title: The role of VuMATE1 expression in aluminium-inducible citrate secretion in rice bean (Vigna umbellata) roots.
abstract: Aluminium (Al)-activated citrate secretion plays an important role in Al resistance in a number of plant species, such as rice bean (Vigna umbellata). This study further characterized the regulation of VuMATE1, an aluminium-activated citrate transporter. Al stress induced VuMATE1 expression, followed by the secretion of citrate. Citrate secretion was specific to Al stress, whereas VuMATE1 expression was not, which could be explained by a combined regulation of VuMATE1 expression and Al-specific activation of VuMATE1 protein. Pre-treatment with a protein translation inhibitor suppressed VuMATE1 expression, indicating that de novo biosynthesis of proteins is required for gene expression. Furthermore, post-treatment with a protein translation inhibitor inhibited citrate secretion, indicating that post-transcriptional regulation of VuMATE1 is critical for citrate secretion. Protein kinase and phosphatase inhibitor studies showed that reversible phosphorylation was important not only for transcriptional regulation of VuMATE1 expression but also for post-translational regulation of VuMATE1 protein activity. These results suggest that citrate secretion is dependent on both transcriptional and post-transcriptional regulation of VuMATE1. Additionally, VuMATE1 promoter-β-glucuronidase fusion lines revealed that VuMATE1 expression was restricted to the root apex and was entirely Al induced, indicating the presence of cis-acting elements regulating root tip-specific and Al-inducible gene expression, which will be an important resource for genetic improvement of plant Al resistance.
authors: State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058, PR China.
authors: Mei Ya
authors: MY
authors: Liu
authors: Wei Wei
authors: WW
authors: Chen
authors: Jia Meng
authors: JM
authors: Xu
authors: Wei
authors: W
authors: Fan
authors: Jian Li
authors: JL
authors: Yang
authors: Shao Jian
authors: SJ
authors: Zheng
mesh_terms: D000535:Aluminum / Q000494:pharmacology*; D019343:Citric Acid / Q000378:metabolism*; D007887:Fabaceae / Q000187:drug effects* / Q000235:genetics* / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000187:drug effects* / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; D019343:Citric Acid; D000535:Aluminum