Naturally Occurring Broad-Spectrum Powdery Mildew Resistance in a Central American Tomato Accession Is Caused by Loss of Mlo Function

The resistant cherry tomato (Solanum lycopersicum var. cerasiforme) line LC-95, derived from an accession collected in Ecuador, harbors a natural allele (ol-2) that confers broad-spectrum and recessively inherited resistance to powdery mildew (Oidium neolycopersici). As both the genetic and phytopat...

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Main Authors: Yuling Bai, Stefano Pavan, Zheng Zheng, Nana F. Zappel, Anja Reinstädler, Concetta Lotti, Claudio De Giovanni, Luigi Ricciardi, Pim Lindhout, Richard Visser, Klaus Theres, Ralph Panstruga
Format: Article
Language:English
Published: The American Phytopathological Society 2008-01-01
Series:Molecular Plant-Microbe Interactions
Subjects:
Online Access:https://apsjournals.apsnet.org/doi/10.1094/MPMI-21-1-0030
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author Yuling Bai
Stefano Pavan
Zheng Zheng
Nana F. Zappel
Anja Reinstädler
Concetta Lotti
Claudio De Giovanni
Luigi Ricciardi
Pim Lindhout
Richard Visser
Klaus Theres
Ralph Panstruga
author_facet Yuling Bai
Stefano Pavan
Zheng Zheng
Nana F. Zappel
Anja Reinstädler
Concetta Lotti
Claudio De Giovanni
Luigi Ricciardi
Pim Lindhout
Richard Visser
Klaus Theres
Ralph Panstruga
author_sort Yuling Bai
collection DOAJ
description The resistant cherry tomato (Solanum lycopersicum var. cerasiforme) line LC-95, derived from an accession collected in Ecuador, harbors a natural allele (ol-2) that confers broad-spectrum and recessively inherited resistance to powdery mildew (Oidium neolycopersici). As both the genetic and phytopathological characteristics of ol-2–mediated resistance are reminiscent of powdery mildew immunity conferred by loss-of-function mlo alleles in barley and Arabidopsis, we initiated a candidate-gene approach to clone Ol-2. A tomato Mlo gene (SlMlo1) with high sequence-relatedness to barley Mlo and Arabidopsis AtMLO2 mapped to the chromosomal region harboring the Ol-2 locus. Complementation experiments using transgenic tomato lines as well as virus-induced gene silencing assays suggested that loss of SlMlo1 function is responsible for powdery mildew resistance conferred by ol-2. In progeny of a cross between a resistant line bearing ol-2 and the susceptible tomato cultivar Moneymaker, a 19-bp deletion disrupting the SlMlo1 coding region cosegregated with resistance. This polymorphism results in a frameshift and, thus, a truncated nonfunctional SlMlo1 protein. Our findings reveal the second example of a natural mlo mutant that possibly arose post-domestication, suggesting that natural mlo alleles might be evolutionarily short-lived due to fitness costs related to loss of mlo function.
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spelling doaj.art-801efb3b103743139cf2ea4eb1a041c52022-12-22T03:20:07ZengThe American Phytopathological SocietyMolecular Plant-Microbe Interactions0894-02821943-77062008-01-01211303910.1094/MPMI-21-1-0030Naturally Occurring Broad-Spectrum Powdery Mildew Resistance in a Central American Tomato Accession Is Caused by Loss of Mlo FunctionYuling BaiStefano PavanZheng ZhengNana F. ZappelAnja ReinstädlerConcetta LottiClaudio De GiovanniLuigi RicciardiPim LindhoutRichard VisserKlaus TheresRalph PanstrugaThe resistant cherry tomato (Solanum lycopersicum var. cerasiforme) line LC-95, derived from an accession collected in Ecuador, harbors a natural allele (ol-2) that confers broad-spectrum and recessively inherited resistance to powdery mildew (Oidium neolycopersici). As both the genetic and phytopathological characteristics of ol-2–mediated resistance are reminiscent of powdery mildew immunity conferred by loss-of-function mlo alleles in barley and Arabidopsis, we initiated a candidate-gene approach to clone Ol-2. A tomato Mlo gene (SlMlo1) with high sequence-relatedness to barley Mlo and Arabidopsis AtMLO2 mapped to the chromosomal region harboring the Ol-2 locus. Complementation experiments using transgenic tomato lines as well as virus-induced gene silencing assays suggested that loss of SlMlo1 function is responsible for powdery mildew resistance conferred by ol-2. In progeny of a cross between a resistant line bearing ol-2 and the susceptible tomato cultivar Moneymaker, a 19-bp deletion disrupting the SlMlo1 coding region cosegregated with resistance. This polymorphism results in a frameshift and, thus, a truncated nonfunctional SlMlo1 protein. Our findings reveal the second example of a natural mlo mutant that possibly arose post-domestication, suggesting that natural mlo alleles might be evolutionarily short-lived due to fitness costs related to loss of mlo function.https://apsjournals.apsnet.org/doi/10.1094/MPMI-21-1-0030comparative geneticsco-orthologsintrogression linespleiotropic effects
spellingShingle Yuling Bai
Stefano Pavan
Zheng Zheng
Nana F. Zappel
Anja Reinstädler
Concetta Lotti
Claudio De Giovanni
Luigi Ricciardi
Pim Lindhout
Richard Visser
Klaus Theres
Ralph Panstruga
Naturally Occurring Broad-Spectrum Powdery Mildew Resistance in a Central American Tomato Accession Is Caused by Loss of Mlo Function
Molecular Plant-Microbe Interactions
comparative genetics
co-orthologs
introgression lines
pleiotropic effects
title Naturally Occurring Broad-Spectrum Powdery Mildew Resistance in a Central American Tomato Accession Is Caused by Loss of Mlo Function
title_full Naturally Occurring Broad-Spectrum Powdery Mildew Resistance in a Central American Tomato Accession Is Caused by Loss of Mlo Function
title_fullStr Naturally Occurring Broad-Spectrum Powdery Mildew Resistance in a Central American Tomato Accession Is Caused by Loss of Mlo Function
title_full_unstemmed Naturally Occurring Broad-Spectrum Powdery Mildew Resistance in a Central American Tomato Accession Is Caused by Loss of Mlo Function
title_short Naturally Occurring Broad-Spectrum Powdery Mildew Resistance in a Central American Tomato Accession Is Caused by Loss of Mlo Function
title_sort naturally occurring broad spectrum powdery mildew resistance in a central american tomato accession is caused by loss of mlo function
topic comparative genetics
co-orthologs
introgression lines
pleiotropic effects
url https://apsjournals.apsnet.org/doi/10.1094/MPMI-21-1-0030
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