Browse Articles

Article|01 Jul 2020|OPEN
MdWRKY11 improves copper tolerance by directly promoting the expression of the copper transporter gene MdHMA5
Kun Shi1 , Xuan Liu1 , Yunpeng Zhu1 , Yixue Bai1 , Dongqian Shan1 , Xiaodong Zheng1 , Lin Wang1 , Haixia Zhang1 , Chanyu Wang1 , Tianci Yan1 , Fangfang Zhou1,2 , Zehui Hu1 , Yanzhao Sun1 and Yan Guo2 , Jin Kong,1 ,
1College of Horticulture, China Agricultural University, 100193 Beijing, China
2College of Biological Sciences, China Agricultural University, 100193 Beijing, China
*Corresponding author. E-mail: jinkong@cau.edu.cn

Horticulture Research 7,
Article number: 105 (2020)
doi: https://doi.org/10.1038/s41438-020-0326-0
Views: 901

Received: 06 Jan 2020
Revised: 16 Apr 2020
Accepted: 20 Apr 2020
Published online: 01 Jul 2020

Abstract

Overuse of fungicides and fertilizers has resulted in copper (Cu) contamination of soils and toxic levels of Cu in apple fruits. To breed Cu-resistant apple (Malus domestica) cultivars, the underlying molecular mechanisms and key genes involved in Cu resistance must be identified. Here, we show that MdWRKY11 increases Cu tolerance by directly promoting the transcription of MdHMA5. MdHMA5 is a Cu transporter that may function in the storage of excess Cu in root cell walls and stems for Cu tolerance in apple. The transcription factor MdWRKY11 is highly induced by excess Cu. MdWRKY11 overexpression in transgenic apple enhanced Cu tolerance and decreased Cu accumulation. Apple calli transformed with an MdWRKY11-RNAi construct exhibited the opposite phenotype. Both an in vivo chromatin immunoprecipitation assay and an in vitro electrophoretic mobility shift assay indicated that MdWRKY11 binds to the promoter of MdHMA5. Furthermore, MdWRKY11 promoted MdHMA5 expression in transgenic apple plants, as revealed by quantitative PCR. Moreover, inhibition of MdWRKY11 expression by RNA interference led to a significant decrease in MdHMA5 transcription. Thus, MdWRKY11 directly regulates MdHMA5 transcription. Our work resulted in the identification of a novel MdWRKY11-MdHMA5 pathway that mediates Cu resistance in apple.