Phenylalanine ammonia-lyase activity and anthocyanin content in different varieties of lettuce under the cadmium influence

Cadmium ions influence on the content of anthocyanins as non-plastid pigments and the activity of phenylalanine ammonia-lyase (EC 4.3.1.24) as primary enzyme of their biosynthesis in two lettuce varieties (Lactuca sativa L.) with different anthocyanin content was investigated. The increases in anthocyanin content and enzymatic activity of phenylalanine ammonia-lyase of both lettuce plant varieties during the 14-day exposure in solution of cadmium nitrate (0.1 mmol) were established. The difference in levels of adaptive capacity in two lettuce varieties with different content of anthocyanins under the effect of cadmium ions was revealed. The indexes of tolerance have shown faster adaptive response and higher resistance in red variety plants, compared with plants of the green lettuce variety. These data are consistent with the corresponding changes in anthocyanins content and indicate their active participation in neutralizing the negative impact of cadmium stress.