早期光诱导基因PjELIPs在花叶矢竹叶色动态变化中作用机制研究

The bamboo species with color-changing leaves are important ornamental plants. Pseudosasa japonica f. Akebonosuji is one of unique bamboo, of which the leaves exhibited abundant variation during development and could turn to green in the final stage. This make Pseudosasa japonica f. Akebonosuji a precious material not only of the ornamental purpose, but also for the studies on leaf color changes..Previously, we performed a transcription analysis with the samples collected in 5 different time points during leaf development, based on which we predicted a regulatory network and found that the PjELIP genes, which expressed highly in the early stage of leaf development, are central players. The detail of PjELIP s-regulated network are very interesting and worth for further study. Here, we will monitor the dynamic expression patterns of PjELIPs in response to light; build the overexpression and knock-out lines of PjELIPs; analysis the transcriptional difference between wild type, PjELIPs overexpression line and knock-out line to further dissecting the functional and regulatory network. Our project will provide information for understanding the mechanisms of leaf color changes, metabolism of leaf pigments and development of plastids, which will further supports the specific leaf color induction and the breeding of new ornamental materials.

竹叶发生、生长过程中叶色动态变化是竹子重要的观赏性状之一，花叶矢竹既具有不稳定的叶色条纹变化，又有独特的可逆复绿现象，且每一片新叶发育都经历此动态过程，是研究叶色变化的珍贵材料，在丰富园林品种和造景上具广泛应用价值。在前期研究中基于花叶矢竹白叶形成5个动态点的转录组数据，我们构建了基因调控网络，PjELIPs作为调控网络的关键节点基因，在早期持续高表达，以其为核心的基因网络如何调控和作用于花叶矢竹叶色动态变化尚不清楚。本研究通过PjELIPs基因在花叶矢竹叶色动态变化中表达特性和对光响应特性研究，对转基因植株的表型解析及相关基因的表达分析，进一步验证PjELIPs与相关蛋白互作关系，揭示PjELIPs基因在花叶矢竹叶色动态变化中的作用机制，既能为探索竹子叶色变异机理、竹子色素代谢、质体发育等基础理论研究奠定基础，又可通过定向诱导叶色变异为创制新观赏竹种提供技术。

竹叶发生、生长过程中叶色动态变化是竹子重要的观赏性状之一，花叶矢竹既具有不稳定的叶色条纹变化，又有独特的可逆复绿现象，且每一片新叶发育都经历此动态过程，是研究叶色变化的珍贵材料，在丰富园林品种和造景上具广泛应用价值。PjELIPs基因，在早期持续高表达，以其为核心的基因20多个基因共同作用在白叶形成和复绿过程，在不同光质的光照下，叶色复绿程度和趋势与PjELIPs等基因表达趋势一致，在蓝光下复绿速度最快，PjELIPs表达上升的幅度最大；PjELIPs过表达到拟南芥和水稻中，过表达植株表型不同，拟南芥叶片色素含量下降，但是水稻出现了与花叶矢竹叶色变异类型一致，即有白叶、绿叶、条纹叶、白叶能够复绿，因此推测，.PjELIPs是花叶矢竹叶色变异的关键基因，PjELIPs基因的表达与PjGATA22变化趋势一致，两个蛋白的互作关系和模式还在进一步研究中。因此，在花叶矢竹叶色动态变化中PjELIPs起了关键作用，对光的响应特性也表明了花叶矢竹叶色变异与受光影响的质体发育有重要的关联，这为竹子质体发育和光合作用等基础理论研究奠定基础，花叶矢竹愈伤组织分化后苗发生矮化变异，这为定向诱导变异创制新观赏竹种提供技术。