Transcriptomic Insights into the Molecular Mechanism of Abietic Acid Promoting Growth and Branching in Armillaria gallica

Armillaria gallica, a valuable edible and medicinal fungus, is essential for the symbiotic cultivation of the traditional Chinese medicinal herb Gastrodia elata. Abietic acid, a plant-derived secondary metabolite, modulates microbial growth and metabolism. This study explores the effects of abietic acid on A. gallica growth and branching, employing phenotypic analysis and transcriptomic approaches to uncover its molecular mechanisms. The experiment included an abietic acid treatment group (0.6 g/L) and a control group. The results showed that abietic acid significantly promoted the growth and branching of A. gallica, with the most pronounced effects observed on the third day, where the dry biomass weight and the total number of rhizomorphs increased by 302% and 378.4%, respectively (p < 0.01). Transcriptomic analysis revealed that under the influence of abietic acid, the experimental group genes promoted the growth and branching of A. gallica by synergistically upregulating the expression of GH5, GH16, MFS, and NAD(P)-binding protein, thereby optimizing carbon source utilization, accelerating cell wall remodeling and nutrient transport, and thus enhancing fungal development. This study elucidates the impact on the growth regulation mechanisms of A. gallica and provides a theoretical basis for optimizing the symbiotic cultivation of Gastrodia elata and A. gallica