The accumulation of endogenous proline induces changes in gene expression of several antioxidant enzymes in leaves of transgenic Swingle citrumelo
The accumulation of endogenous proline induces changes in gene expression of several antioxidant enzymes in leaves of transgenic Swingle citrumelo
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DOI：
10.1007/s11033-012-2402-5
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发表时间：
2013-04-01
影响因子：
2.8
通讯作者：
Esteves Vieira, Luiz Gonzaga
中科院分区：
文献类型：
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作者：
de Carvalho, Kenia;Freitas de Campos, Marilia Kaphan;Esteves Vieira, Luiz Gonzaga
植物暴露在非生物胁迫下会导致活性氧的积累，并伴随着抗氧化防御机制的增强。以往的研究表明，外源应用Pro能够增加抗氧化酶的活性，从而减轻氧化应激造成的有害影响。然而，在正常供水条件下或在水分亏缺条件下，还没有关于内源高积累的Pro对抗氧化酶基因转录模式的影响的报道。在此，我们发现四种抗氧化酶基因(抗坏血酸过氧化物酶-APX、过氧化氢酶-CAT、超氧化物歧化酶-超氧化物歧化酶-SOD和谷胱甘肽还原酶-GR)的异构体在水分亏缺和正常供水条件下内源脯氨酸积累量较高的转基因植株叶片中存在差异调节。在水分亏缺过程中，Pro本身引起APX1、APXCL、CAT2和Cu/ZnSOD2转录活性的两倍变化，同时影响APXS和铜/ZnSODS亚型MnSODmit和GRCL的mRNAs水平。这项研究增加了关于脯氨酸在干旱条件下的作用的新信息，更重要的是，没有缺水造成的潜在混杂影响。我们发现，除了对植物各种生理生化过程的已知影响外，高内源脯氨酸还可以作为一种调节/信号分子来改变逆境相关基因的转录水平。
Plant exposure to abiotic stresses leads to an accumulation of reactive oxygen species with the concomitant increase in antioxidant defense mechanisms. Previous studies showed that exogenous application of proline mitigate the deleterious effects caused by oxidative stress due to its ability to increase the activity of antioxidant enzymes. However, there are no reports of the effects of high endogenous accumulation of proline in the transcriptional pattern of antioxidant enzymes genes under normal conditions of water supply or in response to water deficit. Here, we show that isoforms of four antioxidant enzymes genes (Ascorbate peroxidase-APX, Catalase-CAT, Superoxide dismutase-SOD and Glutathione reductase-GR) were differentially regulated in leaves of Swingle citrumelo transgenic plants with high endogenous proline accumulation submitted to water deficits and also under normal water supply condition. Proline per se caused a two-fold change in the transcription activity of APX1, APXcl, CAT2 and Cu/ZnSOD2, while during water deficit proline influenced mRNAs levels in APXs and Cu/ZnSODs isoforms, MnSODmit and GRcl. This study adds new information on the role of proline during drought conditions and, more important, without the potential confounding effects imposed by water deficiency. We showed that, in addition to its known effects on diverse plant physiological and biochemical processes, high endogenous proline can also acts as a regulatory/signalling molecule capable of altering the transcript levels of stress-related genes.