【作者】 朱政；

【导师】 江昌俊；

【作者基本信息】 安徽农业大学 ， 遗传学， 2011， 硕士

【摘要】 本研究分别在人工低温条件下和自然低温条件下，对舒茶早和乌牛早两个茶树品种叶片相对电导率、丙二醛含量、可溶性糖含量和脯氨酸含量4项生理指标进行了测定，通过比较分析各项指标随温度的变化规律，发现无论在人工低温条件下，还是在自然越冬过程中，可溶性糖含量的变化与温度变化存在高度负相关性，即随着温度的降低，可溶性糖含量呈现显著而单一的增加趋势，具有较好的变化规律。因此，茶树叶片可溶性糖含量相对其他3项生理指标来说，能更好的反应低温胁迫下茶树抗寒性生理的变化。为了进一步了解低温条件下，可溶性糖含量积累的规律性，本研究利用HPLC技术，对越冬期舒茶早和乌牛早两个茶树品种叶片可溶性糖成分进行了具体的分析，并比较了各种糖成分动态变化的规律，发现蔗糖在茶树叶片可溶性糖成分中占据主导地位，其含量变化与月平均气温存在高度负相关，随着外界气温的降低，蔗糖含量呈现显著的增加趋势，并且舒茶早和乌牛早增加的幅度具有较大差异，生产实践中抗寒性较强的舒茶早，蔗糖含量从23.13mg/g（干重）上升到137.03mg/g（干重），增加了近5倍，生产中抗寒性较弱的茶树品种乌牛早蔗糖含量从42.46mg/g（干重）上升到112.14mg/g（干重），增加了约2倍。另外，在低温的月份（12月、1月和2月），舒茶早蔗糖含量水平均显著高于乌牛早。在此结论的基础上，本研究旨在为建立一种通过测定和比较低温条件下不同品种茶树叶片中蔗糖含量来鉴定茶树抗寒性的方法提供理论依据，该方法可能比传统的测定可溶性总糖的方法更加科学、可靠。在证实茶树叶片蔗糖含量积累与其抗寒性有着密切关系之后，对调控蔗糖合成的关键酶—蔗糖磷酸合成酶（SPS）及其编码基因的研究将有助于进一步从分子水平上研究糖积累及糖代谢过程与茶树抗寒性的关系。本研究对茶树叶片SPS基因进行了全长克隆，得到其全长序列为3635bp，含有3108bp的开放阅读框，编码1036个氨基酸，其氨基酸序列与烟草、咖啡、碧桃、甜瓜、马铃薯、番茄的同源性均在80%以上，命名为CsSPS。这将为后续研究低温条件下CsSPS的表达与调控提供必要的参考。更多还原

【Abstract】 In this study，we detected4physiological indexes that included the Relative Electric Conductivity(REC), MDA content, soluble sugar content and proline content in leaves of Shuchazao and Wuniuzao under artificial low temperature conditions and natural low temperature conditions. The result showed that there was a high negative correlation between the change of soluble sugar content and the change of temperature either in artificial low temperature conditions or in natural low temperature conditions by comparing and analysing the regularity of changes of the four indexes with the temperature. As the temperature fell, the soluble sugar content showed a significant and single increasing trend, which had a good regularity of change. So compared with other indexes, the soluble sugar content in leaves of Camellia sinensis can better reflect the physiological change of Camellia sinensis under cold stress.To further understand the regularity of the accumulation of the soluble sugar content under low temperature, this study utilized HPLC technology to detected the compositions of the soluble sugar in leaves of Shuchazao and Wuniuzao under natural low temperature conditions. By comparing the dynamic change of various sugars, we found sucrose accounted for dominant position in the compositions of the soluble sugar in leaves of Camellia sinensis, and there was a high negative correlation between sucrose content and monthly average temperature. As the temperature fell, the sucrose content showed a significant increasing trend, and there were a large differences in the rate of increase between Shuchazao and Wuniuzao. The sucrose content of Shuchazao that had stronger cold resistance in production practice increased from23.13mg/g (dry weight) to137.03mg/g (dry weight), increased by5times. The sucrose content of Wuniuzao that had weaker cold resistance in production practice increased from42.46mg/g (dry weight) to112.14mg/g (dry weight), increased by2times. In addition, on low-temperature months (December, January and February), the sucrose content of Shuchazao was significantly higher than that of Wuniuzao. Based on this conclusion, this study aimed to provided a theoretical basis for establishing a method that can identify the cold resistance of Camellia sinensis by detecting the sucrose content in leaves of different various of Camellia sinensis. After confirming the close relationship between the accumulation of sucrose content and the cold resistance of Camellia sinensis, the study on Sucrose Phosphate Synthase (SPS) that is the key enzyme of regulating the synthesis of sucrose and the SPS gene will help to understand the relationship between sugar metabolism and cold resistance of Camellia sinensis. In this study, we cloned full-length cDNA of SPS of Camellia sinensis. The sequence analysis showed that the SPS gene called CsSPS contained3635bp and coded1036amino acid residues. Compared with Solanum tuberosum, Coffea canephora, Cucumis melo, Nicotiana tabacum, Prunus persica and Solanum lycopersicum, the homology of its amino acid sequence reached above80%. This work will supply some necessary information for further study on the expression of CsSPS under cold stress.更多还原