Zi Wang

Publications (3)7.08 Total impact

• Article: Antioxidative response of metal-accumulator and non-accumulator plants under cadmium stress

  Zi Wang, Yuxiu Zhang, Zhibo Huang, Lin Huang
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  ABSTRACT: The present study aims to elucidate the role of antioxidative enzyme in the adaptive responses of metal-accumulators (Thlaspi caerulescens and Brassica juncea) and non-accumulator plant (Nicotiana tabacum) to Cadmium stress. When seedlings of plants were grown in hydroponic condition for a period of 4days in the presence of 200 or 400μM CdCl2, photosynthetic rate, transpiration rate and stomatal conductance in metal-accumulators decreased more slowly than that in tobacco. MDA content and electrolyte leakage increased with elevated Cd concentration and exposure time in all plant species, while the oxidative damage in tobacco was more serious than that in metal-accumulators. The activities of SOD and CAT in metal-accumulators were significantly higher than that in tobacco under normal condition, whereas there was no significant difference in the activity of POD between Indian mustard and tobacco. The activities of antioxidative enzymes increased rapidly in metal-accumulators in response to the Cd treatments, especially SOD and CAT. In tobacco, CAT activity declined rapidly by exposure to the Cd treatment, though the activity of SOD and POD was enhanced, indicating that the antioxidative enzymes in tobacco could not fully scavenge ROS generated by Cd toxicity. These results collectively indicate that the enzymatic antioxidation capacity is one of the important mechanisms responsible for metal tolerance in metal-accumulator plant species.
  Plant and Soil 04/2012; 310(1):137-149. · 2.73 Impact Factor
• Article: Indian mustard aquaporin improves drought and heavy-metal resistance in tobacco.

  Yuxiu Zhang, Zi Wang, Tuanyao Chai, Zhensong Wen, Hongmei Zhang
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  ABSTRACT: An aquaporin cDNA BjPIP1 isolated from heavy-metal accumulator Indian mustard (Brassica juncea L.) encodes a 286-residue protein. The deduced amino acid sequence of BjPIP1 with six putative transmembrane domains showed highest identity (85-99%) to PIP1 subfamily members. Semi-quantitative RT-PCR analysis revealed that BjPIP1 transcripts were more abundantly expressed in roots compared to aerial parts of Indian mustard. However, the expression of BjPIP1 in leaves was up-regulated by drought, salt, low temperature, and heavy metal stress, suggesting that BjPIP1 was involved in resistance to abiotic stresses. BjPIP1 under the control of 35S promoter was introduced into tobacco mediated with Agrobacterium tumefaciens, the transgenic tobacco exhibited a lower water loss rate, a decreased transpiration rate, and stomatal conductance compared to the wild-type plants under osmotic stress, indicating that BjPIP1 might enhance plant drought resistance by decreasing transpiration via reducing stomatal conductance. Furthermore, overexpression of BjPIP1 in tobacco enhanced Cd resistance of root growth, and lowered transpiration rate and stomatal conductance upon Cd exposure, suggesting that BjPIP1 might increase heavy-metal resistance by maintaining reasonable water status in tobacco. Moreover, the BjPIP1-overexpressing plants showed higher activities of antioxidative enzymes, and lower level of electrolyte leakage and malondialdehyde content under Cd stress, indicating BjPIP1 might enhance the antioxidative activity and membrane integrity in transgenic plants. Taken together, these results suggested that BjPIP1 might improve plant heavy-metal resistance through alleviating water deficit and oxidative damage induced by metal ions.
  Molecular Biotechnology 08/2008; 40(3):280-92. · 2.17 Impact Factor
• Article: BjDHNs confer heavy-metal tolerance in plants.

  Jin Xu, Yu Xiu Zhang, Wei Wei, Lu Han, Zi Qiu Guan, Zi Wang, Tuan Yao Chai
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  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.
  Molecular Biotechnology 03/2008; 38(2):91-8. · 2.17 Impact Factor