Xiang Meirong, Wang Pengyue, Han Keda, Liu Jianjian, Huang Ziting, Wang Chaonan, Jing Xinxin, Du Jiao, Sun Bingjian, Li Honglian, Zhang Chao, Li Pengbai
The Engineering Research Center for Plant Health Protection Technology in Henan Province, College of Plant Protection, Henan Agricultural University, Zhengzhou, Henan, China.
Fujian Province Key Laboratory of Plant Virology, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China.
Mol Plant Pathol. 2025 May;26(5):e70092. doi: 10.1111/mpp.70092.
Plant viral diseases pose a significant threat to agricultural production, and the availability of effective drugs against viral diseases remains limited. In this study, we discovered that betulinic acid (BA), a pentacyclic triterpenoid derived from plants, delays infection by turnip mosaic virus (TuMV) in Nicotiana benthamiana. Transcriptomic analysis revealed that BA treatment specifically induced the expression of N. benthamiana phytosulfokine 3 (NbPSK3), a plant pentapeptide hormone with diverse functions, while TuMV infection suppressed its expression. Further study demonstrated that NbPSK3 positively regulates antiviral defence against TuMV infection. Disruption of PSK signalling by targeting the membrane-bound PSK receptors (PSKRs) promoted viral infection. Additionally, exogenous sulphonated PSK (active form) treatment significantly delayed infection by TuMV in N. benthamiana compared to unmodified PSK peptides (dPSK, inactive form) or control treatments, while silencing the receptor NbPSKR1 abolished the ability of PSK to inhibit TuMV infection. Moreover, the inhibition of TuMV infection by BA is dependent on the PSK-PSKR signalling pathway. Overall, these findings not only underscore the potential of BA as a promising and environmentally friendly agent for modulating plant viral diseases but also emphasise the role of the PSK signalling pathway in promoting at least partial resistance to TuMV, which might have interest for crop breeding.
植物病毒病对农业生产构成重大威胁，而针对病毒病的有效药物仍然有限。在本研究中，我们发现源自植物的五环三萜类化合物桦木酸（BA）可延缓本氏烟草中芜菁花叶病毒（TuMV）的感染。转录组分析表明，BA处理特异性诱导了本氏烟草植物磺肽素3（NbPSK3）的表达，NbPSK3是一种具有多种功能的植物五肽激素，而TuMV感染则抑制了其表达。进一步研究表明，NbPSK3正向调节对TuMV感染的抗病毒防御。通过靶向膜结合的PSK受体（PSKRs）破坏PSK信号传导会促进病毒感染。此外，与未修饰的PSK肽（dPSK，无活性形式）或对照处理相比，外源磺化PSK（活性形式）处理显著延缓了本氏烟草中TuMV的感染，而沉默受体NbPSKR1则消除了PSK抑制TuMV感染的能力。此外，BA对TuMV感染的抑制作用依赖于PSK-PSKR信号通路。总体而言，这些发现不仅强调了BA作为一种有前景的环境友好型植物病毒病调节剂的潜力，还强调了PSK信号通路在促进对TuMV至少部分抗性方面的作用，这可能对作物育种具有重要意义。
