Journal of Integrative Agriculture ›› 2023, Vol. 22 ›› Issue (5): 1424-1433.DOI: 10.1016/j.jia.2022.08.124

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液泡加工酶VPE正向调节植物对寄生疫霉的抗病性及细胞死亡

  

  • 收稿日期:2022-03-01 接受日期:2022-07-10 出版日期:2023-05-20 发布日期:2022-07-10

Vacuolar processing enzyme positively modulates plant resistance and cell death in response to Phytophthora parasitica infection

GAO Xian-xian, TANG Ya-ling, SHI Qing-yao, WEI Yu-shu, WANG Xiao-xue, SHAN Wei-xing, QIANG Xiao-yu#   

  1. State Key Laboratory of Crop Stress Biology for Arid Areas/College of Agronomy, Northwest A&F University, Yangling 712100, P.R.China

  • Received:2022-03-01 Accepted:2022-07-10 Online:2023-05-20 Published:2022-07-10
  • About author:GAO Xian-xian, E-mail: gao_xianer@163.com; #Correspondence QIANG Xiao-yu, E-mail: qiangxiaoyu@nwafu.edu.cn
  • Supported by:
    This work was supported by the National Natural Science Foundation of China (31872657), the National Key R&D Program of China (2017YFD0200602-2), the Chinese Universities Scientific Fund (2452020146), the China Agriculture Research System (CARS-09), and the Program of Introducing Talents of Innovative Discipline to Universities (Project 111) from the State Administration of Foreign Experts Affairs, China (B18042).

摘要:

疫霉属卵菌引致马铃薯晚疫病等作物灾难性病害,严重威胁作物可持续生产。由于其独特的遗传变异机制,导致作物品种抗病性丧失问题极为突出,因此亟需挖掘和探索新型抗病基因资源及其免疫调控机理,并将之有效应用于作物抗病分子育种。拟南芥RTP1 (Resistance to Phytophthora parasitica 1)前期研究鉴定获得的免疫负调控因子,RTP1基因缺失的拟南芥rtp1突变体植株呈现出对多种病原菌的抗病性,并在病菌侵染初期产生快速细胞死亡和活性氧累积。基于细胞死亡在植物免疫中的重要作用,本研究旨在探究RTP1介导的植物细胞死亡机理,鉴定到一类液泡加工酶γVPE能够影响rtp1突变体响应寄生疫霉侵染而引发的抗病反应及细胞死亡。以寄生疫霉侵染的拟南芥野生型Columbia-0 (Col-0)rtp1突变体植株为材料,通过实时定量PCR分析VPE基因表达模式,并利用VPE/Caspase-1蛋白酶的特异荧光底物分析酶活性水平,结果表明,相较于野生型Col-0,寄生疫霉侵染的拟南芥rtp1突变体中γVPE基因上调表达,并伴随着升高的VPE/caspase-1酶活性水平。进一步利用特异酶活性抑制剂,结果揭示了拟南芥植株响应寄生疫霉侵染而产生的细胞死亡以及rtp1突变体对寄生疫霉的抗病性均依赖于VPE/caspase-1酶活性。利用拟南芥γvpe突变体植株或农杆菌介导的AtγVPE瞬时过表达烟草叶片进行接菌表型分析,结果证明了AtγVPE能够正向调节植物对寄生疫霉的抗病性。综上所述,本研究不仅揭示了γVPE是植物响应寄生疫霉侵染过程中参与调节植物抗病反应和细胞死亡的关键因子,还有助于深入理解感病因子RTP1介导的细胞死亡调节机制,为作物抗病分子育种提供了新型基因资源与新思路。

Abstract:

Oomycete, particularly Phytophthora species, causes the most devastating crop diseases, such as potato late blight, and threatens the sustainable crop production worldwide.  Our previous studies identified Resistance to Phytophthora parasitica 1 (RTP1) as a negative regulator of Arabidopsis resistance to multiple biotrophic pathogens and RTP1 loss-of-function plants displayed rapid cell death and reactive oxygen species (ROS) production during early colonization of Pparasitica.  In this study, we aim to decipher the mechanism of RTP1-mediated cell death, and identify a member of vaculoar processing enzymes (VPEs), γVPE, playing a role in rtp1-mediated resistance to Pparasitica and cell death occurrence.  Our results showed up-regulation of the expression of γVPE as well as increased VPE/caspase 1-like protease activity in Pparasitica-infected rtp1 mutant plants.  Besides, we found that the VPE/caspase 1-like protease activity was required for the cell death occurrence in Arabidopsis plants during the infection of Pparasitica as well as rtp1-mediated resistance to Pparasitica.  Further pathogenicity assays on either Arabidopsis γvpe mutant plants or leaves of Nicotiana benthamiana with transient overexpression of γVPE demonstrated γVPE could positively affect plant resistance to Pparasitica.  Together, our studies suggest that γVPE might function as an important regulator of plant defense and cell death occurrence in response to Pparasitica infection, and VPE/caspase 1-like protease activity is required for rtp1-mediated resistance to Pparasitica.

Key words: cell death , caspase 1 ,  plant resistance ,  Phytophthora parasitica ,  RTP1 ,  susceptibility factor ,  vacuolar processing enzyme