UMP焦磷酸化酶
1.cDNA CLONING AND STRUCTURAL ANALYSIS OF RICE ADP GLUCOSE PYROPHOSPHORYLASE GENE
2.(4) The changes of ADPG-PPase(AGP), soluble starch synthase(SSS), granule-bound starch synthase (GBSS) and starch branching enzyme (SBE) activities in the caryopses is a single peak curve.
3.The results indicated that the changes in activities of AGPP,UGPP,SSS,GBSS and SBE of different cultivars all showed a single-peak curve.
4.There are four keyenzymes in the starch synthesis process: ADP-glucose pyrophosphorylase(AGP), starch synthase (SS), starch branching enzyme (SBE) anddebranching enzyme (DBE).
5.The change patterns of sucrose synthase, ADPglucose pyrophosphorylase, soluble starch synthase and starch branching enzyme (Q enzyme) correlated well with the curve of grain filling rate. There was no significant correlation between the activity of UDPglocuse pyrophosphorylase and grain filling rate.
6.Cloning of the Small Subunit cDNA of ADP Glucose Pyrophosphorylase from Potato and Its Expression in Yeast Pichia-methabolica
7.The results strongly suggest that ADPglucose pyrophosphorylase, soluble starch synthase, sucrose synthase and Q enzyme play a key role in starch synthesis of rice endosperm. And the insoluble starch synthase is mainly response for the synthesis of amylose in endosperm.
8.②Excessive N application reduced both sucrose phosphate synthase (SPS) activity in leaves and the activities of sucrose synthase (SS) and ADP glucose pyrophosphorylase (ADPG PPase) in grains, inhibited the formation of sucrose in leaves and that of starch in grains, which results in decrease in economical yield.
9.Further analysis elucidated that when tubers stored at 4℃, the activities of ADP glucose pyrophosphorylase (AGPase), UDP glucose pyrophosphorylase (UGPase) and sucrose synthase (SuSy) were negatively exponential to the RS content significantly while that of acid invertase and alkaline invertase were significantly linear to RS content. It suggested that these enzymes could play main roles in the cold sweetening of potato tubers through regulating starch-sugar metabolism.
10.Further analysis elucidated that when tubers stored at 4℃, the activities of ADP glucose pyrophosphorylase (AGPase), UDP glucose pyrophosphorylase (UGPase) and sucrose synthase (SuSy) were negatively exponential to the RS content significantly while that of acid invertase and alkaline invertase was significantly linear to RS content. It is suggested that these enzymes can play main roles in the low temperature sweetening of potato tubers through regulating starch-sugar metabolism.
