Study On The Regulation Of Sugar Metabolism And Sugar Metabolism Respond To Auxin Signaling In Developing Fruits Of Strawberry

The sugar content is one of important qualities of strawberry and sugar accumulation depends on the metabolism of sucrose in fruit.Forthermore,the metabolism of sugar is correlated to plant hormones. The strawberry(Fragaria ananassa Duch.)(All-Star) fruit was used as materials to investigate the regulation of sugar metabolism so that the effects of polar auxin transport inhibitors on the sugar accumulation and metabolism can be clearly elucidated.Study methods emphasized on exogenous inhibitors of polar auxin transport application(NPA,TIBA).Experimental results were obtained as following.1.Sucrose,fructose and glucose were determined throughout the developmental stages in the receptacles and achenes and reached the highest in maturity.The sugar content in the receptacles was much higher than that in the achenes.The total sugar content in the receptacles was 2.4 times of achenes. The sucrose,fructose and glucose in the receptacles were respectively accounted for 35.12%,40.27% and 19.54%in total sugar content in ripe fruit.And their proportions in the achenes were sharply lower, respectively accounted for 2.64%,18.68%and 10.87%.The sugar was accumulated rapidly in the later fruit developmental stage.2.During the whole developmental stages,SS and SPS which had physiological function almost existed in the cytoplasm.The activities of SS and AI in the receptacles were significantly related to sugar accumulation.And SPS activity in receptacles could control the accumulation of hexose in the later developmental stage.The SS cleavage activity in cytoplasm and AI activity of the achenes could have played critical roles on sugar metabolism.3.NPA and TIBA treatments had restrained the increase of the horizontal diameter,vertical diameter fruit weight and water content.And they also increased the carbohydrate content(sucrose, fructose,glucose and total sugar content) in the receptacles and achenes.The effect of NPA was stronger than TIBA.Sucrose and glucose in the receptacles responded to anxin signaling strong,as well as the glucose and fructose in the achenes.4.AI and SS in the receptacles responded to anxin signaling strongly.NPA and TIBA treatments had increased AI,SS and SPS activities in the green later stage to ripe stage in achenes.The activities of AI in the cell wall and SS cleavage activity in achenes responded to anxin signaling strongly.The research indicated the regulation of sugar metabolism and the effects of polar auxin transport inhibitors on the sugar accumulation and activities of sugar metabolism enzymes of strawberry fruits. These researches settle the important foundation for the further research on auxin control to sugar metabolism and growth mechanism in strawberry fruit.