Chemically induced resistance

Priming has been observed in various pathosystems as an integral part of both SAR and ISR as well as in chemically induced resistance [69]. Early reports on priming were purely descriptive. The response of the plants was accelerated and they proved also to be more resistant [70,71,72,73]. In parsley cell cultures low doses of the SAR inducers SA,... 

Faoro, R, Maffi, D., Cantu, D. et al. 2008. Chemical-induced resistance against powdery mildew in barley The effects of chitosan and benzothiadiazole. Biocontrol 53 387-401. 

The process control of the post-exposure bake that is required for chemically amplified resist systems deserves special attention. Several considerations are apparent from the previous fundamental discussion. In addition for the need to understand the chemical reactions and kinetics of each step, it is important to account for the diffusion of the acid. Not only is the reaction rate of the acid-induced deprotection controlled by temperature but so is the diffusion distance and rate of diffusion of acid. An understanding of the chemistry and chemical kinetics leads one to predict that several process parameters associated with the PEB will need to be optimized if these materials are to be used in a submicron lithographic process. Specific important process parameters include ... 

Many plasmids are known to possess three properties (1) increased resistance to the bactericidal effects of UV and chemical mutagens, (2) increased spontaneous mutagenesis, and (3) increased susceptibility to UV and chemically induced mutagenesis. Some plasmids possess all three properties others may possess just one, for example, increased susceptibility to mutagenesis (review Mortelmans and Dousman, 1986). Often the profile of activity depends on the DNA repair status of the host cell (Pinney, 1980). Plasmid pKMIOl carries DNA repair genes and has been widely used in strains used in bacterial mutagenicity tests. 

Toth et al. 2005), induced resistance was found only in the top blades of S.filipendula (Taylor et al. 2002). The authors concluded that valuable basal stipes are mechanically and constitutively defended, while the valuable meristematic tissues have inducible chemical defenses (Taylor et al. 2002). 

Bendy SC, Halsall LC. 1988. GMI ganglioside enhances synaptosomal resistance to chemically induced damage. Neuroscience Letters 84(2) 229-233. 

Induced resistance is the qualitative or quantitative enhancement of a plant s defense mechanisms against pests in response to extrinsic physical or chemical stimuli. These extrinsic stimuli are known as inducers or elicitors. 

Thaler, J. S., Fidantsef, A. L., Duffey, S. S. and Bostock, R. M. (1999). Trade-offs in plant defense against pathogens and herbivores a field demonstration of chemical elicitors of induced resistance. Journal of Chemical Ecology 25 1597-1609. 

Regardless of the pathways of induced resistance, the end result is identical - a plant with stimulated resistance to plant pathogens. Effective use of induced resistance promoters in I PM systems will likely dramatically reduce the use of conventional chemical fungicides and bactericides in commercial agriculture. It is likely that there are many nontoxic natural substances and microbial species awaiting discovery as induced resistance promoters. 

A number of exogenously applied chemicals, including polyacrylic acid, acetylsalicylic acid, salicylic acid and isonicotinic acid (NA) derivatives, have also been shown to induce resistance. Usually the resistance is localised to the treated parts of the plants (Gianinazzi Kassanis, 1974 White, 1979), but in the IN A compounds the resistance can be systemic (Metraux et al., 1991). These observations led to the suggestion that SAR might provide a new strategy for crop protection, either by discovering... 

The possibility exists that induced resistance in plants may be longer lasting than the effect of fungicides, which may be broken down or washed off by rain. Immunization of plant tissue, which might take place at hormonal level, may require extremely low concentrations of a specific chemical. Increased research efforts are needed to evaluate these speculations. 

Our ENVIRONMENT exposes us daily to a wide variety of xenobiotics in our food, in the air we breathe, or as a result of industrial exposure and toxic wastes. However, despite this exposure, most of us are living long, healthy lives. Certainly individual variation could account for some of the variability in resistance to disease, but other factors are undoubtedly involved. According to a growing body of evidence, diet may be extremely important in increasing resistance to chronic disease. One is tempted to speculate, or hope, that improved dietary habits could improve individual resistance to chemically induced chronic disease. 

Dietary fiber has been suggested to play a protective role against chemically-induced toxicity (1) and against colon cancer (2). However, the mechanism(s) by which dietary fiber modulates chemical toxicity or colon cancer has not been well studied. The fiber fraction of the diet is resistant to mammalian digestive enzymes and consequently dietary fiber is not absorbed from the small intestine (3). However, certain types of dietary fiber specifically fermentable fibers, including the pectic substances and hemicelluloses, are readily digested by the intestinal microflora (4,5). Pectic... 

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