Xia_2026_Environ.Microbiol_28_e70251

Green mould disease caused by Trichoderma spp. severely threatens Lentinula edodes cultivation, resulting in heavy yield losses. This study developed a quantifiable image-based evaluation method using Trichoderma infection rate (TIR) to assess L. edodes resistance. By quantifying TIR in a shiitake association panel, we performed a genome-wide association study (GWAS) and identified 239 SNPs and 245 nearby genes. Among these genes, a subset involved in cell membrane integrity maintenance, substance transport and environmental stress response may be associated with resistance to Trichoderma. Notably, three single-nucleotide polymorphisms (SNPs) on chromosomes 3, 9 and 10 were stably associated with multiple TIR traits. Most importantly, an alpha/beta hydrolase gene, LeABH, was prioritised and functionally validated. Overexpression of LeABH in L. edodes significantly enhanced resistance by 26.7%-33.4% against T. harzianum and by 21.4%-49.7% against T. atroviride, and inhibited conidiation. These results confirmed LeABH as a key causal gene underlying L. edodes resistance to Trichoderma. Taken together, our findings have provided new insights into the genetic basis of L. edodes resistance to Trichoderma. The improved resistance evaluation method, along with the identified genetic variations and candidate genes, has offered valuable resources for the molecular marker-assisted breeding of disease-resistant L. edodes strains.