Effects Of MeJA And 6-BA On The Synthesis And Accumulation Of Sugar And Acid In Apple

Apple quality affects its commodity value and market competitiveness,while sugar and acid are important components of its intrinsic quality.The synthesis and accumulation of sugar and acid in apple are not only regulated by their own genetic factors,but also by external factors such as external environmental factors and exogenous plant growth regulators.To study the effects of exogenous methyl jasmonate(Me JA)and 6-benzylaminopurine(6-BA)on the synthesis and accumulation of sugar and acid in apple,in this paper,the fruit of 'Changfu 2' apple was used as a test material and soaked in different concentrations of Me JA and 6-BA,then measuring and analysing the changes of color parameters of 'Changfu 2' apple peel,the changes of the types and contents of soluble sugars and organic acids,and the changes in activity of enzymes involved in sugar and acid metabolism(sucrose phosphate synthase(SPS),sucrose synthase(SS),acid invertase(AI),malate dehydrogenase(NAD–MDH),phosphoenolpyruvate carboxylase(PEPC)and malic enzyme(cy ME)).The purpose of our research was to preliminarily elucidated the mechanism of Me JA and 6-BA on the synthesis and accumulation of sugar and acid in apple,so as to provide theoretical basis for the further study of the molecular mechanism of exogenous Me JA and 6-BA affecting the sugar and acid metabolism of apple,and to provide practical basis for improving the quality of apple fruits in production by using exogenous plant growth regulators.The main conclusion are as follows:1.In this study,compared with the control,Me JA increased the L*,b* and ho values,while reduced a* and c* values.However,the 6-BA treatment was reversed.2.In this study,compared with the control,Me JA and 6-BA increased the content of total sugar,sucrose,glucose and fructose,while the content of sorbitol,total acid,malic acid,tartaric acid,oxalic acid and citric acid decreased.But the effect of Me JA was better than that of 6-BA,and the effect of 10 mmol/L Me JA was the best.Experimental data showed that total sugar,sucrose,glucose and fructose content of the apple fruit continued to rise during each treatment.After 170 days of flowering,compared with the control,10 mmol/L Me JA made total sugar,sucrose,glucose and fructose increased by 19.07%,26.90%,26.30% and 11.53%,respectively.The contents of sorbitol,total acid,malic acid,tartaric acid,oxalic acid and citric acid continued to decrease.After 170 days of flowering,compared with the control,10 mmol/L Me JA made sorbitol,total acid,malic acid,tartaric acid,oxalic acid and citric acid content reduced by 39.13%,39.58%,53.96%,3.62%,85.75% and 33.66%,respectively.3.In this study,compared with the control,both Me JA and 6-BA increased the activity of SPS,SS and cy ME,while the activities of AI,NAD-MDH and PEPC decreased.But the effect of Me JA was better than that of 6-BA,and the effect of 10 mmol/L was the best.Experimental data showed that the activity of SPS,SS and cy ME of apple fruit increased continuously under each treatment.After 170 days of flowering,compared with the control,10 mmol/L Me JA made the activity of SPS,SS and cy ME increased by 28.82%,42.51% and 14.03%,respectively.The activity of cy MDH and PEPC continued to decrease,and the activity of AI fluctuated.After 170 days of flowering,10 mmol/L Me JA reduced the activity of AI,NAD–MDH and PEPC by 16.91%,19.61% and 17.62%,respectively.