Phytophthora infestans, inhibition

The fungicidal activity of sceptrin at 10 ppm was found to be >65 % inhibition of Phytophthora infestans (potato late blight) [103]. In addition to its antimicrobial, antiviral [104], antimuscarinic [22], and antihistaminic [30] properties, sceptrin was shown to be the first and most potent nonpeptide somatostatin inhibitor in the submicromolar range [105]. 

In phenylamide-resistant strains, phenylamides are not able to inhibit ribosomal RNA synthesis, as is indicated by the inability of metalaxyl to interfere with uridine incorporation in a phenylamide-resistant strain of P. megasperma f. sp. megasperma obtained in the laboratory after mutagenic treatment (14) and a phenylamide-resistant strain of Phytophthora infestans (Table III) originating from a potato field (15). 

A common response of plants, often associated with disease resistance, is the localized and rapid death of plant cells at the infection site. This reaction, referred to as a hypersensitive response (HR), Includes the accumulation of phytoalexins (low molecular weight compounds which Inhibit microbial development). In some plant-parasite interactions, different races of a pathogen can be distinguished by the type of response they elicit in different cultivars. Incompatible races of Phytophthora infestans elicit the accumulation of sesquiterpenoid phytoalexins, principally rishitin and lubimin, in tubers of resistant (R-gene) cultivars faster to higher levels following infection than do... 

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