title: The volatile 6-pentyl-2H-pyran-2-one from Trichoderma atroviride regulates Arabidopsis thaliana root morphogenesis via auxin signaling and ETHYLENE INSENSITIVE 2 functioning.
abstract: Plants interact with root microbes via chemical signaling, which modulates competence or symbiosis. Although several volatile organic compounds (VOCs) from fungi may affect plant growth and development, the signal transduction pathways mediating VOC sensing are not fully understood. 6-pentyl-2H-pyran-2-one (6-PP) is a major VOC biosynthesized by Trichoderma spp. which is probably involved in plant-fungus cross-kingdom signaling. Using microscopy and confocal imaging, the effects of 6-PP on root morphogenesis were found to be correlated with DR5:GFP, DR5:VENUS, H2B::GFP, PIN1::PIN1::GFP, PIN2::PIN2::GFP, PIN3::PIN3::GFP and PIN7::PIN7::GFP gene expression. A genetic screen for primary root growth resistance to 6-PP in wild-type seedlings and auxin- and ethylene-related mutants allowed identification of genes controlling root architectural responses to this metabolite. Trichoderma atroviride produced 6-PP, which promoted plant growth and regulated root architecture, inhibiting primary root growth and inducing lateral root formation. 6-PP modulated expression of PIN auxin-transport proteins in a specific and dose-dependent manner in primary roots. TIR1, AFB2 and AFB3 auxin receptors and ARF7 and ARF19 transcription factors influenced the lateral root response to 6-PP, whereas EIN2 modulated 6-PP sensing in primary roots. These results indicate that root responses to 6-PP involve components of auxin transport and signaling and the ethylene-response modulator EIN2.
authors.affiliation: Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo. Edificio B3, Ciudad Universitaria. CP 58030, Morelia, Michoacán, México.
authors.forename: Amira
authors.initials: A
authors.lastname: Garnica-Vergara
authors.affiliation: Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo. Edificio B3, Ciudad Universitaria. CP 58030, Morelia, Michoacán, México.
authors.forename: Salvador
authors.initials: S
authors.lastname: Barrera-Ortiz
authors.affiliation: Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo. Edificio B3, Ciudad Universitaria. CP 58030, Morelia, Michoacán, México.
authors.forename: Edith
authors.initials: E
authors.lastname: Muñoz-Parra
authors.affiliation: Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo. Edificio B3, Ciudad Universitaria. CP 58030, Morelia, Michoacán, México.
authors.forename: Javier
authors.initials: J
authors.lastname: Raya-González
authors.affiliation: Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo. Edificio B3, Ciudad Universitaria. CP 58030, Morelia, Michoacán, México.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Méndez-Bravo
authors.affiliation: Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo. Edificio B3, Ciudad Universitaria. CP 58030, Morelia, Michoacán, México.
authors.forename: Lourdes
authors.initials: L
authors.lastname: Macías-Rodríguez
authors.affiliation: Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo. Edificio B3, Ciudad Universitaria. CP 58030, Morelia, Michoacán, México.
authors.forename: León Francisco
authors.initials: LF
authors.lastname: Ruiz-Herrera
authors.affiliation: Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo. Edificio B3, Ciudad Universitaria. CP 58030, Morelia, Michoacán, México.
authors.forename: José
authors.initials: J
authors.lastname: López-Bucio
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000378:metabolism*; D001692:Biological Transport / Q000187:drug effects; D018533:Biomass; D003624:Darkness; D005030:Ethylenes / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D007210:Indoleacetic Acids / Q000378:metabolism*; D009024:Morphogenesis / Q000187:drug effects*; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development*; D011753:Pyrones / Q000737:chemistry / Q000494:pharmacology; D011956:Receptors, Cell Surface / Q000378:metabolism*; D036226:Seedlings / Q000187:drug effects / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D014242:Trichoderma / Q000737:chemistry*; D055549:Volatile Organic Compounds / Q000737:chemistry / Q000494:pharmacology*
chemical_list: C008798:6-pentylpyrone; D029681:Arabidopsis Proteins; C119963:EIN2 protein, Arabidopsis; D005030:Ethylenes; D007210:Indoleacetic Acids; D011753:Pyrones; D011956:Receptors, Cell Surface; D055549:Volatile Organic Compounds; C036216:ethylene
keywords: 6-pentyl-2H-pyran-2-one (6-PP); Trichoderma; auxin; ethylene (ET); phytostimulation; root development