Seed development in relation to desiccation tolerance: A comparison between desiccation-sensitive (recalcitrant) seeds of Avicennia marina and desiccation-tolerant types

1993 ◽  
Vol 3 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Jill M. Farrant ◽  
N. W. Pammenter ◽  
Patricia Berjak
Keyword(s):  
Seed Development ◽  
Seedling Establishment ◽  
Soluble Sugars ◽  
Avicennia Marina ◽  
Sensu Stricto ◽  
Starch Accumulation ◽  
Recalcitrant Seeds ◽  
Recalcitrant Seed ◽  
Orthodox Seeds

AbstractDevelopment of the highly desiccation-sensitive (recalcitrant) seeds of primarily one species, Avicennia marina, is reviewed and compared with the ontogeny of desiccation-tolerant (orthodox) seeds. A. marina seeds undergo no maturation drying and remain metabolically active throughout development, which grades almost imperceptibly into germination. While PGR control of histodifferentiation is essentially similar to that characterizing desiccation-tolerant seeds, the phase of growth and reserve deposition is characterized by exceedingly high cytokinin levels which, it is proposed, promote a sink for assimilate import. While some starch accumulation does occur, the predominant reserves are soluble sugars which are readily available for the immediate onset of seedling establishment upon shedding. ABA levels are negligible in the embryo tissues during seed maturation, but increase in the pericarp, which imposes a constraint upon germination until these outer coverings are sloughed or otherwise removed. The pattern of proteins synthesized remains qualitatively similar throughout seed development in A. marina, and no LEA proteins are produced. This suggests both that seedling establishment is independent of maturation proteins and that the absence of LEAs and desiccation sensitivity might be causally related. The study on A. marina reveals that for this recalcitrant seed-type, germination per se cannot be defined: rather, it is considered as the continuation of development temporarily constrained by the pericarp ABA levels. This leads to a reexamination of the role of rehydration as key event sensu stricto, in the germination processes in desiccation-tolerant (orthodox) seeds.

Indeterminate development in desiccation-sensitive seeds of Quercus robur L.

1994 ◽  
Vol 4 (2) ◽  
pp. 127-133 ◽  
Author(s):  
W. E. Finch-Savage ◽  
P. S. Blake
Keyword(s):  
Moisture Content ◽  
Seed Development ◽  
Desiccation Tolerance ◽  
Quercus Robur ◽  
Soluble Sugars ◽  
Avicennia Marina ◽  
Terminal Phase ◽  
Embryonic Axes ◽  
Single Tree ◽  
Orthodox Seeds

AbstractFruit and seed development in Quercus robur L. were studied on a single tree over five consecutive seasons. Patterns of growth in the cotyledons and embryonic axes differed between years and resulted in seeds of very different sizes. Moisture content at shedding also differed between years, and late-shed seeds had lower moisture contents than early-shed seeds. Moisture content at shedding was negatively correlated with desiccation tolerance. Seed development in Q. robur therefore appeared indeterminate and did not end in a period of rapid desiccation.Sensitivity to desiccation in Q. robur was not due to an inability to accumulate dehydrin proteins, ABA or soluble sugars, substances that have been linked with the acquisition of desiccation tolerance in orthodox seeds. There were great similarities between several aspects of Q. robur seed development and that of orthodox seeds before the latter entered the terminal phase of rapid desiccation. This pattern of seed development contrasted with that reported for the highly desiccation-sensitive seeds of Avicennia marina.

scholarly journals A new approach towards the so-called recalcitrant seeds

2018 ◽  
Vol 40 (3) ◽  
pp. 221-236 ◽  
Author(s):  
Claudio José Barbedo
Keyword(s):  
Plant Conservation ◽  
Point Of View ◽  
Recalcitrant Seeds ◽  
New Approach ◽  
Recalcitrant Seed ◽  
Seed Conservation ◽  
Conservation Technology ◽  
Orthodox Seeds ◽  
Standard Life ◽  
Life Behavior

