, semi-arid regions, degraded areas and environments prone to fire. The occurrence of Cajaninae species in these different environments may be related to the presence of secretory structures, such as vesicular glands and bulbous based-trichomes. Despite the knowledge about the existence of these peculiar structures in this group since the 19th century, no detailed study of anatomy, ultrastructure or evolutionary approach studies had been performed. The subtribe has been considered monophyletic, but the few existing phylogenetic works address Phaseoleae as a whole, having a very low sampling of Cajaninae representatives, which does not clarify its monophyly. Considering the little knowledge about the phylogenetic relationships in Cajaninae, on the secretory structures that are peculiar to this group and the... (Complete abstract click electronic access below)
Doutor

Anacampserotaceae pertence à ordem Caryophyllales, subordem Portulacineae, atualmente constituída por três gêneros (Anacampseros L., Grahamia Gill ex Hook e Talinopsis A. Gray) antes pertencentes à família Portulacaceae. Os representantes de Anacampserotaceae apresentam estruturas axilares lignificadas muito características, como tricomas, escamas (scales) e cerdas (bristles) e também apresentam células do tipo WBT que ocorre somente em mais outras duas famílias de Caryophyllales, Aizoaceae e Cactaceae. Os caracteres axilares são muito informativos para o clado ACPT (Anacampserotaceae, Cactaceae, Portulacaceae e Talinaceae) e vêm revelando importantes dados aos estudos filogenéticos da subordem Portulacineae, no entanto, há uma controvérsia quanto a origem ontogenética das estruturas axilares de Anacampserotaceae, o que pode levar a interpretações equivocadas das relações filogenéticas do grupo. Diante disso, este trabalho realizou um estudo ontogenético das estruturas presentes na região da axila foliar de oito espécies de Anacampserotaceae e analisou as WBTs do caule e de folhas quanto seu tipo de espessamento e medidas quantitativas de seis espécies. Os resultados apontam a 1) origem estipular das escamas e não protodérmica, como mencionado na literatura; 2) primeiro relato de profilos na família e 3) WBTs ocorrem em Anacampseros e estão ausente em Talinopsis, grupo considerado basal na família.
Anacampserotaceae belongs to the order Caryophyllales, suborder Portulacineae, currently consists of three genus (Anacampseros L., Grahamia Gill ex Hook and Talinopsis A. Gray) formerly circumscribed to the family Portulacaceae. Anacampserotaceae\'s representative presents lignified axillary structures very distinctive, like trichomes, scales and bristles and also WBT cells that is presented only by two other families of Caryophyllales, Aizoaceae e Cactaceae. The axillary characters are very informative for the ACPT clade (Anacampserotaceae, Cactaceae, Portulacaceae and Talinaceae) and has been revealing important data for the phylogenetic studies on the Portulacineae suborder, nevertheless, there is a controversy regarding the Anacampserotaceae axillary structures ontogenetic origin, what may lead to misguided interpretations for the ACPT phylogenetic relationships. Before it, this research have accomplished the ontogenetic study of the structures present on the leaf axil of eight Anacampserotaceae species and examined stem and leaf WBTs, as for its secondary thickening type and quantitative measurements of six species. The results points 1) that at least one structure (scale) has leaf origin instead of protodermic origin, as stated by some authors; 2) first report of prophylls for the family and 3) WBTs occur in Anacampseros but they are absent in Talinopsis, a basal group of Anacampserotaceae.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico
