The Arabidopsis Ethylene-Insensitive 2 gene is required for lead resistance

• Published in: Plant physiology and biochemistry 2009-04, Vol.47 (4), p.308-312
• Main Authors: Cao, Shuqing, Chen, Zhengyi, Liu, Guoqing, Jiang, Li, Yuan, Huaibo, Ren, Guang, Bian, Xiaohui, Jian, Hongyong, Ma, Xinliang
• Format: Article
• Language: English
• Subjects: Arabidopsis; Arabidopsis - drug effects; Arabidopsis - genetics; Arabidopsis - metabolism; Arabidopsis Proteins - genetics; Arabidopsis Proteins - physiology; Biological and medical sciences; Cytoplasm; Ethylene-Insensitive 2 gene; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Plant - drug effects; Gene Expression Regulation, Plant - genetics; Glutathione - metabolism; Lead; Lead - toxicity; Plant physiology and development; Plants, Genetically Modified - drug effects; Plants, Genetically Modified - genetics; Receptors, Cell Surface - genetics; Receptors, Cell Surface - physiology; Reverse Transcriptase Polymerase Chain Reaction
• ISSN: 0981-9428; 1873-2690
• DOI: 10.1016/j.plaphy.2008.12.013

The Arabidopsis Ethylene-Insensitive 2 ( EIN2) gene has been shown to be involved in the regulation of abiotic and biotic stresses, including ozone stress, high salt, oxidative stress and disease resistance. However, little is known about the role of EIN2 gene in lead (Pb) resistance in Arabidopsis. In this study, we showed that EIN2 gene is required for Pb(II) resistance in Arabidopsis. EIN2 gene was induced by Pb(II) treatment, and the ein2-1 mutant showed enhanced sensitivity to Pb(II). A higher Pb content was detected in ein2-1 plants than in wild-type plants when subjected to Pb(II) treatment, which was associated, at least in part, with reduction in expression of AtPDR12 gene, a pump excluding Pb(II) and/or Pb(II)-containing toxic compounds from the cytoplasm. Moreover, the ein2-1 mutation also impaired glutathione (GSH)-dependent Pb(II) resistance, which was related to constitutive reduction of express of GSH1 gene involved in GSH synthesis and consequently reduced GSH content. Taken together, all these results suggest that EIN2 gene mediates Pb(II) resistance, at least in part, through two distinct mechanisms, a GSH-dependent mechanism and a GSH-independent AtPDR12-mediated mechanism.