title: Foliar herbivory triggers local and long distance defense responses in maize.
abstract: Many studies have documented the induction of belowground defenses in plants in response to aboveground herbivory and vice versa, but the genes and signaling molecules mediating systemic induction are not well understood. We performed comparative microarray analysis on maize whorl and root tissues from the insect resistant inbred Mp708 in response to foliar feeding by fall armyworm (Spodoptera frugiperda) caterpillars. Although Mp708 has elevated jasmonic acid (JA) levels prior to herbivory, genes involved in JA biosynthesis were up-regulated in whorls in response to fall armyworm feeding. Alternatively, genes possibly involved in regulating ethylene (ET) perception and signaling were up-regulated in roots following foliar herbivory. Transcript levels of genes encoding proteins involved in direct defenses against herbivores were enhanced both in roots and leaves, but transcriptional factors and genes involved in various biosynthetic pathways were selectively down-regulated in the whorl. The results indicate that foliar herbivory by fall armyworm changes root gene expression pathways suggesting profound long distance signaling. Tissue specific induction and suppression of JA and ET signaling pathway genes provides a clue to their possible roles in signaling between the two distant tissue types that eventually triggers defense responses in the roots in response to foliar herbivory.
authors.affiliation: Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology Mississippi State University, MS, United States. aankala@emory.edu
authors.forename: Arunkanth
authors.initials: A
authors.lastname: Ankala
authors.forename: Rowena Y
authors.initials: RY
authors.lastname: Kelley
authors.forename: Dennis E
authors.initials: DE
authors.lastname: Rowe
authors.forename: William P
authors.initials: WP
authors.lastname: Williams
authors.forename: Dawn S
authors.initials: DS
authors.lastname: Luthe
mesh_terms: D000818:Animals; D053898:Biosynthetic Pathways / Q000235:genetics; D003517:Cyclopentanes / Q000378:metabolism; D005030:Ethylenes / Q000378:metabolism; D005247:Feeding Behavior; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000235:genetics*; D017343:Genes, Plant / Q000235:genetics*; D005838:Genotype; D060434:Herbivory; D006790:Host-Parasite Interactions; D020411:Oligonucleotide Array Sequence Analysis; D009928:Organ Specificity; D054883:Oxylipins / Q000378:metabolism; D010935:Plant Diseases / Q000276:immunology* / Q000469:parasitology; D018515:Plant Leaves / Q000235:genetics / Q000276:immunology / Q000469:parasitology / Q000502:physiology; D018517:Plant Roots / Q000235:genetics / Q000276:immunology / Q000469:parasitology / Q000502:physiology; D018520:Plant Shoots / Q000235:genetics / Q000276:immunology / Q000469:parasitology / Q000502:physiology; D015398:Signal Transduction / Q000235:genetics; D018411:Spodoptera / Q000502:physiology*; D059467:Transcriptome; D003313:Zea mays / Q000235:genetics / Q000276:immunology* / Q000469:parasitology / Q000502:physiology
chemical_list: D003517:Cyclopentanes; D005030:Ethylenes; D054883:Oxylipins; C011006:jasmonic acid; C036216:ethylene