[Evolutionary changes in amino acid composition of dicotyledonous seeds]

Amino acid composition of dicotyledonous seeds of 82 genera, 67 families, 48 orders, and 8 subclasses (after Takhtadzhyan, 1987). Within the frames of hypothesis of amino acid composition of the least specialized hypothetical taxon we have established a universal trend for all dicotyledonous classes--increased proportion of glutamic acid and arginine. Divergent processes are pronounced in the evolution of amino acid composition within the families and orders. Pairwise comparison of amino acid composition in all analyzed taxons demonstrated high similarity between taxons from different subclasses and at different levels of biochemical specialization. Within the frames of the system proposed by Takhtadzhyan (1987) we interpret this as a clearly pronounced parallel variability of the seed amino acid composition realized during evolution of taxons in various dicotyledonous orders and subclasses.