Improving salt tolerance and mitigating senescence in the presence of high salinity are crucial for sustaining agricultural productivity. Previous research has demonstrated that hydrogen peroxide (H2O2), specifically H2O2 derived from roots and mediated by the respiratory burst oxidase homolog (NADPH), plays a significant role in regulating ion and plant hormone homeostasis in glycophytic plants, such as Arabidopsis. However, the extent to which root-derived H2O2 fulfils similar functions in halophytic plants remains uncertain. Therefore, our study aimed to explore the potential contribution of root-sourced H2O2 in delaying leaf senescence induced by high salinity, utilizing seashore paspalum as a model halophytic plant. The application of the NADPH-oxidase inhibitor DPI, coupled with a series of leaf senescence analyses, we revealed that root-derived H2O2 significantly retards salt-induced leaf senescence. Furthermore, through the application of hormone analysis, lipidomics, ionomics, Non-invasive Micro-test Technology (NMT), and transcriptomics, we established that NADPH-dependent H2O2 induced by salt stress in the roots was indispensable for maintaining the balance of the aging hormone, jasmonic acid (JA), and sodium ion homeostasis within this halophytic plant. Finally, by utilizing AtrbohD Arabidopsis mutants and virus-induced gene silencing (VIGs) in Paspalum vaginatum, we demonstrated the pivotal role played by root-sourced H2O2 in upholding JA homeostasis and regulating JA-triggered leaf senescence in P. vaginatum. This study offers novel insights into the mechanisms that govern plant leaf senescence and its response to salinity-induced stress.

中文翻译：

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根源 H2O2 对于维持茉莉酸和 Na+/K+ 稳态以延缓雀稗草盐胁迫期间叶片衰老至关重要


在高盐度存在下提高耐盐性和缓解衰老对于维持农业生产力至关重要。先前的研究表明，过氧化氢 （H2O2），特别是源自根并由呼吸爆发氧化酶同源物 （NADPH） 介导的 H 2 O 2 ，在调节糖生植物（如拟南芥）的离子和植物激素稳态中起着重要作用。然而，根源来源的 H 2 O 2 在盐生植物中实现类似功能的程度仍不确定。因此，我们的研究旨在探讨根源 H2O2 在延缓高盐度诱导的叶片衰老方面的潜在贡献，以海滨雀稗为模式盐生植物。NADPH-氧化酶抑制剂 DPI 的应用，结合一系列叶片衰老分析，我们发现根源性 H2O2 显着延缓盐诱导的叶片衰老。此外，通过激素分析、脂质组学、离子组学、非侵入性显微检测技术 （NMT） 和转录组学的应用，我们确定根中盐胁迫诱导的 NADPH 依赖性 H2O2 对于维持衰老激素、茉莉酸 （JA） 和钠离子稳态的平衡是必不可少的这种盐生植物。最后，通过利用 AtrbohD 拟南芥突变体和病毒诱导的基因沉默 （VIGs） 在雀稗中，我们证明了根源 H 2 O 2 在维持 JA 稳态和调节 JA 触发的叶片衰老中发挥的关键作用。这项研究为控制植物叶片衰老的机制及其对盐度诱导的胁迫的反应提供了新的见解。