Interplay between the NADP-Linked Thioredoxin and Glutathione Systems in Arabidopsis Auxin Signaling
Interplay between the NADP-Linked Thioredoxin and Glutathione Systems in Arabidopsis Auxin Signaling
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DOI：
10.1105/tpc.109.071225
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发表时间：
2010-02-01
期刊：
影响因子：
11.6
通讯作者：
Reichheld, Jean-Philippe
中科院分区：
文献类型：
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作者：
Bashandy, Talaat;Guilleminot, Jocelyne;Reichheld, Jean-Philippe
细胞内氧化还原状态是决定植物在生物和非生物胁迫下发育的关键参数。硫氧还蛋白(Trx)和谷胱甘肽(Glutathione)是氧化还原动态平衡的关键调节者，而Trx和Glutathione途径是胚胎后分生组织活动所必需的。在这里，我们通过关联Trx还原酶(NTRA Ntrb)和谷胱甘肽生物合成(CAD2)突变表明，这两个硫醇还原途径通过调节生长素信号来干扰发育过程。三重NTRA ntrb cad2突变体在莲座期正常发育，经历开花过渡，但产生几乎裸露的茎，这使人想起几个影响生长素运输或生物合成的突变体的表型。此外，NTRA ntrb cad2突变体表现出顶端优势的丧失、维管系统的缺陷和次生根产量的减少，这些表型受到生长素的严格调控。我们进一步表明，在突变体中生长素的运输能力和生长素水平受到干扰，这表明NTR-谷胱甘肽途径改变了生长素的运输和代谢。对NTR和谷胱甘肽生物合成突变体的分析表明，谷胱甘肽稳态在生长素运输中起主要作用，因为NTR和谷胱甘肽途径都参与了生长素稳态。
Intracellular redox status is a critical parameter determining plant development in response to biotic and abiotic stress. Thioredoxin (TRX) and glutathione are key regulators of redox homeostasis, and the TRX and glutathione pathways are essential for postembryonic meristematic activities. Here, we show by associating TRX reductases (ntra ntrb) and glutathione biosynthesis (cad2) mutations that these two thiol reduction pathways interfere with developmental processes through modulation of auxin signaling. The triple ntra ntrb cad2 mutant develops normally at the rosette stage, undergoes the floral transition, but produces almost naked stems, reminiscent of the phenotype of several mutants affected in auxin transport or biosynthesis. In addition, the ntra ntrb cad2 mutant shows a loss of apical dominance, vasculature defects, and reduced secondary root production, several phenotypes tightly regulated by auxin. We further show that auxin transport capacities and auxin levels are perturbed in the mutant, suggesting that the NTR-glutathione pathways alter both auxin transport and metabolism. Analysis of ntr and glutathione biosynthesis mutants suggests that glutathione homeostasis plays a major role in auxin transport as both NTR and glutathione pathways are involved in auxin homeostasis.