Integrated transcriptome and metabolome profiling unveils the tolerance network to potassium deficiency in wild...

Potassium (K⁺) is an essential macronutrient for plant growth, yet potassium deficiency in agricultural soils poses a severe threat to global crop production. Wild soybean (Glycine soja), as a valuable genetic resource, exhibits remarkable tolerance to nutrient stresses, though its underlying mechanisms remain incompletely elucidated. This study employed an integrated transcriptomic and metabolomic approach to compare the responses of two wild soybean ecotypes -common wild soybean (GS1) and barren-tolerant wild soybean (GS2)- to low potassium stress. Under low potassium stress, GS2 maintained superior root growth and ion homeostasis, characterized by a higher K⁺/Na⁺ ratio. Multi-omics profiling revealed that GS2 coordinates a comprehensive adaptive network through enhanced expression of potassium transporters and sodium exclusion genes, reprogrammed carbon metabolism with elevated sucrose synthesis and a stabilized TCA cycle, coordinated accumulation of osmolytes including galactinol, mannose and proline, and reinforced membrane stability via unsaturated fatty acid enrichment. Notably, lipid remodeling was found to potentially optimize the membrane environment for K⁺ transporter activity. These findings systematically delineate the transcriptional and metabolic basis of low-potassium tolerance in wild soybean, providing both fundamental insights into plant nutrient stress adaptation and valuable genetic resources for crop improvement.