Hydrogen-rich water regulates cucumber adventitious root development in a heme oxygenase-1/carbon monoxide-dependent manner

详细信息    查看全文

• 作者：Yuting Lin ; Wei Zhang ; Fang Qi ; Weiti Cui ; Yanjie Xie ; Wenbiao Shen
• 关键词：AR ; adventitious roots ; AsA ; ascorbic acid ; BR ; bilirubin ; Fe2+ ; FeSO4· ; 7H2O ; H2 ; hydrogen gas ; H2O2 ; hydrogen peroxide ; HRW ; hydrogen-rich water ; H2S ; hydrogen sulfide ; HO-1/CO ; heme oxygenase-1/carbon monoxide ; NO ; nitric oxide ; NPA ; N-1-naphthylphthalamic acid ; ZnPP ; zinc protoporphyrin IX
• 刊名：Journal of Plant Physiology
• 出版年：15 January, 2014
• 年：2014
• 卷：171
• 期：2
• 页码：1-8
• 全文大小：1734 K

文摘

Hydrogen gas (H₂) is an endogenous gaseous molecule in plants. Although its reputation is as a 鈥渂iologically inert gas鈥? recent results suggested that H₂ has therapeutic antioxidant properties in animals and plays fundamental roles in plant responses to environmental stresses. However, whether H₂ regulates root morphological patterns is largely unknown. In this report, hydrogen-rich water (HRW) was used to characterize H₂ physiological roles and possible signaling transduction pathways in the promotion of adventitious root (AR) formation in cucumber explants. Our results showed that a 50% concentration of HRW was able to mimic the effect of hemin, an inducer of a carbon monoxide (CO) synthetic enzyme, and heme oxygenase-1 (HO-1), in restoring AR formation in comparison with the inhibition effect conferred by auxin-depletion treatment alone. It was further shown that the inducible effect of HRW could be further blocked by the co-treatment with N-1-naphthylphtalamic acid (NPA; an auxin transport inhibitor). The HRW-induced response, at least partially, was HO-1-dependent. This conclusion was supported by the fact that the exposure of cucumber explants to HRW up-regulates cucumber HO-1 gene expression and its protein levels. HRW-mediated induction of representative target genes related to auxin signaling and AR formation, such as CsDNAJ-1, CsCDPK1/5, CsCDC6, CsAUX22B-like, and CsAUX22D-like, and thereafter AR formation (particularly in the AR length) was differentially sensitive to the HO-1 inhibitor zinc protoporphyrin IX (ZnPP). Above blocking actions were clearly reversed by CO, further confirming that the above response was HO-1/CO-specific. However, the addition of a well-known antioxidant, ascorbic acid (AsA), failed to influence AR formation triggered by HRW, thus ruling out the involvement of redox homeostasis in this process. Together, these results indicated that HRW-induced adventitious rooting is, at least partially, correlated with the HO-1/CO-mediated responses. We also suggested that exogenous HRW treatment on plants might be a good option to induce root organogenesis.