Potato Expressing Beetle-Specific Bacillus thuringiensis Cry3Aa Toxin Reduces Performance of a Moth

Abstract

Expression of the Bacillus thuringiensis beetle-specific toxin Cry3Aa, which renders a genetically modified potato cultivar resistant to the Colorado potato beetle Leptinotarsa decemlineata, exerts a deleterious effect on the polyphagous moth Spodoptera littoralis. The caterpillars of S. littoralis feed less and produce smaller pupae on the genetically modified cultivar (NewLeaf Superior) than on the parental nontransgenic cultivar (Superior). The conversion efficiencies of total dry matter, combustion heat, carbon, and nitrogen from leaves to insect biomass are similar on both cultivars. In spite of similar food utilization and a relatively small difference in the body mass at pupation, female adults that developed from caterpillars fed on NewLeaf Superior lay a mean of 309 eggs compared to a mean of 713 eggs deposited by females that developed from caterpillars fed on Superior. Because of this difference and a simultaneous reduction in fertility (egg hatchability) from 78 to 48%, a pair of adults that fed as larvae on NewLeaf Superior produces only 148 larvae, whereas a pair of adults that fed as larvae on Superior produces 556 larvae. We suggest that small amounts of Cry3Aa that accumulate in insect tissue and persist until the adult stage are responsible for the decline in reproduction.

Effect of Host Plants on Biochemical Markers of Oxidative Stress within Tissues of Pea Aphid

“…These differences may be associated with diversity of defense mechanisms of host plants against the aphids. Hussein et al (2006) found that growth and reproduction of Spodoptera littoralis (Boisduval) was reduced after potato plants were substituted for the semi-artificial diet. This diet switch caused a rise of ROS as well as an elevation of the antioxidant enzymes within the tissues of S. littoralis (Krishnan and Kodrik 2006).…”

THE INFLUENCE OF DIETARY α‐SOLANINE ON THE WAXMOTH Galleria mellonella L

“…This is in line with results of Adamski et al () who showed that plant‐extracted glycoalkaloids decreased hatching success of Spodoptera exigua eggs, which was correlated with chemical concentrations. Hussein et al () also reported that potato plants decreased life‐table parameters including growth and reproduction of the lepidopteran pest moth, S. littoralis . We infer that GST reduces α‐solanine‐induced oxidative stress in G. mellonella as suggested for some other insect groups (Leszczynski et al, ).…”

Insecticidal Effects of Hemocoelic Delivery of Bacillus thuringiensis Cry Toxins in Achaea janata Larvae

“…No organ or cell other than the midgut epithelial cell has been established as target organ for Cry toxin action in insect pests. However, reports do suggest interaction of Cry toxins with other tissues in the insect body cavity (Arpaia et al, 2000; Cerstians et al, 2001; Hussein et al, 2006). In the larval hemocoel, the major tissues or organs present include the fat body, Malpighian tubule, and salivary gland, where they all play important functions during post-embryonic development.…”

“…Earlier studies have suggested a possible mechanism where Cry toxins ingested along with the feed can also penetrate from gut through the gut wall to hemolymph in the insect hemocoel, which accumulate in the insect body and suppress the reproductive potential (Arpaia et al, 2000; Hussein et al, 2006). The fat body of lepidopteran larvae is the principal metabolic center, synthesizes, and releases a large number of haemolymph proteins including hexamerins, which play an important role during the pupal-adult transformation (Kanost et al, 1990).…”