Comparison of Photosynthetic Activities in Triazine-Resistant and Susceptible Biotypes of Chenopodium album
V ictor B. Curwiel, G ert Schansker, O scar J . de Vos, and Jack J. S. van Rensen Department of Plant Physiology, Agricultural University Wageningen, Arboretumlaan 4, 6703 BD Wageningen, The Netherlands Z. Naturforsch. 4 8 c , 2 7 8 -2 8 2 (1993); received November 26, 1992 Chloroplasts, Triazine-Resistance, Photosystem II, Photoinhibition, Fluorescence Triazine-resistant and susceptible Chenopodium album plants were grown at low and at high light irradiances. At the lower light irradiance the dry matter production of the resistant and the susceptible plants were almost similar. At the higher irradiance the resistant biotype had a significantly lower production. Fluorescence studies showed that the photochemical yield and the photosystem II electron transport rate were lower in the resistant biotype. It could be demonstrated in intact leaves that the lower productivity of the resistant biotype is caused by a higher sensitivity to photoinhibition. However, when studying effects of photoinhibition on electron flow and photophosphorylation in isolated thylakoids of the two biotypes, no signifi cant differences between resistant and susceptible plant materials were observed. It is suggest ed that the difference between resistant and susceptible biotypes connected with processes pro tective against photoinhibition in intact leaves, are lost during the isolation of thylakoids.
Comparison of the Photosynthetic Capacity between Intact Leaves of Triazine-Resistant and -Susceptible Biotypes of Six Weed Species
The rate o f photosynthesis in intact leaves o f a triazine-resistant biotype o f Amaranthus retroflexus was about 15% lower than that o f a triazine-susceptible biotype. Differences in photosyn thesis between resistant and susceptible biotypes o f Polygonum lapathifolium, Poa annua and Solanum nigrum were not significant, and absent in Chenopodium album and Stellaria media. The results are br...متن کامل
Lipid composition of chloroplast membranes from weed biotypes differentially sensitive to triazine herbicides.
Chloroplasts were isolated from triazine-sensitive and triazine-resistant biotypes of common groundsel (Senecio vulgaris L.), common lambsquarter (Chenopodium album L.), and redroot pigweed (Amaranthus retroflexus L.). Chloroplast lipids were extracted and analyzed for differences among sensitive and resistant biotypes. The distribution of lipid between major lipid classes differed in chloropla...متن کامل
Photosynthetic electron transport inhibition by 2-substituted 4-alkyl-6-benzylamino-1,3,5-triazines with thylakoids from wild-type and atrazine-resistant Chenopodium album.
The effect of 2-benzylamino-1,3,5-triazines on photosynthetic electron transport (PET) was measured with thylakoids isolated from atrazine-resistant, wild-type Chenopodium album, and spinach to find novel 1,3,5-triazine herbicides bearing a strong PET inhibition. The PET inhibition assay with Chenopodium (wild-type and resistant), yielded a resistance ratio (R/W = I50 (resistant)/I50 (wild-type...متن کامل
In 1985–2002 thirteen weeds resistant to atrazine were selected by a repeated application of triazine herbicides on arable land, in orchards, non-agricultural land and at railways in the Czech Republic. Recently Digitaria sanguinalis biotypes resistant to atrazine have been found at three railway junctions. Long-lasting application of the active ingredient imazapyr at railways caused selection ...متن کامل
Reduction of Nitrate and Nitrite in Lambsquarters (Chenopodium album) Biotypes Resistant and Susceptible to Atrazine Toxicity.
The nitrite-reducing activity of the normal susceptible biotype of lambsquarters (Chenopodium album L.) was strongly inhibited by atrazine in the assay medium, both in the case of the in vivo assays of leaf discs in light, and in vitro photoreduction assays of crude extracts. In vitro assays of crude extracts with methylviologen or ferredoxin supplying the reducing potential were not inhibited ...متن کامل