MAN3 gene regulates cadmium tolerance through the glutathione‐dependent pathway in Arabidopsis thaliana. Issue 2 (20th October 2014)

• Record Type: Journal Article
• Authors: Chen, Jian; Yang, Libo; Gu, Ju; Bai, Xiaoya; Ren, Yongbin; Fan, Tingting; Han, Yi; Jiang, Li; Xiao, Fangming; Liu, Yongsheng; Cao, Shuqing
• Is Part Of: New phytologist. Volume 205:Issue 2(2015)
• Page Start: 570
• Page End: 582
• Publication Date: 2014-10-20
• Subjects: Botany -- Periodicals; 580
• DOI: 10.1111/nph.13101
• Languages: English
• ISSNs: 0028-646X

Abstract

<abstract abstract-type="main" id="nph13101-abs-0001"> <title>Summary</title> <p> <list id="nph13101-list-0001" list-type="bullet"> <list-item> <p>Pollution of soil by the heavy metal cadmium (Cd) is a global environmental problem. The glutathione (GSH)‐dependent phytochelatin (PC) synthesis pathway is one of the most important mechanisms contributing to Cd accumulation and tolerance. However, the regulation of this pathway is poorly understood.</p> </list-item> <list-item> <p>Here, we identified an <italic>Arabidopsis thaliana</italic> cadmium‐tolerant dominant mutant <italic>xcd1‐D</italic> (<italic>XVE system‐induced cadmium‐tolerance 1</italic>) and cloned <italic>XCD1</italic> gene (previously called <italic>MAN3</italic>), which encodes an endo‐β‐mannanase. Overexpression of <italic>MAN3</italic> led to enhanced Cd accumulation and tolerance, whereas loss‐of‐function of <italic>MAN3</italic> resulted in decreased Cd accumulation and tolerance. In the presence of estradiol, enhanced Cd accumulation and tolerance in <italic>xcd1‐D</italic> was associated with GSH‐dependent, Cd‐activated synthesis of PCs, which was correlated with coordinated activation of gene expression.</p> </list-item> <list-item> <p>Cd stress‐induced expression of <italic>MAN3</italic> and the consequently increased mannanase activity, led to increased mannose content in cell walls. Moreover, mannose treatment not only rescued the Cd‐sensitive phenotype of the <italic>xcd1‐2</italic> mutant, but also improved the Cd tolerance of wild‐type plants. Significantly, this mannose‐mediated Cd accumulation and tolerance is dependent on GSH‐dependent PC concentrations via coordinated control of expression of genes involved in PC synthesis.</p> </list-item> <list-item> <p>Our results suggest that <italic>MAN3</italic> regulates the GSH‐dependent PC synthesis pathway that contributes to Cd accumulation and tolerance in <italic>A. thaliana</italic> by coordinated control of gene expression.</p> </list-item> </list> </p> </abstract>