Trichoderma longibrachiatum Inoculation Improves Drought Resistance and Growth of Pinus massoniana Seedlings through Regulating Physiological Responses and Soil Microbial Community

Drought stress poses a serious threat to Pinus massoniana seedling growth in southern China. Trichoderma species, as beneficial microorganisms, have been widely used agriculture enhance plant and drought tolerance, but the interaction mechanisms remain unclear. To investigate effect of drought-resistant longibrachiatum inoculation on P. under stress, physiological indicators rhizosphere microbiome diversity were measured identify Trichoderma-activated mechanisms. significantly promoted treatment, enhanced nitrogen, phosphorus, potassium absorption compared with those non-inoculated seedlings. treatment alleviated damage cell membranes needle tissue structure, increased antioxidant enzyme activities, osmotic substance contents, photosynthesis response stress. Soil nutrient activities sucrase, phosphatase, urease well relative abundances dominant genera Burkholderia, Rhodanobacter, elevated soil inoculated T. A network analysis showed that certain crucial taxa driven by inoculation, including Penicillium, Trichoderma, Simplicillium, Saitozyma, Bradyrhizobium, Sinomonas, Mycobacterium, had more correlations other microorganisms soil. regulating responses microbial community.