Alternative σ factors in bacteria redirect RNA polymerase to recognize alternative promoters, thereby facilitating coordinated gene expression necessary for adaptive responses. The gene sig8 (sav_741) in Streptomyces avermitilis encodes an alternative σ factor, σ8, highly homologous to σB in Streptomyces coelicolor. Studies reported here demonstrate that σ8 is an important regulator of both ave...

The combined toxicity of five insecticides (chlorpyrifos, avermectin, imidacloprid, λ-cyhalothrin, and phoxim), two herbicides (atrazine and butachlor) and a heavy metal (cadmium) has been examined with the earthworm acute toxicity test. Toxicological interactions of these chemicals in four, five, six, seven, and eight-component mixtures were studied using the combination-index (CI) equation me...

Abamectin (Avermectin B1a), is a natural fermentation product derived from the soil bacterium Streptomyces avermitilis. Abamectin (Avermectin B1a) is widely used as an insecticide, acaricide, and anthelmintic. The present study assessed the effects of repeated subacute and subchronic exposure to the commercial formulation of abamectin (Vertemic, 1.8% EC) in albino male rats. The toxic effects o...

The psyllid Diaphorina citri Kuwayama (Hemiptera: Psyllidae) is one of the most important pests of citrus worldwide because it efÞciently vectors three bacteria in the genus Candidatus Liberibacter that cause the devastating citrus greening disease (huanglongbing). Current management practices for this insect pest rely on multiple sprays of foliar insecticides and one or two applications of soi...

Aim. Studying of the influence avermectin-containing polyfunctional preparations Avercom and Nova on enhancement resistance to fusarium wilt tomato plants in vitro. Methods. Tomato were cultivated vitro for 30 days presence 25 μl/l Nova. Analysis was carried out by spraying with a conidia suspension Fusarium oxysporum f. sp. lycopersici F. solani. Resistance has been evaluated 15 after inoculat...