ABSTRACT: Water is essential, irreplaceable, and indispensable for any kind of carbon-based-life metabolic activity. Water-dependent living beings are the expected pattern in nature. However, some organisms can survive for some time at a minimum water content, such as seeds of some species (orthodox seeds). Nevertheless, the expected standard life behavior is found in seeds of another group of species, the so-called recalcitrant seeds, which are sensitive to desiccation. A huge range of different behaviors can be found between these two groups, leading authors to consider that orthodoxy and recalcitrance is not an all-or-nothing situation. Notwithstanding, we are still too far from understanding the differences and similarities between all these kinds of seeds and this has been a serious barrier to the development of plant conservation technologies. A new approach to understanding the differences between these seeds is presented here based on seed maturation, environmental influences, and evolution. From this point of view, all kinds of seed behavior are contemplated and, consequently, some new perspectives are considered for the recalcitrant seed conservation technology, the most intensely desired technology nowadays in this area.

Response of the recalcitrant seeds of Avicennia marina to hydrated storage: events occurring at the root primordia

1997 ◽  
Vol 7 (2) ◽  
pp. 169-178 ◽  
Author(s):  
Nthabiseng Motete ◽  
N. W. Pammenter ◽  
Patricia Berjak ◽  
Jillian C. Frédéric
Keyword(s):  
Water Stress ◽  
Avicennia Marina ◽  
Recalcitrant Seeds ◽  
Fungal Contamination ◽  
Root Primordia ◽  
Recalcitrant Seed ◽  
Main Effect ◽  
Additional Water ◽  
Mild Water Stress ◽  
Alginate Coating

AbstractThis study was undertaken to test the hypotheses that germinative metabolism of recalcitrant seeds in storage induces a requirement for additional water, which may result in the development of mild water stress, and that a reduction of the rate of this germinative metabolism will increase the storage lifespan of recalcitrant seeds. Studies were undertaken on seeds of Avicennia marina (Forssk.) Vierh. and concentrated on root primordia as these constitute the tissue that undergoes most change during storage. Encapsulating seeds from which the pericarp had been removed (naked seeds) in an alginate gel increased storage lifespan fourfold compared with naked seeds. Measures of metabolic rate such as time to first germination in storage and rate of protein synthesis did not indicate differences between alginate-coated and naked seeds, although ultrastructural observations indicated that both germinative and deteriorative processes were occurring more slowly in the alginate-coated seeds. Measures of water content and water and turgor potentials did not reveal signs of a mild water stress in either treatment. However, the number of seeds visibly contaminated with fungi and the rapidity with which this contamination became apparent were much reduced in alginate-coated seeds. It is suggested that fungal contamination constitutes a major cause of deterioration in stored, hydrated seeds of A. marina (and possibly other recalcitrant seed species) and the main effect of the alginate coating was to reduce the incidence of fungal contamination.

Variation in carbon content and size in developing fruit of Actinidia deliciosa genotypes

2010 ◽  
Vol 37 (6) ◽  
pp. 545 ◽  
Author(s):  
Simona Nardozza ◽  
Helen L. Boldingh ◽  
Annette C. Richardson ◽  
Guglielmo Costa ◽  
Hinga Marsh ◽  
...  
Keyword(s):  
Organic Acids ◽  
Fruit Development ◽  
Soluble Sugars ◽  
Seed Mass ◽  
Actinidia Deliciosa ◽  
Starch Accumulation ◽  
Minor Role ◽  
Dry Matter Content ◽  
Final Composition