O presente trabalho teve por objetivos: (a) analisar a capacidade fotossintética de dois grupos de material vegetal sob condições de campo: plantas adultas com frutos verdes pilosos e plantas com frutos avermelhados pilosos; (b) avaliar o desenvolvimento de explantes cultivados in vitro submetidos a diferentes densidades de fluxo de luz; e (c) estudo anatômico de folhas de plantas adultas e in vitro. As hipóteses testadas foram: (a) existem diferenças na capacidade fotossintética entre os dois grupos de planta analisados; (b) alguns dos parâmetros das curvas de resposta da fotossíntese líquida à luz e ao CO² devem estar correlacionados com os teores dos pigmentos cloroplastídicos; (c) os carotenóides totais presentes nas folhas de Urucum podem desempenhar papel foto-protetor ao estresse foto-oxidativo, possibilitando que explantes cultivados in vitro possam se desenvolver a altas densidades de fluxo de luz. Verificou-se que ambos os grupos de plantas não apresentaram diferenças estatísticas significativas em seus parâmetros das curvas de resposta da fotossíntese líquida à luz e ao CO² . Assim sendo, para estes grupos foram encontrados os valores médios seguintes: 19,17 μmol m-² s-¹ para a estimativa assintótica da taxa fotossintética bruta máxima, 22,6 μmol m-² s-¹ para o ponto de compensação de luz, 1274 μmol m-² s-¹ para o ponto de saturação de luz, 15,38 μmol m -2 s -1 para a estimativa assintótica da taxa fotossintética líquida máxima, 63,0 μmol mol-¹ para o ponto de compensação de CO² e 0,1403 mol m-² s-¹ para a eficiência carboxilativa da Rubisco. Foram observadas as seguintes correlações lineares: entre a eficiência quântica máxima e a irradiância de saturação (r = -0,7794; P = 0,0176), entre a estimativa assintótica da taxa fotossintética bruta máxima e a irradiância de saturação (r = 0,8780; P = 0,0018), entre a estimativa assintótica da taxa fotossintética líquida máxima e o ponto de compensação de CO² (r = -0,6242; P = 0,0408), entre a eficiência carboxilativa e o ponto de compensação de CO² (r = -0,8208; P = 0,0067), entre a limitação estomática à fotossíntese e a concentração intercelular de CO² para uma concentração ambiental de 400 μmol mol-¹ (r = -0,8927; P = 0,0012), entre a eficiência quântica e o teor de clorofila a (r = -0,8887; P = 0,0014), clorofila b (r = -0,8505; P = 0,0037) e clorofilas totais (r = -0,9033; P = 0,0008) e entre a limitação estomática à fotossíntese e o ponto de compensação de luz (r = -0,6751; P = 0,0460). Verificou-se que ambos grupos não diferiram entre si nos teores de pigmentos cloroplastídicos, com uma média de 1629,6 mg kg-¹ de clorofila a, 643,4 mg kg-¹ de clorofila b e 2272,9 mg kg-¹ de carotenóides totais; também não houve diferença estatística entre os teores de bixina nas sementes das plantas de ambos os grupos, com um valor médio de 4,42% que as classificam como boas produtoras do corante. Os teores de bixina não se correlacionaram com nenhuma das variáveis da capacidade fotossintética das plantas. Verificou-se a presença de um grande número de idioblastos ramificados nas folhas das plantas adultas e in vitro com presença de substâncias lipofílicas identificadas como sendo bixina, por meio de reação com Sudan IV e cromatografia em camada fina. Os explantes de Urucum cultivados in vitro apresentaram foto-inibição a partir de uma densidade de fluxo de 150 μmol m-² s-¹ , identificado pela relação F v /F m igual a 0,581 aos 45 dias de exposição. Sob condições de foto-inibição, apenas a atividade da peroxidase apresentou incremento estatisticamente significativo, ao passo que a superóxido dismutase e a catalase não alteraram significativamente suas atividades, concluindo-se que os carotenóides não foram ativos na mitigação desse estresse.
