Transcriptomic Profiling Identifies Symbiosis-Induced GDSL Lipase Genes Associated with Soybean–Arbuscular Mycorrhizal Symbiosis

Abstract

The symbiotic association between soybean and arbuscular mycorrhizal (AM) fungi enhances phosphorus acquisition, improving crop yield and quality. However, the molecular mechanisms underlying nutrient exchange in this symbiosis remain poorly understood. We performed transcriptomic profiling of Glycine max cv. Williams 82 roots across three time points during colonization by Rhizophagus irregularis BEG141, revealing distinct transcriptional reprogramming between mycorrhizal and non-mycorrhizal roots. Differentially expressed genes (DEGs) were significantly enriched in pathways related to fatty acid biosynthesis, carbon metabolism, and redox homeostasis. Time-course comparisons further identified DEGs associated with transcriptional regulation, biosynthetic processes, and nitrogen metabolism. Notably, five GDSL lipase genes (GmGELP6, GmGELP29, GmGELP140, GmGELP141, and GmGELP151) exhibited AM-associated expression patterns and were associated with AM-induced lipid-related transcriptional programs. CRISPR/Cas9-mediated disruption of these genes in soybean transgenic hairy roots altered arbuscule development and was associated with reduced expression of mycorrhiza-inducible fatty acid metabolism genes, suggesting that these genes are associated with normal AM colonization and arbuscule development. This study provides a transcriptomic resource and identifies AM-induced GmGELP candidate genes associated with normal soybean–AM symbiosis for future functional and mechanistic studies.