Plant pathogenicity

Quinoline derivatives of formula 115 are outstandingly active as microbiocides and can be preferentially used as agricultural fungicides and bactericides for the control of undesired plant pathogens (96EUP703234). 

In addition, naturally growing plants resist plant pathogen and Insect attack because resistance develops over time via natural selection (35). Also, most natural and crop plants have, as a part of their basic physical and chemical makeup, a wide array of mechanisms that help them resist pest attack. These Include chemical toxicants, repellents, altered plant nutrients, hairiness, thorns, and diverse combinations of these (35). 

Insect and plant pathogen attacks are reduced because 1) natural enemies of the pests are increased in the polyculture ecosystem because the array of hosts for the natural enemies is increased, 2) and the movement of pests from one host plant to another is interrupted by the presence of a different host plant growing nearby (36). In this way overall pest damage is substantially reduced. 

Water Management. For some crops water management directly and indirectly helps control weeds, Insects, and plant pathogens. With... 

Biological and Natural Controls. Parasites and predators are effective in limiting the numbers of pest Insects and plant pathogens both in nature and for crops (35). This basic fact led to the development of biological controls. For example, the vedalia beetle, which was Introduced for control of cottony cushion scale on citrus in California, has provided continuous effective control of this pest for many decades. Worldwide only approximately 1% of the pests have been effectively controlled by Introduced biological control agents (43). 

El Gueddari N.E. Rauchhaus U. Moerschbacher B.M. Deising H.B. (2002) Developmentally regulated conversion of surface-exposed chitin to chitosan in cell walls of plant pathogenic fimgi // New Phytologist. V. 156. P. 103-112. 

Group 2 includes some 80 sesquiterpene trichothecenes, which are particularly associated with fungi belonging to the group Fusarium. Fusarium species are widely known both as plant pathogens and contaminants of stored foods snch as maize. Trichothecenes are strong inhibitors of protein synthesis in mammalian cells. There have been many incidents of poisoning of farm animals cansed by contamination of their food by these componnds. 

Selective toxicity is also important in relation to the development of resistance or tolerance to pollutants from two distinct points of view. On the one hand, there is interest among scientists concerned with crop protection and disease control in mechanisms by which crop pests, vectors of disease, plant pathogens, and weeds develop resistance to pesticides. Understanding the mechanism should point to ways of overcoming resistance, for example, other compounds not affected by resistance mechanisms or synergists to inhibit enzymes that provide a resistance mechanism. On the other hand, the development of resistance can be a useful indication of the environmental impact of pollutants. 

Cervone F., De Lorenzo G., Salvl G. and Camardella L. in Biology and Molecular Biology of Plant-Pathogenic Interactions. NATO ASI Series, Vol. HI, ed. J. Bailey (Springer-Verlag, Berlin, FRG, 1986) p. 385. 

Hahn M. G., Bucheli P., Cervone F., Doares S. H., O Neill R. A., Darvill A. Albersheim P. (1989). Roles of cell wall constituents in plant-pathogen interactions. In Nester E. Kosuge T., ed. Plant Microbe Interactions, Vol. 4. McGraw-Hill Publishing Co., 131-181. 

Misaghi I. J. (1982). The role of pathogen-produced cell-wall-degrading enzymes in pathogenesis. In Physiology and Biochemistry of Plant Pathogen Interactions. Plenum Press, 17-34. 

The endo-action of the K. marxianus PG was demonstrated by a extremely rapid attack on plant tissue. This activity appears to be at least equivalent to that of several commercial preparations used for separating plant cells for protoplast preparation (RMC, unpublished data). Most of the endo-PGs produced by plant pathogens and saprophytes have so far been reported to possess macerating activity. PG secreted by K. marxianus CCT 3172 also had a strong activity in reducing the viscosity of cocoa pulp. Cocoa pulp generally contains 1 - 1.5% (w/w) of pectin consisting of 68% esterification and 11.6% methoxyl content [18]. 

Rohde BH, R Schmid, MS Ullrich (1999) Thermoregulated expression and characterization of an NAD(P)H-dependent 2-cyclohexen-l-one reductase in the plant pathogenic bacterium Pseudomonas syringae pv. glycineti J Bacteriol 181 814-822. 

Li H-Q, 1 Matsuda, Y Eujise, A Ichiyama (1999) Short-chain acyl-CoA-dependent production of oxalate from oxaloacetate by Burkholderia glumae, a plant pathogen which causes grain rot and seedling rot of rice via oxalate production. J Biochem 126 243-253. 

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