Multigenerational Adaptation Can Enhance the Pathogen Resistance of Plants via Changes in Rhizosphere Microbial Community Assembly

Plants withstand pathogen attacks
by recruiting beneficial bacteria
to the rhizosphere and passing their legacy on to the next generation.
However, the underlying mechanisms involved in this process remain
unclear. In our study, we combined microbiomic and transcriptomic
analyses to reveal how the rhizosphere microbiome assembled through
multiple generations and defense-related genes expressed in Arabidopsis thaliana under pathogen attack stress. Our results
showed that continuous exposure to the pathogen Pseudomonas
syringae pv tomato DC3000 led to improved growth and increased
disease resistance in a third generation of rps2 mutant Arabidopsis thaliana. It could be attributed to the enrichment
of specific rhizosphere bacteria, such as Bacillus and Bacteroides. Pathways associated with plant
immunity and growth in A. thaliana, such as MAPK signaling pathways, phytohormone signal transduction,
ABC transporter proteins, and flavonoid biosynthesis, were activated
under the influence of rhizosphere bacterial communities. Our findings
provide a scientific basis for explaining the relationship between
beneficial microbes and defense-related gene expression. Understanding
microbial communities and the mechanisms involved in plant responses
to disease can contribute to better plant management and reduction
of pesticide use.