基于转录组学的山药 (Dioscorea opposita) 块茎膨大期淀粉合成的机理研究

山药(Dioscorea spp.)是我国粮、菜、药兼用的重要特色作物。淀粉是山药块茎的主要成分，随山药块茎的膨大而合成积累。块茎中淀粉含量及性质决定山药品质，也是研究块茎膨大机制的重要指标之一。本研究以高淀粉含量品种大和长芋山药(Dioscorea opposita Thunb.)为材料，低淀粉含量品种内蒙古毕克齐山药(Dioscorea opposita Thunb.)为对照，用转录组测序技术对山药块茎形成过程中淀粉积累表达基因测序，筛选差异表达基因，通过生物信息学解析相关基因的功能和表达；根据已知基因片段设计引物，克隆淀粉合成相关基因cDNA全长序列和对应的gDNA序列，进行生物信息学分析和基因结构分析；构建植物瞬时表达载体；对候选基因进行亚细胞定位；及山药不同组织和外源蔗糖处理叶片的表达分析。旨在明确山药块茎淀粉合成机制，挖掘功能基因，为山药优良资源的利用发挥重要的作用。

Yam (Dioscorea spp.) is the most important and characteristic crops for vegetable, food and Chinese medicine. Starch synthesis and accumulation in yam tubers with the tuber development. So starch is the principle constituent of yam tubers and is one of considerable importance factor during tuber swelling period of yam. Starch is also the important factor of yam tuber quality and yield. .However, a description of the complete inventory of genes involved in starch metabolism and their genome organization in yam plants is still missing. Moreover, mechanisms regulating the expression of starch genes in tubers remain elusive with regard to complicated in starch metabolism. There are not sufficient transcriptomic and genomic data in public databases for understanding of the molecular mechanism underlying the tuberous formation and development. Thus, high throughput transcriptome sequencing is need to generate enormous transcript sequences from yam tuber for gene discovery and molecular marker development. In addition to its agricultural importance, the yam tuber, involved in carbohydrate storage and vegetative propagation, is also a unique organ, which has the value of biological research for organogenesis and evolution. .This program aimed at identifying and mapping the complete set of yam starch genes and studying their expression pattern in tubers by different sets of transcriptome data. On the base of our previous research about yam, the material Dahechangyu yam (Dioscorea opposita Thunb.) , a high starch yam and Bikeqi yam (Dioscorea opposita Thunb.), a low starch yam as control were selected respectively. The project intends to sequences cDNA fragment sequences of expresses by RNA-sequence technique and to construct gene expression pool then to isolate different expression genes about starch synthesis in yam tuber. Function and expression of these differential genes were primarily elucidate by bioinformatics technologies such as GO classification and KEGG Pathway analysis. Complete length sequence of genome DNA and cDNA of these genes related starch synthesis in yam tuber will be clone by RACE techniques with designed primers based on differential fragment sequenced known. These starch synthesis related genes will further testified in express pattern by real-time fluorescence quantitative PCR, subcellular localization and the structures of these gens will be analysis too. .In this project will offering valuable sequence resource to yam community, an efficient, inexpensive and reliable approach for transcriptome sequencing that could be adopt by researchers studying non-model organisms will be provided.