Phenotypic plasticity couples with transcriptomic flexibility in Leymus chinensis under diverse edaphic conditions

Phenotypic plasticity is widespread in all organisms. This biological property is particularly important for sessile organisms like plants to cope with the ever-changing environmental conditions. Leymus chinensis is a predominantly clonal grass that adapts to diverse stressful habitats including drought, cold and salinity-alkalinity. Previous studies suggest that the remarkable environmental adaption of L. chinensis is probably due to its high degree of phenotypic plasticity; however, the underlying molecular mechanism remains unexplored. In this study, we grew L. chinensis clonal plants in four soil types that differ in nutrient content, nitrate-nitrogen concentration and pH. We observed plasticity in several phenotypic traits in response to specific edaphic factors. By employing de novo RNA-sequencing assembly, we curated differentially expressed genes (DEGs) under each soil type. We found that DEGs under each edaphic condition were enriched for highly specific as well as common GO or KEGG terms known to be biologically relevant to the respective conditions. Moreover, gene activation or silencing was also highly condition-dependent. Together, our results suggest that the high phenotypic plasticity of L. chinensis is likely rooted in its evolved intrinsic property of expressing specific transcriptome profiles in response to diverse niche conditions.