Analysis and modulation of photosynthetic metabolism through the mutagenesis of ferredoxin

通过铁氧还蛋白诱变分析和调节光合代谢

基本信息

批准号：
08640828
负责人：
HASE Toshiharu
金额：
$ 1.41万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1997
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08640828/
关键词：
photosynthetic electron transfer ferredoxin glutamate synthase cyanobacterium maize petF 光独立栄養

项目摘要

The mechanisms of electron partitioning to several metabolic pathways in photosynthetic cells were studied in focusing structure, function, and gene expression of an electron carrier protein, ferredoxin (Fd). Following results have been obtained in this study.1) cDNA and gene for a nitrate inducible Fd isoprotein (FdVI) were cloned from maize roots, and its gene expression was found to be regulated with a manner similar to the nitrate assimilatory enzymes.2) Two different Fd isoproteins, FdI and FdII,were distributed in the mesophyll cells and the bundle sheath cells, respectively, and the cell specific expressions were observed in the transcriptional level. Genes to FdI and FdII were transformed a Fd-deficient cyanobacterium to complement the photosynthetic growth, and the two Fds showed a different activity to C and N assimilations.3) Study on the functions of recombinant Fds identified amino acid residues involved in the redox properties of the [Fe-2S] cluster and interaction sites to Fd-dependent enzymes. These mutant Fds will be used for modulate the photosynthetic ability of transgenic plants.4) Genes encoding two glutamate synthase, Fd-GOGAT and NADH-GOGAT,have been cloned, and the gene-disrupted mutants were isolated to study in vivo function of the enzymes. Fd-GOGAT was found to be the isozyme responsible to N assimilation in concert with an elevated CO2 fixation under sufficient light condition.

研究了电子载体蛋白铁氧还蛋白（FD）的聚焦结构，功能和基因表达中的电子分配到光合细胞中几种代谢途径的机制。在这项研究中已经获得了以下结果。1）硝酸盐诱导型FD异蛋白（FDVI）的cDNA和基因从玉米根中克隆，发现其基因表达以类似于硝酸盐同化酶的方式调节。在转录水平上分别观察到细胞特异性表达。 Genes to FdI and FdII were transformed a Fd-deficient cyanobacterium to complement the photosynthetic growth, and the two Fds showed a different activity to C and N assimilations.3) Study on the functions of recombinant Fds identified amino acid residues involved in the redox properties of the [Fe-2S] cluster and interaction sites to Fd-dependent enzymes.这些突变体FD将用于调节转基因植物的光合作用能力。4）编码两个谷氨酸合酶FD-GOGAT和NADH-GOGAT的基因已被克隆，并分离出基因脱落的突变体以研究酶的酶活性。发现FD-GOGAT是在足够光条件下与二氧化碳固定升高的同化同化的同工酶。