Seed coat suberin forms a barrier against chromium (Cr3+) during early seed germination in Arabidopsis thaliana

2021 ◽  
pp. 104632
Author(s):  
Nayana D.G. de Silva ◽  
Céline Boutin ◽  
Anna O. Lukina ◽  
Tamara L. Western ◽  
Isabel Molina ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Seed Germination ◽  
Seed Coat

scholarly journals Asymbiotic germination of Vanilla planifolia in relation to the timing of seed collection and seed pretreatments

2021 ◽  
Vol 62 (1) ◽  
Author(s):  
Chih-Hsin Yeh ◽  
Kai-Yi Chen ◽  
Yung-I. Lee
Keyword(s):  
Seed Germination ◽  
Seed Development ◽  
Seed Coat ◽  
Germination Percentage ◽  
Vanilla Planifolia ◽  
Outermost Layer ◽  
Seed Collection ◽  
Seed Pretreatment ◽  
Immature Seeds ◽  
Mature Seeds

Abstract Background Vanilla planifolia is an important tropical orchid for production of natural vanilla flavor. Traditionally, V. planifolia is propagated by stem cuttings, which produces identical genotype that are sensitive to virulent pathogens. However, propagation with seed germination of V. planifolia is intricate and unstable because the seed coat is extremely hard with strong hydrophobic nature. A better understanding of seed development, especially the formation of impermeable seed coat would provide insights into seed propagation and conservation of genetic resources of Vanilla. Results We found that soaking mature seeds in 4% sodium hypochlorite solution from 75 to 90 min significantly increased germination. For the culture of immature seeds, the seed collection at 45 days after pollination (DAP) had the highest germination percentage. We then investigated the anatomical features during seed development that associated with the effect of seed pretreatment on raising seed germination percentage. The 45-DAP immature seeds have developed globular embryos and the thickened non-lignified cell wall at the outermost layer of the outer seed coat. Seeds at 60 DAP and subsequent stages germinated poorly. As the seed approached maturity, the cell wall of the outermost layer of the outer seed coat became lignified and finally compressed into a thick envelope at maturity. On toluidine blue O staining, the wall of outer seed coat stained greenish blue, indicating the presence of phenolic compounds. As well, on Nile red staining, a cuticular substance was detected in the surface wall of the embryo proper and the innermost wall of the inner seed coat. Conclusion We report a reliable protocol for seed pretreatment of mature seeds and for immature seeds culture based on a defined time schedule of V. plantifolia seed development. The window for successful germination of culturing immature seed was short. The quick accumulation of lignin, phenolics and/or phytomelanins in the seed coat may seriously inhibit seed germination after 45 DAP. As seeds matured, the thickened and lignified seed coat formed an impermeable envelope surrounding the embryo, which may play an important role in inducing dormancy. Further studies covering different maturity of green capsules are required to understand the optimal seed maturity and germination of seeds.

scholarly journals Two β-glucuronosyltransferases involved in the biosynthesis of type II arabinogalactans function in mucilage polysaccharide matrix organization in Arabidopsis thaliana

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Oyeyemi O. Ajayi ◽  
Michael A. Held ◽  
Allan M. Showalter
Keyword(s):  
Arabidopsis Thaliana ◽  
Seed Size ◽  
Seed Coat ◽  
Glucuronic Acid ◽  
Industrial Applications ◽  
Crystalline Cellulose ◽  
Sugar Residue ◽  
Composition Analysis ◽  
Cellulose Content ◽  
Type Ii

Abstract Background Arabinogalactan-proteins (AGPs) are heavily glycosylated with type II arabinogalactan (AG) polysaccharides attached to hydroxyproline residues in their protein backbone. Type II AGs are necessary for plant growth and critically important for the establishment of normal cellular functions. Despite the importance of type II AGs in plant development, our understanding of the underlying role of these glycans/sugar residues in mucilage formation and seed coat epidermal cell development is poorly understood and far from complete. One such sugar residue is the glucuronic acid residues of AGPs that are transferred onto AGP glycans by the action of β-glucuronosyltransferase genes/enzymes. Results Here, we have characterized two β-glucuronosyltransferase genes, GLCAT14A and GLCAT14C, that are involved in the transfer of β-glucuronic acid (GlcA) to type II AGs. Using a reverse genetics approach, we observed that glcat14a-1 mutants displayed subtle alterations in mucilage pectin homogalacturonan (HG) compared to wild type (WT), while glcat14a-1glcat14c-1 mutants displayed much more severe mucilage phenotypes, including loss of adherent mucilage and significant alterations in cellulose ray formation and seed coat morphology. Monosaccharide composition analysis showed significant alterations in the sugar amounts of glcat14a-1glcat14c-1 mutants relative to WT in the adherent and non-adherent seed mucilage. Also, a reduction in total mucilage content was observed in glcat14a-1glcat14c-1 mutants relative to WT. In addition, glcat14a-1glcat14c-1 mutants showed defects in pectin formation, calcium content and the degree of pectin methyl-esterification (DM) as well as reductions in crystalline cellulose content and seed size. Conclusions These results raise important questions regarding cell wall polymer interactions and organization during mucilage formation. We propose that the enzymatic activities of GLCAT14A and GLCAT14C play partially redundant roles and are required for the organization of the mucilage matrix and seed size in Arabidopsis thaliana. This work brings us a step closer towards identifying potential gene targets for engineering plant cell walls for industrial applications.

