| Title: | Plants on constant alert: elevated levels of jasmonic acid and jasmonate-induced transcripts in caterpillar-resistant maize |
| Author(s): | Shivaji R; Camas A; Ankala A; Engelberth J; Tumlinson JH; Williams WP; Wilkinson JR; Luthe DS; |
| Address: | "Department of Biochemistry and Molecular Biology, Mississippi State University, Mississippi State, MS 39762, USA" |
| DOI: | 10.1007/s10886-010-9752-z |
| ISSN/ISBN: | 1573-1561 (Electronic) 0098-0331 (Linking) |
| Abstract: | "This study was conducted to determine if constitutive levels of jasmonic acid (JA) and other octadecanoid compounds were elevated prior to herbivory in a maize genotype with documented resistance to fall armyworm (Spodoptera frugiperda) and other lepidopteran pests. The resistant inbred Mp708 had approximately 3-fold higher levels of jasmonic acid (JA) prior to herbivore feeding than the susceptible inbred Tx601. Constitutive levels of cis-12-oxo-phytodienoic acid (OPDA) also were higher in Mp708 than Tx601. In addition, the constitutive expression of JA-inducible genes, including those in the JA biosynthetic pathway, was higher in Mp708 than Tx601. In response to herbivory, Mp708 generated comparatively higher levels of hydrogen peroxide, and had a greater abundance of NADPH oxidase transcripts before and after caterpillar feeding. Before herbivore feeding, low levels of transcripts encoding the maize insect resistance cysteine protease (Mir1-CP) and the Mir1-CP protein were detected consistently. Thus, Mp708 appears to have a portion of its defense pathway primed, which results in constitutive defenses and the ability to mount a stronger defense when caterpillars attack. Although the molecular mechanisms that regulate the constitutive accumulation of JA in Mp708 are unknown, it might account for its enhanced resistance to lepidopteran pests. This genotype could be valuable in studying the signaling pathways that maize uses to response to insect herbivores" |
| Keywords: | "Animals Breeding Cyclopentanes/*metabolism Fatty Acids, Unsaturated/metabolism Gene Expression Regulation, Plant Hydrogen Peroxide/metabolism Lepidoptera/*physiology NADPH Oxidases/genetics Oxidoreductases Acting on CH-CH Group Donors/genetics Oxylipins/*;" |
| Notes: | "MedlineShivaji, Renuka Camas, Alberto Ankala, Arunkanth Engelberth, Jurgen Tumlinson, James H Williams, W Paul Wilkinson, Jeff R Luthe, Dawn Sywassink eng Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. 2010/02/12 J Chem Ecol. 2010 Feb; 36(2):179-91. doi: 10.1007/s10886-010-9752-z. Epub 2010 Feb 11" |
