title: MtLAX2, a Functional Homologue of the Arabidopsis Auxin Influx Transporter AUX1, Is Required for Nodule Organogenesis.
abstract: Most legume plants can form nodules, specialized lateral organs that form on roots, and house nitrogen-fixing bacteria collectively called rhizobia. The uptake of the phytohormone auxin into cells is known to be crucial for development of lateral roots. To test the role of auxin influx in nodulation we used the auxin influx inhibitors 1-naphthoxyacetic acid (1-NOA) and 2-NOA, which we found reduced nodulation ofMedicago truncatula.This suggested the possible involvement of the AUX/LAX family of auxin influx transporters in nodulation. Gene expression studies identifiedMtLAX2, a paralogue of Arabidopsis (Arabidopsis thaliana)AUX1, as being induced at early stages of nodule development.MtLAX2is expressed in nodule primordia, the vasculature of developing nodules, and at the apex of mature nodules. TheMtLAX2promoter contains several auxin response elements, and treatment with indole-acetic acid strongly inducesMtLAX2expression in roots.mtlax2mutants displayed root phenotypes similar to Arabidopsisaux1mutants, including altered root gravitropism, fewer lateral roots, shorter root hairs, and auxin resistance. In addition, the activity of the synthetic DR5-GUS auxin reporter was strongly reduced inmtlax2roots. Following inoculation with rhizobia,mtlax2roots developed fewer nodules, had decreased DR5-GUS activity associated with infection sites, and had decreased expression of the early auxin responsive geneARF16aOur data indicate that MtLAX2 is a functional analog of Arabidopsis AUX1 and is required for the accumulation of auxin during nodule formation in tissues underlying sites of rhizobial infection.
authors.affiliation: Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom (S.R., F.R., J.L., C.-W.L., J.S., D.C., C.B., G.O., J.D.M.).|Plant Biology Division, Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, Oklahoma 73401 (S.R., X.C., J.W.).|Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom (S.W., J.A.D.).|Plant and Crop Science Division, School of Biosciences, University of Nottingham, Nr Loughborough LE12 5RD, United Kingdom (M.J.B., R.S.); and.|Babraham Institute, Babraham Hall, Babraham CB22 3AT, United Kingdom (S.W.).
authors.forename: Sonali
authors.identifier: http://orcid.org/0000-0002-8114-8300
authors.initials: S
authors.lastname: Roy
authors.affiliation: Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom (S.R., F.R., J.L., C.-W.L., J.S., D.C., C.B., G.O., J.D.M.).|Plant Biology Division, Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, Oklahoma 73401 (S.R., X.C., J.W.).|Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom (S.W., J.A.D.).|Plant and Crop Science Division, School of Biosciences, University of Nottingham, Nr Loughborough LE12 5RD, United Kingdom (M.J.B., R.S.); and.|Babraham Institute, Babraham Hall, Babraham CB22 3AT, United Kingdom (S.W.).
authors.forename: Fran
authors.identifier: http://orcid.org/0000-0003-2734-5124
authors.initials: F
authors.lastname: Robson
authors.affiliation: Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom (S.R., F.R., J.L., C.-W.L., J.S., D.C., C.B., G.O., J.D.M.).|Plant Biology Division, Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, Oklahoma 73401 (S.R., X.C., J.W.).|Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom (S.W., J.A.D.).|Plant and Crop Science Division, School of Biosciences, University of Nottingham, Nr Loughborough LE12 5RD, United Kingdom (M.J.B., R.S.); and.|Babraham Institute, Babraham Hall, Babraham CB22 3AT, United Kingdom (S.W.).
authors.forename: Jodi
authors.initials: J
authors.lastname: Lilley
authors.affiliation: Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom (S.R., F.R., J.L., C.-W.L., J.S., D.C., C.B., G.O., J.D.M.).|Plant Biology Division, Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, Oklahoma 73401 (S.R., X.C., J.W.).|Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom (S.W., J.A.D.).|Plant and Crop Science Division, School of Biosciences, University of Nottingham, Nr Loughborough LE12 5RD, United Kingdom (M.J.B., R.S.); and.|Babraham Institute, Babraham Hall, Babraham CB22 3AT, United Kingdom (S.W.).