This study identifies the developmental processes contributing to variation in green-fleshed kiwifruit (Actinidia deliciosa (A. Chev.) C.F. Liang et A.R. Ferguson var. deliciosa) fruit dry matter content (DM) and fresh weight (FW) by comparing genotypes with either high or low final DM. Results are compared with the model for fruit development, the tomato (Solanum lycopersicum L.). Differences in final composition were attributable to a higher rate of starch accumulation from 70 days after anthesis in high DM genotypes, with no other consistent differences in accumulation of soluble sugars or organic acids. High DM genotypes had 70% higher starch content and differed from low DM genotypes in the allocation of carbon between storage and other components. DM was negatively correlated with final fruit FW only in high DM genotypes, whereas starch was a constant proportion of dry weight (DW), suggesting a dilution effect rather than an interaction between fruit size and carbohydrate metabolism. Compared with tomato, the organic acids, particularly quinic acid, contributed more to estimated osmotic pressure during growth in FW than the soluble sugars, regardless of final composition or size. Seed mass per unit FW was highest in high DM genotypes, suggesting a previously unrecognised role for kiwifruit seeds in accumulation of carbohydrate by the pericarp. Anatomical comparisons also identified a role for differences in the packing of the two principal cell types, with an increased frequency of the larger cell type correlated with reduced DM. These genotypes demonstrate that kiwifruit differs from tomato in the role of starch as the principal stored carbohydrate, the reduced importance of dilution by growth in FW and the more minor role of the sugars compared with the organic acids during fruit development.

Subcellular organization and metabolic activity during the development of seeds that attain different levels of desiccation tolerance

1997 ◽  
Vol 7 (2) ◽  
pp. 135-144 ◽  
Author(s):  
Jill M. Farrant ◽  
N. W. Pammenter ◽  
Patricia Berjak ◽  
Christina Walters
Keyword(s):  
Phaseolus Vulgaris ◽  
Desiccation Tolerance ◽  
Avicennia Marina ◽  
Metabolic Rates ◽  
Recalcitrant Seeds ◽  
Concomitant Increase ◽  
Orthodox Seeds ◽  
Similar Development ◽  
Different Levels ◽  
Water Contents

AbstractWater contents, desiccation tolerance, respiratory rates and subcellular characteristics of three contrasting seed types were studied during development.Avicennia marina(a tropical wetland species) andAesculus hippocastanum(a temperate species) produce recalcitrant seeds andPhaseolus vulgarisproduces orthodox seeds. During development,A. hippocastanumandP. vulgarisseeds showed a decline in water content and respiration rate with a concomitant increase in desiccation tolerance. These parameters did not change during the development ofA. marinaseeds once they had become germinable. There was a decrease in the degree of vacuolation and an increase in the deposition of insoluble reserves inA. hippocastanumandP. vulgarisseeds, whileA. marinaseeds remained highly vacuolated and did not accumulate insoluble reserves. Mitochondria and endomembranes degenerated during the development ofA. hippocastanumandP. vulgarisseeds, but remained unchanged inA. marinaseeds. The data are consistent with the hypothesis that extensive vacuolation and high metabolic rates contribute to desiccation sensitivity. However, the development of recalcitrantA. hippocastanumseeds is similar to that of orthodoxP. vulgarisseeds. These data are in accord with the concept of seed recalcitrance being a consequence of truncated development. The results suggest that there may be three categories of seeds: orthodox seeds which develop desiccation tolerance, seeds which show similar development to orthodox seeds, but are shed before desiccation tolerance is well developed, and seeds which show no developmental trends giving rise to increased tolerance.

scholarly journals Morpho-Physiological and Transcriptome Changes in Tomato Anthers of Different Developmental Stages under Drought Stress

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1809
Author(s):  
Anthony Tumbeh Lamin-Samu ◽  
Mohamed Farghal ◽  
Muhammad Ali ◽  
Gang Lu
Keyword(s):  
Drought Stress ◽  
Molecular Mechanisms ◽  
Developmental Stages ◽  
Soluble Sugars ◽  
Anther Development ◽  
Starch Accumulation ◽  
Pollen Abortion ◽  
Metabolic Genes ◽  
Floral Bud

