Maximal activities of some respiratory enzymes.

<p>Variation of the total activities of malate dehydrogenase (MDH) and pyruvate kinase (PK) in the leaves of <i>C. arabica</i> (Icatu and IPR 108) and <i>C. canephora</i> (Conilon CL 153) grown under 380 (white bar) and 700 (black bar) μL CO₂ L^-1. For each enzyme, the mean values + SE (n = 4) followed by different letters express significant differences between cultivars for the same CO₂ treatment (a, b) or between CO₂ treatments within the same cultivar (r, s). The ANOVAs for MDH and PK showed significant differences between the cultivars for the same CO₂ treatment and between CO₂ treatments within the same cultivar.