title: Gibberellic acid alleviates cadmium toxicity by reducing nitric oxide accumulation and expression of IRT1 in Arabidopsis thaliana.
abstract: Gibberellic acid (GA) is involved in not only plant growth and development but also plant responses to abiotic stresses. Here it was found that treating the plants with GA concentrations from 0.1 to 5 μM for 24 h had no obvious effect on root elongation in the absence of cadmium (Cd), whereas in the presence of Cd2+, GA at 5 μM improved root growth, reduced Cd content and lipid peroxidation in the roots, indicating that GA can partially alleviate Cd toxicity. Cd2+ increased nitric oxide (NO) accumulation in the roots, but GA remarkably reduced it, and suppressed the up-regulation of the expression of IRT1. In contrary, the beneficial effect of GA on alleviating Cd toxicity was not observed in an IRT1 knock-out mutant irt1, suggesting the involvement of IRT1 in Cd2+ absorption. Furthermore, the GA-induced reduction of NO and Cd content can also be partially reversed by the application of a NO donor (S-nitrosoglutathione [GSNO]). Taken all these together, the results showed that GA-alleviated Cd toxicity is mediated through the reduction of the Cd-dependent NO accumulation and expression of Cd2+ uptake related gene-IRT1 in Arabidopsis.
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
authors.forename: Xiao Fang
authors.initials: XF
authors.lastname: Zhu
authors.forename: Tao
authors.initials: T
authors.lastname: Jiang
authors.forename: Zhi Wei
authors.initials: ZW
authors.lastname: Wang
authors.forename: Gui Jie
authors.initials: GJ
authors.lastname: Lei
authors.forename: Yuan Zhi
authors.initials: YZ
authors.lastname: Shi
authors.forename: Gui Xin
authors.initials: GX
authors.lastname: Li
authors.forename: Shao Jian
authors.initials: SJ
authors.lastname: Zheng
mesh_terms: D017360:Arabidopsis / Q000187:drug effects* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics; D002104:Cadmium / Q000633:toxicity*; D002352:Carrier Proteins / Q000235:genetics; D004785:Environmental Pollutants / Q000633:toxicity*; D005875:Gibberellins / Q000494:pharmacology*; D015227:Lipid Peroxidation / Q000187:drug effects; D009569:Nitric Oxide / Q000378:metabolism; D010937:Plant Growth Regulators / Q000494:pharmacology*; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism; D020011:Protective Agents / Q000494:pharmacology*
chemical_list: D029681:Arabidopsis Proteins; D002352:Carrier Proteins; D004785:Environmental Pollutants; D005875:Gibberellins; D010937:Plant Growth Regulators; D020011:Protective Agents; D002104:Cadmium; D009569:Nitric Oxide; C007842:gibberellic acid