木薯己糖激酶MeHXK5的催化功能鉴定

该研究利用ISSR分子标记，对分布于福建省内5个样地( 邵武、建阳、建瓯、周宁和屏南)的61个野钩锥(Castanopsis tibetana)单株的遗传多样性进行了分析，并采用聚类分析方法探讨了它们的遗传关系。结果表明： 用10条ISSR引物从61个单株的基因组DNA共扩增出158条带，包含145条多态性条带，多态性条带百分率达91.77%，其中引物 UBC817、UBC819与UBC842的多态性条带百分率（PPB）为100.0%。各居群的多态性条带百分率(PPB)、有效等位基因数(Ne)、Nei’s基因多样度(H)和Shannon’s多样性指数（I）等各遗传指数差异较大，其中各项遗传指标中最高的为邵武居群，而周宁居群则最低。5个居群的基因分化系数和基因流分别为0.144 0和2.973 0，说明5个居群总遗传变异的14.40%存在于居群间，85.60%存在于居群内。种间总基因多样度分别为0.395 8，种内基因多样度分别为0.338 8，表明钩锥种间遗传多样性较高，且种间变异大于种内变异。各居群间的遗传距离差异较大； 其中，邵武与建瓯居群的遗传距离最近，仅为0.081 5； 建阳和周宁居群的遗传距离最远，为0.162 9。通过聚类分析可将5个钩锥居群聚为3支，屏南与周宁的居群各自独立聚为2支；来自邵武、建瓯及建阳的居群聚为一支，且可进一步分为两个亚支，建阳居群为1个亚支，邵武和建瓯居群聚为1个亚支。供试的钩锥具有较高的遗传多样性，存在着较为频繁的基因交流。该研究结果较准确地揭示了钩锥种间的遗传多样性。

Catalytic functional identification of cassava hexokinase MeHXK5

Hexokinase is a key enzyme in the process of catalyzing the phosphorylation of hexose in plants. It is involved in the process of plant growth and development. We cloned hexokinase gene MeHXK5, which is mainly expressed in cassava flowers. In this study, we used the yeast mutant strain YSH7.4-3C to perform yeast functional complementation experiment to determine whether MeHXK5 had the function of catalyzing the phosphorylation of hexose. It was found that YSH7.4-3C yeast with pDR195-MeHXK5 vector could be grown in the medium with glucose or fructose as the sole carbon source, indicating that MeHXK5 could catalyze the phosphorylation of hexose to provide carbohydrate and energy for yeast growth. The results provide information for further study of the physiological functions of MeHXK5 in the flowering process of cassava.