Drought limits the growth and productivity of plants. Reproductive development is sensitive to drought but the underlying physiological and molecular mechanisms remain unclear in tomatoes. Here, we investigated the effect of drought on tomato floral development using morpho-physiological and transcriptome analyses. Drought-induced male sterility through abnormal anther development includes pollen abortion, inadequate pollen starch accumulation and anther indehiscence which caused floral bud and opened flower abortions and reduced fruit set/yield. Under drought stress (DS), pollen mother cell to meiotic (PMC-MEI) anthers survived whereas tetrad to vacuolated uninucleate microspore (TED-VUM) anthers aborted. PMC-MEI anthers had lower ABA increase, reduced IAA and elevated sugar contents under DS relative to well-watered tomato plants. However, TED-VUM anthers had higher ABA increase and IAA levels, and lower accumulation of soluble sugars, indicating abnormal carbohydrate and hormone metabolisms when exposed to drought-stress conditions. Moreover, RNA-Seq analysis identified altogether >15,000 differentially expressed genes that were assigned to multiple pathways, suggesting that tomato anthers utilize complicated mechanisms to cope with drought. In particular, we found that tapetum development and ABA homeostasis genes were drought-induced while sugar utilization and IAA metabolic genes were drought-repressed in PMC-MEI anthers. Our results suggest an important role of phytohormones metabolisms in anther development under DS and provide novel insight into the molecular mechanism underlying drought resistance in tomatoes.

scholarly journals Differential Influx of Natural Plant Growth Regulators during Embryogeny in the Recalcitrant Seeds of Syzygium cumini (L) Skeels

2022 ◽  
Author(s):  
Parvathy S. Nair ◽  
K.G. Ajith Kumar ◽  
G.P. Gayatri ◽  
Ajayakumar .
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Defense Mechanism ◽  
Syzygium Cumini ◽  
Recalcitrant Seeds ◽  
Recalcitrant Seed ◽  
Embryonic Tissues ◽  
Orthodox Seeds ◽  
High Level

Background: The hormonal up-regulation and down-regulation in recalcitrant seeds, on the other hand, has received little research. We tested fou plant growth regulators from distinct families of phytohormones at the same time to better understand their differential input from maternal tissues to growing Syzygium cumini seeds. Methods: During April-June 2020, seeds were collected in their native habitats in the Western Ghats. Seeds were chosen at random from each treatment. The embryonic tissues of seeds were chopped up and frozen for LC-MS/MS hormonal profiling. Result: Except for ABA, the dynamics of key plant hormones in this recalcitrant seed were identical to that of desiccation-tolerant orthodox seeds. When compared to other conventional seeds, SA was shown to accumulate at an unusually high level in mature embryonic tissues, demonstrating the highly hydrated seed’s defense mechanism against fungal attack following seed shedding.

Structural aspects and trends in the evolution of recalcitrant seeds in dicotyledons

1994 ◽  
Vol 4 (2) ◽  
pp. 225-239 ◽  
Author(s):  
I. von Teichman ◽  
A. E. van Wyk
Keyword(s):  
Seed Viability ◽  
Endosperm Development ◽  
Functional Adaptation ◽  
Evolutionary Status ◽  
Character State ◽  
Recalcitrant Seeds ◽  
Recalcitrant Seed ◽  
Ancestral Character State ◽  
Storage Reserve ◽  
Orthodox Seeds

AbstractThis review focuses on the possible evolutionary status and functional significance of recalcitrance and certain associated ovule/seed characters, within the framework of modern systems of angiosperm classification. The presence of recalcitrant seed viability in 45 dicotyledonous families is significantly associated with bitegmic and crassinucellate ovules and with nuclear endosperm development, all considered ancestral (plesiomorphic) character states of the ovule; as well as with greater seed size, woody habit and tropical habitat, also regarded as ancestral character states in the dicotyledons. In many species with recalcitrant seeds, the predominant storage reserve is carbohydrate. Recalcitrance is significantly associated with the exalbuminous type of reserve storage. It is proposed that in large recalcitrant seeds, the transfer of the main storage function from endosperm to embryo was probably an early development. In many species with recalcitrance, the ovules/seeds are characterized by extensive vascularization of the integument(s)/seed coat or by a pachychalaza. Pachychalazy is proposed to be a significant functional adaptation for a more efficient transfer of nutrients to the embryo/seed. Recalcitrance and some of the other character states proposed to be plesiomorphic in dicotyledons are also present in some gymnosperms, including presumed sister groups of the dicotyledons. In relatively advanced dicotyledonous families, mostly with orthodox seeds, recalcitrance probably persisted only in isolated relict members. Determination of character polarity is particularly problematic at lower taxonomic levels, because there is always the possibility that, in some taxa, a character state such as recalcitrance may have arisen secondarily as a reversal. Available evidence supports our view that seed recalcitrance can be regarded as a relatively ancestral character state in dicotyledons.

