TY  - JOUR
A1  - Feierabend, Jürgen
T1  - Comparison of the action of bleaching herbicides
T2  - Zeitschrift für Naturforschung, C
N2  - Among chlorosis-inducing herbicides that interfere with carotenoid synthesis two groups of different potency can be discriminated (group 1: aminotriazole amd haloxidine; group 2 with more extensive photodestructions: pyridazinone herbicides and difunon). After application of herbicides of group 2 colored carotenoids were completely absent and preexisting chlorophyll was degraded by photochemical reactions requiring high light intensity and O2, that occurred also at 0°C. In treatments with group 1 herbicides direct photodegradation of chlorophyll was not sufficient to generate the chlorosis. Light-induced interference with constituents of the chloroplast protein synthesis apparatus being more sensitive to photooxidative damage than chlorophyll, appeared to indirectly mediate the chlorosis. In the absence of chloroplast protein synthesis further chlorophyll accumulation is prevented. Photodegradation of chlorophyll in the presence of group 2 herbicides involved the participation of O2- radicals and was accompanied by lipid peroxidation. In all herbicide treatments the catalase activity of the leaves was very low. Only in the presence of group 2 herbicides chloroplast enzymes of cytoplasmic origin (e.g. NADP-glyceraldehyde-3-phosphate dehydrogenase) were also inactivated. Rapid inactivation of catalase as well as of NADP-glyceraldehyde-3-phosphate dehydrogenase was induced by exposure of dim-light-grown herbicide-treated leaves to bright light, also at 0°C. In treatments with herbicides of group 2 also other peroxisomal enzymes (e.g. glycolate oxidate, hydroxy-pyruvate reductase) were affected. The elimination of these peroxisomal enzymes also appeared to depend on photooxidative processes of the chloroplast.
KW  - Bleaching Herbicides
KW  - Carotenoids
KW  - Catalase
KW  - Chlorosis
KW  - Leaf Peroxisomes
KW  - Photooxidation
Y1  - 2014
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/72327
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-723274
SN  - 0939-5075
SN  - 1865-7125
VL  - 39.1984
IS  - 5
SP  - 450
EP  - 454
PB  - Verlag der Zeitschrift für Naturforschung
CY  - Tübingen
ER  -