Identification of genomic regions associated with the plasticity of carbon 13 ratio in soybean

Abstract

Improving water use efficiency (WUE) for soybean [Glycine max (L.) Merr.] through selection for high carbon isotope (C13) ratio may increase drought tolerance, but increased WUE may limit growth in productive environments. An ideal genotype would be plastic for C13 ratio; that is, be able to alter C13 ratio in response to the environment. Our objective was to identify genomic regions associated with C13 ratio plasticity, C13 ratio stability, and overall C13 ratio in two panels of diverse Maturity Group IV soybean accessions. A second objective was to identify accessions that differed in their C13 ratio plasticity. Panel 1 (205 accessions) was evaluated in seven irrigated and four drought environments, and Panel 2 (373 accessions) was evaluated in four environments. Plasticity was quantified as the slope from regressing C13 ratio of individual genotypes against an environmental index calculated based on the mean within and across environments. The regression intercept was considered a measure of C13 ratio over all environments, and the root mean square error was considered a measure of stability. Combined over both panels, genome‐wide association mapping (GWAM) identified 19 single nucleotide polymorphisms (SNPs) for plasticity, 39 SNPs for C13 ratio, and 16 SNPs for stability. Among these SNPs, 71 candidate genes had annotations associated with transpiration or water conservation and transport, root development, root hair elongation, and stomatal complex morphogenesis. The genomic regions associated with plasticity and stability identified in the current study will be a useful resource for implementing genomic selection for improving drought tolerance in soybean.

Effects of fast and slow-wilting soybean genotypes on fall armyworm ( Spodoptera frugiperda ) growth and development

“…In this study, we examined how variation in WUE traits across soybean genotypes impacts FAW growth and development at three different growth stages of soybeans. We found that faster wilting soybean genotypes tend to be taller and have more leaves, which aligned with previous studies [ 48 ]. No significant difference was observed in herbivore damage between fast and slow wilting varieties as well as across soybean life stages.…”

“…There is also the variation between soybean genotypes and how more significant expansion of Genome-Wide Association Studies (GWAS) is needed to further quantify the diverse traits seen between genotypes. As previously mentioned, WUE traits and drought tolerance traits have multiple genetic markers and, therefore, have varying impacts on plant fitness [ 48 ]. This indicates that secondary metabolite biosynthesis may be triggered by abiotic stress that differs significantly not only between plant species but also within plant genotypes.…”

Genomic approaches to enhance adaptive plasticity to cope with soil constraints amidst climate change in wheat

“…WUE is the quantity of dry matter produced per unit of water transpired by the crop. WUE is positively associated with yield because the seed yield is dependent on total crop mass (Chamarthi et al., 2023; Chen et al., 2011; Sinclair, 2012). In conclusion, it is also important to understand the regulatory mechanisms of the observed patterns in the changing environment to enhance plasticity.…”