Fan Wei, Xu Jia-Meng, Lou He-Qiang, Xiao Chuan, Chen Wei-Wei, Yang Jian-Li
College of Resources and Environment, Yunnan Agricultural University, Kunming 650201, China.
State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
Int J Mol Sci. 2016 Apr 30;17(5):608. doi: 10.3390/ijms17050608.
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.
籽粒苋（Amaranthus hypochondriacus L.）富含草酸盐，并且在铝（Al）胁迫下能够分泌草酸盐。然而，关于铝诱导的有机酸阴离子（OA）分泌特征以及负责OA分泌的潜在基因，人们了解甚少。在此，通过离子色谱法和酶学方法对籽粒苋根系中铝诱导的OA分泌进行了表征，并利用抑制性消减杂交（SSH）和实时定量PCR（qRT-PCR）来鉴定可能参与OA分泌的上调基因。结果表明，籽粒苋根系在铝胁迫下会分泌草酸盐和柠檬酸盐。然而，草酸盐和柠檬酸盐的分泌模式有所不同。氯化镧（La）和氯化镉（Cd）均未诱导OA分泌。总共鉴定出84个受铝上调的基因，其中6个基因被认为可能参与OA分泌。一个属于多药和有毒化合物外排（MATE）家族的基因AhMATE1的表达模式与柠檬酸盐分泌模式密切一致。一个编码液泡膜二羧酸转运蛋白的基因和四个编码ATP结合盒转运蛋白的基因的表达受铝胁迫差异调节，但其表达模式与草酸盐分泌模式的相关性不佳。我们的结果不仅揭示了铝胁迫下籽粒苋根系中草酸盐和柠檬酸盐的分泌模式，还提供了一些遗传信息，这将有助于进一步表征参与铝毒性和耐受机制的基因。
Zotero 插件
