title: Molecular cloning of the tomato Hairless gene implicates actin dynamics in trichome-mediated defense and mechanical properties of stem tissue.
abstract: Trichomes are epidermal structures that provide a first line of defense against arthropod herbivores. The recessive hairless (hl) mutation in tomato (Solanum lycopersicum L.) causes severe distortion of trichomes on all aerial tissues, impairs the accumulation of sesquiterpene and polyphenolic compounds in glandular trichomes, and compromises resistance to the specialist herbivore Manduca sexta Here, we demonstrate that the tomato Hl gene encodes a subunit (SRA1) of the highly conserved WAVE regulatory complex that controls nucleation of actin filaments in a wide range of eukaryotic cells. The tomato SRA1 gene spans a 42-kb region containing both Solyc11g013280 and Solyc11g013290 The hl mutation corresponds to a complex 3-kb deletion that removes the last exon of the gene. Expression of a wild-type SRA1 cDNA in the hl mutant background restored normal trichome development, accumulation of glandular trichome-derived metabolites, and resistance to insect herbivory. These findings establish a role for SRA1 in the development of tomato trichomes and also implicate the actin-cytoskeleton network in cytosolic control of specialized metabolism for plant defense. We also show that the brittleness of hl mutant stems is associated with altered mechanical and cell morphological properties of stem tissue, and demonstrate that this defect is directly linked to the mutation in SRA1.
authors.affiliation: Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA Graduate School of International Agricultural Technology and Crop Biotechnology Institute/GreenBio Science and Technology, Seoul National University, Pyeongchang 25354, Republic of Korea kangjinho@snu.ac.kr howeg@msu.edu.
authors.forename: Jin-Ho
authors.initials: JH
authors.lastname: Kang
authors.affiliation: Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA.
authors.forename: Marcelo L
authors.initials: ML
authors.lastname: Campos
authors.affiliation: Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA Department of Plant Biology, Michigan State University, East Lansing, MI 48824, USA.
authors.forename: Starla
authors.initials: S
authors.lastname: Zemelis-Durfee
authors.affiliation: Department of Plant Biology, Michigan State University, East Lansing, MI 48824, USA.
authors.forename: Jameel M
authors.initials: JM
authors.lastname: Al-Haddad
authors.affiliation: Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA.
authors.forename: A Daniel
authors.initials: AD
authors.lastname: Jones
authors.affiliation: Department of Plant Biology, Michigan State University, East Lansing, MI 48824, USA.
authors.forename: Frank W
authors.initials: FW
authors.lastname: Telewski
authors.affiliation: Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA Department of Plant Biology, Michigan State University, East Lansing, MI 48824, USA.
authors.forename: Federica
authors.initials: F
authors.lastname: Brandizzi
authors.affiliation: Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA kangjinho@snu.ac.kr howeg@msu.edu.
authors.forename: Gregg A
authors.identifier: 0000-0002-9218-979X
authors.initials: GA
authors.lastname: Howe
mesh_terms: D000199:Actins / Q000502:physiology*; D000818:Animals; D003001:Cloning, Molecular; D060467:Disease Resistance / Q000235:genetics* / Q000502:physiology; D017353:Gene Deletion; D017343:Genes, Plant / Q000235:genetics* / Q000502:physiology; D060434:Herbivory; D018551:Solanum lycopersicum / Q000235:genetics* / Q000502:physiology; D018402:Manduca; D018547:Plant Stems / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D064201:Trichomes / Q000502:physiology*
chemical_list: D000199:Actins
keywords: Actin-cytoskeleton network; cell wall; mechanical properties; plant-insect interaction; specialized metabolism; terpenoid; tomato (Solanum lycopersicum); trichome.