光合产物积累对于作物产量形成具有十分重要的作用。本课题在前期研究中，获得一个由于单基因隐性突变导致的水稻突变体，其叶片和穗部颖壳叶绿素含量明显提高，光合能力显著增强，实际产量显著增加，将其命名为hpe1（high photosynthetic efficiency 1）突变体。我们利用图位克隆方法分离了HPE1基因，发现该基因编码蛋白没有已知功能的保守结构域，是一个未见报道的新基因，进一步研究发现其编码蛋白与水稻调控叶绿体发育的重要转录因子GLK（GOLDEN2-LIKE）互作。本课题拟在此基础上，深入研究HPE1基因对水稻叶绿体发育与光合作用的影响、HPE1与OsGLKs的互作模式及其信号转导途径，最终阐明HPE1-OsGLKs参与叶绿体发育并影响光合效率的分子机理，同时为水稻分子设计育种提供优异基因资源和基础材料。

Accumulation of photosynthetic products plays a critical role in the formation of crop yield. Previously, we identified a high photosynthetic efficiency (hpe) rice mutant hpe1 caused by a single recessive gene. The mutant plant had high chlorophyll contents both in leaves and glume and displayed significantly increased photosynthetic capacity and the actual yield. We identified the HPE1 gene by map-based cloning approach, and found that its encoding protein did not have any known-conservative domain and it was a new gene that had not been reported. Our further studies indicated that its encoding protein interacted with the GOLDEN2-LIKE (GLK) transcription factor, which is involved in the regulation of chloroplast development in rice. In this proposed study, the functions of HPE1 gene will be analyzed and characterized in great details based on our previous results. This includes 1) understanding the effects of the HPE1 gene on chloroplast development and photosynthesis; 2) elucidating the mode of molecular interactions between HPE1 and OsGLKs and the signal transduction pathways downstream of HPE1-OsGLKs interactions. The ultimate goals of this proposed project are to elucidate the molecular mechanism of HPE1-OsGLKs regulated chloroplast development and photosynthetic efficiency, and to provide the excellent gene resource and intermediate materials for molecularly designed breeding in rice.