Identification And Analysis Of MiRNAs And PhasiRNAs In Triticum Aestivum

The present studies indicate that plant genes encoded a large number of ncRNAs,including miRNAs and siRNAs.Compared with the studies of miRNAs,studies of siRNAs are relativly slow.In this paper,we studied a new class of plant genes,PHAS,which produces phased siRNAs,called phasiRNAs.Currently,several PHAS gene encoded trans-acting siRNAs,tasiRNAs,have been carefully examined.Through targeting ARF family members,highly conserved TAS3 derived tasiRNAs control the timing and patterning of leaf,flower and root.Except TAS1 to TAS4,it still lacks systematical family classification for siRNAs,and more studies are necessary to elucidate the evolution and functions of more siRNAs.Wheat is one of the largest crops in the world,the purpose of this study was to identify and analyze the miRNAs and phasiRNAs from wheat by bioinformatic analyses.Based on bioinformatic prediction,1088 miRNA loci were identified from wheat,of these 230 loci were the 21 conserved miRNA families.We performed the target prediction of these 1088 loci and found 210 targets in the 21 conserved miRNA families.Furthermore,37 novel miRNA loci and the targets of these loci contained ARFs,F-box,GRFs,MYBs and NBS-LRRs.Finally,we identified and analyzed the phasiRNAs from wheat.We have identified 8 TAS3 loci from wheat,and after performing target prediction,we have found 15 ARF targets in these tasiRNAs.Sequence analysis revealed 29 and 61 loci generating 21nt and 24nt phasiRNAs.Our results shows that some of the nucleotide-binding,leucine-rich repeat(NB-LRR)disease resistance proteins and MYB transcription factors potentially generate phasiRNAs,which is consistent with existing results in other species.