Host plant defenses of black (Solanum nigrum L.) and red nightshade (Solanum villosum Mill.) against specialist Solanaceae herbivore Leptinotarsa decemlineata (Say)

Abstract

Black nightshade (Solanum nigrum, S. nigrum L.) and red nightshade (Solanum villosum, S. villosum Mill.) are medicinal plants from the Solanaceae family that synthesize glycoalkaloids and other secondary metabolites. To recognize the potential insecticide activity of these compounds, leaf extracts (containing glycoalkaloid and methanol fractions) were tested for enzyme inhibition, antifeedant activity and toxicity. For in-vitro glutathione S-transferase (GST) inhibition activity, we used insecticide-resistant Colorado potato beetle, Leptinotarsa decemlineata (L. decemlineata; Say) midgut and fat-body homogenate. In-vivo toxicity and the antifeedant activity were performed using larval bioassays. The methanol extracts had greater GST inhibitory activity compared to the glycoalkaloids, as well as greater 2nd instar larvae mortality and antifeedant activity.Furthermore, the green leaf volatile compound, cis-hex-3-enyl acetate, at the concentration of 5 ppm, caused 50% mortality of 2nd instar larvae. Our findings suggest the Arch. Insect Biochem. Physiol. 2019;101:e21550.wileyonlinelibrary.com/journal/arch

Glyphosate-based herbicide has soil-mediated effects on potato glycoalkaloids and oxidative status of a potato pest

“…In general, the Colorado potato beetle tolerates pesticides relatively well, and has developed resistance to several synthetic insecticides, including organophosphates (Kostic et al, 2016;Piiroinen et al, 2013), used as a control method in potato farms. The metabolic adaptation is manifested by a complex set of detoxifying enzymes, such as GSTs, P450 monooxygenases, and esterases (Ben-Abdallah et al, 2019). Glyphosate also belongs to the organophosphate chemical group, which may potentially affect the susceptibility of the Colorado potato beetles to GBHs.…”