Beijing Key Laboratory of New Technology in Agricultural Application, College of Plant Science and Technology, Beijing University of Agriculture, No. 7 Beinong Road, Changping District, Beijing 102206, PR China.
J Exp Bot. 2011 Oct;62(14):5079-89. doi: 10.1093/jxb/err207. Epub 2011 Jul 21.
Although the plant hormone abscisic acid (ABA) has been suggested to play a role in the ripening of non-climatic fruit, direct genetic/molecular evidence is lacking. In the present study, a strawberry gene homologous to the Arabidopsis ABA receptor gene PYR1, named FaPYR1, was isolated and characterized. The 627 bp cDNA includes an intact open reading frame that encodes a deduced protein of 208 amino acids, in which putative conserved domains were detected by homology analysis. Using tobacco rattle virus-induced gene silencing (VIGS), the FaPYR1 gene was silenced in strawberry fruit. Down-regulation of the FaPYR1 gene not only significantly delayed fruit ripening, but also markedly altered ABA content, ABA sensitivity, and a set of ABA-responsive gene transcripts, including ABI1 and SnRK2. Furthermore, the loss of red colouring in FaPYR1 RNAi (RNA interference) fruits could not be rescued by exogenously applied ABA, which could promote the ripening of wild-type fruits. Collectively, these results demonstrate that the putative ABA receptor FaPYR1 acts as a positive regulator in strawberry fruit ripening. It was also revealed that the application of the VIGS technique in strawberry fruit could be used as a novel tool for studying strawberry fruit development.
虽然植物激素脱落酸（ABA）被认为在非气候果实的成熟中发挥作用，但缺乏直接的遗传/分子证据。本研究从草莓中克隆到一个与拟南芥 ABA 受体基因 PYR1 同源的基因，命名为 FaPYR1。该基因 cDNA 全长 627bp，包含一个完整的开放阅读框，编码一个 208 个氨基酸的推测蛋白，同源分析检测到假定的保守结构域。利用烟草脆裂病毒诱导的基因沉默（VIGS）技术，沉默草莓果实中的 FaPYR1 基因。下调 FaPYR1 基因不仅显著延迟了果实成熟，而且明显改变了 ABA 含量、ABA 敏感性以及一系列 ABA 响应基因的转录本，包括 ABI1 和 SnRK2。此外，FaPYR1 RNAi（RNA 干扰）果实中红色着色的丧失不能被外源施加的 ABA 挽救，ABA 可以促进野生型果实的成熟。总之，这些结果表明，假定的 ABA 受体 FaPYR1 作为草莓果实成熟的正调控因子发挥作用。还揭示了在草莓果实中应用 VIGS 技术可以作为研究草莓果实发育的一种新工具。
