Metabolic Pathway Of The Difference Vc Content In Different Genotypes Of Wucai

Wucai(Brassica campestris L.ssp.chinensis var.rosularis Tsen)is a biennial herb of the cruciferae family.In the growth process of brassica plants,the plants will go through four important stages: seedling stage,rosette stage,adult stage and bolting stage,and the contents of various parameters of wucai will change in different periods.The change process of indicatorsduring the growth process of different genotypes of wucai were studied.According to the level of Vc content,8different varieties of wucai from the two colors(Green varieties W15-7-9,W15-8-6,W16-3,W16-1,purple varieties ZW19-1,ZW19-2,ZW19-3,ZW19-4)were choosed.The indicator contents of leaves and petioles in each period were determined.The results showed that the content of free amino acids reached the maximum at the rosette stage,the contents of soluble sugar and soluble protein reached the maximum at the adult stage,and the total antioxidant capacity reached the maximum at the bolting stage with the growth of wucai.The content of most nutrients in leaves is higher than that in petioles.Except for the later stage of growth(adult stage and bolting stage),the contents of soluble sugars and free amino acids in the petiole of individual varietieswould be higher than that in leaves.In addition,the key enzymes activitiesin the plant ascorbic acid cycle showed that the ascorbic acid content of Zi Wu were generally higher than that of green Wucai.The level of ascorbic acid in Ziwu is affected by enzymes,the most prominent of which is dehydroascorbate reductase(DHAR),and the most prominent of the enzymes that affect the level of ascorbic acid in Luwu is ascorbic acid peroxidase(APX).The activities of ascorbate peroxidase(APX),ascorbate oxidase(AAO)and dehydroascorbate reductase(DHAR)were higher in high-Vc varieties than in low-Vc varieties,while the activity of mono-dehydroascorbate reductase(MDHAR)were higher in low-Vc varieties than in high-Vc varieties.The activities of ascorbate peroxidase(APX),dehydroascorbate reductase(DHAR)and mono-dehydroascorbate reductase(MDHAR)continued to increase with the growth of plants,while the activity of ascorbate oxidase(AAO)decreased continuously with the growth of plants.These results indicated that the high Vc varieties showed strong antioxidant capacity and cell homeostasis.