title: BjDHNs confer heavy-metal tolerance in plants.
abstract: Dehydrin gene transcript could be induced by heavy metals, and some dehydrins possess the ability to bind metals. However, the correlation between dehydrins and heavy-metal stress is unknown. In order to elucidate the contribution of dehydrins to heavy-metal stress tolerance in plants, we cloned two SK(2)-type dehydrin genes from heavy-metal hyperaccumulator Brassica juncea, and investigated their Cd/Zn tolerance in transgenic plants. Semi-quantitative RT-PCR analysis revealed that BjDHN2/BjDHN3 expressed in the leaves, stems and roots at a low level and were up-regulated by heavy metals. Antisense BjDHN3 Brassica juncea plants showed more electrolyte leakage and higher malondialdehyde production than the control plants when exposed to heavy metals, and the total amount of metals accumulated in the whole plant was reduced. Transgenic tobacco plants overexpressing BjDHN2/BjDHN3 showed lower electrolyte leakage and malondialdehyde production than the control plants when exposed to Cd/Zn. These results indicated that BjDHN2/BjDHN3 enhanced the tolerance for heavy metals by reducing lipid peroxidation and maintaining membrane stability in the plants.
authors.affiliation: Department of Biology, Graduate University of Chinese Academy of Sciences, Beijing, 100049, PR China.
authors.forename: Jin
authors.initials: J
authors.lastname: Xu
authors.forename: Yu Xiu
authors.initials: YX
authors.lastname: Zhang
authors.forename: Wei
authors.initials: W
authors.lastname: Wei
authors.forename: Lu
authors.initials: L
authors.lastname: Han
authors.forename: Zi Qiu
authors.initials: ZQ
authors.lastname: Guan
authors.forename: Zi
authors.initials: Z
authors.lastname: Wang
authors.forename: Tuan Yao
authors.initials: TY
authors.lastname: Chai
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D019216:Metals, Heavy / Q000494:pharmacology*; D008969:Molecular Sequence Data; D009149:Mustard Plant / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D016415:Sequence Alignment; D014026:Nicotiana / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D019216:Metals, Heavy; D010940:Plant Proteins; C070556:dehydrin proteins, plant