A fungal microRNA-like RNA regulated effector promotes pathogen infection by targeting a host defense-related transcription factor.
Ming XuChen GaoLin JiLihua ZhuYuqi GaoHao FengLili HuangPublished in: The Plant journal : for cell and molecular biology (2023)
Effectors play important roles in facilitating the infection of plant pathogenic fungi. However, the gene expression regulatory mechanism of effector genes, especially at the post-transcriptional level, is largely unknown. In this study, we uncovered the post-transcriptional regulation of an effector gene VmSP1 by a miRNA-like RNA (Vm-milR16) facilitating the infection of the apple tree Valsa canker pathogen Valsa mali. Genetic and molecular biological assays indicated that the expression of VmSP1 could be suppressed by Vm-milR16-mediated mRNA cleavage in a sequence-specific manner. During V. mali infection, Vm-milR16 was down-regulated, whereas VmSP1 was upregulated, which further indicated the regulation relationship. VmSP1 was further demonstrated to be a secreted protein and could suppress plant immunity. Deletion of VmSP1 did not affect the vegetative growth but significantly reduced the virulence of V. mali. Further study indicated that VmSP1 could interact with the transcription factor MdbHLH189 of apple. Transiently overexpression of MdbHLH189 enhanced host resistance to V. mali by enhancing the expression of apple defense-related genes, together with the increased callose deposition. Silencing of MdbHLH189 compromised host resistance to V. mali. Our findings uncovered the novel epigenetic regulation mechanism of a virulence-associated effector gene mediated by a fungal milRNA at the post-transcriptional level, and the results enriched the understanding of the function and action mechanism of effectors in tree pathogenic fungi.
Keyphrases
- transcription factor
- genome wide identification
- gene expression
- type iii
- dna binding
- genome wide
- regulatory t cells
- dendritic cells
- poor prognosis
- copy number
- dna methylation
- staphylococcus aureus
- binding protein
- pseudomonas aeruginosa
- cell proliferation
- oxidative stress
- antimicrobial resistance
- immune response
- single molecule
- small molecule
- amino acid
- protein protein