Cowpea lipid transfer protein 1 regulates plant defense by inhibiting the cysteine protease of cowpea mosaic virus

• 成果类型: Article
• 署名作者: Ji, Jie; Du, Shengli; Wang, Kun; Qi, Ziyan; Zhang, Chunyang; Wang, Rui; Bruening, George; Wang, Pengwei; Duanmu, Deqiang; Fan, Qiuling
• 署名单位: Huazhong Agricultural University; Huazhong Agricultural University; Huazhong Agricultural University; University of California System; University of California Davis
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-12075
• DOI: 10.1073/pnas.2403424121
• 发表日期: 2024-08-27
• 关键词: endoplasmic-reticulum; chloroplasts; resistance; transport

摘要

Many virus genomes encode proteases that facilitate infection. The molecular mechanism of plant recognition of viral proteases is largely unexplored. Using the system of Vigna unguiculata and cowpea mosaic virus (CPMV), we identified a cowpea lipid transfer protein (LTP1) which interacts with CPMV- encoded 24KPro, a cysteine protease, but not with the enzymatically inactive mutant 24KPro(C166A). Biochemical assays showed that LTP1 inhibited 24KPro proteolytic cleavage of the coat protein precursor large coat protein- small coat protein. Transient overexpression of LTP1 in cowpea reduced CPMV infection, whereas RNA interference- mediated LTP1 silencing increased CPMV accumulation in cowpea. LTP1 is mainly localized in the apoplast of uninfected plant cells, and after CPMV infection, most of the LTP1 is relocated to intracellular benthamiana plants, LTP1 repressed soybean mosaic virus (SMV) nuclear inclusion a protease activity, and accumulation of SMV was significantly reduced. We propose that cowpea LTP1 suppresses CPMV and SMV accumulation by directly inhibiting viral cysteine protease activity.