Effects of Sucrose, Glutamine and Plant Hormones in the Culture Medium on Starch Accumulation of Detached Rice Panicles
Pan Xiaohua Li Muying Xiong Wei Cao Liming(College of Agronomy, JAU, Nanchang 330045)
The influences of sucrose, glutamine and plant hormones in the culture medium on the volume of solution and sucrose absorption, starch accumulation in the grain and the starch-synthesis enzyme activities in the endosperm were investigated, with detached panicles of rice hybrid shanyou 10 and KA/2469 cultured 4～6d. Increasing the sucrose supply in the culture liquid from 5g/L to 15g/L resulted in significant increase in the volume of solution and sucrose absorption , starch accumulation in the developing grain. The activities of sucrose synthase, ADP-glucose pyrophosphorylase, starch synthase and branching enzyme were also increased significantly in the developing endosperm. Decreasing the concentration of glutamine in the culture medium reduced starch accumulation and activities of starch-synthesis enzymes. Abscisic acid treatment increased the activities of enzymes that involved in starch synthesis in the developing rice endosperm, but the other hormone treatments showed a negative effects on the volume of solution and sucrose absorption by the grain, and on the activities of starch synthesis enzymes. It is suggested that the starch accumulation in developing endosperm were influenced mainly by the sucrose supply.