| Title: | Tomato Chemical Defenses Intensify Corn Earworm (Helicoverpa zea) Mortality from Opportunistic Bacterial Pathogens |
| Author(s): | Mason CJ; Peiffer M; Hoover K; Felton G; |
| Address: | "501 ASI Building Department of Entomology, The Pennsylvania State University, University Park, PA, 16823, USA. charles.mason@usda.gov. Tropical Pest Genetics and Molecular Biology Research Unit, Daniel K Inouye U.S. Pacific Basin Agricultural Research Center, Agricultural Research Service, USDA, 64 Nowelo Street, Hilo, HI, 96720, USA. charles.mason@usda.gov. 501 ASI Building Department of Entomology, The Pennsylvania State University, University Park, PA, 16823, USA" |
| DOI: | 10.1007/s10886-023-01420-7 |
| ISSN/ISBN: | 1573-1561 (Electronic) 0098-0331 (Linking) |
| Abstract: | "Insect herbivores face multiple challenges to their ability to grow and reproduce. Plants can produce a series of defenses that disrupt and damage the herbivore digestive system, which are heightened upon injury by insect feeding. Additionally, insects face threats from virulent microorganisms that can incur their own set of potential costs to hosts. Microorganisms that invade through the digestive system may function in concert with defenses generated by plants, creating combined assailments on host insects. In our study, we evaluated how tomato defenses interact with an enteric bacterial isolate, Serratia marcescens, in the corn earworm (Helicoverpa zea). We performed bioassays using different tomato cultivars that were induced by methyl jasmonate and larvae orally inoculated with a S. marcescens isolate. Untreated corn earworm larval mortality was low on constitutive tomato, while larvae inoculated with S. marcescens exhibited > 50% mortality within 5 days. Induction treatments elevated both control mortality (~ 45%) and in combination with S. marcescens (> 95%). Larvae also died faster when encountering induced defenses and Serratia. Using a tomato mutant, foliar polyphenol oxidase activity likely had stronger impacts on S. marcescens-mediated larval mortality. Induction treatments also elevated the number of bacterial colony-forming units in the hemolymph of larvae inoculated with Serratia. Larval mortality by S. marcescens was low (< 10%) on artificial diets. Our results demonstrate that plant chemical defenses enhance larval mortality from an opportunistic gut microbe. We propose that the combined damage from both the plant and microbial agent overwhelm the herbivore to increase mortality rates and expedite host death" |
| Keywords: | Animals Zea mays *Solanum lycopersicum *Moths Larva/microbiology Bacteria Induction Jasmonate Lepidoptera Midgut Noctuidae Oxidative Stress; |
| Notes: | "MedlineMason, Charles J Peiffer, Michelle Hoover, Kelli Felton, Gary eng 2018-67012-27979/National Institute of Food and Agriculture/ 2017-67013-26596/National Institute of Food and Agriculture/ 2023/03/26 J Chem Ecol. 2023 Jun; 49(5-6):313-324. doi: 10.1007/s10886-023-01420-7. Epub 2023 Mar 25" |
