%0 Journal Article %A SUN Yuyan %A ZHANG Huiqing %A FAN Min %A HE Yanjun %A GUO Ping'an %T Identification of MIR319 Family Members and Their Target Genes in Response to Cucumber Green Mottle Mosaic Virus Infection in Watermelon %D 2021 %R 10.11869/j.issn.100-8551.2021.05.1048 %J Journal of Nuclear Agricultural Sciences %P 1048-1059 %V 35 %N 5 %X In order to reveal the possible roles of MIR319 family (miR319, miR319a and miR319a-3p) under the CGMMV stress, mature sequences of MIR319 were blasted against the watermelon genome to obtain the precursor gene. MEGA was used to analyze the evolutional relationship of precursor genes for MIR319. PlantCARE was used to analyze the cis-acting regulatory elements of the precursor gene promoter. Degradome sequencing was used to identify target genes of MIR319, and transcriptome sequencing and qRT-PCR were used to obtain the expression of target genes. The common precursor gene of MIR319, Pre-MIR319 was obtained, which was 170 bp in length, able to form the stem-loop structure. Sequence alignment showed that mature sequences of MIR319 were highly conserved at the 2~14 bases of 5'-terminal. Phylogenetic analysis of watermelon Pre-MIR319 and 116 miR319 precursor sequences from 35 species divided these precursor sequences into four branches. Watermelon Pre-MIR319 was closest to potato precursor gene miR319a (MI0025952). The promoter of Pre-MIR319 contain several cis-acting regulatory elements, such as light responsive element, gibberellin responsive element, ethylene responsive element, methyl jasmonate response element, MYB, MYC and etc. Five target genes of MIR319 family, Cla019567, Cla013523, Cla023342, Cla002428 and Cla013668, were predicted by degradome sequencing results. Among which, Cla019567, Cla013523, Cla023342 and Cla002428 are annotated as TCP transcription factor and Cla013668 is annotated as MYB transcription factor. The cleavage sites were located at the 10th of MIR319 at the 5'-terminal end. The amino acids number, molecular weight and theoretical isoelectric point of target genes were 319~554 aa, 34.94~61.21 kDa and 5.29~7.80, respectively. These proteins do not contain transmembrane domains and was located in the nucleus/cytoplasm. Expression profiles of target genes using transcriptome and qRT-PCR analysis revealed that miR319a negatively regulated its target gene Cla013523 (TCP). These results clarified the role of MIR319 family members in CGMMV stress response and revealed the regulation of MIR319 on their target genes. %U https://www.hnxb.org.cn/EN/10.11869/j.issn.100-8551.2021.05.1048