Tannins pathogens

Hence tannin-tolerant insects with elevated gut pH s may be relatively resistant to these pathogens. According to theory (69,70), early successional plants should have low tannin contents and their herbivores should have lower gut pH values... 

How does chemical variability enter into this pH scenario First, by concentrating on low-tannin tissues, an insect may be able to feed on a tree species with high average tannin values while maintaining a lower gut pH. However, this could increase pathogen risk (Figure 4). Second, gut pH may fluctuate with the... 

The role of tannins and terpenoids in the resistance of cottonseed to necrotrophic pathogens also has been investigated. Cottonseed does not form phytoalexins until the seed moisture level reaches 20% or higher (67) at this level germination has already... 

Increased resistance to necrotrophs also could result from changes that increase antibiotic efficiency. Other approaches for these pathogens should aim at increasing constitutive defenses. Such things as higher tannin and lignin concentration, thicker cuticle structure, and increased suberization would be expected to improve resistance. 

Tannins - Tannins promote inhibition of pathogenic miCTobial growth and reduce reproduction of viruses and bacteria. They also have astringent, tanning and hemostatic actions, and increase stability of capillary walls. 

Many tannins are cytotoxic to cell cultures. Tannins may exhibit antibiotic activity by complexation of extracellular enzymes that the pathogens produce or by interference with the metabolism of the pathogen itself. 

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