Zeaxanthin and the Induction and Relaxation Kinetics of the Dissipation of Excess Excitation Energy in Leaves in 2% O(2), 0% CO(2).

The relationship between the carotenoid zeaxanthin, formed by violaxanthin de-epoxidation, and nonphotochemical fluorescence quenching (q(NP)) in the light was investigated in leaves of Glycine max during a transient from dark to light in 2% O(2), 0% CO(2) at 100 to 200 micromoles of photons per square meter per second. (a) Up to a q(NP) (which can vary between 0 and 1) of about 0.7, the zeaxanthin content of leaves was linearly correlated with q(NP) as well as with the rate constant for radiationless energy dissipation in the antenna chlorophyll (k(D)).