Abstract
Soil salinity is a worldwide problem threatening crop yields.Some plant growth-promoting rhizo-bacteria(PGPR)could survive in high salt envi-ronment and assist plant adaptation to stress.Nevertheless,the genomic and metabolic fea-tures,as well as the regulatory mechanisms pro-moting salt tolerance in plants by these bacteria remain largely unknown.In the current work,a novel halotolerant PGPR strain,namely,Bacillus sp.strain RA can enhance tomato tolerance to salt stress.Comparative genomic analysis of strain RA with its closely related species indicated a high level of evolutionary plasticity exhibited by strain-specific genes and evolutionary constraints driven by purifying selection,which facilitated its ge-nomic adaptation to salt-affected soils.The tran-scriptome further showed that strain RA could tolerate salt stress by balancing energy metabo-lism via the reprogramming of biosynthetic path-ways.Plants exude a plethora of metabolites that can strongly influence plant fitness.The accumu-lation of myo-inositol in leaves under salt stress was observed,leading to the promotion of plant growth triggered by Bacillus sp.strain RA.Im-portantly,myo-inositol serves as a selective force in the assembly of the phyllosphere microbiome and the recruitment of plant-beneficial species.It promotes destabilizing properties in phyllosphere bacterial co-occurrence networks,but not in fungal networks.Furthermore,interdomain interactions between bacteria and fungi were strengthened by myo-inositol in response to salt stress.This work highlights the genetic adaptation of RA to salt-affected soils and its ability to impact phyllosphere microorganisms through the adjustment of myo-inositol metabolites,thereby imparting enduring resistance against salt stress in tomato.
基金项目
National Natural Science Research Foundation of China(32272040)
National Key R&D Program of China(2022YFD1201702)
Natural Science Foundation Youth Project of Shandong Province(ZR2022QC191)
Agricultural Fine Seed Project of Shandong Province(2021LZGC006)
Special Funds forTaiShan Scholars(tsqn202211106)
维普
万方数据