SpCTP3 from the hyperaccumulator Sedum plumbizincicola positively regulates cadmium tolerance by interacting with SpMDH1

Shaocui Li; Zhengquan He; Wenmin Qiu; Miao Yu; Longhua Wu; Xiaojiao Han; Renying Zhuo

doi:10.1016/j.jhazmat.2024.134517

SpCTP3 from the hyperaccumulator Sedum plumbizincicola positively regulates cadmium tolerance by interacting with SpMDH1

J Hazard Mater. 2024 May 4:472:134517. doi: 10.1016/j.jhazmat.2024.134517. Online ahead of print.

Authors

Shaocui Li¹, Zhengquan He², Wenmin Qiu³, Miao Yu³, Longhua Wu⁴, Xiaojiao Han⁵, Renying Zhuo⁶

Affiliations

¹ State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding of Zhejiang Province, the Research Institute of Subtropical Forestry Chinese Academy of Forestry, Hangzhou, Zhejiang 311400, PR China; Zhejiang Xiaoshan Institute of Cotton & Bast Fiber Crops, Zhejiang Institute of Landscape Plants and Flowers, Zhejiang Academy of Agricultural Sciences, Hangzhou 311251, China.
² Key Laboratory of Three Gorges Regional Plant Genetic & Germplasm Enhancement (CTGU)/ Biotechnology Research Center, China Three Gorges University, Yichang 443002, Hubei, PR China.
³ State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding of Zhejiang Province, the Research Institute of Subtropical Forestry Chinese Academy of Forestry, Hangzhou, Zhejiang 311400, PR China.
⁴ Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, PR China.
⁵ State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding of Zhejiang Province, the Research Institute of Subtropical Forestry Chinese Academy of Forestry, Hangzhou, Zhejiang 311400, PR China. Electronic address: hanxiaojiao1004@163.com.
⁶ State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding of Zhejiang Province, the Research Institute of Subtropical Forestry Chinese Academy of Forestry, Hangzhou, Zhejiang 311400, PR China. Electronic address: zhuory@gmail.com.

PMID: 38739960
DOI: 10.1016/j.jhazmat.2024.134517

Abstract

Cadmium (Cd) is a heavy metal pollutant mainly originating from the discharge of industrial sewage, irrigation with contaminated water, and the use of fertilizers. The phytoremediation of Cd polluted soil depends on the identification of the associated genes in hyperaccumulators. Here, a novel Cd tolerance gene (SpCTP3) was identified in hyperaccumulator Sedum plumbizincicola. The results of Cd²⁺ binding and thermodynamic analyses, revealed the CXXC motif in SpCTP3 functions is a Cd²⁺ binding site. A mutated CXXC motif decreased binding to Cd by 59.93%. The subcellular localization analysis suggested that SpCTP3 is primarily a cytoplasmic protein. Additionally, the SpCTP3-overexpressing (OE) plants were more tolerant to Cd and accumulated more Cd than wild-type Sedum alfredii (NHE-WT). The Cd concentrations in the cytoplasm of root and leaf cells were significantly higher (53.75% and 71.87%, respectively) in SpCTP3-OE plants than in NHE-WT. Furthermore, malic acid levels increased and decreased in SpCTP3-OE and SpCTP3-RNAi plants, respectively. Moreover, SpCTP3 interacted with malate dehydrogenase 1 (MDH1). Thus, SpCTP3 helps regulate the subcellular distribution of Cd and increases Cd accumulation when it is overexpressed in plants, ultimately Cd tolerance through its interaction with SpMDH1. This study provides new insights relevant to improving the Cd uptake by Sedum plumbizincicola.

Keywords: Cadmium; Malic acid; Phytoremediation; SpCTP3; SpMDH1.