authors.forename: Cheng-Wu
authors.identifier: http://orcid.org/0000-0002-6650-6245
authors.initials: CW
authors.lastname: Liu
authors.affiliation: Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom (S.R., F.R., J.L., C.-W.L., J.S., D.C., C.B., G.O., J.D.M.).|Plant Biology Division, Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, Oklahoma 73401 (S.R., X.C., J.W.).|Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom (S.W., J.A.D.).|Plant and Crop Science Division, School of Biosciences, University of Nottingham, Nr Loughborough LE12 5RD, United Kingdom (M.J.B., R.S.); and.|Babraham Institute, Babraham Hall, Babraham CB22 3AT, United Kingdom (S.W.).
authors.forename: Xiaofei
authors.initials: X
authors.lastname: Cheng
authors.affiliation: Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom (S.R., F.R., J.L., C.-W.L., J.S., D.C., C.B., G.O., J.D.M.).|Plant Biology Division, Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, Oklahoma 73401 (S.R., X.C., J.W.).|Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom (S.W., J.A.D.).|Plant and Crop Science Division, School of Biosciences, University of Nottingham, Nr Loughborough LE12 5RD, United Kingdom (M.J.B., R.S.); and.|Babraham Institute, Babraham Hall, Babraham CB22 3AT, United Kingdom (S.W.).
authors.forename: Jiangqi
authors.identifier: http://orcid.org/0000-0001-5113-7750
authors.initials: J
authors.lastname: Wen
authors.affiliation: Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom (S.R., F.R., J.L., C.-W.L., J.S., D.C., C.B., G.O., J.D.M.).|Plant Biology Division, Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, Oklahoma 73401 (S.R., X.C., J.W.).|Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom (S.W., J.A.D.).|Plant and Crop Science Division, School of Biosciences, University of Nottingham, Nr Loughborough LE12 5RD, United Kingdom (M.J.B., R.S.); and.|Babraham Institute, Babraham Hall, Babraham CB22 3AT, United Kingdom (S.W.).
authors.forename: Simon
authors.identifier: http://orcid.org/0000-0001-9185-4922
authors.initials: S
authors.lastname: Walker
authors.affiliation: Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom (S.R., F.R., J.L., C.-W.L., J.S., D.C., C.B., G.O., J.D.M.).|Plant Biology Division, Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, Oklahoma 73401 (S.R., X.C., J.W.).|Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom (S.W., J.A.D.).|Plant and Crop Science Division, School of Biosciences, University of Nottingham, Nr Loughborough LE12 5RD, United Kingdom (M.J.B., R.S.); and.|Babraham Institute, Babraham Hall, Babraham CB22 3AT, United Kingdom (S.W.).
authors.forename: Jongho
authors.identifier: http://orcid.org/0000-0002-3705-3072
authors.initials: J
authors.lastname: Sun
authors.affiliation: Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom (S.R., F.R., J.L., C.-W.L., J.S., D.C., C.B., G.O., J.D.M.).|Plant Biology Division, Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, Oklahoma 73401 (S.R., X.C., J.W.).|Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom (S.W., J.A.D.).|Plant and Crop Science Division, School of Biosciences, University of Nottingham, Nr Loughborough LE12 5RD, United Kingdom (M.J.B., R.S.); and.|Babraham Institute, Babraham Hall, Babraham CB22 3AT, United Kingdom (S.W.).
authors.forename: Donna
authors.identifier: http://orcid.org/0000-0003-2527-8896
authors.initials: D
authors.lastname: Cousins
authors.affiliation: Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom (S.R., F.R., J.L., C.-W.L., J.S., D.C., C.B., G.O., J.D.M.).|Plant Biology Division, Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, Oklahoma 73401 (S.R., X.C., J.W.).|Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom (S.W., J.A.D.).|Plant and Crop Science Division, School of Biosciences, University of Nottingham, Nr Loughborough LE12 5RD, United Kingdom (M.J.B., R.S.); and.|Babraham Institute, Babraham Hall, Babraham CB22 3AT, United Kingdom (S.W.).
