Xue Xiaojing, Geng Tiantian, Liu Haifeng, Yang Wei, Zhong Weiran, Zhang Zhiliang, Zhu Changxiang, Chu Zhaohui
State Key Laboratory of Crop Biology, College of Agronomy, Shandong Agricultural University, Tai'an, China.
Key Laboratory of Quality Improvement of Agricultural Products of Zhejiang Province, School of Agriculture and Food Science, Zhejiang A&F University, Hangzhou, China.
Front Plant Sci. 2021 Jan 28;12:609870. doi: 10.3389/fpls.2021.609870. eCollection 2021.
Late blight (LB), caused by the oomycete pathogen , is a devastating disease of potato that is necessary to control by regularly treatment with fungicides. Silicon (Si) has been used to enhance plant resistance against a broad range of bacterial and fungal pathogens; however, the enhanced LB resistance and the molecular mechanisms involving the plant hormone pathways remain unclear. In this study, Si treatment of potato plants was found to enhance LB resistance in both detached leaves and living plants accompanied by induction of reactive oxygen species (ROS) production and pathogenesis-related genes expression. Regarding the hormone pathways involved in Si-mediated LB resistance, we found a rapidly increased content of ethylene (ET) 15 min after spraying with Si. Increased jasmonic acid (JA) and JA-Ile and decreased salicylic acid (SA) were identified in plants at 1 day after spraying with Si and an additional 1 day after EC1 infection. Furthermore, pretreatment with Me-JA enhanced resistance to EC1, while pretreatment with DIECA, an inhibitor of JA synthesis, enhanced the susceptibility and attenuated the Si-mediated resistance to LB. Consistent with these hormonal alterations, Si-mediated LB resistance was significantly attenuated in -, -, -, -, -, and repressed plants but not in and repressed plants using virus-induced gene silencing (VIGS). The Si-mediated accumulation of JA/JA-Ile was significantly attenuated in -, -, and - plants but not in -, and plants. Overall, we reveal that Si can be used as a putative alternative to fungicides to control LB, and conclude that Si-mediated LB resistance is dependent on the ET/JA-signaling pathways in a and dependent manner.
晚疫病（LB）由卵菌病原体引起，是马铃薯的一种毁灭性病害，需要通过定期使用杀菌剂进行防治。硅（Si）已被用于增强植物对多种细菌和真菌病原体的抗性；然而，增强的晚疫病抗性以及涉及植物激素途径的分子机制仍不清楚。在本研究中，发现用硅处理马铃薯植株可增强离体叶片和活体植株对晚疫病的抗性，同时诱导活性氧（ROS）产生和病程相关基因表达。关于参与硅介导的晚疫病抗性的激素途径，我们发现喷施硅后15分钟乙烯（ET）含量迅速增加。喷施硅1天后以及接种EC1再1天后，植株中茉莉酸（JA）和茉莉酸异亮氨酸（JA-Ile）含量增加，水杨酸（SA）含量降低。此外，用茉莉酸甲酯（Me-JA）预处理可增强对EC1的抗性，而用茉莉酸合成抑制剂二碘乙酸（DIECA）预处理则增强了易感性并减弱了硅介导的对晚疫病的抗性。与这些激素变化一致，使用病毒诱导基因沉默（VIGS）技术，在乙烯不敏感、茉莉酸不敏感、水杨酸不敏感、乙烯信号转导负调控、茉莉酸信号转导负调控和水杨酸信号转导负调控的植株中，硅介导的晚疫病抗性显著减弱，但在乙烯信号转导正调控和水杨酸信号转导正调控的植株中没有减弱。在乙烯不敏感、茉莉酸不敏感、乙烯信号转导负调控和水杨酸信号转导负调控的植株中，硅介导的茉莉酸/茉莉酸异亮氨酸积累显著减弱，但在乙烯信号转导正调控、茉莉酸信号转导正调控和水杨酸信号转导正调控的植株中没有减弱。总体而言，我们揭示了硅可作为杀菌剂的一种潜在替代品用于防治晚疫病，并得出结论：硅介导的晚疫病抗性以乙烯和茉莉酸依赖的方式依赖于乙烯/茉莉酸信号途径。
