水稻miR169基因家族成员的进化及热应激响应研究OA北大核心CSTPCD

MicroRNAs(miRNAs)are 18～22 nt and highly conserved non-coding RNAs involved in plant response to various abiotic stresses.Some members of the miR169 family were found to respond to heat stress based on previous high-throughput small RNA sequencing.This study used bioinformatic tools to analyze and predict the chromosome distribution,sequence structural characteristics,phylogenetic relationships,and duplication of the miR169 family;qRT-PCR was used to detect the expression of miR169 family members and their target genes in rice(Oryza sativa)seedlings at multiple time points under high-temperature stress treatments.The results showed that the miR169 family had 2 major evolutionary branches,and the members expanded mainly through tandem duplication events and chromosome segmental duplication.MiR169h,miR169l,miR169i and miR169m locating in the same branch were active gene clusters in the evolution of rice.Among them,3 members,miR169h,miR169l and miR169i,all responded actively to heat stress,and the predicted target gene,nuclear factor Y-A1(NF-YA1),showed down-regulated expression trend under high temperature treatment for 16～24 h.In summary,the rice miR169 gene family miR169h,miR169i and miR169l responded to intense heat stress in rice and might play an important role in rice heat tolerance.This study provides basic data for in-depth exploration of the molecular regulatory mechanism of miRNA involved in heat stress in rice.