Effects of genetic and environmental factors on variations of seed heteromorphism in Suaeda aralocaspica

Abstract

Seed heteromorphism (SH) is an adaptive strategy towards adversity in many halophytes. However, the underlying mechanisms and ecological significance of SH have not been deeply explored. Using Suaeda aralocaspica, a typical C4 annual halophyte without Kranz anatomy, we studied seed morphology, differentiation of morphs and fruit-setting patterns, and correlated these traits with germination responses, seed characteristics and heteromorphic seed ratio. To elucidate the genetic basis of SH, we analyzed correlated patterns of gene-expression for seed development related genes as well. We observed that S. aralocaspica produced three types of seed morph: brown, large black and small black with differences in color, size, mass and germination behavior; the latter two were further distinguished by their origin in female or bisexual flowers respectively. Further analysis revealed that SH was associated with genetic aspects including seed positioning, seed coat differentiation and seed developmental gene expression, while variations in SH may be associated with environmental conditions, e.g. annual precipitation, temperature, daylight, and their monthly distribution in different calendar years. SH and its variations in S. aralocaspica show multi-level regulation of the bet-hedging strategy that influences phenotypic plasticity, which is a consequence of internal genetic and external environmental factor interaction. Our findings contribute to the understanding of SH as a potential adaptive trait of desert plant species.

Influência da heteromorfia de sementes na morfometria, germinação, vigor e caracterização morfológica de plântulas de Parahancornia fasciculata (Poir) Benoist – ‘Amapá Amargoso’

“…A plasticidade fenotípica de algumas espécies heteromórficas, como as proporções e os números de morfologia de frutos e sementes, tem sido considerada um mecanismo da espécie para lidar com ambientes imprevisíveis (Cao, et al, 2020).…”

The Developmental Delay of Seedlings With Cotyledons Only Confers Stress Tolerance to Suaeda aralocaspica (Chenopodiaceae) by Unique Performance on Morphology, Physiology, and Gene Expression

“…Suaeda aralocaspica has developed various strategies to adapt to heterogeneous conditions at different developmental stages, e.g., seed heteromorphism in the germination stage, SC C 4 assimilation pathway in the adult stage, growth enhancement by salt in the whole life cycle, etc. (Voznesenskaya et al, 2001 ; Wang et al, 2008 ; Cao et al, 2015 , 2020 ). However, the specific mechanism for early seedling development in an extreme environment has not been well understood so far.…”

“…According to meteorological data from 2008 to 2012 of the natural habitat of S. aralocaspica , the average annual precipitation is about 165 mm but is usually much less during the first 4 months (Cao et al, 2020 ). The higher moisture of soil in spring along with a much higher evaporation rate promotes the seasonal accumulation of large amounts of salinity on soil surface, which creates a hostile environment for seedling growth (Ma et al, 2018 ).…”

Assessing variation inCitrus limon‘Assam lemon’: morphological, seed availability pattern, and biochemical diversity across different districts of Assam

“…The combination of environmental conditions, genetic mutations, and soil nutrient variations across districts may contribute to the observed diversity in seed counts. It was previously reported that the environmental factors and genetic mutations act as a potential influencer on the seeding pattern of fruits (Cao et al 2020). Also, the variation in the soil nutrients in different districts of Assam may be a reason, which contributes to the differences in seeding patterns among the accessions in the current study (Gnan et al 2014).…”