Location: Crop Bioprotection Research
Title: Examination of the Effects of the Anti-Apoptotic Protein P35 on Caterpillars When Expressed in Corn Authors
Submitted to: Plant Biology Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: August 9, 2006
Publication Date: August 5, 2006
Citation: Pinkerton, T.S., Dowd, P.F., Behle, R.W. 2006. Examination of the effects of the anti-apoptotic protein p35 on caterpillars when expressed in corn [abstract]. American Society for Plant Biologists. Paper No. P46027. Technical Abstract: Autographica californica gene p35 encodes a caspase inhibitor that facilitates viral infection by blocking apoptosis in insect cells. The p35 gene has been expressed in plants, enhancing resistance to plant pathogens that induce apoptosis. Given the effect that p35 has on insect cells susceptibility to viral infection, we investigated the effect of p35 expressing maize on corn earworms(CW) and fall army worms (FW). Maize cultivar OH43 was transformed with a construct containing the p35 gene under control of the maize ubiquitin promoter and the BAR selectable marker. Presence of the gene was confirmed by PCR on genomic DNA from transgenic plants. Gene expression was confirmed by RT-PCR; however, no protein was observed by Western blots with a commercial anti-p35 antibody similar to previous observations with p35 in other plant species. Recombinant p35 protein in diets reduced growth of both CWs and FWs by over 50%. Mortality of CWs treated with Anticarsia gemmatalis virus was significantly increased when p35 was added. Occurrence of reduced feeding, size of larvae, and/or mortality of FWs and CWs fed to leaf disks was highly associated with the production of p35 mRNA. Occurrence of reduced feeding by FWs and CWs fed T1 leaf disks was highly associated with plant resistance to 1% Finale leaf painting. Low levels of nucleopolyhedronviruses were detected in colonies of FW and CW when moribund larvae were examined microscopically and by PCR; however, the p35 gene was not detected. This information suggests that efficacy of the viruses was enhanced by the presence of p35 in in vitro assays and when fed corn tissue expressing p35, although additional observations suggest an additional mode of action. Results indicate that p35 may have potential use for in planta insect control.