Expression Of Sucrose Phosphate Synthase Gene And Its Influence To Sugar Accumulation In Sweet Sorghum

Sweet sorghum is one of the most potential energy crops. It is the ideal crop that accords with the condition of the soil and climate of our country. The concentration of sweet sorghum is the major norm to measure the value in use of sweet sorghum stem. So it has important significance to improve the sugar content of sweet sorghums. To better understand the correlation between sucrose content and sucrose phosphate synthetase (SPS) expression and the factors of the sugar content different between sweet and grain sorghum, the mechanism of sugar content accumulation was analyzed by monitoring the expression of SPS in leaves. The expression of SPS gene was investigated by using real-time PCR in sweet sorghum LTR102 sorghum 654 and F5 high sugar colony and low sugar colony. The results were reported as the follow:1 Parents and F5 were used to study the changing law of sugar and sucrose, glucose and fructose.The result indicated that there are positive correlation between sugar and sucrose (R=0.741, P=0.001),negative correlation between sugar and glucose (R=-0.384, P=1.142) and there are not correlation between sugar and fructose.2 In mature stage, the highest sucrose contents is high sugar group, and the lowest sucrose contents is male. It was the half of sucrose content in the leaves of high group. The change of sucrose content would affect the total sugar content. The sucrose content was the one of factors that leading to difference of sugar in sweet sorghum and grain sorghum.3 The trends in expression of SPS gene was consistent with the sucrose content and the activity of SPS in the leaves of parents, F5 high sugar group and low sugar group by the qualitative and quantitative analysis of SPS gene. SPS gene affects the accumulation of sucrose content. The different sugar content between sweet sorghum and grain sorghum and the accumulation of sucrose content were regulated by SPS gene.4 The high sugar group was the best in the accumulation of sucrose the activity of SPS and the expression of SPS gene by researching the change of SPS gene and accumulation of sucrose. Therefore breeding should be focused on high sugar group.