Abstract: MicroRNA（miRNA）is a kind of small single-stranded RNA molecule with a length of about 22 nt,which is ubiquitous in eukaryotes. A large number of studies have found that miRNA is widely involved in the growth and development of plant,metabolism,material transport,stress response,pathogen defense and other biochemical processes. At present,a large number of miRNAs have been identified from plants,while there are few studies on miRNA involved in the regulation of plants pathogens. As an important transcriptional regulator,miRNAs can be involved in the regulation of PAMP-triggered immunity and effector-triggered immunity. In Arabidopsis,miRNA393 negatively regulates auxin by targeting the auxin receptor gene,thereby plays a role in resisting bacterial infection. In rice,miRNA528 can be in response to the infection of rice stripe virus（RSV）,and the increase of miRNA528 level using artificial means will help maintain the rice resistance to RSV. This paper describes the mechanism of action of miRNAs,the progress of miRNAs related to plant bacterial,fungal,viral infections,and summarizes the research on pathogen-regulated miRNAs in fruit trees with important economic value such as grapes,apples,pears,and peaches,aiming at providing a comprehensive theoretical basis for miRNA research in plants,especially in fruit tree.

Key words: miRNA, plant, fruit tree, pathogen, regulation