title: Maize Plants Recognize Herbivore-Associated Cues from Caterpillar Frass.
abstract: Caterpillar behaviors such as feeding, crawling, and oviposition are known to induce defenses in maize and other plant species. We examined plant defense responses to another important caterpillar behavior, their defecation. Fall armyworms (FAW, Spodoptera frugiperda), a major threat to maize (Zea mays), are voracious eaters and deposit copious amounts of frass in the enclosed whorl tissue surrounding their feeding site, where it remains for long periods of time. FAW frass is composed of molecules derived from the host plant, the insect itself, and associated microbes, and hence provides abundant cues that may alter plant defense responses. We observed that proteins from FAW frass initially induced wound-responsive defense genes in maize; however, a pathogenesis-related (pr) defense gene was induced as the time after application increased. Elicitation of pathogen defenses by frass proteins was correlated with increased herbivore performance and reduced fungal pathogen performance over time. These responses differ from the typical plant response to oral secretions of the FAW. The results pave the way for identification of protein molecule(s) from the excretion of an herbivore that elicits pathogen defense responses while attenuating herbivore defenses in plants.
authors: Intercollegiate Graduate Program in Plant Biology, Huck Institute of Life Sciences, Pennsylvania State University, University Park, PA, USA.|Department of Plant Science, Pennsylvania State University, University Park, PA, USA.|Center for Chemical Ecology, Pennsylvania State University, University Park, PA, USA.
authors: Swayamjit
authors: S
authors: Ray
authors: Department of Plant Science, Pennsylvania State University, University Park, PA, USA.
authors: Iffa
authors: I
authors: Gaffor
authors: Center for Chemical Ecology, Pennsylvania State University, University Park, PA, USA.|Department of Entomology, Pennsylvania State University, University Park, PA, USA.
authors: Flor E
authors: FE
authors: Acevedo
authors: Center for Chemical Ecology, Pennsylvania State University, University Park, PA, USA.|Department of Entomology, Pennsylvania State University, University Park, PA, USA.
authors: Anjel
authors: A
authors: Helms
authors: Department of Agronomy, National Taiwan University, Taipei, Taiwan.
authors: Wen-Po
authors: WP
authors: Chuang
authors: Center for Chemical Ecology, Pennsylvania State University, University Park, PA, USA.|Department of Entomology, Pennsylvania State University, University Park, PA, USA.
authors: John
authors: J
authors: Tooker
authors: Center for Chemical Ecology, Pennsylvania State University, University Park, PA, USA.|Department of Entomology, Pennsylvania State University, University Park, PA, USA.
authors: Gary W
authors: GW
authors: Felton
authors: Department of Plant Science, Pennsylvania State University, University Park, PA, USA. dsl14@psu.edu.
authors: Dawn S
authors: DS
authors: Luthe
mesh_terms: D000818:Animals; D001203:Ascomycota / Q000502:physiology*; D018506:Gene Expression Regulation, Plant; D060434:Herbivory; D019476:Insect Proteins / Q000378:metabolism; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology*; D054790:Ribosome Inactivating Proteins, Type 2 / Q000235:genetics / Q000378:metabolism; D018411:Spodoptera / Q000502:physiology*; D003313:Zea mays / Q000235:genetics / Q000382:microbiology* / Q000502:physiology*
chemical_list: D019476:Insect Proteins; D054790:Ribosome Inactivating Proteins, Type 2; C093156:ribosome-inactivating protein 2, maize
keywords: Fall armyworm; Frass; Maize