College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
Plant Cell Rep. 2012 Sep;31(9):1563-72. doi: 10.1007/s00299-012-1270-8. Epub 2012 Apr 25.
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.
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.
我们之前的研究结果表明，β-环糊精-血红素复合物（CDH）通过调节血红素加氧酶-1（HO-1）基因表达，对苜蓿幼苗根中镉诱导的氧化损伤和毒性表现出重要的保护作用。在本报告中，我们进一步测试 CDH 是否表现出类似激素的反应。CDH 和 HO-1 的诱导剂血红素的应用能够诱导黄瓜 HO-1 基因（CsHO1）的表达上调，进而促进黄瓜外植体的不定根形成。这种作用是特异性的HO-1，因为强效的 HO-1 抑制剂锌原卟啉 IX（ZnPP）阻断了 CDH 触发的上述反应，当添加 30%饱和度的 CO 水溶液时，抑制作用进一步逆转。此外，分子证据表明，CDH 触发了 HO-1 介导的负责不定根形成的靶基因的增加，包括一个 DnaJ 样基因（CsDNAJ-1）和两个钙依赖性蛋白激酶（CDPK）基因（CsCDPK1 和 CsCDPK5），并被 ZnPP 抑制，被 CO 逆转。钙（Ca2+）螯合剂乙二醇双（2-氨基乙基醚）-N，N，N'，N'-四乙酸（EGTA）和钙通道阻滞剂氯化镧（LaCl3）不仅损害了 CDH 诱导的不定根形成的诱导作用，而且降低了上述三个靶基因的转录本。然而，植物中一种众所周知的抗氧化剂抗坏血酸（AsA）的应用未能表现出对不定根形成的类似诱导作用。总之，上述结果表明，CDH 在诱导黄瓜不定根形成中的反应可能是通过 HO-1 依赖性机制和钙信号转导。
生理、药理和分子证据表明，β-环糊精-血红素复合物（CDH）能够通过血红素加氧酶-1（HO-1）依赖性机制和钙信号转导诱导黄瓜不定根形成。
