Characterization of conserved and novel microRNAs and their targets, including a TuMV-induced TIR-NBS-LRR class R gene-derived novel miRNA in Brassica.
Nine conserved miRNA families and three potential novel miRNAs in Brassica rapa were identified from a small RNA library. The expression patterns of some conserved miRNAs had different tissue specificity in Brassica and Arabidopsis. One of the three potential miRNAs, named bra-miR1885, was verified as a true functional miRNA. It could be induced specifically by Turnip mosaic virus (TuMV) infection, and target TIR-NBS-LRR class disease-resistant transcripts for cleavage. Based on the hypothesis for de novo generation of new miRNA genes and the sequence similarity between bra-MIR1885 precursor loci and target transcript sequences, we suggest that bra-MIR1885 is a new miRNA gene that originated through inverted duplication events from TIR-NBS-LRR class disease-resistant protein-coding gene sequences, which became bra-miR1885 targets.
State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Microbiology, Chinese Academy of Sciences, 100101 Beijing, China.
Xiang-Feng
XF
He
Yuan-Yuan
YY
Fang
Lei
L
Feng
Hui-Shan
HS
Guo
D001483:Base Sequence; D029741:Brassica rapa / Q000235:genetics* / Q000378:metabolism / Q000821:virology; D003001:Cloning, Molecular; D017124:Conserved Sequence; D035683:MicroRNAs / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010935:Plant Diseases / Q000235:genetics* / Q000821:virology*; D017800:Potyvirus; D012333:RNA, Messenger / Q000737:chemistry / Q000378:metabolism; D018749:RNA, Plant / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
D035683:MicroRNAs; D012333:RNA, Messenger; D018749:RNA, Plant