被子植物基部类群无被花三白草A和B类MADS-box基因表达、功能与进化的研究

项目名称： 被子植物基部类群无被花三白草A和B类MADS-box基因表达、功能与进化的研究

项目编号： No.31460053

项目类型： 地区科学基金项目

立项/批准年度： 2015

项目学科： 生物科学

项目作者： 赵银河

作者单位： 云南农业大学

项目金额： 50万元

中文摘要： 花发育在高等植物中研究得比较多，但关于花的起源和演化过程还有许多问题有待于解决。无被花三白草在系统发育树中处于被子植物基部以及花结构的特殊性和开花时顶端苞片变成花瓣状，所以，三白草研究对于了解被子植物花的起源和演化具有重要意义。 申请者已经从三白草中构建了4个cDNA文库，用芯片分析方法筛选到上调的A和B类MADS-box EST片段，在高等真双子叶植物花器官中，这些基因主要控制花被发育。与被子植物基部类群中分离的基因相比较，从三白草中分离的B类基因有氨基酸缺失。 本项目进一步通过蛋白互作、基因表达、转基因和进化分析等方法，首次在三白草中对氨基酸位点发生缺失的蛋白进行互作以及花瓣状苞片进行研究。探索无被花三白草中A，B-class MADS-box基因的表达模式和功能演化以及花被的缺失和花瓣状苞片的发育，这对正确理解花被起源和演化过程以及深入了解花器官发育在进化过程中遗传变化具有重要意义。

中文关键词： 三白草；MADS-box基因；基因表达；基因功能；进化

英文摘要： Floral development has been studied quite extensively in higher eudicots. However, many important questions concerning the origin and evolution of flowers have remained largely unanswered. It is an important species of a perianthless Saururus chinensis in relation to understanding the origin and evolution of angiosperm flowers, due to its basal position in the angiosperms and unusual floral composition and petaloid bracts during flowering. Based on the four subtracted cDNA libraries from developing inflorescences and showy bracts,and compared expression profiles of inflorescences and different developmental petaloid bracts using cDNA microarrays, we have obtained up-regulated A, B-class MADS-box transcription factor homologues EST isolated from perianthless paleoherb S. chinensis，which control petal and stamen identity in floral organ of the higher eudicots. To further analyzed, we found that B-class MADS-box amine acid showed deletion from perianthless S. chinensis compared with genes from other basal angiosperm species. In the current project, methods of proteins interaction, gene expression, transgene will be performed and phylogenetic trees will be reconstructed.The interaction between the proteins which key amine acid sites showed deletion and petaloid bracts development will be studied in perianthless S.chinensis for the first time. The expression and functional evolution of A, B-class MADS-box transcription factors isolated from perianthless paleoherb Saururus chinensis and the absent perianth and petaloid bracts development will be explored. It is very important to correctly understand the origin and evolution of the perianth, and deep understand the origin and diversification of flowers in angiosperms.

英文关键词： Saururus chinensis;MADS-box gene;gene expression;gene function;phylogenetic analysis