6533b832fe1ef96bd129a24f

RESEARCH PRODUCT

Wirkung der Insektizide Allethrin, Lindan und Jacutin-Fogetten-Sublimat auf den photosynthetischen Elektronentransport

subject

description

Summary During our studies of Hill-reactions of isolated chloroplasts we observed an inhibition of electron transport after an application of the smoke of «Jacutine-Fogetten» in the plant growth chamber. Therefore we tested the influence of the insecticides Lindane (Gammexan), the sublimate formed by the fumigation of «Jacutin Fogetten», and of Allethrin on the photosynthetic electron transport reactions of PS II and PS I. 39 μ M Lindane inhibits the basal, coupled and uncoupled electron transport to ferricyanide of broken chloroplasts isolated from leaves of Pisum sativum up to 35%. A higher inhibitory effect with higher concentrations is limited by the low water solubility of Lindane. On the contrary Lindane stimulates the PS I activity measured with methylviologen as electron acceptor and the ascorbate/dichlorophenolindophenol donor system. The precipitate formed by the sublimation of the Lindane containing «Jacutin-Fogetten» depresses electron transport much more than pure Lindane. 50 μ g of the sublimate per ml reaction medium causes an inhibition of 80% of the coupled and uncoupled ferricyanide Hill-reaction. Thus we believe that an additional substance inhibiting the electron transport exists in the sublimate together with Lindane. 50 μ M Allethrin causes an inhibition of 80% of the benzoquinone and ferricyanide Hill-reactions. The coupled and uncoupled electron transport to ferricyanide shows an inhibition of 50% at the concentrations of 17 μ M (pI 50 = 4.77) and 27 μ M (pI 50 = 4.57) respectively. With benzoqinone as the electron acceptor 50% inhibition is reached with 19 μ M (pI 50 = 4.72). The PS I activity with methylviologen as an acceptor is not influenced by Allethrin. In spite of our first working hypothesis, Allethrin is not contained in the sublimate of the «Jacutin-Fogetten» as shown by gas chromatography.