The team of Professor Fang Yulin of the School of Wine of Northwestern University of Agriculture, Forage and Technology has made new progress in the field of improving grape phenols

Original title: Professor Yulin Fang, School of Wine, Northwestern University of Agriculture, Forgrust science and Technology, has made new progress in improving grape phenols
December 15, 2020
a
professor at the School of Fine Arts and Wines published a cover article entitled "Foliar Phenylalanine Application Publiced Antioxidant Activities in Cabernet Sauvignon by Regulatoring Phenolic Biosynthesis" in Journal of Agricultural and Food Chemistry.
Xianghan
2017 Ph.D. student at The Grape and Wine Institute, is the first author, and Professor Fang Yulin and young teacher Sun Xiangyu are co-authors.
the study found that in low-nitrogen vineyards, the application of phenylalanine fertilizer to grape leaves during the transition period increased the antioxidant activity of the fruit by promoting the biosynthetic synthesis of the Carcass beads.oxidative stress is associated with the formation of certain diseases in humans. Phenols in grapes and wines are increasingly popular with consumers because of their antioxidant properties, which can counteract the negative effects of these oxidative stresses. As a result, wine grape growers have been looking for ways to further improve the quality of their wines by increasing the cultivation of phenolic substances in their fruits. The transcoloration period is the demarcation period between nutritional growth and reproductive development, during which a small amount of nitrogen fertilizer is supplemented to the grape leaves, which not only does not affect the nutritional growth of the plant, but also improves the phenolic substances of the grape fruits in the low nitrogen vineyards.this trial studied the effects of foliar phenylalanine application when veraison (FPV) on the biosynthetic composition of grape phenols and the relationship between phenolic components and antioxidant activity. During the transcoloration, phenylalanine (Pe1 and Pe2) and nitrogen-free blank aqueous solutions (CK) of 69 and 138 mg N/strains were sprayed on the grape leaves three times. And in the field and greenhouse sanding at the same time carried out the experiment has found that FPV can significantly improve the antioxidant activity of grapes. Compared with CK, the phenolic components that have the greatest impact on antioxidant activity after FPV treatment are anthromosine and phenolic substances. From the first FPV application to harvest, the metabolic levels of phenolic synthesis pathways of the prebium phenolic substance phenylalanine, shedding acid content and VvPAL, VvCHS, VvF3H, VvUFGT and VvSTS expression levels were improved. Although Pe2 significantly increased the total phenol content of grapes compared to Pe1, the dose of phenylalanine did not significantly affect its antioxidant activity on the fruit. In summary, our research shows that FPV is an effective nitrogen supplement that can increase the level of grape phenols in nitrogen-deficing vineyards and thus increase their antioxidant activity.
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