کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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4570530 | 1332044 | 2014 | 14 صفحه PDF | دانلود رایگان |
ABSTRACTAbscisic acid (ABA) regulates ion channel activity and stomatal movements in response to drought and other stresses. Here, we show that the Arabidopsis thaliana gene NRGA1 is a putative mitochondrial pyruvate carrier which negatively regulates ABA-induced guard cell signaling. NRGA1 transcript was abundant in the A. thaliana leaf and particularly in the guard cells, and its product was directed to the mitochondria. The heterologous co-expression of NRGA1 and AtMPC1 in yeast complemented a loss-of-function mitochondrial pyruvate carrier (MPC) mutant. The nrga1 loss-of-function mutant was very sensitive to the presence of ABA in the context of stomatal movements, and exhibited a heightened tolerance to drought stress. Disruption of NRGA1 gene resulted in increased ABA inhibition of inward K+ currents and ABA activation of slow anion currents in guard cells. The nrga1/NRGA1 functional complementation lines restored the mutant's phenotypes. Furthermore, transgenic lines of constitutively overexpressing NRGA1 showed opposite stomatal responses, reduced drought tolerance, and ABA sensitivity of guard cell inward K+ channel inhibition and anion channel activation. Our findings highlight a putative role for the mitochondrial pyruvate carrier in guard cell ABA signaling in response to drought.
Journal: - Volume 7, Issue 10, October 2014, Pages 1508–1521