Ammonium-dependent respiratory increase is dependent on the cytochrome pathway in Arabidopsis thaliana shoots
Ammonium-dependent respiratory increase is dependent on the cytochrome pathway in Arabidopsis thaliana shoots
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DOI：
10.1111/j.1365-3040.2010.02189.x
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发表时间：
2010-11-01
影响因子：
7.3
通讯作者：
Noguchi, Ko
中科院分区：
文献类型：
--
作者：
Hachiya, Takushi;Watanabe, Chihiro K.;Noguchi, Ko
当浓铵代替硝酸盐作为唯一氮源时，氧吸收速率增加。对这种呼吸增加的几种解释已经提出，但潜在的机制仍然不清楚。为了研究可能的因素，负责这种呼吸增加，我们测量了O（2）的吸收率，活性和呼吸成分的转录水平，和浓度的腺苷酸拟南芥芽生长在培养基中含有各种N源。O（2）吸收速率与地上部NH 4+和ATP浓度相关，而与NH 4+同化量无关。当高浓度铵为唯一氮源时，ATP偶联细胞色素途径（CP）及其相关基因的能力被上调，而ATP解偶联的交替氧化酶则不影响呼吸增加的程度。上述结果表明，氨依赖性的O（2）吸收速率的增加可以通过CP的上调来解释，CP的上调可能与质膜H ~+-ATP酶消耗ATP有关。
Oxygen uptake rates are increased when concentrated ammonium instead of nitrate is used as sole N source. Several explanations for this increased respiration have been suggested, but the underlying mechanisms are still unclear. To investigate possible factors responsible for this respiratory increase, we measured the O(2) uptake rate, activity and transcript level of respiratory components, and concentration of adenylates using Arabidopsis thaliana shoots grown in media containing various N sources. The O(2) uptake rate was correlated with concentrations of ammonium and ATP in shoots, but not related to the ammonium assimilation. The capacity of the ATP-coupling cytochrome pathway (CP) and its related genes were up-regulated when concentrated ammonium was sole N source, whereas the ATP-uncoupling alternative oxidase did not influence the extent of the respiratory increase. Our results suggest that the ammonium-dependent increase of the O(2) uptake rate can be explained by the up-regulation of the CP, which may be related to the ATP consumption by the plasma-membrane H+-ATPase.