RESUMEN
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.
Asunto(s)
Arabidopsis , Resistencia a la Enfermedad , Enfermedades de las Plantas , Pseudomonas syringae , Rizosfera , Arabidopsis/microbiología , Arabidopsis/genética , Arabidopsis/inmunología , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/inmunología , Resistencia a la Enfermedad/genética , Microbiota , Bacterias/genética , Bacterias/clasificación , Bacterias/metabolismo , Bacterias/aislamiento & purificación , Microbiología del Suelo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Adaptación Fisiológica , Raíces de Plantas/microbiología , Raíces de Plantas/genética , Raíces de Plantas/inmunología , Raíces de Plantas/metabolismo , Regulación de la Expresión Génica de las PlantasRESUMEN
The rhizosphere is one of the key determinants of plant health and productivity. Mixtures of pesticides are commonly used in intensified agriculture. However, the combined mechanisms underlying their impacts on soil microbiota remain unknown. The present study revealed that the rhizosphere microbiota was more sensitive to azoxystrobin and oxytetracycline, two commonly used pesticides, than was the microbiota present in bulk soil. Moreover, the rhizosphere microbiota enhanced network complexity and stability and increased carbohydrate metabolism and xenobiotic biodegradation as well as the expression of metabolic genes involved in defence against pesticide stress. Co-exposure to azoxystrobin and oxytetracycline had antagonistic effects on Arabidopsis thaliana growth and soil microbial variation by recruiting organic-degrading bacteria and regulating ABC transporters to reduce pesticide uptake. Our study explored the composition and function of soil microorganisms through amplicon sequencing and metagenomic approaches, providing comprehensive insights into the synergistic effect of plants and rhizosphere microbiota on pesticides and contributing to our understanding of the ecological risks associated with pesticide use.