The present work had by objectives: (a) analysis of the photosynthetic capacity of two groups of plant material (plants with hairy green fruits and plants with hairy like- red fruits) under field conditions; (b) evaluate the development of in vitro explants under different light flux density; and (c) histological analysis of adult and in vitro- grown leaves. The experimental hypotheses were: (a) the occurrence of differences in the photosynthetic capacity between the two groups of plants; (b) some response parameters linked to net photosynthesis, light and CO² may be correlated with the amount of chloroplastidic pigments; (c) total carotenoids in Annatto leaves may have a photo-protective role against photo-oxidative stress, though enabling in vitro cultured explants to develop under high light flux density. Both groups of plants did not show statistical differences in the response curve parameters to net photosynthesis, light and CO² . These groups displayed the following mean values: 19.17 μmol m-² s-¹ for maximum gross photosynthesis rate; 22.6 μmol m-² s-¹ for light compensation point; 1274 μmol m-² s-¹ light saturation point; 15.38 μmol m-² s-¹ for maximum net photosynthesis rate; 63.0 μmol mol-¹ for CO² compensation point, and 0.1403 mol m-² s-¹ for carboxylation efficiency of Rubisco. There were linear correlations between maximum quantum efficiency and light saturation point (r = -0.7794; P = 0.0176); maximum gross photosynthesis rate and light saturation point (r = 0.8780; P = 0.0018); maximum net photosynthesis rate and CO² compensation point (r = -0.6242; P = 0.0408); carboxylation efficiency and CO² compensation point (r = -0.8208; P = 0.0067); stomatal limitation of photosynthesis and intercellular CO² concentration for an environmental concentration of 400 μmol mol-¹ (r = -0.8927; P = 0.0012); quantum yield and the amount of chlorophyll a (r = -0.8887; P = 0.0014); chlorophyll b (r = -0.8505; P = 0.0037) and total chlorophylls (r = -0,9033; P = 0,0008); and stomatal limitation of photosynthesis and light compensation point (r = -0.6751; P = 0.0460). No differences were detected in the amount of chloroplastidic pigments whose means were: 1629.6 mg kg-¹ chlorophyll a, 643.4 mg kg-¹ chlorophyll b and 2272.9 mg kg-¹ total carotenoids. Likewise, no differences were detected between the amount of bixin in seeds of both groups, averaging 4.42%. The amount of bixin dit not correlate with any variable of the photosynthetic capacity of the Annatto plants. Leaves of field and in vitro-plants contained a lot of branched idioblasts with lipophylic content, identified as bixin, by means of histochemical assay with Sudan IV and thin layer chromatography. Explants of Annatto showed photo-inhibition from 150 μmol m-² s-¹ light flux density, as indicated by F v /F m (0.581) at 45 days of culture. Under photo-inhibitory conditions, only the peroxidases activity displayed significant increase, whereas superoxide dismutase and catalase did not alter their activities, leading to the conclusion that carotenoids did not play any role in reducing stress.
Tese importada do Alexandria

Rhododendron is a monophyletic group that inhabits many different climates. One clearly defined diversification was from temperate ancestors into tropical habitats. The focus of this work was to explore leaf and stem anatomical traits in relation to habitat (temperate and tropical) and elevation of the native range. A closely-related group of Rhododendron was selected to reduce variation in genetic history and reveal environment–associated adaptive traits. Vessel anatomical traits of Rhododendron accessions were assayed for the trade of between safety (protection against catastrophic failure) and efficiency (high theoretical conductivity). Rhododendron wood and vessels were found to be relatively safe. The metrics of wood efficiency were higher for the tropical species. Thus, a trade-off between safety and efficiency was found although the wood of Rhododendron is characterized as highly safe. Leaf anatomical traits of Rhododendron were assayed for habitat and elevation. Leaves on tropical species were thicker and denser compared with temperate species. Idioblasts were always found in tropical leaves but not in temperate species. Leaves of tropical species were more xeromorphic (drought tolerant) than those of temperate species. Increasing elevation of the native range did not influence leaf anatomical traits. Idioblast abundance and leaf water relations traits were assayed for tropical Rhododendron species. Idioblast expression varied from 5% to 28% and stomatal pore index varied from 0.08 to 3.3. Idioblast expression was highly correlated with leaf succulence, and water deficit at the turgor loss point. Idioblast expression was positively associated with leaf capacitance for thin (< 0.5 mm) leaves. Thus, idioblasts can serve as a water buffer for relatively thin leaves. Synthesis–Wood traits of evergreen Rhododendron shrubs reflect adaptation for safety. Although tropical species have significantly higher efficiency, wood safety is still the dominant feature. The implication of high wood safety is constrained water flow and a potential for low water potential. Both leaf succulence and the presence of idioblasts in thin leaves enhances leaf capacitance and provides some buffering against short-term drought. These leaf adaptations in tropical Rhododendron shrubs likely reflect the abundance of epiphytes in this group.
