Soluble Acid Invertase and Sucrose Phosphate Synthase are Key Enzymes regulating Sucrose Accumulation in Sweet Sorghum Stem
To assess the relative importance of biochemical factors in the sugar accumulation in the sweet sorghum (Sorghum bicolor L. Moench) stem, we investigated biochemical correlates of sugar accumulation among the ten cultivars. Sugars and four enzymes of sucrose metabolism were extracted from individual internodes of primary stem of ten sweet sorghum cultivars. The fructose, glucose and sucrose concentration are different among the ten cultivars, ranging from 1. 77 mg/g fresh weight for Smith to 12. 43 mg/g for Theis in fructose, from 1.44 mg/g fresh weight for smith -1 to 14.63 mg/g fresh weight for Theis in Glucose, and from 35. 9 mg g -1 fresh weight for MN -2747 to 95.9 mg g -1 fresh weight for Cowley in sucrose. Sweet sorghum stems of different cultivars reveal a different pattern of sugar accumulation with the internode number increasing. There was a significant correlation between glucose and fructose concentration (R2=0. 9575, P <0. 001) in individual internodes (Fig. 3). But the correlation between sucrose and hexose (glucose+fructose) concentration (R2=0. 3825) is not significant. The level and timing of sucrose and hexose accumulation in the whole stalk were correlated with the downregulation and upregulation of soluble acid invertase (SAI) activity respectively. High SA1 activity prevented sucrose accumulation but promoted hexose accumulation. This result also shows that the hexose mainly come from degradation of sucrose in stem by the SAI. Major differences in Sucrose accumulation among the ten cultivars were attributed to the difference activities of SAI.
Liu Yang Dun Baoqing Zhao Xiangna Yue Meiqi Zhang Baoming Lu Ming Li Guiying
National Key Facility for Crop Gene Resources and Genetic Improvement/ Research Center for Biomass Energy /Institute of Crop Science,Chinese Academy of Agricultural Sciences,Beijing 100081
国际会议
陕西杨凌
英文
142-148
2010-10-09（万方平台首次上网日期，不代表论文的发表时间）