Structure and Function of the Mucilaginous Seed Coats of Plantago Coronopus Inhabiting the Negev Desert of Israel

Gutterman, Yitzchak; Shem-Tov, Shachar

doi:10.1080/07929978.1996.10676641

Cited by 69 publications

(33 citation statements)

References 7 publications

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“…Seed mucilage is very essential in many seed mucilage-bearing plants. Some of the important attributes of seed mucilage include its ability to prevent drying of seeds, reduce drought stress during germination, and facilitate rapid germination and early seedling establishment and growth [5,6,11,12]. Seed mucilage also plays important roles in seed dispersal, seed adhesion to soil, and minimizing seed removal by water and predators [6,13].…”

Section: Discussionmentioning

confidence: 99%

Demucilaging Freshly Stored Seeds of Cocoa (Theobroma cacao L.) Improves Seedling Emergence and Growth

et al. 2017

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Fresh seeds of cocoa (Theobroma cacao L.) are covered by a large amount of mucilage, which plays important ecological roles. However, for stored seeds, mucilage can adversely affect germination. This study investigated the effect of mucilage removal (demucilaging) and seed storage of freshly extracted cocoa seeds on seedling emergence and growth. The study showed that demucilaging cocoa seeds confers several advantages over mucilage intact seeds provided the seeds have been stored for at least three days before sowing. Demucilaging increased germination rate (T 50 ) and percentage germination and presence of mucilage increased days to seedling emergence and cessation of germination when seeds were stored for over two days. For up to 21 days of seed storage, there was generally no difference in many traits for demucilaged seeds. Demucilaged seeds had 80-100% germination after 21 days of storage, and rate of germination increased with increasing duration of seed storage. Intact mucilage seeds maintained 80-100% germination for only 2 days after seed extraction and rate of germination decreased with increasing seed storage duration. We conclude that (i) if seeds are sown on the day of extraction demucilaging before sowing would be superfluous and (ii) demucilaging and storage can provide advantages to smallholder farmers when environmental or socioeconomic conditions preclude immediate sowing.

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Section: Discussionmentioning

confidence: 99%

Demucilaging Freshly Stored Seeds of Cocoa (Theobroma cacao L.) Improves Seedling Emergence and Growth

et al. 2017

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“…On imbibition, the hydrated polysaccharides expand, rupture the outer tangential cell wall, and form a viscous mucilage that encapsulates the seed. The physiological role of seed mucilage remains to be determined, but functions in the control of germination or seed dispersal have been proposed (Witztum et al, 1969;Young and Evans, 1973;Gutterman and Shem-Tov, 1996;Penfield et al, 2001;Arsovski et al, 2009). In Arabidopsis, the major component of seed mucilage is the pectin rhamnogalacturonan I (RG I; Goto, 1985;Western et al, 2000Western et al, , 2001Western et al, , 2004Penfield et al, 2001, Usadel et al, 2004Macquet et al, 2007a).…”

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confidence: 99%

CESA5 Is Required for the Synthesis of Cellulose with a Role in Structuring the Adherent Mucilage of Arabidopsis Seeds

et al. 2011

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Imbibed Arabidopsis (Arabidopsis thaliana) seeds are encapsulated by mucilage that is formed of hydrated polysaccharides released from seed coat epidermal cells. The mucilage is structured with water-soluble and adherent layers, with cellulose present uniquely in an inner domain of the latter. Using a reverse-genetic approach to identify the cellulose synthases (CESAs) that produce mucilage cellulose, cesa5 mutants were shown to be required for the correct formation of these layers. Expression of CESA5 in the seed coat was specific to epidermal cells and coincided with the accumulation of mucilage polysaccharides in their apoplast. Analysis of sugar composition showed that although total sugar composition or amounts were unchanged, their partition between layers was different in the mutant, with redistribution from adherent to water-soluble mucilage. The macromolecular characteristics of the water-soluble mucilage were also modified. In accordance with a role for CESA5 in mucilage cellulose synthesis, crystalline cellulose contents were reduced in mutant seeds and birefringent microfibrils were absent from adherent mucilage. Although the mucilage-modified5 mutant showed similar defects to cesa5 in the distribution of sugar components between water-soluble and adherent mucilage, labeling of residual adherent mucilage indicated that cesa5 contained less cellulose and less pectin methyl esterification. Together, the results demonstrate that CESA5 plays a major and essential role in cellulose production in seed mucilage, which is critical for the establishment of mucilage structured in layers and domains.

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“…Released mucilage subsequently envelops the seed in a gelatinous gel (Western et al, 2000). While the function of seed mucilage is not well understood, suggested roles include aiding seed dispersal, protecting the germinating seed against dehydration, and, in some species, maintaining seed viability in harsh environments (Gutterman and Shemtov, 1996;Penfield et al, 2001).…”

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confidence: 99%

The Transcriptional Regulator LEUNIG_HOMOLOG Regulates Mucilage Release from the Arabidopsis Testa

et al. 2011

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Exposure of the mature Arabidopsis (Arabidopsis thaliana) seed to water results in the rapid release of pectinaceous mucilage from the outer cells of the testa. Once released, mucilage completely envelops the seed in a gel-like capsule. The physical force required to rupture the outer cell wall of the testa comes from the swelling of the mucilage as it expands rapidly following hydration. In this study, we show that mutations in the transcriptional regulator LEUNIG_HOMOLOG (LUH) cause a mucilage extrusion defect due to altered mucilage swelling. Based on sugar linkage and immunomicroscopic analyses, we show that the structure of luh mucilage is altered, having both an increase in substituted rhamnogalacturonan I and in methyl-esterified homogalacturonan. Also correlated with the structural modification of luh mucilage is a significant decrease in MUCILAGE MODIFIED2 (MUM2; a b-galactosidase) expression in the luh seed coat, raising the possibility that reduced activity of this glycosidase is directly responsible for the luh mucilage defects. Consistent with this is the structural similarity between mum2 and luh mucilage as well as the observation that elevating MUM2 expression in luh mutants completely suppresses the mucilage extrusion defect. Suppression of the luh mutant phenotype was also observed when LEUNIG, a transcriptional corepressor closely related to LUH, was introduced in luh mutants under the control of the LUH promoter. Based on these data, we propose a new model for the regulation of pectin biosynthesis during plant growth and development.

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Structure and Function of the Mucilaginous Seed Coats of Plantago Coronopus Inhabiting the Negev Desert of Israel

Cited by 69 publications

References 7 publications

Demucilaging Freshly Stored Seeds of Cocoa (Theobroma cacao L.) Improves Seedling Emergence and Growth

Demucilaging Freshly Stored Seeds of Cocoa (Theobroma cacao L.) Improves Seedling Emergence and Growth

CESA5 Is Required for the Synthesis of Cellulose with a Role in Structuring the Adherent Mucilage of Arabidopsis Seeds

The Transcriptional Regulator LEUNIG_HOMOLOG Regulates Mucilage Release from the Arabidopsis Testa

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