Nitric oxide (NO) and reactive oxygen species (ROS) are important signaling molecules regulating development of plants. However under metal stress, in developmental processes of plants their implications are not largely known. Therefore, in the present study, role of NO and ROS crosstalk in the regulation of formation of new adventitious roots (NARs) and primary root biomass accumulation (PRBA) has been investigated in rice seedlings under arsenate (AsV) stress. Addition of sodium nitroprusside (SNP, a donor of NO) induced formation of NARs, increased PRBA, and maintained the redox status of ascorbate and cell cycle dynamics. However, addition of NG-nitro-l-arginine methyl ester (L-NAME, an inhibitor of nitric oxide synthase) and 2-4-carboxyphenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (c-PTIO, a NO scavenger) either in presence of SNP or in its absence blocked formation of NARs and reduced PRBA. Further, to decipher crosstalk of NO and ROS, we used diphenylene iodonium (DPI, an inhibitor of NADPH oxidase), and even in presence of SNP it blocked formation of NARs which indicate that ROS are also essential for formation of NARs. Further a connection of NO-ROS signaling with the redox status of ascorbate and the cell cycle dynamics, governing formation of NARs and PRBA in rice seedlings under AsV stress is discussed.

中文翻译：

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砷胁迫下水稻幼苗中一氧化氮和反应性氧物种调节着新的不定根形成和主要根系生物量的积累。

一氧化氮（NO）和活性氧（ROS）是调节植物发育的重要信号分子。然而，在金属胁迫下，在植物的发育过程中其影响尚不为人所知。因此，在本研究中，已经研究了砷（AsV）胁迫下水稻幼苗中不定根（NAR）和原生根生物量积累（PRBA）的形成中NO和ROS串扰的作用。加入硝普钠（SNP，NO的供体）诱导NAR的形成，增加PRBA，并维持抗坏血酸的氧化还原状态和细胞周期动力学。但是，添加了NG-硝基-1-精氨酸甲酯（L-NAME，一氧化氮合酶的抑制剂）和2-4-羧基苯基-4,4,5,5-四甲基咪唑啉-1-氧基-3-氧化物（ c-PTIO SNP的存在或不存在时，NO清除剂会阻止NAR的形成并降低PRBA。此外，为了破译NO和ROS的串扰，我们使用了二亚苯基碘鎓（DPI，NADPH氧化酶的抑制剂），甚至在存在SNP的情况下，它也阻止了NAR的形成，这表明ROS对于NAR的形成也是必不可少的。进一步讨论了NO-ROS信号与抗坏血酸的氧化还原状态和细胞周期动态之间的联系，控制ASV胁迫下水稻幼苗中NAR和PRBA的形成。