title: Methane-rich water induces cucumber adventitious rooting through heme oxygenase1/carbon monoxide and Ca(2+) pathways.
abstract: Methane-rich water triggered adventitious rooting by regulating heme oxygenase1/carbon monoxide and calcium pathways in cucumber explants. Heme oxygenase1/carbon monoxide (HO1/CO) and calcium (Ca(2+)) were reported as the downstream signals in auxin-induced cucumber adventitious root (AR) formation. Here, we observed that application of methane-rich water (MRW; 80% saturation) obviously induced AR formation in IAA-depleted cucumber explants. To address the universality, we checked adventitious rooting in soybean and mung bean explants, and found that MRW (50 and 10% saturation, respectively) exhibited the similar inducing results. To further determine if the HO1/CO system participated in MRW-induced adventitious rooting, MRW, HO1 inducer hemin, its activity inhibitor zinc protoporphyrin IX (ZnPP), and its catalytic by-products CO, bilirubin, and Fe(2+) were used to detect their effects on cucumber adventitious rooting in IAA-depleted explants. Subsequent results showed that MRW-induced adventitious rooting was blocked by ZnPP and further reversed by 20% saturation CO aqueous solution. However, the other two by-products of HO1, bilirubin and Fe(2+), failed to induce AR formation. Above responses were consistent with the MRW-induced increases of HO1 transcript and corresponding protein level. Further molecular evidence indicted that expression of marker genes, including auxin signaling-related genes and cell cycle regulatory genes, were modulated by MRW alone but blocked by the cotreatment with ZnPP, the latter of which could be significantly rescued by the addition of CO. By using the Ca(2+)-channel blocker and Ca(2+) chelator, the involvement of Ca(2+) pathway in MRW-induced adventitious rooting was also suggested. Together, our results indicate that MRW might serve as a stimulator of adventitious rooting, which was partially mediated by HO1/CO and Ca(2+) pathways.
authors.affiliation: College of Life Sciences, Laboratory Center of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Weiti
authors.initials: W
authors.lastname: Cui
authors.forename: Fang
authors.initials: F
authors.lastname: Qi
authors.forename: Yihua
authors.initials: Y
authors.lastname: Zhang
authors.forename: Hong
authors.initials: H
authors.lastname: Cao
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.forename: Ren
authors.initials: R
authors.lastname: Wang
authors.forename: Wenbiao
authors.initials: W
authors.lastname: Shen
mesh_terms: D020013:Calcium Signaling / Q000187:drug effects; D002248:Carbon Monoxide / Q000378:metabolism* / Q000494:pharmacology; D018553:Cucumis sativus / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D051547:Heme Oxygenase-1 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D007210:Indoleacetic Acids / Q000378:metabolism; D053858:Metabolic Networks and Pathways / Q000187:drug effects; D008697:Methane / Q000494:pharmacology*; D010940:Plant Proteins / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D011524:Protoporphyrins / Q000494:pharmacology; D014867:Water / Q000737:chemistry / Q000494:pharmacology
chemical_list: D007210:Indoleacetic Acids; D010940:Plant Proteins; D011524:Protoporphyrins; D014867:Water; C017803:zinc protoporphyrin; D002248:Carbon Monoxide; D051547:Heme Oxygenase-1; D008697:Methane