The expressions of ZjmiR390s during phase change of Chinese jujube and their target genes

Plant phase change refers to the process of transition from juvenile to adult period, marked by flowering. miR390s can play some roles in many processes, including leaf morphogenesis, lateral root growth, and can inhibit the differentiation of plant flower buds, in which they affect the plant growth and development by regulating target genes. However, whether miR390s participate in the phase transition in jujube tree was largely unknown. In this study, two-year-old jujube seedlings of hybrid progeny were used as material, and bearing shoots in three stages of juvenile, transition and adult period were selected to study. First, the ZjmiR390a and ZjmiR390b with different expression levels during phase change were screened out. Then, the construction of phylogenetic tree and homology comparison analysis were carried out on the miR390 family among different species. Meanwhile, Target Finder software was used to predict target genes, and four target genes corresponding to each miRNA were predicted. Finally, the expressions of ZjmiR390a, ZjmiR390b and their eight target genes in the jujube phase change were verified by qRT-PCR. The results showed that there was a positive or negative regulation relationship among zjmiR390a/zjmiR390b and their target genes. The study provides some clues for studying the regulation mechanism of miRNAs during the phase change of jujube.