The cyanobacterium Nostoc strain ATCC 53789, a known cryptophycin producer, was tested for its potential as a source of natural pesticides. The antibacterial, antifungal, insecticidal, nematocidal, and cytotoxic activities of methanolic extracts of the cyanobacterium were evaluated. Among the target organisms, nine fungi (Armillaria sp., Fusarium oxysporum f. sp. melonis, Penicillium expansum, ...

The strongly antifungal phytoalexins brassilexin and sinalexin were metabolized by the stem rot fungus Sclerotinia sclerotiorum to glucosyl derivatives, whereas the phytoalexins brassicanal A, spirobrassinin and 1-methoxyspirobrassinin, displaying lower antifungal activity, were transformed via non-glucosylating pathways. Significantly, these transformations led to metabolites displaying no det...

Microbial opsins play a crucial role in responses to various environmental signals. Here, we report that the microbial opsin homolog gene sop1 from the necrotrophic phytopathogenic fungus Sclerotinia sclerotiorum was dramatically up-regulated during infection and sclerotial development compared with the vegetative growth stage. Further, study showed that sop1 was essential for growth, sclerotia...

The pathogenicity of 47 isolates of Sclerotinia sclerotiorum from oilseed rape (Brassica napus L.) in Anhui, China, was tested by detached leaf inoculation using the susceptible rape cultivar Wanyou-14. All isolates were pathogenic to the cultivar and could be grouped into 3 categories based on the lesion length on the leaves tested: weak pathogenicity type, intermediate pathogenicity type, and...

The ascomycete fungus Fusarium graminearum is a major causal agent for Fusarium head blight in cereals and produces mycotoxins such as trichothecenes and zearalenone. Isolation of the fungal strains from air or cereals can be hampered by various other airborne fungal pathogens and saprophytic fungi. In this study, we developed a selective medium specific to F. graminearum using toxoflavin produ...

Filamentous fungi belonging to the Fusarium genus are responsible for large economic losses due to their high pathogenicity and toxigenicity. Fusarium sp. may produce variety of mycotoxins, one of them is zearalenone (ZEA). The presence of the PKS4 gene shows the possibility of zearalenone biosynthesis by Fusarium sp. In this study, in four Fusarium graminearum and one Fusarium poae strains the...

Sclerotinia sclerotiorum, the causal agent of Sclerotinia stem rot, is a devastating fungal pathogen of soybean that can cause significant yield losses to growers when environmental conditions are favorable for the disease. The development of resistant varieties has proven difficult. However, poor resistance in commercial cultivars can be improved through additional breeding efforts and underst...

Lettuce drop, caused by the soil borne pathogen Sclerotinia sclerotiorum, is one of the most common and serious diseases of lettuce worldwide. Increased concerns about the side effects of chemical pesticides have resulted in greater interest in developing biocontrol strategies against S. sclerotiorum. However, relatively little is known about the mechanisms of Streptomyces spp. as biological co...

Sclerotinia sclerotiorum (Sclerotiniaceae) is a plant pathogenic fungus that causes white mold disease in vegetable crops, including the common bean (Phaseolus vulgaris). Proteases produced by fungi are normally an important part of the pathogenic process in the host. We examined the effect of different carbon sources--pectin, glucose, and cell wall of P. vulgaris on the production of proteases...

The main objective of this work was to develop a PCR protocol for the identification of Fusarium graminearum, based on a pair of primers targeted to a segment of the 3´coding region of the gaoA gene that codes for the enzyme galactose oxidase (GO). This region has low homology with the same region of GO genes from other fungi. Genomic DNA from 17 strains of Fusarium spp. isolated from diseased ...