INSECT HERBIVORY IS A MAJOR LIMITING FACTOR FOR MAIZE PRODUCTION. THE IDENTITY OF THE SIGNAL(S) THAT CONVEY INFORMATION FROM THE AREA OF A PLANT INFESTED WITH INSECTS TO UNINFESTED SYSTEMIC TISSUE OR TO NEIGHBORING PLANTS, WHICH PREPARES THE UNCHALLENGED TISSUES FOR DEFENSE, REMAINS ELUSIVE. UNLIKE IN DICOTS WHERE SYSTEMIC SIGNALING IS BETTER UNDERSTOOD, MONOCOTS ARE MOST VULNERABLE TO INSECT DAMAGE AT THE SEEDLING STAGE WHERE ALL THE ABOVEGROUND ORGANS ARE CONNECTED TO EACH OTHER SOLELY THROUGH THEIR ROOT SYSTEMS. THIS REALIZATION PROMPTS THE HYPOTHESIS THAT IN INTRA-PLANT SIGNALING, IN ADDITION TO VOLATILE-MEDIATED PRIMING, A DAMAGED LEAF-DERIVED NON-VOLATILE SIGNAL MUST TRAVERSE ROOTS BEFORE ACCESSING OTHER LEAVES. TO TEST THIS HYPOTHESIS, THIS PROJECT WILL UTILIZE A UNIQUE COLLECTION OF MAIZE KNOCK-OUT MUTANTS AFFECTED IN SYSTEMIC SIGNALING, COUPLED WITH THE POWER OF TRANSCRIPTOME AND OXYLIPIN PROFILING TO IDENTIFY (1) A NON-VOLATILE SIGNAL(S) PRODUCED IN AN INSECT DAMAGED AREA, WHICH IS SUBSEQUENTLY TRANSPORTED VIA PHLOEM INTO ROOTS BEFORE SYSTEMIC DISTRIBUTION; AND/OR (2) A SECONDARY SIGNAL(S) PRODUCED IN ROOTS TRANSPORTED BY XYLEM TO THE REST OF THE PLANT. THE OTHER MAJOR GOAL OF THE PROJECT WILL EXPLORE A VOLATILE ORIGIN OF INSECT-INDUCED LONG DISTANCE INTER- AND INTRA-PLANT SIGNALING. THIS PROPOSAL'S CENTRAL PREMISE IS ROOTED IN THE DISCOVERY THAT MAIZE GREEN LEAF VOLATILES (GLV)- AND TRAUMATIN (TA)-DEFICIENT LIPOXYGENASE10 (LOX10) MUTANT IS UNABLE TO SYSTEMICALLY INDUCE NOT ONLY THE MAJOR DEFENSE HORMONES ABA AND JA, BUT ALSO A NUMBER OF NOVEL OXYLIPINS NAMED HERE AS SYSTEMIC OXYLIPIN SIGNALS (SOS) IN RESPONSE TO LOCAL HERBIVORY. THIS AND MASSIVE TRANSCRIPTOME REPROGRAMMING OBSERVED IN WILD TYPE BUT NOT IN THE LOX10 MUTANT ROOTS SUGGEST THAT LOX10 IS A MASTER REGULATOR OF HERBIVORE-INDUCED SYSTEMIC RESISTANCE (ISR). LOX10 MUTANTS AND OTHER SOS MUTANTS IMPACTED IN LONG-DISTANCE SIGNALING, WILL BE USED AS EXCELLENT GENETIC TOOLS TO ELUCIDATE THE ISR SIGNALS. THE PROJECT IS EXPECTED TO YIELD: 1) NOVEL VOLATILE AND NON-VOLATILE SOS, SIGNALING PEPTIDES, AND ISR GENETIC NETWORKS. 2) IDENTIFICATION OF NEW FUNCTIONS FOR UNCHARACTERIZED OXYLIPINS; 3) CONNECT THE BELOW-GROUND ORGANS WITH THE PRODUCTION AND TRANSDUCTION OF ORGANISMAL-WIDE SYSTEMIC AND INTER-PLANT DEFENSE SIGNALING. THIS PROJECT IS INSPIRED BY THE JUXTAPOSITION BETWEEN PLANT VS HUMAN OXYLIPIN BIOLOGY KNOWLEDGE. HUMAN OXYLIPIN RESEARCH HAS REVOLUTIONIZED DIVERSE MEDICAL FIELDS RESULTING IN THE DEVELOPMENT OF ~60% OF THE CURRENT HUMAN DRUGS, ALL OF WHICH TARGET OXYLIPIN PRODUCTION, TRANSPORT, PERCEPTION, OR EFFECTS. WITH THE EXCEPTION OF THE PROGRESS MADE IN OUR UNDERSTANDING OF THE DEFENSE HORMONE JA, PRACTICALLY NOTHING IS KNOWN ABOUT THE BIOLOGICAL RELEVANCE OF THE OTHER ~600 REPORTED PLANT OXYLIPIN SPECIES. BRIDGING THE GAPS IN KNOWLEDGE AND UNCOVERING THE BIOLOGY OF PLANT OXYLIPINS IN THE INDUCTION OF LONG LASTING SSYTEMIC RESISTANCE IS THE MAJOR FOCUS OF THIS PROJECT.