Ph. D.

碩士
國立臺灣大學
植物學研究所
91
In this study the distribution and the ultrastructural changes of raphide crystal idioblasts in roots of Anoectochilus formosanus Hay. T1 cultivars were investigated. The raphide idioblasts sporadically occurred in the third or fourth layer of cortex inside the epidermis. The development of the crystal idioblasts can be divided into six stages: (1) crystal idioblast initiation, (2) crystal chamber formation, (3) crystal growth, (4) ER expanded, (5) mucilage accumulation, and (6) crystal idioblast maturation. The crystal initials formed central vacuole earlier than the neighboring ordinary cortex cells. In the central vacuole the electron-dense materials gradually formulated the crystal chambers and then the crystals accumulated in these chambers. When the chambers were saturated with crystals, mucilage appeared around the crystals. The mucilage gradually permeated into the central vacuole and formed an electron-dense mucilage sheath outside the crystal needles. Eventually, lamellaed crystal sheaths came into existent, and the transverse view of the crystals turned from tetragon to hexagon or octagon. During the entire process, abundant organells were found in the cytoplasm of the crystal cells indicating an higher cellular physiological activities. The crystalloplastids showed diverse morphology. In the stage of mucilage accumulation, multiple lobes were found along the margin of the crystalloplastid. Certain secretory materials surrounded the crstalloplastid and formed an unfilled region. There were some ER spreaded outside this region, thus the crystalloplastid may be related to the formation of the mucilage. In the early and late stages, the crystalloplastids contain a few starch grains which were not found in the crystal idioblasts of leaves and that in the other species. The results of histochemical tests showed that the differentiating crystalloplastids contained little polysaccharide and protein, excluded lipid. The amorphous electron-dense materials and crystal chambers mainly contained protein. In the mature crystal cells, the mucilage matrix contained little polysaccharide and protein. The components of mucilage sheaths were mainly proteins. Using the stable isotope ratios (δ13C) analysis for consulting the results of previous studies, it is confirmed that when the plants of Anoectochilus formosanus Hay. cultivated without plastic bags covered, they are typically CAM plants and were obviously grown slowly. However, those cultivated with plastic bags covered were carrying out both the C3 and CAM CO2 fixation pathways. The plants might obtain from CO2 from the air and the culture substratum, and in the daytime they decomposed the organic acids stored in the vacuoles and meanwhile captured CO2 from the air, thus increased the growth rate. With supplying five different calcium ion concentration medium: 0 Ca (0 Mm)、1/8 Ca (0.19 mM)、1 Ca (1.50 mM)、8 Ca (11.97 mM) and 16 Ca (23.94 mM), the T2 cultivars showed strong endurance in both high Ca and low Ca conditions. After four months of cultured period, little difference in morphology and growth rate have been observed. Until the sixth month, the apical buds of those plants grown under 0 Ca condition turned to brown and died. Total Ca contents of the roots and leaves were correlated to the calcium ion concentrations in the medium. However, during the first two months, the soluble and insoluble oxalate contents and the crystal density of the leaves of all the cultured conditions remained stable, which meant they didn’t vary with the calcium ion concentrations in the medium. After four months, the raphide crystal density of the newly formed leaves and of the roots began to vary with the calcium ion concentration. And the 16 Ca cultured old leaves produced a large number of tiny crystals with various morphology. The results showed that when the calcium ion concentration in the environment varied, at the beginning, the crystal density remained stable. However, in the newly formed organs, it changed. Therefore, for Anoectochilus formosanus Hay. T2 cultivars, the formation of calcium oxalate crystals in the cells may still have the function of regulating cellular calcium ion concentration. Comparing to the previous study on the T1 cultivars, it is interested to note that somewhat different regulating strategy in calcium crystal formation in these two cultivars

