Abstract：
The objective of this study was to investigate the mechanism underlying LW-1-induced resistance to TMV in wild-type and salicylic acid (SA)-deficient NahG transgenic tobacco plants. Our findings revealed that LW-1 failed to induce antivirus infection activity and increase SA content in NahG tobacco, indicating the crucial role of SA in these processes. Meanwhile, LW-1 triggered defense-related early-signaling nitric oxide (NO) generation, as evidenced by the emergence of NO fluorescence in both types of tobacco upon treatment with LW-1, however, NO fluorescence was stronger in NahG compared to wild-type tobacco. Notably, both of them were eliminated by the NO scavenger cPTIO, which also reversed LW-1-induced antivirus activity and the increase of SA content, suggesting that NO participates in LW-1-induced resistance to TMV, and may act upstream of the SA pathway. Defense-related enzymes and genes were detected in tobacco with or without TMV inoculation, and the results showed that LW-1 regulated both enzyme activity (β-1,3-glucanase [GLU], catalase [CAT] and phenylalanine ammonia-lyase [PAL]) and gene expression (PR1, PAL, WYKY4) through NO signaling in both SA-dependent and SA-independent pathways.
摘要：
这项研究的目的是研究LW-1在野生型和水杨酸（SA）缺陷的NahG转基因烟草植物中诱导对TMV抗性的潜在机制。我们的发现表明，LW-1未能诱导抗病毒感染活性并增加NahG烟草中的SA含量，表明SA在这些过程中的关键作用。同时,LW-1触发防御相关的早期信号一氧化氮（NO）的产生，然而，正如在用LW-1处理后两种类型的烟草中NO荧光的出现所证明的那样，与野生型烟草相比,NahG中的NO荧光更强。值得注意的是,它们都被NO清除剂cPTIO消除，这也逆转了LW-1诱导的防病毒活性和SA含量的增加，表明NO参与LW-1诱导的TMV抗性，并且可能在SA途径的上游起作用。在有或没有接种TMV的烟草中检测到防御相关的酶和基因，结果表明，LW-1调节两种酶的活性（β-1,3-葡聚糖酶[GLU]，过氧化氢酶[CAT]和苯丙氨酸解氨酶[PAL]）和基因表达（PR1，PAL，WYKY4）通过SA依赖性和SA非依赖性途径中的NO信号传导。
