Soybean SUMO Protease GmOTSa Targets the GmLOX31 to Promote Drought and Salt Tolerance in Soybean

Soybean productivity is significantly impacted by drought and salt stress, yet the precise molecular mechanisms responsible for abiotic stress tolerance mediated by the SUMO protease GmOTSa remain unclear. To address this gap, GmOTSa-overexpressing and CRISPR/Cas9-edited knockout soybean lines were developed to investigate its function and regulatory pathways. GmOTSa boosts drought and salt tolerance by scavenging reactive oxygen species, modulating ABA-mediated stomatal movement, and increasing the expression of stress-responsive genes. Analysis using label-free quantitative proteomics revealed an enrichment of pathways related to linoleic acid metabolism under the stress conditions. Furthermore, GmOTSa physically interacts with the 13-lipoxygenase GmLOX31, facilitating its deSUMOylation, which, in turn, stabilizes the GmLOX31 protein and enhances jasmonic acid biosynthesis. Co-overexpression of GmOTSa and GmLOX31 results in a synergistic improvement in stress tolerance. This investigation unveils a novel regulatory module involving GmOTSa and GmLOX31 deSUMOylation, connecting deSUMOylation to lipid metabolism and the adaptation of soybeans to abiotic stress.