Bacillus cereus AR156 triggers induced systemic resistance against Pseudomonas syringae pv. tomato DC3

摘要

Small RNAs play an important role in plant innate immunity. However, their regulatory function in induced systemic resistance (ISR) triggered by plant growth‐promoting rhizobacteria remains unclear. Here, using as a model system, one plant endogenous small RNA, miR472, was identified as an important regulator involved in the process of AR156 ISR against pv. (Pst) DC3000. The results revealed that miR472 was down‐regulated with AR156 treatment by comparing small RNA profiles and northern blot analysis of with or without AR156 treatment. Plants overexpressing miR472 showed higher susceptibility to Pst DC3000; by contrast, plant lines with miR472 knocked down/out showed the opposite. The transcriptome sequencing revealed thousands of differentially expressed genes in the transgenic plants. Target prediction showed that miR472 targets lots of coiled coil nucleotide‐binding site (NBS) and leucine‐rich repeat (LRR) type resistance genes and the expression of these targets was negatively correlated with the expression of miR472. In addition, transgenic plants with knocked‐out target genes exhibited decreased resistance to Pst DC3000 invasion. Quantitative reverse transcription PCR results indicated that target genes of miR472 were expressed during the process of AR156‐triggered ISR. Taken together, our results demonstrate that the miR472‐mediated silencing pathway is an important regulatory checkpoint occurring via post‐transcriptional control of NBS‐LRR genes during AR156‐triggered ISR in .