Metabolism of dimethoate in bean plants in relation to its mode of application

Study the effect of insecticide dimethoate on photosynthetic pigments and photosynthetic activity of pigeon pea: Laser-induced chlorophyll fluorescence spectroscopy

“…Increase in plant growth may be possible due to cellular degradation of organophosphorus insecticide ultimately leading to increased phosphate content which accelerated the plant growth [41]. Dimethoate absorbed by plants is rapidly translocated to the leaf tissue.…”

“…Both these moieties are utilized by the plant as structural materials. Phosphate moiety is more rapidly utilized than carbonyl moiety [41]. There are several reports of increased growth of plant and cyanobacteria under low dose of dimethoate treatment [14,20,42].…”

“…Dimethoate degradation generates various toxic derivatives and oxygen analogs in plant leaves [41]. The integrity of the plasma membrane is altered under dimethoate treatment.…”

“…Decrease in root length is more pronounced than in shoot length, which is probably due to greater accumulation of dimethoate in roots as it is in direct contact with the insecticide. Dimethoate accumulates in plant leaves, which are the major sites of metabolic activities and thus inhibits plant growth [41]. Such inhibition in plant morphology may be associated with changes in cell division and cell elongation [44] or is due to the conversion of indole-3 acetic acid (IAA) into various photo oxidative products [45] and excessive reactive oxygen species (ROS) production [14].…”

“…Dimethoate accumulated in the leaves of the pigeon pea plants; thus, the increase in the photosynthetic pigment content for 10 ppm of dimethoate after 10 days of treatment is due to partial degradation of dimethoate leading to release of phosphorus [41]. Decrease in the photosynthetic pigments after 20 and 30 days of treatment (for all the used concentrations of dimethoate treatment) and also for 20, 40 and 80 ppm of dimethoate after 10 days of treatment could be due to inhibition of Chl biosynthesis by inhibiting d-aminolevulinic acid dehydratase and protochloropyllide reductase activities and breakdown of pigments or their precursors, as reported for other stresses [47,48].…”