Ontogenetic, Light, and Circadian Regulation of PAP Protein Genes during Seed Germination of Arabidopsis thaliana

2021 ◽  
Vol 500 (1) ◽  
pp. 312-316
Author(s):  
A. A. Andreeva ◽  
N. V. Kudryakova ◽  
Vl. V. Kuznetsov ◽  
V. V. Kusnetsov
Keyword(s):  
Arabidopsis Thaliana ◽  
Seed Germination ◽  
Circadian Regulation

scholarly journals Scarification with sulphuric acid of Schizolobium amazonicum Huber ex Ducke seeds - FABACEAE

2007 ◽  
Vol 64 (3) ◽  
pp. 308-313 ◽  
Author(s):  
Eniel David Cruz ◽  
José Edmar Urano de Carvalho ◽  
Rafaela Josemara Barbosa Queiroz
Keyword(s):  
Statistical Analysis ◽  
Experimental Design ◽  
Seed Germination ◽  
Sulphuric Acid ◽  
Seed Coat ◽  
Immersion Time ◽  
Germination Index ◽  
Efficient Treatment ◽  
Tukey Test

Seed coat impermeability to water occurs in many species, including Schizolobium amazonicum Huber ex Ducke. To promote germination in seeds with coat impermeability the use of sulphuric acid (H2SO4) is recommended. The objective of this study was to identify a better time for the scarification with sulphuric acid for S. amazonicum seeds. The effect of scarification with sulphuric acid for 20, 40 and 60 min on germination and speed germination was studied for seeds that were either sowed immediately after scarification or after a 24-hour period of immersion in water. Seeds were sown on a mix of sand and sawdust (1:1). The experimental design was completely randomized with four replications of 50 seeds. The statistical analysis of germination was carried out at six, nine, 12, 15, 18, 21 and 24 days after sowing, in a factorial scheme. For speed germination the means were compared by the Tukey test. There was an interaction between treatments to overcome dormancy and immersion time after scarification in most evaluations. Immersion in water accelerated the beginning of germination. All treatments to overcome dormancy promoted seed germination. However, scarification for 60 min, showed better germination, 92% when immediately sown and 86.5% when sown after 24 hours. Speed germination index was highest for scarified seeds for 60 min followed by immersion in water. Scarification for 60 min was the most efficient treatment to promote germination in S. amazonicum seeds.

scholarly journals Activation of rape (Brassica napus L.) embryo during seed germination. V. The first zones of ultrastructural changes and their expansion

2014 ◽  
Vol 56 (1) ◽  
pp. 77-91 ◽  
Author(s):  
Mieczysław Karaś
Keyword(s):  
Brassica Napus ◽  
Seed Germination ◽  
Seed Coat ◽  
Basal Part ◽  
Ultrastructural Changes ◽  
Embryo Axis ◽  
Brassica Napus L ◽  
Root Cells ◽  
Basal Zone

In the germinating rape embryo the columella and basal part of hypocotyl undergo earliest activation. Its first ultrastructural symptom is the appearance of numerous ER vesicles after 3-6 h of seed swelling. Their number is the highest in the external layers of the columella and decreases in basipetal direction. Dermatogen cells in the basal zone of the hypocotyl contain the greatest amount of ER structures, whereas decreasing amounts are found in both directions along the embryo axis and centripetally. Further changes in the ER spread in a similar order. The vesicles merge and form a tubular and plate-like ER. Then, they disappear and are replaced by tubular and vesicular forms. The changes in the ER are gradually followed by ultrastructural symptoms of activation of mitochondria, plastids and dictyosomes. The highest number of ER structures and other organelles accumulate in root cells shortly before piercing of the seed coat. After germination their amount decreases and remains almost stable.

scholarly journals Genome-Wide Characterization and Expression Analysis of KH Family Genes Response to ABA and SA in Arabidopsis thaliana

2022 ◽  
Vol 23 (1) ◽  
pp. 511
Author(s):  
Yanjie Zhang ◽  
Yu Ma ◽  
Ruiqi Liu ◽  
Guanglin Li
Keyword(s):  
Arabidopsis Thaliana ◽  
Seed Germination ◽  
Nucleic Acid Binding ◽  
Phylogenetic Tree Analysis ◽  
Genome Wide ◽  
Binding Factor ◽  
Pathogenesis Related ◽  
Kh Domain ◽  
Family Based ◽  
Related Proteins

K-homologous (KH) family is a type of nucleic acid-binding protein containing the KH domain and has been found to affect splicing and transcriptional regulation. However, KH family genes haven’t been investigated in plant species systematically. In this study, we identified 30 genes that belonged to the KH family based on HMM of the KH domain in Arabidopsis thaliana. Phylogenetic tree analysis showed that the KH family is grouped into three subgroups. Synteny analysis showed that AtKH9 and AtKH29 have the conserved synteny relationship between A. thaliana and the other five species. The AtKH9 and AtKH29 were located in the cytoplasm and nucleus. The seed germination rates of the mutants atkh9 and atkh29 were higher than wild-type after abscisic acid (ABA) and salicylic acid (SA) treatments. In addition, the expression of ABA-related genes, such as ABRE-binding factor 2 (ABF2), ABRE-binding factor 4 (ABF4), and delta 1-pyrroline-5-carboxylate synthase (P5CS), and an SA-related gene pathogenesis-related proteins b (PR1b) were downregulated after ABA and SA treatments, respectively. These results suggested that atkh9 and atkh29 mutants inhibit the effect of ABA and SA on seed germination. In conclusion, our results provide valuable information for further exploration of the function of KH family genes and propose directions and ideas for the identification and characterization of KH family genes in other plants.

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