Chitinase Genes

Many of the genes and cDNAs encoding PR proteins have been isolated and characterized for several PR proteins over the past two decades. With the advancements in tools for genetic engineering, several PR-protein genes have been mobilized into plant systems and the resulting transgenic plants have been extensively studied. Most of the studies have resulted in the constitutive overexpression of PR proteins in all tissues, although some studies involve expression of these genes in the antisense...

Natural And Synthetic Elicitors Of Prprotein Genes

Several molecules that are derived from pathogens or from host-pathogen interactions can serve as elicitors of PR-protein induction. The elicitors derived from pathogens include oligosaccharides derived from chitin, glucan, and pectin, fungal cell wall derivatives, extracellular glycoproteins, polysaccharides, oligosaccharides, and harpins produced by pathogenic and nonpathogenic bacteria and fungi. Mechanical wounding, insect feeding, chemical elicitors, and environmental stresses also can...

The Application Of Induced Resistance

The broad-spectrum nature of induced resistance to fungal pathogens makes this type of resistance a potentially useful approach to disease management. Early field research by Kuc and colleagues Kuc, 1982 demonstrated that field-grown cucumber plants could be protected against infection by C orbiculare by a prior localized infection by the same pathogen. Although the approach worked, the need to individually inoculate plants makes any practical application of this method highly impractical for...

Transgenic Plants With Combinations Of Pr Proteins

Tomato plants individually expressing achitinase 3-1,3-glucanase did not show any resistance to the Fusarium wilt pathogen, whereas combined expression of both of the transgenes achieved a higher level of resistance Jach et al., 1995 Jongedijk et al., 1995 . Tobacco lines expressing either a rice chitinase or an alfalfa glucanase were crossed to obtain hybrids containing both transgenes. The progenies were selfed to obtain homozygous plants which were then tested for resistance to frog eye...