Effect of directed selection of amylose content on activities of key amylosynthetase

The japonica parent plants and their hybrid progenies with significantly different amylose content were investigated to reveal the grain amylose accumulation and the activities of key amylosynthetase during the course of their grain filling.The results showed that prior selection of grain amylose content could not only lead to the increase or decrease of grain amylose content in the hybrid progenies,but also obviously change the activity of key enzymes for starch synthesis in grain.The activities of ADP glucose pyrophosphorylase(AGPP) and soluble starch synthase(SSS) arrived the peak in the hybrid progenies with lower amylose content more quickly than those with higher amylose content;however,the activities of starch branching enzyme(SBE) arrived the peak in the hybrid progenies with lower amylose content more slowly than those with higher amylose content instead.