Abstract To characterize transcriptional regulation of the abscisic acid (ABA) signal transduction pathway during peach fruit early development and ripening, genes encoding the core components of the pathway, including 7 PpPYR (ABA receptor), 10 PpPP2C (type 2C protein phosphatase), and 7 PpSnRK2 (subfamily 2 of SNF1-related kinases), were identified from the peach (Prunus persica) reference genome. PpPYRs, PpPP2Cs, and PpSnRK2s from peach were putative homologous to proteins from tomato and Arabidopsis. Phylogenetic analysis showed that PpPYRs and PpSnRK2s were clustered into three subfamilies/subclasses. Transcript profile indicated that PpPYR2, PpPYR6, and PpPYR7 expression decreased sharply while ABA concentration increased during peach fruit ripening. Expression of PpPP2C4, PpPP2C9, and PpPP2C10 increased along with ABA concentration during fruit ripening. Expression of PpSnRK2.4 and PpSnRK2.6 also increased together with ABA concentration during fruit ripening. Furthermore, PpPP2C10 could interact with PpSnRK2.6 was determined by Yeast two-hybrid and BiFC analyses. The results will improve our understanding of ABA signal transduction genes in peach and lay the foundation for further exploring the mechanisms underlying peach fruit ripening.

中文翻译：

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桃果实成熟过程中脱落酸信号转导基因的鉴定及表达分析

摘要 为了表征桃果实早期发育和成熟过程中脱落酸 (ABA) 信号转导途径的转录调控，编码该途径核心成分的基因，包括 7 PpPYR（ABA 受体）、10 PpPP2C（2C 型蛋白磷酸酶）和从桃 (Prunus persica) 参考基因组中鉴定了 7 个 PpSnRK2（SNF1 相关激酶的亚家族 2）。来自桃子的 PpPYRs、PpPP2Cs 和 PpSnRK2s 被推定与来自番茄和拟南芥的蛋白质同源。系统发育分析表明 PpPYRs 和 PpSnRK2s 分为三个亚科/亚类。转录谱表明，在桃果实成熟期间，PpPYR2、PpPYR6 和 PpPYR7 的表达急剧下降，而 ABA 浓度增加。PpPP2C4、PpPP2C9、PpPP2C10 在果实成熟过程中随着 ABA 浓度的增加而增加。在果实成熟过程中，PpSnRK2.4 和 PpSnRK2.6 的表达也随着 ABA 浓度的增加而增加。此外，通过酵母双杂交和 BiFC 分析确定 PpPP2C10 可以与 PpSnRK2.6 相互作用。研究结果将提高我们对桃中ABA信号转导基因的认识，为进一步探索桃果实成熟的机制奠定基础。