title: Physiological and Molecular Analysis of Aluminium-Induced Organic Acid Anion Secretion from Grain Amaranth (Amaranthus hypochondriacus L.) Roots.
abstract: Grain amaranth (Amaranthus hypochondriacus L.) is abundant in oxalate and can secrete oxalate under aluminium (Al) stress. However, the features of Al-induced secretion of organic acid anions (OA) and potential genes responsible for OA secretion are poorly understood. Here, Al-induced OA secretion in grain amaranth roots was characterized by ion charomatography and enzymology methods, and suppression subtractive hybridization (SSH) together with quantitative real-time PCR (qRT-PCR) was used to identify up-regulated genes that are potentially involved in OA secretion. The results showed that grain amaranth roots secrete both oxalate and citrate in response to Al stress. The secretion pattern, however, differs between oxalate and citrate. Neither lanthanum chloride (La) nor cadmium chloride (Cd) induced OA secretion. A total of 84 genes were identified as up-regulated by Al, in which six genes were considered as being potentially involved in OA secretion. The expression pattern of a gene belonging to multidrug and toxic compound extrusion (MATE) family, AhMATE1, was in close agreement with that of citrate secretion. The expression of a gene encoding tonoplast dicarboxylate transporter and four genes encoding ATP-binding cassette transporters was differentially regulated by Al stress, but the expression pattern was not correlated well with that of oxalate secretion. Our results not only reveal the secretion pattern of oxalate and citrate from grain amaranth roots under Al stress, but also provide some genetic information that will be useful for further characterization of genes involved in Al toxicity and tolerance mechanisms.
authors.affiliation: College of Resources and Environment, Yunnan Agricultural University, Kunming 650201, China. fanwei1128@aliyun.com.|State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058, China. fanwei1128@aliyun.com.
authors.forename: Wei
authors.initials: W
authors.lastname: Fan
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058, China. xujiamengican@163.com.
authors.forename: Jia-Meng
authors.initials: JM
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058, China. louheqiang@126.com.
authors.forename: He-Qiang
authors.initials: HQ
authors.lastname: Lou
authors.affiliation: Institute of Resource Biology and Biotechnology, Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China. xiaochuanapple@163.com.
authors.forename: Chuan
authors.initials: C
authors.lastname: Xiao
authors.affiliation: College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China. 15858223807@163.com.
authors.forename: Wei-Wei
authors.initials: WW
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058, China. yangjianli@zju.edu.cn.
authors.forename: Jian-Li
authors.initials: JL
authors.lastname: Yang
mesh_terms: D000535:Aluminum / Q000494:pharmacology*; D027721:Amaranthus / Q000187:drug effects* / Q000378:metabolism; D000838:Anions / Q000378:metabolism; D002264:Carboxylic Acids / Q000378:metabolism*; D019343:Citric Acid / Q000378:metabolism; D027701:Organic Cation Transport Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D010070:Oxalates / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D000838:Anions; D002264:Carboxylic Acids; D027701:Organic Cation Transport Proteins; D010070:Oxalates; D010940:Plant Proteins; D019343:Citric Acid; D000535:Aluminum
keywords: aluminium; citrate; grain amaranth; oxalate; suppression subtractive hybridization