TITLE:
Optimum Dark Adaptation Period for Evaluating the Maximum Quantum Efficiency of Photosystem II in Ozone-Exposed Rice Leaves
AUTHORS:
Hiroki Hiroki Kobayakawa, Katsu Imai
KEYWORDS:
Dark-Adapted State; Oryza sativa; Ozone Stress; Photosystem II; Quantum Efficiency
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.4 No.9,
August
29,
2013
ABSTRACT: Because the
transient O3 injury of leaves is lost with time, the evaluation of O3 effect on the maximum quantum efficiency of PSII (Fv/Fm)
is difficult. Thus, the authors examined Fv/Fm in rice leaves exposed to
different O3 concentrations (0, 0.1, and 0.3 cm3·m-3,
expressed as O0, O0.1, and O0.3) under
different dark adaptation periods (0, 1, 5, 10, 20, and 30 min, expressed as D0,
D1, D5, D10, D20, and D30)
to ascertain its optimum time span. Fv/Fm was inhibited by O3;
however in the O0 and O0.1 plants, it recovered during
dark adaptation. In the O0.3 plants, Fv/Fm decreased gradually with time. F0 was found to be increased by O3, and it increased further in the O0.3 plants during dark adaptation. Under a high light intensity, Fm was decreased by O3,
and the O3-induced damage to Fv/Fm was therefore more
pronounced. However, the sensitivity of F