title: Involvement of heme oxygenase-1 in β-cyclodextrin-hemin complex-induced cucumber adventitious rooting process.
abstract: Our previous results showed that β-cyclodextrin-hemin complex (CDH) exhibited a vital protective role against cadmium-induced oxidative damage and toxicity in alfalfa seedling roots by the regulation of heme oxygenase-1 (HO-1) gene expression. In this report, we further test whether CDH exhibited the hormonal-like response. The application of CDH and an inducer of HO-1, hemin, were able to induce the up-regulation of cucumber HO-1 gene (CsHO1) expression and thereafter the promotion of adventitious rooting in cucumber explants. The effect is specific for HO-1 since the potent HO-1 inhibitor zinc protoporphyrin IX (ZnPP) blocked the above responses triggered by CDH, and the inhibitory effects were reversed further when 30% saturation of CO aqueous solution was added together. Further, molecular evidence showed that CDH triggered the increases of the HO-1-mediated target genes responsible for adventitious rooting, including one DnaJ-like gene (CsDNAJ-1) and two calcium-dependent protein kinase (CDPK) genes (CsCDPK1 and CsCDPK5), and were inhibited by ZnPP and reversed by CO. The calcium (Ca2+) chelator ethylene glycol-bis (2-aminoethylether)-N,N,N',N'-tetraacetic acid (EGTA) and the Ca2+ channel blocker lanthanum chloride (LaCl3) not only compromised the induction of adventitious rooting induced by CDH but also decreased the transcripts of above three target genes. However, the application of ascorbic acid (AsA), a well-known antioxidant in plants, failed to exhibit similar inducible effect on adventitious root formation. In short, above results illustrated that the response of CDH in the induction of cucumber adventitious rooting might be through HO-1-dependent mechanism and calcium signaling.
  
  
  CONCLUSIONS
  Physiological, pharmacological and molecular evidence showed that β-cyclodextrin-hemin complex (CDH) was able to induce cucumber adventitious rooting through heme oxygenase-1 (HO-1)-dependent mechanism and calcium signaling.
authors.affiliation: College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Yuting
authors.initials: Y
authors.lastname: Lin
authors.forename: Meiyue
authors.initials: M
authors.lastname: Li
authors.forename: Liqin
authors.initials: L
authors.lastname: Huang
authors.forename: Wenbiao
authors.initials: W
authors.lastname: Shen
authors.forename: Yong
authors.initials: Y
authors.lastname: Ren
mesh_terms: D001205:Ascorbic Acid / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D002248:Carbon Monoxide / Q000494:pharmacology; D018553:Cucumis sativus / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development*; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D051547:Heme Oxygenase-1 / Q000235:genetics / Q000378:metabolism*; D006427:Hemin / Q000494:pharmacology*; D009280:Naphthaleneacetic Acids / Q000494:pharmacology; D010797:Phthalimides / Q000494:pharmacology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development*; D011524:Protoporphyrins / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013997:Time Factors; D015854:Up-Regulation / Q000187:drug effects / Q000235:genetics; D047392:beta-Cyclodextrins / Q000494:pharmacology*
chemical_list: D009280:Naphthaleneacetic Acids; D010797:Phthalimides; D010940:Plant Proteins; D011524:Protoporphyrins; D012333:RNA, Messenger; D047392:beta-Cyclodextrins; C017803:zinc protoporphyrin; C002687:alpha-naphthylphthalamic acid; D006427:Hemin; D002248:Carbon Monoxide; D051547:Heme Oxygenase-1; C031215:betadex; D001205:Ascorbic Acid; D002118:Calcium