Differential expression analysis of soybean pod tissue between Canadian environments identifies differences in...

Soybean seeds are rich in oil and protein; however, the seed composition is influenced by genotype and environment. For years, it has been observed that soybeans grown in western Canada have lower seed protein concentration (by ∼1%-5% total seed weight) than those grown in eastern Canada. In this study, soybean seeds harvested from five varieties were grown in four different locations in Canada (east and west growing regions) and analyzed using RNA-sequencing. Using gene ontology and biological pathway mapping, we identified a difference in cysteine and methionine metabolism between soybeans grown in eastern and western Canada that may attribute to the difference in seed protein concentration. Further, we identified differential gene expression within the oil biosynthesis pathway, specifically upregulation of lipoxygenases in western-grown soybeans, which may also influence seed composition and/or membrane fluidity. The information gained in this study is useful for marker assisted selection in soybean breeding programs across Canada and globally.