Effects Of The Difference Of Sugar Accumulation During Fruit Development Of Strawberry And Light Quality On Sugar Metabolic Pathways

Sugar is an important material basis in fruit development, research has shown that the Sugar content and ratio in fruit will directly affect the fruit flavor and sweetness.At the same time, the sugar and carotenoids,acid and other nutrients and aromatic substances, such as synthetic raw material, the basis of affecting fruit edible value and product value.Strawberry (Fragaria Xananassa Duch.) as one of China's traditional outstanding berries fruit,because of its unique flavor,taste and pleasant characteristics and consumer favorite.This experiment use the 'toyonoka strawberry' plants as the main material,wait 7 day after flowering,and put it in the artificial climate box use the white light, red light, blue light, half red and blue light to treatment,comparison of the white light, as to research how the different light environment affect the strawberry fruit sugar content and sucrose metabolic pathways.At the same time, this experiment analysis and comparison the different varieties of strawberry's sucrose metabolic pathway.By determination of the content of soluble sugar in fruit under different conditions.and combined with fluorescence quantitative PCR research the control of sucrose metabolism related enzyme gene,AI,NI,andSPS,SS hexokinase gene expression patterns in the development process of strawberry fruit ripening to analyze their relationship with the sugar metabolic pathways and the results of it regulated by the light qualitative.The results show that:1. In the process of strawberry fruit growth, sugar content increase gradually with the maturity of the fruit, and sugar content in different varieties, especially in the 'akihime fruit, sucrose content and glucose content were obviously higher than the other two varieties.In the 'toyonoka strawberry fruit, the content of fructose was obviously higher than that of the other two varieties.In the three varieties of strawberry, total sugar content can be seen from more to less, respectively is:fructose> sucrose> glucose.Before the period of the ginkgo,glucose levels are low,it's about 1/9 of the highest content of period.2. Through the improved CTAB method to extract strawberry fruit total RNA.reverse transcription for cDNA. and designed FaAI, FaNI, TaSS. FaSPS hexokinase and sucrose anabolism key genes (FaHXK) family of three members of the quantitative PCR primers.By reverse transcription of cDNA template, the research of the four genes in the process of strawberry fruit development period of seven (the little green, green, gingko,1/4 red,1/2,3/4 red, full red) patterns of expression.Results show that the amount of related enzyme gene expression in strawberry fruit,acid invertase genes (FaAI) and sucrose phosphate synthase gene (FaSPS) expression as the fruit growth showed no regularity, and the relative expression of sucrose phosphate synthase gene (FaSPS) in akihime fruit and neutral invertase genes (FaNI) is significantly higher than the other two kinds of strawberry,The expression of sucrose synthase gene (FaSS) quantity in addition to outside the little green period is higher,other times are generally lower.And in addition to the sucrose phosphate synthase gene (FaSPS), the other three kinds of enzyme gene expression quantity are relatively high in the small green stage.3. After treated with different light quality,through determination of sugar content and related enzyme gene expression quantity determination,it shows that the grapes content higher than dealing with content in addition to field planting during the 21 day period,in rest of the time are lower than the experimental treatment. And after processing the fruits of glucose,sucrose and fructose content under blue light has the obvious increase,but in more cases the lowest resulst in the white light (CK) treatment.In terms of amount of gene expression, in a different light quality after processing,in addition to the 25 d FaSS,28 d FaSS, FaAl expression capacity,the remaining period of enzyme gene expression were significantly improved.lt shows the light quality really play a regulatory role of strawberry fruit sugar content,and the control methods of dates back to the gene regulation.Comprehensive the above results can be concluded:sugar content increases rapidly are inseparable from the nutrition of the fruit growth and maturity.From the results it is concluded that, in the strawberry fruits,especially 'akihime' strawberry fruit,rapid accumulation of glucose is the major contributors to the accumulation of the late fruit sugar metabolism. In the regulation of sucrose and the strawberry glucose metabolism, FaSS can play a role of main control, and in the decomposition of fructose and glucose, FaHXK2 and FaHXK3 is the key enzyme genes, and was significantly negative correlation with sugar content. In the regulation of strawberries' glucose metabolism, related enzyme gene can directly impact on the regulation and control function of the sugar content, and it also can be oppositely regulated by the sugar content. It can be inferred from the changing enzyme activity that could be done. And the effect of light environment of sugar accumulation and metabolism is quite obvious, red or blue light can promote the sucrose decomposition direction, and different amount of enzyme gene expression is obviously controled by different light quality,especially in the hexokinase. Finally, the experiments also show that the blue light inside the facilities can effectively improve the light environment of strawberry'cultivation, so as to improve the quality of strawberry fruit.