水稻叶色基因lc7参与叶绿素合成、氮代谢和抗病的分子机制

叶绿素合成、氮代谢和抗病是影响水稻产量的三个重要因素。通过Co60γ射线辐射诱变日本晴水稻种子，获得一个叶色突变体lc7。该突变体叶绿素含量比野生型降低一倍左右，总氮含量比野生型低40%，对菲律宾白叶枯菌7个小种表现高抗。lc7具有多重的生物学功能，是研究叶绿素合成、氮代谢和抗病途径以及它们相互关系的重要材料。遗传分析表明lc7突变体由单个核基因隐性突变造成。通过图位克隆获得了lc7基因，并通过将野生型基因Lc7转入lc7突变体获得了叶色表型恢复正常的转基因植株。本项目深入研究lc7在叶绿素合成、氮代谢和抗病途径中的功能，通过数字表达谱、实时PCR、酵母双杂交以及转基因技术等分析与lc7基因相互作用的基因，明确lc7基因参与叶绿素合成、氮代谢和抗病途径的分子机制以及相互关系。研究结果有助于为提高水稻产量提供新思路。

Chlorophyll biosynthesis, nitrogen metabolism and disease resistance are the three key influence factors on rice yield. We obtained a leaf color mutant, lc7, through Co60-γ radiation treatment of japonica Nipponbare. The content of total N and Chlorophyll in the lc7 mutant was approximately 40% and 50% respectively lower than that in the wild type. In addition to this, lc7 mutant also has a broad-spectrum resistance to seven Philippine races of Xanthomonas oryzae pv. oryzae (Xoo). Multiple biological functions of lc7 make it an important material to study chlorophyll biosynthesis, nitrogen metabolism and disease resistance. Genetic analysis indicates that the leaf color phenotype is controlled by a recessive nuclear gene. Lc7 gene was isolated through map-based cloning method and transformed to lc7 mutant. The phenotype of leaf color is recovered in these transgenic plants. To study the functions of lc7 gene on chlorophyll biosynthesis, nitrogen metabolism and disease resistance in depth, Digital Ggene Expression Profile(DGE), Realtime PCR, Yeast Two Hybrid, Transgene and other methods are used to analysis the genes interacted with lc7 to resolve its molecular mechanism on chlorophyll biosynthetic, nitrogen metabolism and disease resistance pathways in the proposal. The results will help to provide a new idea for improving rice yield.