Mobilization and Role of Starch, Protein, and Fat Reserves during Seed Germination of Six Wild Grassland Species.

Ming Zhao,Hong Yan,Hongxiang Zhang,Lu Qiu,Carol C Baskin

doi:10.3389/fpls.2018.00234

Abstract

Since seed reserves can influence seed germination, the quantitative and qualitative differences in seed reserves may relate to the germination characteristics of species. The purpose of our study was to evaluate the correlation between germination and seed reserves, as well as their mobilization during germination of six grassland species (Chloris virgata, Kochia scoparia, Lespedeza hedysaroides, Astragalus adsurgens, Leonurus artemisia, and Dracocephalum moldavica) and compare the results with domesticated species. We measured starch, protein, and fat content in dry seeds and the initial absorption of water during imbibition. Starch, soluble protein, fat, and soluble sugar content also were determined at five stages during germination. Starch, protein, and fat reserves in dry seeds were not significantly correlated with germination percentage and rate (speed), but soluble sugar and soluble protein contents at different germination stages were positively significantly correlated with germination rate for the six species. Starch was mainly used during seed imbibition, and soluble protein was used from the imbibition stage to the highest germination stage. Fat content for all species remained relatively constant throughout germination for six species, regardless of the proportion of other seed reserves in the seeds. Our results for fat utilization differ from those obtained for cultivated grasses and legumes. These results provide new insight on the role of seed reserves as energy resources in germination for wild species.

Highlights

Seed germination is the beginning of the life history for seed plants (Donohue et al, 2010; Nonogaki et al, 2010; Lai et al, 2015)
It has been suggested that one way in which the environment indirectly affects seed germination is through the types and amounts of compounds transferred from the mother plant to the seeds (Donohue, 2009; Baskin and Baskin, 2014; Li et al, 2017)
The six wild species selected for study include Chloris virgata, Kochia scoparia, Lespedeza hedysaroides, Astragalus adsurgens, Leonurus artemisia, and Dracocephalum moldavica

Summary

Introduction

Seed germination is the beginning of the life history for seed plants (Donohue et al, 2010; Nonogaki et al, 2010; Lai et al, 2015). It has been suggested that one way in which the environment indirectly affects seed germination is through the types and amounts of compounds transferred from the mother plant to the seeds (Donohue, 2009; Baskin and Baskin, 2014; Li et al, 2017). This transfer of compounds to seeds includes carbohydrates, proteins and lipids, which are the major reserves in most seeds (Alencar et al, 2012). Storage protein (e.g., 11S globulins) mobilization can occur during the seed maturation process, albeit to a lower extent than during seed germination and seedling establishment (Job et al, 1997; Bourgne et al, 2000; Gallardo et al, 2001)

Objectives

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Conclusion