The effect of calcium deficiency on the activity of ammonia-lyases in the shikimic pathway

Calcium deficiency resulted in a 20% increase in the total content of phenolic compounds in the shoots of 10-day-old wheat plants and in a 10% decrease in the roots compared with the control. Differences in specific activities of the lyases of the shikimate pathway (L-phenylalanine ammonia-lyase, E.C.4.3.1.5, PAL; L-tyrosine ammonia-lyase, TAL) were established between control and Ca-deficient wheat and pumpkin plants. The lyase activities were higher in the shoots of Ca-deficient plants and lower in their roots, compared with the control. Thus, there is a certain correlation between PAL and TAL activities on the one hand and the content of phenolic compounds on the other. The time course of PAL activity during a few first days of growth and the dependence of TAL activity on pH were also investigated.