Modulation of progressive leaf senescence by the red: far-red ratio of incident light

GUIAMET JJ; WILLEMOES JG; MONTALDI ER

BOTANICAL GAZETTE

UNIV CHICAGO PRESS

Lugar: Chicago; Año: 1989 vol. 150 p. 148 - 151

0006-8071

Unifoliate soybean leaves were irradiated with different red:far-red ratios (R:FR) while the shoot above the leaves was kept under a constant R:FR The R:FR was changed by lowering the red photon fluence rate. An R:FR of 0.07 accelerated chlorophyAl and protein loss and enhanced the rate of exudation of amino acids from the detached irradiated leaves. Different photon fluence rates of far-red were added to a back- ground of cool white fluorescent light, to lower R:FR without significantly changing photosynthetically active radiation. R:FR of 0.09-0.18 accelerated chlorophyll loss. These results are consistent with the view that the R: FR may modulate progressive senescence and that low R: FR occurring in shadelight may promote senescence.