Starter Grant: A Survey of Nuclear - and Plastid - Encoded Thylakoid Genes in the Scrophulariaceae/Orobanchaceae

小行星9632675 一组有机体的详细和有力的支持性进化提供了一个框架或路线图的生长，发育和生活史的关键研究。俄亥俄州州立大学的安德里亚·沃尔夫博士正在利用这种系统发育知识来探索寄生植物光合作用的分子进化变化。玄参科/列当科植物群包括自养的、完全光合作用的物种（例如金鱼草），所谓的半寄生物，其形成对其他植物的根附着，以及异养的、非光合作用的寄生物，如山毛榉（Epifagus属）等。寄生虫必须附着在宿主植物上以吸收碳营养物来生存;这一群体的系统发育树表明寄生虫在几个谱系中从光合形式进化而来。沃尔夫博士正在分析叶绿体中捕光类囊体的基因，以确定参与光合能量转移的核基因和质体基因的变化。她正在解决的问题包括：在分子水平上是否有“关键创新”引导植物寄生;当光合作用功能丧失时，核和质体基因突变的模式和顺序是什么;当突变破坏或破坏光合作用的关键酶时，叶绿体活动是否有备份或互补的基因系统？ 现代分子生物学工具使精细尺度的遗传解剖植物光合作用过程中的光捕获和能量捕获的酶过程成为可能。沃尔夫博士利用包括寄生物种在内的植物群的系统发育知识，设计了一个富有想象力的研究计划，密切关注一系列植物物种的光合功能衰退，这些植物物种已经进化出越来越多的寄生生活方式。在这样做的过程中，她正在分析生物化学途径进化的关键阶段，并帮助理解植物进化中生命史的转变。

9632675 Wolfe A detailed and strongly supported phylogeny of a group of organisms provides a framework or road map for critical studies of growth, development, and life history. Dr. Andrea Wolfe at Ohio State University is taking advantage of just such phylogenetic knowledge to explore molecular evolutionary changes in photosynthesis in plants that have become parasitic. The Scrophulariaceae/Orobanchaceae group of plants includes autotrophic, fully photosynthetic species (the snapdragons for example), so-called hemiparasites that form root attachments to other plants, and heterotrophic, non-photosynthetic parasites like beechdrops (genus Epifagus) and others. The parasites must attach themselves to host plants to absorb carbon nutrients for survival; the phylogenetic tree for this group demonstrates that parasites have evolved from photosynthetic forms in several lineages. Dr. Wolfe is analyzing genes for the light-harvesting thylakoid apparatus of the chloroplast, to determine changes in nuclear and plastid genes involved in photosynthetic energy transfer. Questions she is addressing include: are there "key innovations" at the molecular level that channel a plant toward parasitism; what are the patterns and sequence of mutations in nuclear and plastid genes as photosynthetic function is lost; are there backup or complementary gene systems to chloroplast activities, as mutations damage or destroy critical enzymes of photosynthesis? Modern tools of molecular biology make possible the fine-scale genetic dissection of enzymatic processes of light-harvesting and energy-capture during photosynthesis in plants. Taking advantage of phylogenetic knowledge of plant groups that include parasitic species, Dr. Wolfe has designed an imaginative program of study that looks closely at the decay of photosynthetic function in a series of plant species that have evolved an increasingly parasitic mode of life. In so doing, she is analyzing critical stages in the evolution of biochemical pathways and also help ing to understand shifts in life history in plant evolution.