Joint studies on the nuclear-encoded photosystem genes.

本研究项目旨在促进日本（上述五位科学家）、美国（加州大学伯克利分校Anastasios Melis教授）和德国（耶拿Friedrich-Schiller大学ralf Oelmueller教授）对高等植物和藻类光系统复合物生物发生的国际联合研究。在资助期内，共有21位科学家相互访问实验室，共停留148天，开展合作研究。论文发表26篇，在国际会议上发表17篇，在国内会议上发表29篇，申请专利2项。主要的科学发现如下：1、首次发现植物光系统基因具有独特的启动子结构和转录起始机制；2、我们发现光系统复合体的生物发生受到光合电子流的正反馈调节；3、光系统基因的氧化还原调控不仅与mRNA丰度有关，还与多核糖体装载有关；4、我们开发了一套特殊的LED光源，可以交替激发PSI和PSII；我们发现叶绿素b的丰度对光收集天线的生物发生并不那么重要；6、叶绿素加氧酶（CAO）在调节天线尺寸以适应环境光强方面起重要作用；基于对CAO基因的系统发育分析，我们提出了一个全新的假说来解释叶绿体的起源和进化。

This research project was planned for promoting the international joint studies by the plant physiologists of Japan (five scientists mentioned above), US (Prof. Anastasios Melis, University of California, Berkeley), and Germany (Prof.Ralf Oelmueller, Friedrich-Schiller Universitaet, Jena) on the biogenesis of photosystem complexes in higher plants and algae. During the period supported by the grant, 21 scientists in total have visited the laboratories one another and stayed there for the total days of 148, and performed the cooperative studies. The outcomes of these research are 26 papers published in the journals and books, 17 presentations in the international meetings, and 29 presentations at domestic meetings, and two patent applications. The major scientific findings are as follows ;1, We found that plant photosystem genes have unique promoter architecture and transcription initiation mechanisms for the first time ;2, We showed that the biogenesis of photosystem complexes is subjected to positive feedback regulation by photosynthetic electron flow ;3, The redox regulation of photosystem genes operates not only on mRNA abundance but also on poly-ribosome loading ;4, We developed a set of special LED light sources that excite PSI and PSII alternatively ;5, We revealed that the abundance of chlorophyll b is not so important for the biogenesis of light-harvesting antennas ;6, CAO (chlorophyll-oxygenase) plays important roles in adjusting the antennae size to environmental light strength ;7, We proposed a quite new hypothesis to explain the origin and evolution of chloroplats, based on the phylogenetic analyzes of CAO genes.