Transcriptional analysis of physiological pathways in a generalist herbivore: responses to different host plants and plant structures by the cotton bollworm (CBW) Helicoverpa armigera [CottonStructures]

Transcriptional profiling comparing gut tissue from fifth instar larvae exposed to five different diets, namely cotton fruit or boll (B), cotton flower bud or square (SQ), cotton leaf (L), pinto bean-based artificial diet (PB) and wheat-based artificial Lepidoptera diet (BIO). The generalist lepidopteran herbivore Helicoverpa armigera can consume host plants in more than 40 plant families, and often utilizes several different tissues on the same plant. It is believed that generalists owe their success to the deployment of various members of multigene families of detoxicative and digestive enzymes, a strategy that may also be responsible for rapid evolution of insecticide resistance. However studies of generalist adaptations have been limited to specific genes or gene families, and an overview of how these adaptations are orchestrated at the transcriptional level is lacking. To investigate the previously-shown CBW preferences for different cotton plant structures, we measured net weight gain of larvae that fed on different cotton organs and compared the transcript profiles of larval guts in response to these organs and towards two different artificial diets commonly used for laboratory rearing of this species, using a two-color alternating loop design microarray experiment. Two-color alternating loop design. Biological replicates: 4 (10 individuals per replicate). 20 samples total.