Influence of nitrogen on the primary and secondary metabolism and synthesis of flavonoids in Chrysanthemum morifolium Ramat

Abstract

The effects of nitrogen (N) supply on nitrogen metabolism in leaves of Chrysanthemum morifolium Ramat. were examined in five different stages throughout the growing season. The results suggested that flavonoids content was positively related to phenylalanine ammonia-lyase activity through the whole growing stage of the plant but with a decreasing correlation coefficient for increasing nitrogen supply. There was no correlation between flavonoids and 4-coumarate coenzyme A ligase. Soluble protein content was positively correlated with phenylalanine ammonia-lyase activity because there was little competition for the phenylalanine in the leaves under low nitrogen supply. Phenylalanine ammonia-lyase activity decreased gradually with increasing nitrogen supply because of the competition for the phenylalanine in protein synthesizes. The results suggest that nitrogen nutrition plays a key role in biosynthesis of enzymes in the leaves of C. morifolium.