The biochemistry of Rubisco in Flaveria.

C(4) plants have been reported to have Rubiscos with higher maximum carboxylation rates (kcat(CO(2))) and Michaelis-Menten constants (K(m)) for CO(2) (K(c)) than the enzyme from C(3) species, but variation in other kinetic parameters between the two photosynthetic pathways has not been extensively examined. The CO(2)/O(2) specificity (S(C/O)), kcat(CO(2)), K(c), and the K(m) for O(2) (K(o)) and RuBP (K(m-RuBP)), were measured at 25 degrees C, in Rubisco purified from 16 species of Flaveria (Asteraceae). Our analysis included two C(3) species of Flaveria, four C(4) species, and ten C(3)-C(4) or C(4)-like species, in addition to other C(4) (Zea mays and Amaranthus edulis) and C(3) (Spinacea oleracea and Chenopodium album) plants.