Stress biotic

Franklin G, Conceicao LF, Kombrink E and Dias AC. 2009. Xanthone biosynthesis in Hypericum perforatum cells provides antioxidant and antimicrobial protection upon biotic stress. Phytochem 70(l) 60-68. 

In plants, biosynthesis and exudation of allelochemicals follows developmental, diurnal, and abiotic/biotic stress-dependent dynamics. Compounds from 14 different chemical classes have been linked to allelopathic interactions, including several simple phenolic acids (e.g., benzoic and hydroxycinnamic acids) and flavonoids [Rice, 1984 Macias et al., 2007]. The existence of several soil biophysical processes that can reduce the effective concentration and bioactivity of these compounds casts doubts on their actual relevance in allelopathic interactions [Olofsdotter et al., 2002]. However, there are well-documented examples of phenylpropanoid-mediated incompatible interactions among plants. Several Gramineae mediate allelopathic interactions by means of... 

Latch, G.C.M. Physiological interactions of endophytic fungi and their hosts. Biotic stress tolerance imparted to grasses by endophytes. Agri Eco Sys Environ 1993 44 143-156. 

Functional roles treated above are strictly organismal responses to biotic stresses. The use of chemical means to address physical stresses is largely nonexistent. A notable exception to this is the response many organisms make to harmful ultraviolet (UV) radiation. Sunscreens are small organic molecules which absorb UV radiation so that damage to DNA via cross-linking219 225 is prevented. Production of micosporin-like amino acids (MAA) appears to be widespread in shallow-water Antarctic marine invertebrates and macroalgae,223,224 which may be particularly adaptive at present because of the Antarctic ozone hole. 

For a long time, dieback and decline of specific forest species, somewhere in the temperate zone, has been common. Age, climate, or biotic stress factors have frequently been judged to be the principal causes for declines. Again, however, it is difficult to assign responsibility for specific cause and effect. Trees are large and long-lived and their health integrates all the stresses to which they are exposed over time. 

Environmental conditions also impact the extent of activity of allelopathic phenolics, with a number of abiotic and biotic stresses probably accentuating their action. Stress may result from pathogens, herbivory, herbicides,... 

These examples show that despite our extensive knowledge on flavonoid biosynthesis and regulation, we still know little on how development or abiotic/biotic stresses affect pigmentation. 

Inositols and Their Metabolites in Abiotic and Biotic Stress Responses... 

Inositols and their metabolites in abiotic and biotic stress responses 241... 

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