Abstract:

MicroRNAs (miRNAs) are one kind of small RNAs that do not encode any proteins, however play critical role in developmental processes, metabolism and stress responses in plant. Here we present a study of bioinformatics prediction of miRNAs in Prunus using bioinformatics-based gene search based on blasting ESTs and GSSs in NCBI. Eleven precursors coding 11 mature miRNAs were found from 107 982 ESTs and 48 273 GSSs of Prunus, and 19 target genes, which encode proteins involved in developmental processes, metabolism and transcriptional regulation, were predicted. Further analysis of the miRbase database showed that 11 miRNAs belonged to 8 miRNA families from Prunus persica and Prunus mume, and were from 20 to 23 bp in length with 6 miRNAs being 21 bp in length. The miRNAs of ppe-miR162a and ppe-miR164f were the most conservative. In order to prove accuracy of the prediction, ppe-miR156h, pmu-miR482, ppe-miR399a, ppe-miR171 were identified by RT-PCR. The results showed that ppe-miR156h was expressed in flower buds of Prunus mume, and pmu-miR482, ppe-miR399a, and ppe-miR171a were expressed in leaves of Prunus persica.

Key words: microRNA, bioinformatics prediction, Prunus, drupe fruit trees, EST(expressed sequence tag), GSS(genome survey sequences)