Herbicides photosynthesis inhibition

Yanase, D., and A. Andoh. 1992. Translocation of Photosynthesis-Inhibiting Herbicides in Wheat Leaves Measured by Phytofluorography, the Chlorophyll Fluorescence Imaging. Pestic. Biochem. Physiol. 44, 60-67. 

Yerkes, C.N. and S.C. Weller (1995). Response of atrazine-susceptible and -resistant photoautotropic cells to photosynthesis inhibiting herbicides. Weed Sci. Soc., Abstract 264 88. 

Some responses, such as mortality, are irreversible. However, many sublethal responses may be reversible, such as the impact of the photosynthesis-inhibiting herbicide linuron on macrophytes (Snel et al. 1998). Linuron inhibits photosynthesis by disturbing electron transport in photosystem II. Table 6.2 presents the kinetics of photosynthesis inhibition when shoots of macrophytes are placed in water with 50 pg/L linuron, and subsequent recovery when placed in uncontaminated water. The EC50 values are remarkably similar between macrophytes, and half-life estimates for inhibition and recovery are less than 2 hours (Table 6.2). Except for Potamogeton... 

Brock TCM, Crum SJH, Deneer JW, Heimbach F, Roijackers RMM, Sinkeldam JA. 2004. Comparing aquatic risk assessment methods for the photosynthesis-inhibiting herbicides metribuzin and metamitron. Environ Pollut 130 403-426. 

Tchan, Y. T., Roseby, J. E., and Funnell, G. R. 1975. A new rapid specific bioassay method for photosynthesis inhibiting herbicides. Soil Sci. Biochem. 7, 39-44... 

Breton, F. Rouillon, R. Piletska, E.V. Karim, K. Guerreiro, A. Chianella, I. Piletsky, S. A. Virtual imprinting as a tool to design efficient MIPs for photosynthesis-inhibiting herbicides, Biosens. Bioelectron. 2007, 22, 1948-1954... 

Ioxynil and bromoxynil are photosynthesis inhibiting herbicides. They inhibit the electron flow near the quinone component of electron transport (Wain, 1964 Smith et al., 1966 Paton and Smith, 1965,1967). In addition to the strong inhibition of oxidative phosphorylation, both herbicides prevent COj fixation (Friend and Olson, 1967). 

Piletskaya EV, Piletsky SA, Sergeyeva TA et al. Thylakoid membranes-based test-system for detecting of trace quantities of the photosynthesis-inhibiting herbicides in drinking water. Anal Chim... 

Environmental pollution by toxic chemicals has become one of the worlds most serious problems. Among the most widespread pesticides is photosynthesis inhibiting herbicides, such as atrazine, metribuzin, diuron, bromacil, ioxynil and dinoseb. They all beloi to different families but have a common mode of action binding specifically to the chloroplast D1 protein with subsequent intetmption of the electron and proton flow through Photosystem II. The goal of this chapter is to evaluate the possibility of application of the natural receptor properties of D1 protein in various biosensor systems for herbicide detection. 

Environmental pollution by pesticides is a very serious problem. The appearance of herbicides in ground water and in agricultural products poses considerable problems in the control of drinking water and produa quality. Regulations governing herbicide concentration in drinking water are very strictly enforced by the European Community virith a maximum allowable at 0.1 pg/L level for each individual substances and 0.5 Pg/L for sum of photosynthesis inhibiting herbicides. ... 

Piletskaya EV, Piletsky SA, El skaya AV et al. D1 protein- an effective substitute for immunoglobulins in ELISA for the detection of photosynthesis inhibiting herbicides. Anal Chim Acta 1999 398 49-56. 

The first photosynthesis-inhibiting herbicides such as arylurea (e.g., diuron) and triazines derivatives (e.g., atrazine) were identified in 1956 even before the photosynthetic reactions and two photosystems were known and before plastoquinone had been discovered. Surprisingly, this group of herbicides still dominates the field. The second group, which includes phenolic compounds such as bromoxynil and ioxynil, were recognized later. Although phenolic herbicides inhibit the PS II reaction centre differently from triazine herbicides, they also interfere with the Qg function and bind the DI protein. 

Natural Receptors for Photosynthesis-Inhibiting Herbicides D1 Protein... 

The main amino acids that participate in specific intetactions between herbicide s natural receptors and photosynthesis-inhibiting herbicides were identified and analyzed. A reasonable similarity was found between the structural units and behavior of natural and synthetic receptors. Although synthetic receptors did not possessed the complexity of natural receptors, the basic mechanism governing the molecular recognition, such as complementarity for the molecule of interest, was similar to natural receptors. The development of new stable synthetic materials for PSII-herbicides could therefore be beneficial for analytical science and environmental protection. 

The final detection method determines the sample preparation procedures. Highly selective detection methods need less thorough cleanup. That is the case when photosynthesis-inhibiting herbicides are detected on TLC plates by Hill reaction inhibition (3,4). If the final detection is less specific for the pesticides, a greater degree of sample preparation is required. 

Triazine-type herbicides were detected in the lower nanogram range by this photosynthesis inhibition reaction with chloroplasts obtained from parts of oats, spinach, beans, and watercress (170) i /values in five different solvent systems are given in Table 12. This useful, sensitive method for residue analysis was patented (171) for the quantitative determination of photosynthesis-inhibiting herbicides. 

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