Singh Bansh Narayan, Dwivedi Padmanabh, Sarma Birinchi Kumar, Singh Harikesh Bahadur
Institute of Environment and Sustainable Development, Banaras Hindu University Varanasi 221005 India.
Department of Plant Physiology, Institute of Agricultural Sciences, Banaras Hindu University Varanasi 221005 India
RSC Adv. 2019 Dec 3;9(68):39793-39810. doi: 10.1039/c9ra06802c. eCollection 2019 Dec 2.
has been explored and found to play a vital role in the defense mechanism of plants. However, its effects on host disease management in the presence of N nutrients remains elusive. The present study aimed to assess the latent effects of T42 on oxidative burst-mediated defense mechanisms against pv. () in tobacco plants fed 10 mM NO and 3 mM NH nutrients. The nitrate-fed tobacco plants displayed an increased HR when infected, which was enhanced in the -treated plants. This mechanism was enhanced by the involvement of , which elicited NO production and enhanced the expression pattern of NO-modulating genes (, and ). The real-time NO fluorescence intensity was alleviated in the NH -fed tobacco plants compared to that fed NO nutrient, suggesting the significant role of -elicited NO. The nitrite content and NR activity demonstration further confirmed that nitrate metabolism led to NO generation. The production of ROS (HO) in the plant leaves well-corroborated that the disease resistance was mediated through the oxidative burst mechanism. Nitrate application resulted in greater ROS production compared to NH nutrient after infection at 12 h post-infection (hpi). Additionally, the mechanism of enhanced plant defense under NO and NH nutrients mediated by involved NO, ROS production and induction of and antioxidant enzyme transcription level. Moreover, the use of sodium nitroprusside (100 μM) with suspension in the leaves matched the disease resistance mediated NO burst. Altogether, this study provides novel insights into the fundamental mechanism behind the role of in the activation of plant defense against non-host pathogens under N nutrients.
已被探索并发现其在植物防御机制中发挥着至关重要的作用。然而，在存在氮养分的情况下，其对宿主病害管理的影响仍不明确。本研究旨在评估T42对在供给10 mM硝酸根和3 mM铵根养分的烟草植株中，针对丁香假单胞菌（Pseudomonas syringae pv. tabaci）的氧化爆发介导防御机制的潜在影响。供给硝酸盐的烟草植株在感染时显示出增强的过敏反应（HR），在经T42处理的植株中这种反应进一步增强。该机制因一氧化氮合酶（NOS）的参与而增强，一氧化氮合酶引发一氧化氮（NO）的产生并增强了一氧化氮调节基因（NR、NOA1和NOB1）的表达模式。与供给硝酸根养分的烟草植株相比，供给铵根的烟草植株中实时NO荧光强度有所降低，表明一氧化氮合酶引发的NO具有重要作用。亚硝酸盐含量和硝酸还原酶（NR）活性的测定进一步证实硝酸盐代谢导致NO生成。植物叶片中活性氧（H2O2）的产生充分证实抗病性是通过氧化爆发机制介导的。在感染后12小时（hpi），与铵根养分相比，施用硝酸盐导致感染后产生更多的活性氧。此外，在一氧化氮合酶和铵根养分介导下增强植物防御的机制涉及NO、活性氧的产生以及病程相关蛋白（PR）和抗氧化酶转录水平的诱导。此外，在叶片中使用硝普钠（100 μM）与T42悬浮液相匹配，介导了由NO爆发引起的抗病性。总之，本研究为在氮养分条件下，T42在激活植物对非宿主病原体防御作用背后的基本机制提供了新的见解。
需注意，原文中部分英文缩写未给出全称，翻译时根据语境进行了合理推测补充，可能与原文实际含义存在一定偏差。
