Project description:The purpose of this experiment was to assess the effect of a synergistic combination of natural pyrethrin and an ethylacetate extract of Piper nigrum seeds (a botanical insecticide). This effect was compared to the effects of P. nigrum or pyrethrin used alone. Due to the synergistic nature of the mixture, it was predicted that gene expression profiles in this treatment would reflect this effect. Keywords: insecticide response, stress-response
Project description:Nicotiana attenuata and Solanum nigrum were challenged with different insects: Manduca sexta and Tupiocoris notatus in different combinations Goals of the study are first to haracterize the transcriptional response of two native Solanaceous plants (Nicotiana attenuata and Solanum nigrum) to attack from two herbivorous pests common on Solanaceous crops (Manduca sexta and Tupiocoris notatus). And second to identify genes involved in herbivore vaccination phenomenon. After germination, inbred and genetically characterized lines of N. attenuata DI92 and S. nigrum Sn30 originally collected from southwestern Utah in 1988, and Jena Germany in 2000, respectively, were grown in a greenhouse. Eggs of Manduca sexta (abbreviated M. s.) came from the North Carolina State University - Entomology Insectary and were hatched under 37°C. Nymphs and adults of Tupiocoris notatus (abbreviated T. n.) came from laboratory colonies started in 2000 with individuals collected from our Utah field sites. Plant were challenged with these different insect and combinations of them. All plants for a given treatment were enclosed in glass-and-mesh insect cages to avoid cross-infection. After 24 h or 5 days the herbivores and their frass were removed, and the above ground biomass of each plant was flash-frozen in liquid nitrogen and stored at -80 °C until RNA extraction. Three independent replicate cages (biological replicates) were used for each of the 7 treatments resulting in a total of 21 cages per species. RNA extraction was performed according to the protocol using Trizol. The RNA samples represent a pooled sample from 4 plants grown in a cage. Keywords: Direct comparison