title: Host-induced gene silencing inhibits the biotrophic pathogen causing downy mildew of lettuce.
abstract: Host-induced gene silencing (HIGS) is an RNA interference-based approach in which small interfering RNAs (siRNAs) are produced in the host plant and subsequently move into the pathogen to silence pathogen genes. As a proof-of-concept, we generated stable transgenic lettuce plants expressing siRNAs targeting potentially vital genes of Bremia lactucae, a biotrophic oomycete that causes downy mildew, the most important disease of lettuce worldwide. Transgenic plants, expressing inverted repeats of fragments of either the Highly Abundant Message #34 (HAM34) or Cellulose Synthase (CES1) genes of B. lactucae, specifically suppressed expression of these genes, resulting in greatly reduced growth and inhibition of sporulation of B. lactucae. This demonstrates that HIGS can provide effective control of B. lactucae in lettuce; such control does not rely on ephemeral resistance conferred by major resistance genes and therefore offers new opportunities for durable control of diverse diseases in numerous crops.
authors.affiliation: Genome Center, University of California, Davis, CA, USA.
authors.forename: Manjula
authors.initials: M
authors.lastname: Govindarajulu
authors.affiliation: Department of Plant Pathology, University of California, Davis, CA, USA.
authors.forename: Lynn
authors.initials: L
authors.lastname: Epstein
authors.affiliation: Genome Center, University of California, Davis, CA, USA.
authors.forename: Tadeusz
authors.initials: T
authors.lastname: Wroblewski
authors.affiliation: Genome Center, University of California, Davis, CA, USA.|Departments of Plant Science, Molecular & Cellular Biology, Medical Microbiology & Immunology, University of California, Davis, CA, USA.
authors.forename: Richard W
authors.initials: RW
authors.lastname: Michelmore
mesh_terms: D020868:Gene Silencing; D018545:Lactuca / Q000235:genetics / Q000382:microbiology*; D009868:Oomycetes / Q000235:genetics / Q000502:physiology*; D010935:Plant Diseases / Q000276:immunology / Q000382:microbiology*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000382:microbiology*; D034622:RNA Interference
keywords: Bremia lactucae; HIGS; Lactuca sativa; RNA interference; disease resistance; gene silencing