碩士
國立臺灣大學
植物學研究所
89
The morphology and distribution of calcium crystals and silica deposition in the leaves of nine species (seven genera) of terrestrial orchids and thirteen species (ten genera） of epiphytic orchids were investigated. All of the studied orchids contain calcium oxalate crystals in the shape of six-eight sided raphides. Dendrobium aurantiacum, D. falconer, Dendrochilum uncatum, Pomatocalpa acuminata and Calanthe densiflora have druses in the leaf. Pholidota cantonensis has styloids. The results show that there are more types of calcium oxalate crystals in the epiphytic orchids. Nevertheless, the density of raphides in the leaves of the terrestrial orchids is higher than that in the epiphytic orchids.Most of the studied epiphytic orchids have silica body in the bundle sheath cells. However, there is no silica body in the leaves of Bulbophyllum affine, Holcoglossum guasipinifolium, and Pomatocalpa acuminata. Otherwise, the silica body was observed only in the leaves of Bletilla formosana, and not in the other studied terrestrial orchids. Two types of silica bodies were found. In B. formosana, Dendrochilum uncatum, and Oncidium Sweet Sugar the silica bodies are conical in shape, and the others are spherical in shape. Besides, the ultrastructural changes of the leaf development and the formation of the calcium oxalate crystal idioblasts in the mesophyll of Anoectochilus formosanus were studied. Effects of calcium concentrations on the leaf development of A. formosanus were studied by tissue culture processes.The leaf morphogenesis of A. formosanus is as follows: crescent-shaped leaf primordium (＜0.1 mm), hood-shaped leaf primordium (0.1-0.3 mm), straight leaf primordium (0.3-1 mm), rolled-leaf (1-33 mm), and unfolded mature leaf (16-42 mm). Crystal initial idioblasts are found in the apex of 1 mm leaf primodium and large number are detected in the 2-3.5 mm rolled-leaves. The development of the raphide crystal idioblast is divided to six stages: (1) crystal idioblast initiation, (2) crystal chamber formation, (3) crystal growth, (4) ER expanded, (5) mucilage accumulation, and (6) crystal idioblast maturation. There are an enlarged nucleus and nucleoli in crystal idioblast of all stages and numerous spherosomes in initiation stage. The vacuoles contain electron-dense amorphous materials, which are association with the crystals and attached to the tonoplast. The morphology of plastids in some crystal idioblast are different from that in normal cells, and early literatures described that in crystal idioblast as the crystalloplatids One to several lobe regions are formed on the periphery of the crystalloplastids. The crystalloplastids contain insoluble polysaccharides and proteins. After the crystal chamber form in the vacuole, the crystal accumulates in these chambers and mucilage fills in the vacuole. There is high electron-dense mucilage sheath packed the raphide. In the mature raphide crystal cells, there are many lamellae sheath between the crystal. There are no distinct effects on the development of the leaves of A. formosanus cultured with different concentrations of calcium ion in the medium: 1/8 Ca (0.19 mM), 1/4 Ca (0.374 mM), 1 Ca (1.496 mM), 4 Ca (5.586 mM), and 8 Ca (11.972 mM). However, the density of crystals in leaves is increased with increasing concentrations of calcium ion.

The article presents the results of microscopic analysis of the leaves of L. officinalis. The main anatomical and diagnostic features that can be used in identifying and evaluating the authenticity of medicinal plant raw materials are established. Analysis of the anatomical structure showed that the leaves of L. officinalis are dorsoventral; the leaf plastic is hypostomatic, and the stomatal apparatus is anomocytic. The main vein of the leaf blade and petiole is represented by a bicollateral conducting bundle. Idioblasts represented by round- shaped essential oil cells were first identified in the columnar and spongy mesophyll of the leaf and petiole. Single diamond-shaped crystals and calcium oxalate druses were also found in the leaves. The information obtained can serve as a basis for the development of the section "Microscopy" in the draft regulatory documentation.