Poor seed quality, reduced germination, and decreased seedling vigor in soybean is linked to exposure of the maternal lines to drought stress

Abstract

Poor seed quality, reduced germination, and decreased seedling vigor in soybean is linked 1 to exposure of the maternal lines to drought stress 2 3 Abstract 18 Effects of environmental stressors on the parent may be transmitted to the F1 generation of 19 plants that support global food, oil, and energy production for humans and animals. This study 20 was conducted to determine if the effects of drought stress on parental soybean plants are 21 transmitted to the F1 generation. The germination and seedling vigor of F1 soybean whose 22 maternal parents, Asgrow AG5332 and Progeny P5333RY, were exposed to soil moisture stress, 23 that is, 100, 80, 60, 40, and 20% replacement of evapotranspiration (ET) during reproductive 24 growth, were evaluated under controlled conditions. Pooled over cultivars, effects of soil 25 moisture stress on the parents caused a reduction in the seed germination rate, maximum seed 26 germination, and overall seedling performance in the F1 generation. The effect of soil moisture 27 stress on the parent induced an irreversible change in the seed quality in the F1 generation and 28 the effects on seed quality in the F1 generation were exasperated when exposed to increasing 29 levels of drought stress. Results indicate that seed weight and storage reserve are key factors 30 influencing germination traits and seedling growth. Our data confirm that the effects of drought 31 stress on soybean are transferable, causing reduced germination, seedling vigor, and seed quality 32 in the F1 generation. 33 34 35Soybean [Glycine max (L.) Merr.] is a globally important annual crop, and one of the major 36 export commodities providing oil and protein for both human and animal food. It is the second 37 most planted field crop in the U.S. next to corn [1] and accounts for about 90% of U.S. oilseed 38 production. Hence, soybean production provides a substantial input to the economic structure of 39 the United States. 40 Soil moisture stress causes extensive losses to soybean production annually, and losses 41 due to drought stress are projected to increase due to climate change. Climate change models 42 indicate that historical precipitation patterns will change, and drought stress will become more 43 severe in soybean growing regions in the United States [2]. As soil moisture stress episodes are 44 remarkably aggravated, in recent years, greater importance has been directed to research on the 45 unfavorable effects of soil moisture stress on soybean crop performance and yield. 46It is well known that variations in environmental conditions such as photoperiod, water, 47 nutrient status, and solar radiation can have an effect on plant growth and development [3]; 48 however, we now understand that some effects of environmental stressors are transmittable and 49 have fitness and phenotype costs on the F1 generation [4,5,6]. For instance, Nosalewicz et al. [7] 50 reported that exposing barley (Hordeum vulgare (L.)) to drought stress during reproductive 51 stages decreased the shoot: root ratio...

Stress memory and its regulation in plants experiencing recurrent drought conditions

“…While on the one hand drought stress memory is viewed from an evolutionary perspective as an effective strategy that could prepare a plant for later stress by improving the plant’s potential for local acclimation to changing environments, some studies have nevertheless associated it with negative effects like delayed growth and development and reduced yield (Skirycz & Inzé, 2010 ; Crisp et al 2016 ; Wijewardana et al 2019a , b ). Therefore, although mechanisms of drought stress memory could have evolved as adaptive approaches to enhance resistance against drought, the overall performance may be compromised, thereby leading to tradeoffs between yield and stress survival (Godwin & Farrona 2020 ).…”

Will epigenetics be a key player in crop breeding?

“…The value of making the distinction between inter-and transgenerational effects when considering epigenetic inheritance, especially where differential maternal provisioning is clearly the determining factor, is illustrated by studies of these effects in durum wheat (Triticum durum Desf.) in response to a combination of drought and heat stress and in the soybean in response to drought stress (Wijewardana et al, 2019;Liu et al, 2021). In both studies, only the F 1 of stressed parents was evaluated, and performance measures were only for seed and seedling performance.…”

The potential impacts of climate change on ex situ conservation options for recalcitrant-seeded species

“…Global climate change, in altering environmental cues related to temperature and rainfall, could therefore preclude, delay, or enhance regeneration from seeds (Walck et al, 2011;Sentinella et al, 2020;Pritchard et al, 2022). There is also ample direct evidence to suggest that changes in temperature and rainfall will affect the yield and quality of seeds in orthodox crops (Hatzig et al, 2018;Abdul Rahman and Ellis, 2019;Wijewardana et al, 2019;Ben Mariem et al, 2021;Poggi et al, 2022) and native plant species (Buechling et al, 2016;Delgado-Vargas et al, 2018). More recent evidence suggests that these effects may extend to the regulation of dormancy and germination (Bernareggi et al, 2016;Klupczyńska and Pawłowski, 2021) as well viability retention (Ooi et al, 2009;Ooi, 2012) and seed longevity (White et al, 2022).…”