苹果树腐烂病菌Vm-milRNA9通过调控VmPEAMT的表达促进病菌侵染  

Vm-milR9 promotes the infection of Valsa mali by regulating the expression of VmPEAMT

作　　者：李光耀 许铭[1,2] 包继源 张琼 冯浩 黄丽丽[1,2] LI Guangyao;XU Ming;BAO Jiyuan;ZHANG Qiong;FENG Hao;HUANG Lili(College of Plant Protection,Northwest A&F University,Yangling 712100,China;State Key Laboratory of Crop Stress Biology for Arid Areas,Yangling 712100,China)

机构地区：[1]西北农林科技大学植物保护学院,杨凌712100 [2]旱区作物逆境生物学国家重点实验室,杨凌712100

出　　处：《植物病理学报》2023年第6期1131-1140,共10页Acta Phytopathologica Sinica

基　　金：国家自然科学基金(32172375)。

摘　　要：植物病原真菌microRNA-like RNA(milRNA)通过调控靶标基因的表达广泛参与生长发育、逆境胁迫响应以及侵染致病等生命活动。前期在系统鉴定苹果树腐烂病菌(Valsa mali)milRNA的过程中,发现Vm-milR9在菌丝营养生长阶段高度表达,但在侵染过程中显著下调表达,降解组分析发现磷酸乙醇胺甲基转移酶基因VmPEAMT可能是其一个重要靶标基因。然而,Vm-milR9能否通过调控VmPEAMT的表达参与病菌致病仍不明确。为此,本研究首先创制了Vm-milR9的过表达菌株,发现其菌落生长速率和致病力均显著降低。进而分析了过表达菌株中候选靶标基因VmPEAMT的表达水平,发现Vm-milR9的过表达显著抑制了VmPEAMT的表达水平。同时利用烟草共转化技术证实了Vm-milR9在烟草细胞中能够特异性地抑制VmPEAMT的表达。在此基础上,创制了VmPEAMT的敲除突变体,发现突变体的菌落生长速率有一定程度降低,但致病力下降比例更为明显。上述结果表明Vm-milR9可以通过特异靶向抑制VmPEAMT的表达调控V.mali的营养生长和致病力。microRNA-like RNAs(milRNAs)from plant pathogenic fungi are widely involved in growth,stress responses,pathogenicity and other life activities by specifically regulating the expression of their target genes.In the previous study to identify milRNAs in Valsa mali,it was found that Vm-milR9 is highly expressed at the vegetative growth stage of mycelia,but significantly down-regulated during infection.Based on the degradome sequencing data,the phosphoethanolamine N-methyltransferase gene(VmPEAMT)was predicted to be an important target of Vm-milR9.However,whether Vm-milR9 play srole in pathogen pathogenesis by regulating the expression of VmPEAMT remains unclear.In this study,theVm-milR9 overexpression transformant strains were created,and it was found that the growth rate and the pathogenicity of overexpression strains were significantly reduced.In order to analyze the molecular mechanism of Vm-milR9 in regulating pathogen pathogenesis,we examined the expression level of the candidate target gene VmPEAMT in the overexpressing strains and found that Vm-milR9 inhibited the expression of VmPEAMT in vivo.Furthermore,Vm-milR9 was confirmed to inhibit the expression of VmPEAMT in a specific manner based on co-expression in tobacco leaves.Based on these results,the VmPEAMT deletion mutants were further created.Phenotypic analysis showed that the colony growth rate of the mutant decreased slightly,but the decreased proportion of pathogenicity was more obvious.These results indicate that Vm-milR9 could regulate the pathogenicity of V.mali by specifically targeting VmPEAMT and suppressing its expressionlevel.

关 键 词：苹果黑腐皮壳 microRNA-likeRNA 致病力 转录后水平调控 

分 类 号：S432.1[农业科学—植物病理学]