Is seed coat structure at fault for altered permeability and imbibition injury in artificially aged soybean seeds?

Abstract

Ageing induces many deteriorative changes to seeds during storage like genetic damage, protein degradation, enzyme inactivation and loss of membrane integrity. In this study, we subject to investigate the alterations in seed coat structure and its permeability properties due to accelerated ageing affecting the subsequent imbibition of soybean [Glycine max (L.) Merr.] seeds. Two contrasting seed coat colour genotypes, JS 335 (white) and Bhatt (black) were selected and artificially aged for 48 and 72 h. The results of seed ageing on permeability, imbibition and germination proved that permeability and imbibition increased but germination decreased in white genotype due to imbibitional injury, whereas germination increased in black genotype due to breaking of hard seed coat imposed dormancy. The hard seeds in the black genotype with a different seed coat structure compared to the white genotype prevented imbibition injury in aged seeds by regulating permeability. Microscopic studies of seed coat structure in aged seeds revealed a thick cuticle with small hilar fissure and compact, dense hourglass cells in black genotype compared to a thin cuticle with large hilar fissure and loosely packed and distorted hourglass cells in white genotype. Thus the altered permeability and imbibition injury in artificially aged seeds is shown to occur mainly as a result of altered and damaged seed coat structure. INTRODUCTIONSeed ageing is an irreversible and inexorable process of a progressive decrease in vigour ultimately leading to the loss of seed viability (Arc et al., 2011;Lehner et al., 2008;Stewart & Bewley, 1980). The rate of seed ageing depends upon the genotype/ species, the conditions prevailing during storage like moisture content, temperature, humidity and seed composition (Roberts, 1973). It has been reported that high moisture content and high temperature accelerate seed deterioration (Ellis & Hong, 1991;Goel et al., 2003) based on which seeds are accelerated to artificially age by exposing them to high humidity and temperature of about 40-45 ˚C and 100% RH (Delouche & Baskin, 1973). Accelerated ageing is shown to induce many deteriorative changes to seeds during storage

Aqueous extract of coconut shell biochar as a pre-germination treatment increases seed germination and early seedling growth in chiltepín pepper (Capsicum annuum var. glabriusculum)

“…The seeds' good physical quality illustrates the minimal damage that genetic material from wild plants can present, allowing for a quick and easy determination of their germination potential. Generally, seed damage can occur during fruit harvesting or the seed aging process during storage (Satya Srii et al, 2022). Here, we demonstrated that the collected chiltepín pepper seeds had minimal to no physical damage to the pericarp.…”

Seed coat composition in black and white soybean seeds with differential water permeability

“…Seed imbibition used an electronic balance (ESSAE; FB 200‐172‐14666; Integral Industrial Services Private Limited, Noida, India) approach, by measuring weight differences as described in Satya Srii et al . (2022). Three replicates of 10 seeds of each genotype were used.…”

“…A recent study on soybean seeds (Satya Srii et al . 2022) found that white seed coats of JS 335 were more prone to imbibitional injury than black seed coats of Bhatt due to differences in permeability related to variations in seed coat structure. However, this work did not explore the difference in seed coat chemical composition between the two genotypes that might influence seed coat permeability.…”

“…Satya Srii et al . (2022) described the thick cuticle in black soybean compared to that of white seeds, which incurred high imbibition injury, revealing the role of the cuticle in regulating permeability. The cuticle is made of cutin, an insoluble compound with a cross‐linked matrix of lipid polyesters bound to the cell wall (Nawrath et al .…”

“…With this background, and on the basis of results on seed coat permeability and imbibition injury in JS 335 (white) and Bhatt (black) soybean genotypes (Satya Srii et al . 2022), this study investigates chemicals in the different seed coats, like phenols, proteins, tannins, trace elements (Mn, Fe, Cu, Zn), and primary metabolites that might influence permeability of seeds of contrasting colours.…”