Analysis of chloroplastic malate valve by using mutants of metabolite transporters

利用代谢物转运蛋白突变体分析叶绿体苹果酸瓣

• 批准号: 17570033
• 负责人: TANIGUCHI Mitsutaka
• 金额: $ 2.3万
• 依托单位: Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2005
• 资助国家: 日本
• 起止时间: 2005 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-17570033/
• 关键词: plant; chloroplast; photosynthesis; transporter; environmental stress; reductive power; photoinhibition; Arabidopsis thaliana; 環境

Because an Arabidopsis knockout mutant of plastidic 2-oxoglutarate/malate transporter (OMT) gene showed slightly delay of growth, we measured metabolite levels in the leaf tissues. The levels of 2-oxoglutarate and citrate were higher in the knockout plant compared with wild-type plant. Although some amino acids (Glu, Asp, Ala and Ser) were decreased, Gln was abundantly accumulated in the mutant. The knockout plant showed more prominent photoinhibition than wild-type plant under the high-light stress condition. From these results, we concluded that OMT is important in the connection of carbon and nitrogen metabolisms, and malate valve that transports stromal reducing equivalents to cytosol. In contrast, overexpression lines that had several ten-fold higher accumulation of OMT mRNA and two-fold higher activities of substrate transport showed no difference in phenotype compared with the wild-type plant. The Arabidopsis OMT gene expresses transiently in response to inorganic nitrogen supplementation. We revealed that this gene expression is triggered by nitrate ion. In some C_4 plants (sorghum, finger millet and green panic), OMT genes express in a mesophyll cell-specific manner.

由于塑料2-氧化甲酸/苹果酸转运蛋白转运蛋白（OMT）基因的拟南芥基因敲除突变体显示出生长的延迟略有延迟，因此我们测量了叶片组织中的代谢物水平。与野生型植物相比，敲除植物中2-氧气和柠檬酸盐的水平更高。尽管一些氨基酸（GLU，ASP，ALA和SER）减少了，但GLN在突变体中大量积累。在高光应力条件下，敲除植物比野生型植物显示出更为突出的光抑制作用。从这些结果中，我们得出的结论是，OMT在碳和氮代谢的连接以及传递基质还原等效物与细胞质的元素的连接方面很重要。相比之下，与野生型植物相比，OMT mRNA积累的过表达线的积累高十倍，而底物运输的活性高2倍。拟南芥OMT基因对补充无机氮的响应瞬时表达。我们揭示了该基因表达是由硝酸离子触发的。在某些C_4植物（高粱，手指小米和绿色恐慌）中，OMT基因以叶肉细胞特异性方式表达。

项目成果

Salinity stres induces granal development in bundle sheath chloroplasts of maize, an NADP-malic enzyme-type C_4 plant.

盐度胁迫诱导玉米（一种 NADP-苹果酸酶型 C_4 植物）束鞘叶绿体中的粒状发育。

• 发表时间: 2006
• 期刊: Plant Production Science 9
• 作者: Hasan;R.
• 通讯作者: R.

The promoter for C_4-type mitochondrial aspartate aminotransferase does not direst bundle sheath-specific expression in transgenic rice plants

C_4型线粒体天冬氨酸转氨酶的启动子不会影响转基因水稻植物中束鞘特异性表达

• 发表时间: 2005
• 期刊: Plant & Cell Physiology 46
• 作者: Nomura;M.
• 通讯作者: M.

Disruption of RCl2A leads to over-accumulation of Na^+ and increased salt sensitivity in Arabidopsis thaliana plants

RCl2A 的破坏导致拟南芥植物 Na+ 过度积累并增加盐敏感性

• 发表时间: 2005
• 期刊: Planta 222
• 作者: Mitsuya;S. et al.
• 通讯作者: S. et al.