盐胁迫下菊芋糖代谢变化机制研究
毕业论文关键词：菊芋；盐胁迫；高通量测序；转录因子；转录组分析
The research on the mechanism of Sugar metabolic changes of Helianthus tuberosus under salt stress
Abstract：This study uses a new generation of high-throughput sequencing method-the transcriptome sequencing (RNA-Seq) technology, adopting PE150 sequencing strategy, combining with the phenomenon about accumulation and distribution of soluble sugar and reducing sugar in the tube, stem and leaf, to clarify mechanism of expression and regulation of genes related to sugar metabolism under salt stress, then explain the internal causes of the Helianthus tuberosus’s lower production. The soluble sugar and reducing sugar was measured in July and August months, the results showed that the content of two sugars in tuber, stem and leaf are changed in different salt concentration change: (1) The total sugar content of the tuber is highest in high salt treatment in July, it's 847.05 mg/g. And the reducing sugar content is the highest in low-salt environment in July numbered 59.92 mg/g; (2) The peaks of total sugar and reducing sugar in the stalk are present in high salt in August and low salt in July, is 719.04 mg/g and 76.52 mg/g; (3) The highest levels of total sugar and reducing sugar in leaf was found in low salt and high salt in August, were 185.45 mg/g and 84.40 mg/g respectively. The transcriptome sequencing results show that there is 442902313 raw read pairs, and remained 423231876 clean read pairs after quality control, identified 8496 different genes finally. Analysis these different genes, the mechanism of expression and regulation of genes related to sugar metabolism under salt stress were found: (1) Sucrose played an important role in the growth and development of plants, osmotic regulation, cell metabolism and the stress response of plants to adapt to adversity. This sequence of processes was done by the sucrose synthesis (SuSy) . The genes that encode sucrose synthase (SuSy) , which were induced both under the high and low salt stress; (2) The distribution of sugar in plants could be controled through regulating the transport of sugar by hexose transporter. The activity of sugar transporters was reduced when plants were under stress , and then affected the physical activity of plants. The gene that encoded hexose transporter in low-salt environments had been shown to be down.