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摘要：本研究利用新一代高通量测序手段——转录组测序（RNA-Seq）技术，采用PE150测序策略，结合糖分在块茎、茎秆和叶片中的积累与分配情况，以期阐明盐胁迫下菊芋糖代谢变化和糖代谢相关基因的表达调控机制，进而说明盐逆境使菊芋块茎减产的内在原因。对7、8两个月菊芋的可溶性总糖进行了测量，结果显示不同浓度盐胁迫下的菊芋块茎、茎秆及叶片中可溶性糖和还原糖含量变化如下：（1）菊芋块茎总糖含量在7月高盐处理时含量最高，达到了847.05 mg/g；而还原糖含量则是7月低盐环境下最高，为59.92 mg/g；（2）菊芋茎秆中总糖和还原糖含量的最高值分别出现在8月高盐和7月低盐环境下，分别为719.04 mg/g和76.52 mg/g；（3）菊芋叶片中总糖和还原糖含量的最高值则分别出现在8月低盐和高盐环境下，分别为185.45 mg/g和84.40 mg/g。转录组测序结果表明，共测得442902313 raw read pairs，经过质控，得到423231876 clean read pairs，并根据菊芋的差异组合，共鉴定出8496个差异基因。通过对差异基因的功能富集，分析发现了盐胁迫下菊芋糖代谢相关基因的表达调控机制：（1）蔗糖合成酶参与了蔗糖的合成，后者在植物的生长发育、渗透调节和植物适应逆境的胁迫反应过程中都有举足轻重的作用，实验分析表明蔗糖合成酶的基因在菊芋低盐和菊芋高盐中均受胁迫诱导下调表达；（2）菊芋块茎在低盐环境下编码己糖转运蛋白 (hexose transporter) 的基因表现为下调，糖转运蛋白可以通过调节糖的转运来控制植物体内糖分的分配，当植物受到逆境胁迫时，糖转运蛋白的活动受到抑制而减少，进而影响到植物的生理活动。36752
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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.