Tsukamurella tyrosinosolvens P9 enhances drought tolerance and recovery in peanut via regulation of stress resistance and rhizosphere microbiome

Abstract

Plant growth-promoting rhizobacteria (PGPR) have been widely reported to enhance crop drought tolerance; however, mechanisms of rare actinomycetes across the drought-rewatering-maturation continuum in peanut remain unclear. Here, we investigated the effects of inoculation with Tsukamurella tyrosinosolvens P9 on peanut growth, physiological performance, and fruit development under drought stress, post-drought rewatering, and maturation stages, integrating transcriptomic and rhizosphere microbiome analyses. Results showed that P9 alleviated drought-induced oxidative damage and promoted root system development by activating antioxidant defense systems, hormone signal transduction pathways, transcription factor networks, and phenylpropanoid and flavonoid biosynthesis pathways. During rewatering, P9 accelerated recovery via enhanced photosynthetic restoration and carbon metabolism reprogramming. At the maturation stage, inoculation significantly improved pod yield and quality. Concomitantly, P9 continuously reshaped the rhizosphere microbial community across stages, enriching functional taxa associated with nutrient cycling and yield formation, increasing soil available nutrient availability, and ultimately enhancing drought resistance, post-drought recovery, and yield performance in peanut.