Abstract

Molecular and epigenetic mechanisms for regulation of a key TCA enzyme 2-oxoglutarate dehydrogenase (2-OGDH) were investigated in connection with plant metabolism response to alteration of light conditions. It was shown that the activity of 2-OGDH in the leaves of maize (Zea mays L.) depends on illumination. In the dark, the operation of the examined enzyme accelerates what apparently ensures the activation of oxidative processes in mitochondria. In Arabidopsis thaliana (L.) Heynh. plants deficient in the genes of photoreceptors, the mechanism of inhibition of 2-OGDH activity by light (the same as in maize leaves) is mediated via the absorption of red light by phytochrome A and blue light by cryptochrome. The level of transcripts of the genes ogdh-1,ogdh-2, and ogdh-3 encoding peptides of this enzyme complex in maize decreased in the light and upon the exposure to red light; the same reduction was observed for genes ogdh -1 and ogdh-2 in wild-type Arabidopsis. In Arabidopsis plants deficient in the genes of photoreceptors, the regulation of the examined genes was phytochrome- and cryptochrome-dependent. Modification of the extent of methylation of СpG motifs in promoter regions of the genes ogdh-1,ogdh-2, and ogdh-3 under different light conditions suggests that methylation status has a marginal effect on transcription of the examined genes.

中文翻译：

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植物2-氧戊二酸脱氢酶的光调节的分子和生化方面。

摘要

分子和表观遗传机制的关键TCA酶2-氧戊二酸脱氢酶（2-OGDH）的调节进行了研究与植物代谢对光照条件的变化的响应。结果表明，2- OGDH的玉米的叶（活性玉蜀黍L.）取决于照明。在黑暗中，所检查的酶的运行会加速，从而明显确保线粒体中氧化过程的激活。在拟南芥中。对于缺乏光感受器基因的植物，光抑制2-OGDH活性的机制（与玉米叶片相同）是通过植物色素A吸收红光和隐色染料吸收蓝光来介导的。的基因的转录物的水平OGDH-1，OGDH-2，和OGDH-3该酶在玉米复杂的编码肽的光并在暴露于红光下降; 在野生型拟南芥中观察到ogdh -1和ogdh-2基因的相同减少。在缺乏光感受器基因的拟南芥植物中，所检查基因的调节是依赖植物色素和隐色色素的。在不同的光照条件下，基因ogdh-1，ogdh-2和ogdh-3的启动子区域中СpG基序甲基化程度的改变表明，甲基化状态对所检查基因的转录有边际影响。