Zhu Yongchao, Liao Weibiao, Wang Meng, Niu Lijuan, Xu Qingqing, Jin Xin
College of Horticulture, Gansu Agricultural University, Lanzhou 730070, PR China.
College of Horticulture, Gansu Agricultural University, Lanzhou 730070, PR China.
J Plant Physiol. 2016 May 20;195:50-8. doi: 10.1016/j.jplph.2016.02.018. Epub 2016 Mar 15.
Hydrogen gas (H2) is involved in plant development and stress responses. Cucumber explants were used to study whether nitric oxide (NO) is involved in H2-induced adventitious root development. The results revealed that 50% and 100% hydrogen-rich water (HRW) apparently promoted the development of adventitious root in cucumber. While, the responses of HRW-induced adventitious rooting were blocked by a specific NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide potassium salt (cPTIO), NO synthase (NOS) enzyme inhibitor N(G)-nitro-l-arginine methylester hydrochloride (l-NAME) and nitrate reductase (NR) inhibitor NaN3. HRW also increased NO content and NOS and NR activity both in a dose- and time-dependent fashion. Moreover, molecular evidence showed that HRW up-regulated NR genes expression in explants. The results indicate the importance of NOS and NR enzymes, which might be responsible for NO production in explants during H2-induced root organogenesis. Additionally, peroxidase (POD) and indoleacetic acid oxidase (IAAO) activity was significantly decreased in the explants treated with HRW, while HRW treatment significantly increased polyphenol oxidase (PPO) activity. In addition, cPTIO, l-NAME and NaN3 inhibited the actions of HRW on the activity of these enzymes. Together, NO may be involved in H2-induced adventitious rooting, and NO may be acting downstream in plant H2 signaling cascade.
氢气（H₂）参与植物发育和胁迫反应。本研究以黄瓜外植体为材料，探讨一氧化氮（NO）是否参与H₂诱导的不定根发育。结果表明，50%和100%的富氢水（HRW）显著促进黄瓜不定根的发育。然而，HRW诱导不定根形成的反应被特异性NO清除剂2-（4-羧基苯基）-4,4,5,5-四甲基咪唑啉-1-氧基-3-氧化物钾盐（cPTIO）、NO合酶（NOS）抑制剂N（G）-硝基-L-精氨酸甲酯盐酸盐（L-NAME）和硝酸还原酶（NR）抑制剂NaN₃所阻断。HRW还以剂量和时间依赖性方式增加了NO含量以及NOS和NR活性。此外，分子证据表明HRW上调了外植体中NR基因的表达。结果表明NOS和NR酶的重要性，它们可能在外植体H₂诱导的根器官发生过程中负责NO的产生。此外，HRW处理的外植体中过氧化物酶（POD）和吲哚乙酸氧化酶（IAAO）活性显著降低，而HRW处理显著增加了多酚氧化酶（PPO）活性。此外，cPTIO、L-NAME和NaN₃抑制了HRW对这些酶活性的作用。总之，NO可能参与H₂诱导的不定根形成，并且NO可能在植物H₂信号级联反应中起下游作用。
