title: Photosynthetic parameters as indicators of trinitrotoluene (TNT) inhibitory effect: change in chlorophyll a fluorescence induction upon exposure of lactuca sativa to TNT.
abstract: Trinitrotoluene, as a compound of conventional explosive, may cause inhibitory effect on terrestrial plants. When Lactuca sativa was exposed to different concentrations of trinitrotoluene (32-1000 mg/kg), photosynthetic process was investigated by using rapid chlorophyll fluorescence kinetic and pulse modulated fluorometry. The decrease of chlorophyll a variable fluorescence was seen to be caused by the deactivation of photosystem II reaction centers. We found for rapid variable fluorescence to be a useful indicator to evaluate the inhibitory effect of trinitrotoluene on photosystem II primary photochemistry and electron transport. The fluorescence parameters, related to the reduction state of photosystem II and to non-photochemical dissipation of light energy, showed a strong relation between the inhibitory effect of photosystem II activity and concentration of trinitrotoluene. The change of photosynthetic fluorescence parameters induced by trinitrotoluene was a reliable indication of the plant physiological state. We proposed for the reduction state of photosystem II and the non-photochemical energy dissipation to be a useful tool in bioassay toxicity testing of trinitrotoluene polluted soil.
authors.affiliation: Département de chimie, Université du Québec a Montréal, 2101 rue Jeanne-Mance, H2X 2J6 Montréal, Quebec, Canada.
authors.forename: Nadia Ait
authors.initials: NA
authors.lastname: Ali
authors.forename: David
authors.initials: D
authors.lastname: Dewez
authors.forename: Pierre Yves
authors.initials: PY
authors.lastname: Robidoux
authors.forename: Radovan
authors.initials: R
authors.lastname: Popovic
mesh_terms: D018533:Biomass; D002734:Chlorophyll / Q000096:biosynthesis* / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D004784:Environmental Monitoring / Q000379:methods*; D005453:Fluorescence; D006801:Humans; D018545:Lactuca / Q000187:drug effects*; D010788:Photosynthesis / Q000187:drug effects; D018515:Plant Leaves; D012989:Soil Pollutants / Q000633:toxicity*; D014303:Trinitrotoluene / Q000633:toxicity*
chemical_list: D012989:Soil Pollutants; D014303:Trinitrotoluene; D002734:Chlorophyll