Antifeeding Efficacy, Machanisms and molecular response of Potato (Solanum tuberosum L.) Against Black Cutworm (Agrotis ipsilon Hufn.) Larvae

Abstract

The Black cutworm (BCW – Agrotis ipsilon Hufn.), one of the most destructive insect pests of potato (Solanum tuberosum L.), can destroy entire fields if not detected early. Therefore, a no-choice test was performed to evaluate the anti-feeding impact of 10 potato cultivars on BCW larvae compared to castor (a preferred host - control) under laboratory conditions. BCW 2^nd instar larvae were fed leaves of potato cvs. compared to castor and checked daily until adult emergence to record various biological and chemical parameters of the fed larvae. In comparison to castor leaves, feeding larvae on potato cultivars leaves reduced the average weight of both larvae and pupae. The protein, carbohydrate, and fat content of the fed larvae on either 'Lily' or 'Mondial' leaves were lower than control larvae. Feeding 'Lily' leaves to larvae had a negative influence on the amino acid content of the larvae. In comparison to castor leaves, larvae fed on the leaves of 'Carosso,' 'Hermmes,' 'Lily,' 'Mondial,' and 'Princces' reduced the activity of protease and glutathione S-transferase enzymes. According to the findings, ‘Hermmes’, ‘Lily’, and ‘Princces' were resistant to A. ipsilon larvae feeding, whereas ‘Hana’ and ‘Mondial’ were more susceptible. To define anti-feeding mechanisms, two potato cvs., ‘Hana’ as susceptible and ‘Lily’ as resistant’, were subjected to biochemical and molecular analyses. The high antioxidative power, due to flavonoids and catalase, was determined in ‘Lily’. The high antioxidative power, due to flavonoids and catalase activity, was discovered in ‘Lily’. Suggests a higher level of reactive oxygen species (potentially H₂O₂) management in larvae feeding resistance, in addition autotoxicityprevention in nearby intact cells.Phytohormone28-Homobrassinolide was raised in ‘Lily’, while methyl jasmonate amounts were much higher in ‘Hana’ after larva feeding. Jasmonic acid biosynthesis gene OPR (OPDA reductase) was significantly induced in ‘Lily’ comparing to ‘Hana’ in response to larval feeding. Blocking brassinosteroid (BR) biosynthesis using brassinazol (BRZ) elevated the expression of jasmonates biosynthesis gene OPR in both cultivars by almost 4-fold comparing to mock wounded plants. However, the magnitude of expression was much higher with resistant ‘Lily’ than susceptible ‘Hana’ larval feeding wounding. Collectively, the induction of antioxidants in infested potato plants is greatly involved in resistant mechanisms against attacking cutworm larvae. Relative gene expression studies suggest that antagonistic interaction between BR and JA could debilitate the anti-herbivory traits of potato plants against attacking cutworm larvae.