关键词: 桃, 生长素/吲哚乙酸基因, 果实成熟, 生长素

Abstract:

Auxin/indole-3-acetic acid（Aux/IAA）is involved in plant growth，development，and multiple other processes. In this study，the Aux/IAA gene family in the peach genome was identified and analyzed by bioinformatics，additionally，the expression levels of Aux/IAA genes were detected by qRT-PCR in melting-flesh and stony-hard peach fruits during fruit ripening. The results showed that 22 PpAux/IAA candidate genes were found in the peach genome. A chromosome mapping analysis revealed that PpAux/IAA genes were distributed with different densities over 5 chromosomes，with the largest number of PpAux/IAA genes on chromosome 1（8 genes）. The DNA-binding and Aux/IAA domains，as well as motif Ⅰ，Ⅱ，Ⅲ and Ⅳ of the PpAux/IAA gene family were highly conserved. The phylogenetic analysis revealed that PpAux/IAA gene family was divided into 10 groups. The results of an intron-exon structure analysis indicated that PpAux/IAA gene family members were composed of 2–5 exons. qRT-PCR results indicated that the expression level of ten PpAux/IAA genes in melting-flesh peach fruits were higher than in stony-hard peach fruits，and the expression level of 5 genes were upregulated in melting-flesh fruits during fruit ripening，especially for ppa010303m，ppa010871m，and ppa020369m. These results suggested that the PpAux/IAA gene family members are highly and structurally conserved，and some of them（especially for ppa010303m，ppa010871m and ppa020369m）are involved in regulating peach fruit ripening.

Key words: peach, Prunus persica, Aux/IAA gene family, fruit ripening, indole-3-acetic-acid