JXB | 中国农科院李世访与中国农大王红清团队揭示ABI5依赖性下调线粒体ATP合酶OSCP亚基促进苹果坏死花叶病毒感染

以下文章来源于植物胁迫与抗逆研究 ，作者吴昕扬

近日，JXB刊载了由中国农科院李世访与中国农大王红清为共同通讯作者的研究论文《The ABI5-dependent downregulation of mitochondrial ATP synthase OSCP subunit facilitates apple necrotic mosaic virus infection》，该论文揭示了寄主与苹果坏死花叶病毒互作的新机制。

苹果坏死花叶病毒（ApNMV）是我国苹果花叶病的重要致病病毒。然而，对ApNMV感染的机制以及宿主对病毒的防御仍知之甚少。线粒体ATP合酶在植物生长发育的调控中起着重要作用。然而，线粒体ATP合成酶对病毒感染的反应机制仍有待确定。

在本研究中，作者使用酵母双杂交（Y2H）筛选显示，苹果线粒体ATP合酶OSCP亚基（MdATPO）与ApNMV外壳蛋白（CP）相互作用。进一步证实了本氏烟草中MdATPO的过表达抑制了病毒的积累。相反，NbATPO的沉默促进了病毒的积累，表明ATPO在ApNMV感染过程中发挥防御作用。

进一步的研究表明，ApNMV感染加速了脱落酸（ABA）的积累，ABA负调控ATPO的转录，这与ABI5与ATPO启动子的ABA响应元件（ABRE）结合的能力有关。

总之，本研究的结果表明，转录因子ABI5通过直接结合其启动子来负调控ATPO转录，导致苹果和本氏烟对ApNMV感染的敏感性，这有助于我们全面理解宿主对ApNMV的复杂响应。

Apple necrotic mosaic virus (ApNMV) is significantly associated with apple mosaic disease in China. However, the mechanisms of ApNMV infection, as well as host defense against the virus, are still poorly understood. Mitochondrial ATP synthase plays a fundamental role in the regulation of plant growth and development. However, the mechanism of mitochondrial ATP synthase in response to virus infection remains to be defined. In the present study, a yeast two-hybrid (Y2H) screening revealed that the apple mitochondrial ATP synthase OSCP subunit (MdATPO) interacts with ApNMV coat protein (CP). It was further verified that overexpression of MdATPO in Nicotiana benthamiana inhibited viral accumulation. In contrast, silencing of NbATPO facilitated viral accumulation, indicating that ATPO plays a defensive role during ApNMV infection. Further investigation demonstrated that ApNMV infection accelerated abscisic acid (ABA) accumulation, and ABA negatively regulated ATPO transcription, which was related to the capacity of ABA insensitive 5 (ABI5) to bind to the ABA-responsive elements (ABREs) of the ATPO promoter. Altogether, our results indicated that transcription factor ABI5 negatively regulated ATPO transcription by directly binding its promoter, leading to the sensitivity of apple and N. benthamiana to ApNMV infection. The current presentation facilitates our comprehensive understanding of the intricate responses of host to ApNMV.

转自：“植物生物技术Pbj”微信公众号

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