PT - JOURNAL ARTICLE AU - Vered Tzin AU - Yuko Hojo AU - Susan R. Strickler AU - Lee Julia Bartsch AU - Cairo M. Archer AU - Kevin R. Ahern AU - Shawn A. Christensen AU - Ivan Galis AU - Lukas A. Mueller AU - Georg Jander TI - <em>Spodoptera exigua</em> caterpillar feeding induces rapid defense responses in maize leaves AID - 10.1101/108076 DP - 2017 Jan 01 TA - bioRxiv PG - 108076 4099 - http://biorxiv.org/content/early/2017/02/13/108076.short 4100 - http://biorxiv.org/content/early/2017/02/13/108076.full AB - Insects such as beet armyworm caterpillars (Spodoptera exigua) cause extensive damage to maize (Zea mays) by consuming foliar tissue. Maize plants respond to such insect attack by triggering defense mechanisms that involve large changes in gene expression and the biosynthesis of specialized metabolites and defense signaling molecules. To investigate dynamic maize responses to herbivore feeding, leaves of maize inbred line B73 were infested with S. exigua caterpillars for 1 to 24 hours, followed by comprehensive transcriptomic and metabolomic characterization. Our results show that the most significant gene expression responses of maize to S. exigua feeding occur at early time points, within 4 to 6 hours after caterpillar infestation. However, both gene expression and metabolite profiles continued changing during the entire 24-hour experiment while photosynthesis genes were gradually decreased. The primary and specilaze metabolism shift maught be temporal and dynamic processes in the infested leaf tissue. We analyzed the effects of mutating genes in two major defense-related pathways, benzoxazinoids (Bx1 and Bx2) and jasmonic acid (Lox8), using Dissociation (Ds) transposon insertions in maize inbred line W22. Together, these results show that maize leaves shift to implementation of chemical defenses within one hour after the initiation of caterpillar attack. Thus, the induced biosynthesis of specialized metabolites can have major effects in maize-caterpillar interactions.HIGHLIGHT A comprehensive transcriptic and metabolomic profiling time course of maize foliar responses to caterpillar feeding identifies genes for the synthesis of benzoxazinoids and phytohormones.JAJasmonic acidDIMBOA4-dihydroxy-7-methoxy-1,4-benzoxazin-3-oneHDMBOA2-hydroxy-4,7-dimethoxy-1,4-benzoxazin-3-oneGlcglucosideFPKMFragments Per Kilobase of exon per Million fragmentsSAsalicylic acid