authors.forename: Caitlin
authors.identifier: http://orcid.org/0000-0002-5881-3202
authors.initials: C
authors.lastname: Bone
authors.affiliation: Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom (S.R., F.R., J.L., C.-W.L., J.S., D.C., C.B., G.O., J.D.M.).|Plant Biology Division, Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, Oklahoma 73401 (S.R., X.C., J.W.).|Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom (S.W., J.A.D.).|Plant and Crop Science Division, School of Biosciences, University of Nottingham, Nr Loughborough LE12 5RD, United Kingdom (M.J.B., R.S.); and.|Babraham Institute, Babraham Hall, Babraham CB22 3AT, United Kingdom (S.W.).
authors.forename: Malcolm J
authors.identifier: http://orcid.org/0000-0003-0475-390X
authors.initials: MJ
authors.lastname: Bennett
authors.affiliation: Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom (S.R., F.R., J.L., C.-W.L., J.S., D.C., C.B., G.O., J.D.M.).|Plant Biology Division, Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, Oklahoma 73401 (S.R., X.C., J.W.).|Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom (S.W., J.A.D.).|Plant and Crop Science Division, School of Biosciences, University of Nottingham, Nr Loughborough LE12 5RD, United Kingdom (M.J.B., R.S.); and.|Babraham Institute, Babraham Hall, Babraham CB22 3AT, United Kingdom (S.W.).
authors.forename: J Allan
authors.identifier: http://orcid.org/0000-0003-1011-4960
authors.initials: JA
authors.lastname: Downie
authors.affiliation: Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom (S.R., F.R., J.L., C.-W.L., J.S., D.C., C.B., G.O., J.D.M.).|Plant Biology Division, Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, Oklahoma 73401 (S.R., X.C., J.W.).|Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom (S.W., J.A.D.).|Plant and Crop Science Division, School of Biosciences, University of Nottingham, Nr Loughborough LE12 5RD, United Kingdom (M.J.B., R.S.); and.|Babraham Institute, Babraham Hall, Babraham CB22 3AT, United Kingdom (S.W.).
authors.forename: Ranjan
authors.identifier: http://orcid.org/0000-0002-6438-9188
authors.initials: R
authors.lastname: Swarup
authors.affiliation: Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom (S.R., F.R., J.L., C.-W.L., J.S., D.C., C.B., G.O., J.D.M.).|Plant Biology Division, Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, Oklahoma 73401 (S.R., X.C., J.W.).|Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom (S.W., J.A.D.).|Plant and Crop Science Division, School of Biosciences, University of Nottingham, Nr Loughborough LE12 5RD, United Kingdom (M.J.B., R.S.); and.|Babraham Institute, Babraham Hall, Babraham CB22 3AT, United Kingdom (S.W.).
authors.forename: Giles
authors.initials: G
authors.lastname: Oldroyd
authors.affiliation: Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom (S.R., F.R., J.L., C.-W.L., J.S., D.C., C.B., G.O., J.D.M.); jeremy.murray@jic.ac.uk.|Plant Biology Division, Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, Oklahoma 73401 (S.R., X.C., J.W.); jeremy.murray@jic.ac.uk.|Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, United Kingdom (S.W., J.A.D.); jeremy.murray@jic.ac.uk.|Plant and Crop Science Division, School of Biosciences, University of Nottingham, Nr Loughborough LE12 5RD, United Kingdom (M.J.B., R.S.); and jeremy.murray@jic.ac.uk.|Babraham Institute, Babraham Hall, Babraham CB22 3AT, United Kingdom (S.W.) jeremy.murray@jic.ac.uk.
authors.forename: Jeremy D
authors.identifier: http://orcid.org/0000-0003-3000-9199
authors.initials: JD
authors.lastname: Murray
mesh_terms: D001692:Biological Transport; D018506:Gene Expression Regulation, Plant; D018522:Gravitropism / Q000235:genetics; D007210:Indoleacetic Acids / Q000378:metabolism; D046913:Medicago truncatula / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology; D026901:Membrane Transport Proteins / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D055170:Plant Root Nodulation / Q000235:genetics*; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D012231:Rhizobium / Q000502:physiology; D053204:Root Nodules, Plant / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology; D013559:Symbiosis / Q000235:genetics
chemical_list: D007210:Indoleacetic Acids; D026901:Membrane Transport Proteins; D010940:Plant Proteins