Identification of Magnaporthe oryzae-elicited rice novel miRNAs and their targets by miRNA and degradome sequencing

摘要

MicroRNAs (miRNAs) play an important role in plant growth, development and responses to stresses. Rice blast is one of the most devastating diseases in rice production. However, little is known regarding the effects of miRNAs response to rice blast. Herein, by deep sequencing small RNA from the susceptible line ZhongerRuanzhan and its space-induced blast resistant mutant line H4 under normal conditions and upon Magnaporthe oryzae (M. orzyzae) infection, several known miRNAs were detected and their expression profiles were found to be negatively correlated with their targets. And, a total of 50 novel miRNAs induced by M. oryzae infection were also identified from four small RNA libraries. Moreover, 176 putative targets of 23 novel miRNAs, which are involved in the various functions, were validated by two degradome analysis. Six novel miRNAs were selected for further validation with qRT-PCR analysis and the results showed that their expression levels were associated with blast response. The knowledge obtained in this study will help us understanding the functions of miRNAs and their targets in regulating blast resistance.