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ARS Home » Southeast Area » Gainesville, Florida » Center for Medical, Agricultural and Veterinary Entomology » Chemistry Research » Research » Publications at this Location » Publication #372093

Research Project: Molecular and Biochemical Characterization of Biotic and Abiotic Stress on Plant Defense Responses in Maize

Location: Chemistry Research

Title: Genetic elucidation of complex biochemical traits in crop innate immunity

Author
item DING, YEZHANG - University Of California, San Diego
item WECKWERTH, PHILIPP - University Of California, San Diego
item PORETSKY, ELLY - University Of California, San Diego
item MURPHY, KATHERINE - University Of California, Davis
item SIMS, JAMES - Eth Zurich
item SALDIVAR, EVAN - University Of California, San Diego
item Christensen, Shawn
item YANG, BING - University Of Missouri
item CHAR, SI NIAN - University Of Missouri
item TONG, ANH-DAO - University Of California, San Diego
item SHEN, ZHOUXIN - University Of California, San Diego
item KREMLING, KARL - Cornell University - New York
item BUCKLER, EDWARD - Cornell University - New York
item KONO, TOM - University Of Minnesota
item NELSON, DAVID - University Of Tennessee
item BOHLMAN, JORG - University Of British Columbia
item Bakker, Matthew
item Vaughan, Martha
item KHALIL, AHMED - University Of California, San Diego
item BETSIASHVILI, MARIAM - University Of California, San Diego
item BRIGGS, STEVEN - University Of California, San Diego
item ZERBE, PHILIPP - University Of California, Davis
item SCHMELZ, ERIC - University Of California, San Diego
item HUFFAKER, ALISA - University Of California, San Diego

Submitted to: Nature Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/14/2020
Publication Date: N/A
Citation: N/A

Interpretive Summary: Losses in corn production due to microbial pathogens can result in billions of dollars in lost revenue annually. Despite these great economic losses, only a limited amount of research has demonstrated how corn can defend itself against pathogens using innate antibiotics. Scientists at the Center for Medical, Agricultural and Veterinary Entomology in Gainesville, FL in collaboration with researchers at the University of California at San Diego have identified several new corn-produced compounds that exhibit antibiotic activity. These compounds are termed zealexins (Zx). In our study, genetic testing demonstrated that the antibiotic compounds and the genes that produce them play a significant role in disease resistance. Knowledge from these analyses will contribute to breeding practices that can incorporate these antibiotics into maize for greater disease protection, thus to alleviate large economic losses resulting from microbial-based threats to corn production.

Technical Abstract: Specialized metabolites provide key layers of innate immunity underlying crop resistance; however, challenges in resolving pathways limit the understanding of functions and applications. To understand maize (Zea mays) terpenoid antibiotics underlying disease resistance we integrated large-scale omic correlations, association mapping, enzyme-structure function studies and targeted mutagenesis. Three zealexin (Zx) gene clusters comprised of four sesquiterpene synthases (Zx1-4) and six cytochrome P450s (CYP) in the CYP71Z (Zx5-7) and CYP81A (Zx8-10) families drive the production of diverse antibiotic cocktails. Gene duplications, ensuring pathway resiliency to single null mutations, are combined with enzyme substrate-promiscuity to create a biosynthetic hourglass pathway utilizing diverse substrates to yield complex combinatorial mixtures. Zx pathway activation mediating pathogen resistance occurs during a dramatic reorganization of 50% of the measurable proteome and suppression of constitutive defense pathways. The elucidated genetic basis of complex biochemical phenotypes mediating disease resistance informs innovative strategies for transferring durable chemical immunity between crops.