Regulation of phosphoenolpyruvate carboxylase in Pinus halepensis needles submitted to ozone and water stress
Regulation of phosphoenolpyruvate carboxylase in Pinus halepensis needles submitted to ozone and water stress
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DOI：
10.1034/j.1399-3054.2003.00052.x
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发表时间：
2003-04-01
影响因子：
6.4
通讯作者：
Dizengremel, P
中科院分区：
文献类型：
--
作者：
Fontaine, V;Cabané, M;Dizengremel, P
臭氧和/或干旱胁迫对欧洲松磷酸烯醇式丙酮酸羧化酶（PEPc，EC 4.1.1.31）调节的影响在受控条件下对针头进行了3个月的评估。而适度的水分胁迫施加到阿勒颇松PEPc活性没有影响相比，控制，这可能是有关的高耐受性，这个物种的干旱，臭氧胁迫诱导的PEPc活性在松针显着增加。这种回补途径的刺激可以提供修复过程的底物，众所周知，臭氧暴露会增强修复过程。臭氧增加的PEPc活性在一定程度上与蛋白质和mRNA水平的增加有关。还研究了臭氧下PEPc活性增加的酶的磷酸化状态的刺激的可能作用。在证明阿勒颇松PEPc的N末端部分存在磷酸化位点后，结果表明，在臭氧处理下，PEPc的亮/暗活性比和Ki（苹果酸）增加。这加强了与臭氧有关的翻译后过程的假设，这可能是植物适应长期压力的一部分。当臭氧和水分胁迫联合应用时，PEPc活性的增强仅与基因表达的变化有关。PEPc调节的这种差异，与单一压力的影响相比，可能是每个压力对酶的特定作用的结果。这项研究带来了新的见解PEPc在C-3植物，阿勒颇松在这些压力下的调节。根据压力的不同，PEPc发生不同的调节机制。响应臭氧和/或水胁迫的PEPc活性的增加的生理意义进行了讨论。
Effects of ozone and/or drought stresses on phosphoenolpyruvate carboxylase (PEPc, EC 4.1.1.31) regulation in Pinus halepensis Mill. needles were assessed over 3 months in controlled conditions. Whereas moderated water stress applied to Aleppo pine had no effect on PEPc activity compared to the control, which was probably related to the high tolerance of this species to drought, ozone stress induced a dramatic increase of PEPc activity in pine needles. This stimulation of the anaplerotic pathway could provide substrates to repair processes, well known for being enhanced upon ozone exposure. The ozone-increased PEPc activity was related, to a certain extent, to an increase in protein and mRNA levels. The possible role of the stimulation of the phosphorylation status of the enzyme in the increased PEPc activity under ozone was also investigated. Following the demonstration of the existence of the phosphorylation site at the N terminal part of Aleppo pine PEPc, it was shown that, under ozone treatment, the light/dark PEPc activity ratio and the Ki (malate) for PEPc were increased. This strengthens the hypothesis of an ozone-related post-translational process, which could be part of an adaptation of the plants to prolonged stress. When ozone and water stress were applied in combination, the enhancement in PEPc activity was only related to changes in gene expression. This difference in PEPc regulation, compared to the effect of single stress, could be the consequence of the specific action of each stress on the enzyme. This study brings new insights into the regulation of PEPc in a C-3 plant, Aleppo pine under these stresses. A different regulatory mechanism of PEPc is occurring according to the stress. The physiological implications of the increase in PEPc activity in response to ozone and/or water stress are discussed.