Cereal Husks: Versatile Roles in Grain Quality and Seedling Performance

Abstract

The seed is the fundamental unit of the dispersal of dry, dehiscent fruits, in which the fruit splits open at maturity to allow for seed dispersal. However, dry fruits may be indehiscent and therefore represent the dispersal unit (DU). Cereals possess a one-seeded fruit, whereby the seed coat and the fruit coat are fused together to generate the caryopsis. This caryopsis may be covered by floral bracts to generate two types of DUs, namely florets, whereby the caryopsis is enclosed by the lemma and the palea (e.g., Avenasterilis) or spikelet, whereby the floret(s) is further covered by the glumes (Triticum turgidum var. dicoccoides). Here, we highlight the dead coverings enclosing the caryopsis in cereals, namely the husks as an integral component of the dispersal unit that play multifaceted roles in grain biology. Thus, besides protection and dispersal means, the husks function as a rich maternal supply of proteins and metabolites for enhancing growth and development, combat potential pathogens as well as confer tolerance to abiotic stresses. These attributes might have broad implications for crop performance, plant population dynamics and diversity in ecological systems, and for conservation of genetic resources in seed banks.

Detailed analysis of agro-industrial byproducts/wastes to enable efficient sorting for various agro-industrial applications

“…AIBW extracts also accumulate allelopathic substances that selectively inhibit or promote seed germination and post germination growth. Often dead organs enclosing the embryo such as the seed coat, the pericarp and floral bract in grasses (i.e., glume, lemma, paleae) as well as peels enclosing vegetative reproductive organs (bulb) such as garlic peels possess allelopathic substances that can inhibit or promote germination of neighboring plants (Grafi and Singiri 2022 ). Multiple reports have demonstrated selective effects of crop residues on germination and post germination growth of a variety of plant species.…”

Various temperature effects on spikelet growth in hulless oat during grain-filling stage

“…Oat florets are branched cluster of loose lemma and palea. The composition and level of multiple proteins accumulated in Avena husks were significantly changed under multiple stresses (Grafi and Singiri 2022). Because of the high nutrient density in the grains, oat has become extremely popular in recent years.…”