关键词: 桃, 油桃, 生长素酰胺合成酶, 果实发育和成熟, 生长素

Abstract: To explore the role of GH3 gene family during peach fruit development，the members of GH3 gene family were identified and analyzed by bioinformatics；Additionally，the expression levels of GH3 gene were detected in melting-flesh and stony-hard nectarine fruits during fruit development and ripening，as well as in stony-hard nectarine fruits under NAA treatment. The results showed that eight GH3 genes were identified in the peach genome and named as PpGH3-1–PpGH3-8，respectively. Phylogenetic analysis indicated that peach GH3 gene family was divided into two groups，GroupⅠand GroupⅡ. The results of qRT-PCR showed that the expression levels of GH3 genes from GroupⅡ（PpGH3-1，PpGH3-2，PpGH3-3，PpGH3-4 and PpGH3-5）in melting-flesh nectarine fruits were higher than in stony-hard nectarine fruits，especially for PpGH3-3 and PpGH3-4. The expression levels of four genes（PpGH3-1，PpGH3-3，PpGH3-4，and PpGH3-7）in stony-hard nectarine fruits were up-regulated under NAA treatment，especially for PpGH3-3. The results suggested that auxin might play an important role in regulating peach fruit ripening.

Key words: peach, nectarine, GH3（Indole-3-acetic-acid-amido synthase）, fruit development and ripening, indole-3-acetic-acid