خيارات البحث
النتائج 1 - 8 من 8
Comparison of photosynthetic responses to manganese toxicity of deciduous broad-leaved trees in northern Japan
1997
Kitao, M. | Lei, T.T. | Koike, T. (Forestry and Forest Products Research Institute, Hokkaido Research Center, Sapporo 062 (Japan))
Studies on cadmium toxicity in plants: a review
1997
Das, P. | Samantaray, S. | Rout, G.R. (Regional Plant Resource Centre, Bhubaneswar 751015 (India))
Growth stimulation of Triticum aestivum seedlings under Cr-stresses by non-rhizospheric pseudomonad strains
1997
Hasnain, S. | Sabri, A.N. (Botany Department, Q.A. Campus, University of the Punjab, Lahore-54590 (Pakistan))
Effects of herbicides on two submersed aquatic macrophytes, Potamogeton pectinatus L. and Myriophyllum sibiricum Komarov, in a prairie wetland
1997
Forsyth, D.J. | Martin, P.A. | Shaw, G.G. (Canadian Wildlife Service, 115 Perimeter Road, Saskatoon, Saskatchewan S7N 0X4 (Canada))
Differential response of buddleia (Buddleia davidii Franch.) to ozone
1997
Findley, D.A. | Keever, G.J. | Chappelka, A.H. | Eakes, D.J. | Gilliam, C.H. (Department of Horticulture and School of Forestry, Auburn University, Alabama 36849 (USA))
Fluorogenic compound hydrolysis as a measure of toxicity-induced cytoplasmic viscosity and pH changes
1997
Grabowski, J. | Hsiao KeCheng | Baker, P.R. | Bornman, C.H. (Institute of Physics, Poznan University of Technology, ul. Piotrowo 3, 60-965 Poznan (Poland))
Xenobiotics: Substrates and inhibitors of the plant cytochrome P450
1997
Schalk, Michel | Pierrel, Marie-Agnès | Zimmerlin, Alfred | Batard, Yannick | Durst, Francis | Werck-Reichhart, Danièle
The ability of a plant cytochrome P450 to bind and metabolise plant endogenous molecules and xenobiotics was investigated. The work was performed on the yeast-expressed CYP73A1, a cinnamate 4-hydroxylase isolated fromHelianthus tuberosus. CYP73 controls the general phenylpropanoid pathway and is likely to be one of the most abundant sources of P450 in the biosphere. The enzyme shows a high selectivity toward plant secondary metabolites. Nevertheless, it oxygenates several small and planar xenobiotics with low efficiency, including an herbicide (chlorotoluron). One xenobiotic molecule, 2naphthoic acid, is hydroxylated with an efficiency comparable to that of the physiological substrate. This reaction was used to devise a fluorimetric test for the rapid measurement of enzyme activity. A series of herbicidal molecules (hydroxybenzonitriles) are shown to bind the active site without being metabolised. These molecules behave as strong competitive inhibitors of CYP73 with a Kᵢ in the same micromolar range as the Kₘ for the physiological substrate. It is proposed that their inhibition of the phenylpropanoid pathway reinforces their other phytotoxic effects at the level of the chloroplasts. All our results indicate a strong reciprocal interaction between plant P450s and xenobiotics.
اظهر المزيد [+] اقل [-]Effect of As on chlorophyll and protein contents and enzymic activities in greening maize tissues
1997
Jain, M. (Agricultural Univ., Indore (India). School of Biochemistry) | Gadre, R.
