U.S. flagAn official website of the United States government
                    Here's how you know **Official websites use .gov**
                            
                            A **.gov** website belongs to an official government organization in the United States.
 **Secure .gov websites use HTTPS**
                            
                            A **lock** (                            
                              A locked padlock                                                      
                            
                            ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Menu Agricultural Research Service
						
                    U.S. DEPARTMENT OF AGRICULTURE
 Crop Bioprotection Research: Peoria, IL
 close



    Research

                    Research Projects
                                    Publications
                                    Collaborations
                                    News
                People

                    Staff Listing
                                    Careers


        


                    NCAUR HomepageSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home Midwest Area Peoria, Illinois National Center for Agricultural Utilization Research Crop Bioprotection Research Research Publications at this Location





- ARS National Programs
- Search for a scientific manuscript
- Search for a research project
- ARS Software
- Programs and Projects
- Collaborations
- Subjects of Investigation
- Publications

Title:   Author  item
                                            Johnson, Ericitem
                                            Berhow, Markitem
                                            Dowd, Patrick
  Submitted to: Journal of Agricultural and Food Chemistry
                                    Publication Type: Peer Reviewed Journal
                                    Publication Acceptance Date: 3/23/2007
                                    Publication  Date: 4/18/2007
                                    Citation: Johnson, E.T., Berhow, M.A., Dowd, P.F. 2007. Expression of a maize Myb transcription factor driven by a putative silk-specific promoter significantly enhances resistance to Helicoverpa zea in transgenic maize. Journal of Agricultural and Food Chemistry. 55(8):2998-3003.Interpretive Summary: The problem of ear mold toxins/carcinogens (mycotoxins) in corn causes hundreds of millions of dollars of losses to the U.S. each year and limits the exportability of U.S. corn.  Insects can carry mycotoxin-producing fungi and damage corn so that these fungi may more readily colonize corn.  The commercial Bt corn hybrids are effective against some ear feeding pests, but better control of others is needed.  Using natural genes from corn, a novel gene combination directing the synthesis of corn earworm resistance compounds only to corn silks was evaluated in transgenic plants for activity against corn earworms.  Successful synthesis of the resistance compounds was able to increase mortality in a corn earworm susceptible line to a level similar to a more resistant line.  Proper introduction of the gene could result in more resistant corn which would have less insect damage and lower levels of mycotoxins, which would be safer for consumers and more acceptable to importers.
                                Technical Abstract: 
Hi II maize (Zea mays) plants were engineered to express maize p1 cDNA, a Myb transcription factor, controlled by a putative silk specific promoter, for secondary metabolite production and corn earworm resistance.  Transgene expression did not enhance silk color, but about half of the transformed plant silks displayed browning when cut, which indicated the presence of p1-produced secondary metabolites.  Levels of maysin, a secondary metabolite with insect toxicity, were highest in newly emerged browning silks.  Insect resistance of transgenic silks, regardless of a visible browning reaction, was highest at emergence and declined with maturity.  Mean survivor weights of corn earworm larvae fed mature browning transgenic silks were significantly lower than weights of those fed mature non-browning transgenic silks.  Some transgenic pericarps browned with drying and contained similar molecules found in pericarps expressing a dominant p1 allele, suggesting the promoter may not be silk specific.


Return to top


Connect with ARS Sign up


ARS Home
                            USDA.gov
                            Plain Writing
                            Policies & Links
                            Civil Rights Statements
                            FOIA
                            Accessibility Statement
                            Privacy Policy
                            Non-Discrimination Statement
                            Quality of Information
                            USA.gov
                            WhiteHouse.gov