Study On Changes Of Reducing Sugar,G6p And G6P1E In Different Flower Colors In Dianthus Chinensis

Anthocyanin is the most important pigment substance in flower colors.Sugar not only provides metabolic substrate for the anthocyanin synthesis,but also regulates its synthesis as signal molecules.Glucose phosphorylation produces glucose-6-phosphate（G6P）,which is involved in the pentose phosphate,glycolysis and other pathways.Glucose-6-phosphate-1-epimerase（G6P1E）is located at the branch point of the glucose metabolism pathway,and its gene is related to flower colors.In this study,five kinds of Dianthus chinensis with different flower colors were used as plant materials.By measuring the anthocyanin contents,reducing sugar contents,and G6P contents,as well as the G6P1E activities in different developmental stages of flower buds,different flowering times of petals,different parts and different organs,we hope to clarify the role of sugar on the pigmentation of Dianthus chinensis,and provide a theoretical basis for breeding and cultivation in the future.The main results were as follows:1.With the development of flower buds,the colored areas on the petals gradually increased.With the flowering,the color of white flowers turned yellow.The wild,the bicolor of big white with small red and the bicolor of small white with big red became lighter.The bicolor of double red gradually deepened.2.Except the white,anthocyanin contents increased significantly with the development of flower buds.At the same time,anthocyanin contents in the flowers with pigmentations were significantly higher than that in the white.With the flowering,anthocyanin contents changed irregularly.The anthocyanin contents in the colored flowers were significantly higher than that in the white at the same flowering time.On the first day of flowering,the larger the colored areas were,the greater the anthocyanin contents were.The inner parts of the petals were larger than the outer sides in the same bicolor flowers.The anthocyanin contents in petals were significantly higher than those in the other organs,in which there were no difference and the contents had no correlation with the flower color.3.With the development of flower buds,the contents of reducing sugar increased.The contents of reducing sugar changed irregularly with the opening of flowers.At the 1^stand 2^nd day of flowering,the reducing sugar contents in the colored petals were significantly higher than that in the white.There was no difference between different parts of petals in the same bicolor flower,but the same part in different bicolor flowers had a positive correlation with the colors.The reducing sugar contents in petals were significantly higher than those in the other organs.There were no difference among the other organs,in which the contents of reducing sugare were not correlated with the flower colors.4.With the development of flower buds,the contents of G6P decreased,but had no correlation with the flower color.The contents of G6P decreased with the opening of flowers.At the same flowering time,the contents of G6P in the colored petals were related to the flower colors.There was no difference between different parts of the same bicolor petal.The highest were in the petals,and then the second in roots.The G6P contents in the roots,stems and leaves were not correlated with the flower color.5.The G6P1E activities increased with the development of flower buds.At the same stage,the activities in the colored flowers were higher than that in the white.The G6P1E activities changed irregularly at different flowering time.At the same flowering time,the color of petals were related to the G6P1E activity.There was no difference between different parts of the petals in the same bicolor flower.The largest were in the roots and petals.The G6P1E activities in the roots,stems and leaves were not correlated with the flower color.6.The anthocyanin was positively correlated with the reducing sugar and G6P1E,respectively.The reducing sugar was negatively correlated with the G6P and positively correlated with the G6P1E.There was a negative correlation between the G6P and the G6P1E.The above results showed that reducing sugar and its related enzymes are involved in the coloration of flowers in Dianthus chinensis.