Effects of Arbuscular Mycorrhizal Fungi on Growth and Selenium Accumulation in Tea Plants ( <i>Camellia sinensis</i> )

Arbuscular mycorrhizal fungi (AMF) enhance host biomass and nutrient uptake, yet their regulatory mechanisms and gene networks in tea plants remain unclear. This study investigated AMF-induced effects on bud sprouting, selenium (Se) accumulation, secondary metabolite contents, and transcriptome profile changes in tea plants to elucidate these mechanisms. The results showed that AMF accelerated tea bud sprouting by 1 week, increased available Se content in rhizosphere soil and leaves, and elevated l-theanine content while decreasing polyphenols and caffeine levels. The green tea produced under AMF inoculation combined with 100 mg/L Na₂SeO₃ received the highest sensory score. Differential gene expression analysis identified 980, 3099, and 1044 differentially expressed genes in the comparisons of CK vs Se, CK vs AMF, and CK vs Se + AMF, respectively. These results indicate that AMF promotes earlier bud sprouting─enabling earlier market entry─and improves Se fertilizer use efficiency, thereby reducing input costs. This study provides a theoretical basis for elucidating the molecular mechanisms of tea tree-microbe interactions.