Agrobacterium is a phytopathogenic bacterium that induces crown gall disease in many plant species by transferring and integrating a segment of its own DNA (T-DNA) into its host genome. Whereas Agrobacterium usually does not trigger an extensive defense response in its host plants, it induces the expression of several defense-related genes and activates plant stress reactions. In the complex in...

ABBREVIATIONS: AFLP (Amplified Fragment Length Polymorphism); BAC (Bacterial Artificial Chromosome); CAPS (Cleaved Amplified Polymorphic Sequence); CPCSD (California Planting Cotton Seed Distributors); EST (Expressed Sequence Tag); FOV (Fusarium oxysporum f. sp. vasinfectum); FW (Fusarium Wilt); QTL (Quantitative Trait Locus); RAPD (Random Amplified Polymorphic DNA); RIL (Recombinant Inbred Lin...

The genetic polymorphism maintained by host-pathogen coevolution is analyzed in a multilocus model. The model assumes gene-for-gene interactions of the type commonly observed between host plants and their fungal pathogens. Unstable (epidemic) systems maintain more resistance genes, fewer virulence genes, and less overall genetic diversity than stable (endemic) diseases. The stability of the sys...

Understanding the mechanistic basis of why a certain pathogen causes disease in one host plant and not in another has long intrigued and motivated plant pathologists. Plants, in nature, are generally resistant to most pathogens. The ability of a pathogen to cause disease in a host plant is usually the exception, not the rule. This is because plants have an innate ability to recognize potential ...

Twenty-five aphids of three different species, Brevicoryne brassicae L, Myzus persicae Schulzer, and Rhopalosiphum padi L(Hemiptera: Aphididae) were each allowed to infest leaves of a young plant of their respective host plant species for 4 days, except that the oldest expanded leaf (the 'systemic' leaf) was kept free of aphids. Each preinfested plant thus had two types of leaves, local leaves ...

reported here are two cases of delayed postsurgical brucella abscess within the cranium, treated successfully by reoperation and appropriate medical therapy. both patients had an occupational exposure to the pathogenic organism. systemic symptoms of brucellosis became manifest postoperatively in case i and were present in case ii long before operation. the diagnosis was confirmed by serology an...

Relatively few studies have investigated potential interactions of host plant resistance and insecticides for insect control. To examine possible interactions, host plant resistance was measured independently for four tomato cultivars and one wild tomato accession against tomato psyllids, Bactericerca [Paratrioza] cockerelli [Sulc] (Homoptera: Psyllidae). Plant lines tested included the commerc...