scholarly journals SDG711 Is Involved in Rice Seed Development through Regulation of Starch Metabolism Gene Expression in Coordination with Other Histone Modifications

Rice ◽  
2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Xiaoyun Liu ◽  
Junling Luo ◽  
Tiantian Li ◽  
Huilan Yang ◽  
Ping Wang ◽  
...  
Keyword(s):  
Seed Development ◽  
Starch Synthesis ◽  
Endosperm Development ◽  
Starch Accumulation ◽  
Body Region ◽  
Rice Seed ◽  
Normal Seed ◽  
Gene Body Region ◽  
Metabolism Gene

AbstractSDG711 is a histone H3K27me2/3 transmethylase in rice, a homolog of CLF in Arabidopsis, and plays key roles in regulating flowering time and panicle development. In this work, we investigated the role of SDG711 in rice seed development. Overexpression and downregulation of SDG711 lead to a decrease and increase in the expression level of genes related to starch accumulation, resulting in smaller seeds or even seed abortion. ChIP assay showed that SDG711-mediated H3K27me3 changed significantly in genes related to endosperm development, and SDG711 can directly bind to the gene body region of several starch synthesis genes and amylase genes. In addition, H3K4me3 and H3K9ac modifications also cooperate with H3K27me3 to regulate the development of the endosperm. Our results suggest that the crosstalk between SDG711-mediated H3K27me3 and H3K4me3, and H3K9ac are involved in starch accumulation to control normal seed development.

scholarly journals GA/ABA Antagonism in the Physiology of Seed Germination in the Recalcitrant and Vulnerable Tree- Vateria indica L.

2021 ◽  
Author(s):  
G.P. Gayatri ◽  
K.G. Ajith Kumar ◽  
Parvathy S. Nair ◽  
M. Somasekharan Pillai
Keyword(s):  
Seed Germination ◽  
Recalcitrant Seeds ◽  
Tropical Plants ◽  
Recalcitrant Seed ◽  
Retarding Effect ◽  
Western Ghats Of India ◽  
Orthodox Seeds ◽  
Almost All ◽  
Germination And Growth ◽  
Working Out

Background: Seed recalcitrance is a major problem associated with many tropical plants, limiting their natural regeneration. Vateria indica L. is a vulnerable and endemic tree species in South-Western Ghats of India, which is also recalcitrant. ABA and gibberellins are the most important plant hormones required for seed germination. It is the balance between ABA and GA which is responsible for desiccation tolerance in orthodox seeds. Exogenous hormones pretreatment has been also reported to influence seed germination. But such studies had been sparsely done in the case of recalcitrant seeds. This study aims to find out whether GA/ABA antagonism in recalcitrant plants is operating in the same way, like that in the orthodox seeds.Methods: The effect of the exogenous pre-soaking application of phytohormones viz. GA3 and ABA individually as well as their combinations on seed germination and growth of Vateria indica L. were carried out in the present work. The seeds were collected from April to July 2018 and the experiment was designed at Post Graduate and Research Department of Botany, Government College for Women, Thiruvananthapuram. When different concentrations of each phytohormone were externally given to the seeds, ABA reduced the germination and growth in almost all the concentrations. But GA3 gave better results. When combinations of GA3 and ABA were used, germination was poor in the sample where ABA was more than GA3, But in samples with same concentrations of both the hormones and with more GA3 gave better results. Result: This study clearly showed that GA3 when given externally along with ABA, might have affected the endogenous ABA in this recalcitrant seed and suppressed its retarding effect. Thus ABA/GA antagonism is working out, here, in the same way as in orthodox seeds. Since the germination of recalcitrant seeds is a less investigated area, the present study will form a basis and a lot more for further such studies.

Sign in / Sign up

Export Citation Format

Share Document