O. Belbachir, M. Matringe, M. Tissut
Dec 1, 1980
Citations
0
Influential Citations
11
Citations
Journal
Pesticide Biochemistry and Physiology
Abstract
Abstract The herbicide dinoterb is a tert. -butyl-2-dinitro-4,6-phenol. Its effects on the metabolism (water, dry matter, nitrogen, chlorophyll, and flavonol contents) were studied on pea plants ( Pisum sativum L.). Concurrently, photosynthesis and respiration intensities of treated plants or tissues were measured (O 2 emission or uptake measured on leaf fragments in the reaction vessel of a Clark-type electrode system). Dinoterb, which is an inhibitor of photosynthesis of isolated, physiologically active chloroplasts, also appeared to rapidly inhibit photosynthesis in the whole plant. This property was used for an indirect method of analysis of dinoterb movement in the leaf and in the plant. Dinoterb appears to have a complex mode of action: low concentrations of the herbicide, rapidly appearing in the whole treated leaf, inhibited photosynthesis, uncoupled oxidative phosphorylations, and began to inhibit respiratory oxygen consumption. High concentrations of dinoterb were responsible for important necrosis some days after treatment and we could show, by analysis of the flavonolic accumulation, that cells of the upper epidermis seemed to be first affected.