Functional Characterization of <i>MaZIP4</i>, a Gene Regulating Copper Stress Tolerance in Mulberry (<i>Morus atropurpurea</i> R.)
Yisu Shi,
Qiaonan Zhang,
Lei Wang,
Qiuxia Du,
Michael Ackah,
Peng Guo,
Danyan Zheng,
Mengmeng Wu,
Weiguo Zhao
Affiliations
Yisu Shi
Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, School of Biology and Technology, Jiangsu University of Science and Technology, Zhenjiang 212018, China
Qiaonan Zhang
Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, School of Biology and Technology, Jiangsu University of Science and Technology, Zhenjiang 212018, China
Lei Wang
Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, School of Biology and Technology, Jiangsu University of Science and Technology, Zhenjiang 212018, China
Qiuxia Du
Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, School of Biology and Technology, Jiangsu University of Science and Technology, Zhenjiang 212018, China
Michael Ackah
Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, School of Biology and Technology, Jiangsu University of Science and Technology, Zhenjiang 212018, China
Peng Guo
Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, School of Biology and Technology, Jiangsu University of Science and Technology, Zhenjiang 212018, China
Danyan Zheng
Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, School of Biology and Technology, Jiangsu University of Science and Technology, Zhenjiang 212018, China
Mengmeng Wu
Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, School of Biology and Technology, Jiangsu University of Science and Technology, Zhenjiang 212018, China
Weiguo Zhao
Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, School of Biology and Technology, Jiangsu University of Science and Technology, Zhenjiang 212018, China
ZIP4 (zinc transporter 4) plays important roles in transporting Cu2+ ions in plants, which may contribute to the maintenance of plant metal homeostasis in growth, plant development and normal physiological metabolism. However, ZIP4 transporters have not been described in mulberry and the exact function of ZIP4 transporters in regulating the homeostasis of Cu in mulberry remains unclear. In this study, a new ZIP4 gene (MaZIP4) was isolated and cloned from Morus atropurpurea R. Phylogenetic analysis of amino sequences suggested that the amino-acid sequence of the MaZIP4 protein shows high homology with other ZIP4 proteins of Morus notabilis, Trema orientale, Ziziphus jujube and Cannabis sativa. In addition, a MaZIP4 silenced line was successfully constructed using virus-induced gene silencing (VIGS). The analysis of MaZIP4 expression by quantitative real-time PCR in mulberry showed that the level of MaZIP4 expression increased with increasing Cu concentration until the Cu concentration reached 800 ppm. Relative to the blank (WT) and the negative controls, malondialdehyde (MDA) levels increased significantly and rose with increasing Cu concentration in the MaZIP4 silenced line, whereas the soluble protein and proline content, superoxide dismutase (SOD) and peroxidase (POD) activities of these transgenic plants were lower. These results indicated that MaZIP4 may play an important role in the resistance of mulberry to Cu stress.
