Effects of metobromuron and chlorbromuron on photochemical reactions of isolated french bean phaseolus vulgaris cultivar king horn wax and pea pisum sativum cultivar gloire de quimper chloroplasts
E.A.ifi S.; Lang, F.
Photosynthetica 18(3): 317-321
ISSN/ISBN: 0300-3604 Accession: 005314274
The effectiveness of 2 phenylurea herbicides, metobromuron (MBU) and chlorbromuron (CBU), on the photochemical reactions of isolated chloroplasts of French bean (P. vulgaris L.) and pea (P. sativum L.) was tested. The inhibitory potency of the 2 herbicides was determined by using chlorophyll fluorescence induction and electron transport assays. The primary site of action for MBU and CBU is probably on the reducing site of photosystem (PS) 2, between the primary electron acceptor (Q) and the plastoquinone pool. The inhibitory effects increased with increasing herbicide concentration. Estimation of I50 value indicated that CBU was a more potent inhibitor than MBU in both French bean and pea chloroplasts. Isolated pea chloroplasts were relatively more sensitive to CBU than those of French bean.