%0 Journal Article
%A Garcia-Oliveira, Ana Luísa
%A Martins-Lopesa, Paula
%A Tolrác, Roser
%A Poschenrieder, Charlotte
%A Tarquis, Marta
%A Guedes-Pinto, Henrique
%A Benito Jiménez, César
%T Molecular characterization of the citrate transporter gene TaMATE1 and expression analysis of upstream genes involved in organic acid transport under Al stress in bread wheat (Triticum aestivum)
%D 2014
%@ 0031-9317
%U https://hdl.handle.net/20.500.14352/108499
%X In bread wheat, besides malate, the importance of citrate efflux for Al tolerancehas also been reported. For better understanding the Al tolerance mechanismin bread wheat, here, we performed both a molecular characterization of thecitrate transporter gene TaMATE1 and an investigation on the upstream vari-ations in citrate and malate transporter genes. TaMATE1 belong to multidrugtransporter protein family, which are located on the long arm of homoeologousgroup 4 chromosomes (TaMATE1-4A, TaMATE1-4B TaMATE1-4D). TaMATE1homoeologues transcript expression study exhibited the preponderance ofhomoeologue TaMATE1-4B followed by TaMATE1-4D whereas homoeologueTaMATE1-4A seemed to be silenced. TaMATE1, particularly homoeologueTaMATE1-4B and TaALMT1 transcripts were much more expressed in the rootapices than in shoots of Al tolerant genotype Barbela 7/72/92 under both con-trol and Al stress conditions. In addition, in both tissues of Barbela 7/72/92,higher basal levels of these gene transcripts were observed than in Anahuac(Al sensitive). Noticeably, the presence of a transposon in the upstream ofTaMATE1-4B in Barbela 7/72/92 seems to be responsible for its higher tran-script expression where it may confer citrate efflux. Thus, promoter variations(transposon in TaMATE1-4B upstream and type VI promoter in TaALMT1) asso-ciated with higher basal transcript expression of TaMATE1-4B and TaALMT1clearly show how different mechanisms for Al tolerance operate simultane-ously in a single genotype. In conclusion, our results demonstrate that Barbela7/72/92 has favorable alleles for these organic acids transporter genes whichcould be utilized through genomic assisted selection to develop improvedcultivars for acidic soils.Abbreviations – 2D, two-dimensional; AACT, aluminum-activated citrate transporter; ALMT, Al-activated malate transporter;dNTP, deoxyribonucleotide triphosphates; EST, expressed sequence tag; MATE, multidrug and toxic compound exudation;OAs, organic acids; PCR, polymerase chain reaction; RT, reverse transcription; STOP, sensitive to proton rhizotoxicity.Physiol. Plant. 152, 2014 441
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