title: Identification and Characterization of ABA-Responsive MicroRNAs in Rice.
abstract: MicroRNAs (miRNAs) are endogenous non-coding small RNAs that silence genes through mRNA degradation or translational inhibition. The phytohormone abscisic acid (ABA) is essential for plant development and adaptation to abiotic and biotic stresses. In Arabidopsis, miRNAs are implicated in ABA functions. However, ABA-responsive miRNAs have not been systematically studied in rice. Here high throughput sequencing of small RNAs revealed that 107 miRNAs were differentially expressed in the rice ABA deficient mutant, Osaba1. Of these, 13 were confirmed by stem-loop RT-PCR. Among them, miR1425-5P, miR169a, miR169n, miR390-5P, miR397a and miR397b were up-regulated, but miR162b reduced in expression in Osaba1. The targets of these 13 miRNAs were predicted and validated by gene expression profiling. Interestingly, the expression levels of these miRNAs and their targets were regulated by ABA. Cleavage sites were detected on 7 of the miRNA targets by 5'-Rapid Amplification of cDNA Ends (5'-RACE). Finally, miR162b and its target OsTRE1 were shown to affect rice resistance to drought stress, suggesting that miR162b increases resistance to drought by targeting OsTRE1. Our work provides important information for further characterization and functional analysis of ABA-responsive miRNAs in rice.
authors.affiliation: State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Caijuan
authors.initials: C
authors.lastname: Tian
authors.affiliation: State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Zhangli
authors.initials: Z
authors.lastname: Zuo
authors.affiliation: State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China. Electronic address: qiujl@im.ac.cn.
authors.forename: Jin-Long
authors.initials: JL
authors.lastname: Qiu
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology*; D018506:Gene Expression Regulation, Plant / Q000235:genetics; D035683:MicroRNAs / Q000235:genetics*; D012275:Oryza / Q000187:drug effects / Q000235:genetics*; D018749:RNA, Plant / Q000235:genetics*
chemical_list: D035683:MicroRNAs; D018749:RNA, Plant; D000040:Abscisic Acid
keywords: Abscisic acid; High throughput sequencing; MicroRNA; Rice; Target gene