Reduced naphthylphthalamic acid binding in the tir3 mutant of Arabidopsis is associated with a reduction in polar auxin transport and diverse morphological defects.

Polar auxin transport plays a key role in the regulation of plant growth and development. To identify genes involved in this process, we have developed a genetic procedure to screen for mutants of Arabidopsis that are altered in their response to auxin transport inhibitors. We recovered a total of 16 independent mutants that defined seven genes, called TRANSPORT INHIBITOR RESPONSE (TIR) genes. Recessive mutations in one of these genes, TIR3, result in altered responses to transport inhibitors, a reduction in polar auxin transport, and a variety of morphological defects that can be ascribed to changes in indole-3-acetic acid distribution. Most dramatically, tir3 seedlings are strongly deficient in lateral root production, a process that is known to depend on polar auxin transport from the shoot into the root. In addition, tir3 plants display a reduction in apical dominance as well as decreased elongation of siliques, pedicels, roots, and the inflorescence. Biochemical studies indicate that tir3 plants have a reduced number of N-1-naphthylphthalamic (NPA) binding sites, suggesting that the TIR3 gene is required for expression, localization, or stabilization of the NPA binding protein (NBP). Alternatively, the TIR3 gene may encode the NBP. Because the tir3 mutants have a substantial defect in NPA binding, their phenotype provides genetic evidence for a role for the NBP in plant growth and development.

[1]  G. Muday,et al.  Cytoplasmic Orientation of the Naphthylphthalamic Acid-Binding Protein in Zucchini Plasma Membrane Vesicles , 1996, Plant physiology.

[2]  K. Feldmann,et al.  Arabidopsis AUX1 Gene: A Permease-Like Regulator of Root Gravitropism , 1996, Science.

[3]  J. Reagan,et al.  The N-1-Naphthylphthalamic Acid-Binding Protein Is an Integral Membrane Protein , 1996, Plant physiology.

[4]  F. Carland,et al.  LOP1: a gene involved in auxin transport and vascular patterning in Arabidopsis. , 1996, Development.

[5]  D. Söll,et al.  A mutation in protein phosphatase 2A regulatory subunit A affects auxin transport in Arabidopsis. , 1996, The EMBO journal.

[6]  J. Alvarez,et al.  Morphogenesis in pinoid mutants of Arabidopsis thaliana , 1995 .

[7]  L. Feldman,et al.  A biochemical model for the initiation and maintenance of the quiescent center: implications for organization of root meristems , 1995 .

[8]  G. Fink,et al.  A pathway for lateral root formation in Arabidopsis thaliana. , 1995, Genes & development.

[9]  M. Estelle,et al.  The axr4 auxin-resistant mutants of Arabidopsis thaliana define a gene important for root gravitropism and lateral root initiation. , 1995, The Plant journal : for cell and molecular biology.

[10]  G. Muday,et al.  NPA binding activity is peripheral to the plasma membrane and is associated with the cytoskeleton. , 1994, The Plant cell.

[11]  G. Muday,et al.  Tomato root growth, gravitropism, and lateral development: correlation with auxin transport. , 1994, Plant physiology and biochemistry : PPB.

[12]  A. Schäffner,et al.  An Arabidopsis thaliana RFLP mapping set to localize mutations to chromosomal regions , 1994 .

[13]  J. Ecker,et al.  Assignment of 30 microsatellite loci to the linkage map of Arabidopsis. , 1994, Genomics.

[14]  C. Lister,et al.  Recombinant inbred lines for mapping RFLP and phenotypic markers in Arabidopsis thaliana , 1993 .

[15]  G. Muday,et al.  Evidence for a Single Naphthylphthalamic Acid Binding Site on the Zucchini Plasma Membrane , 1993, Plant physiology.

[16]  B. Scheres,et al.  Cellular organisation of the Arabidopsis thaliana root. , 1993, Development.

[17]  G. Jürgens,et al.  The role of the monopteros gene in organising the basal body region of the Arabidopsis embryo , 1993 .

[18]  C. Bell,et al.  Requirement of the Auxin Polar Transport System in Early Stages of Arabidopsis Floral Bud Formation. , 1991, The Plant cell.

[19]  J. Suttle.  Biochemical Bases for the Loss of Basipetal IAA Transport with Advancing Physiological Age in Etiolated Helianthus Hypocotyls: Changes in IAA Movement, Net IAA Uptake, and Phytotropin Binding. , 1991, Plant physiology.

[20]  D. Morris,et al.  Effects of Inhibitors of Protein Synthesis on Transmembrane Auxin Transport in Cucurbita pepo L. Hypocotyl Segments , 1991 .

[21]  M. Evans,et al.  Gravitropism: interaction of sensitivity modulation and effector redistribution. , 1991, Plant physiology.

[22]  M. Estelle,et al.  Growth and Development of the axrl Mutants of Arabidopsis , 1990 .

[23]  P. Rubery,et al.  Naturally Occurring Auxin Transport Regulators , 1988, Science.

[24]  I. Tamàs,et al.  Hormonal Regulation of Apical Dominance , 1987 .

[25]  T. Pugsley,et al.  A rapid filtration assay for soluble receptors using polyethylenimine-treated filters. , 1983, Analytical biochemistry.

[26]  K. Thimann,et al.  Hormonal factors controlling the initiation and development of lateral roots , 1980 .

[27]  Kenneth V. Thimann,et al.  Hormonal factors controlling the initiation and development of lateral roots. 1. Sources of primordia-inducing substances in the primary root of pea seedlings. , 1980 .

[28]  S. Tsurumi,et al.  Transport of 14C-lableled indoleacetic acid in Vicia root segments , 1978 .

[29]  D. Morris,et al.  A Microautoradiographic Study of Auxin Transport in the Stem of Intact Pea Seedlings (Pisum sativum L.) , 1978 .

[30]  G. F. Katekar,et al.  Auxin Transport Inhibitors: III. Chemical Requirements of a Class of Auxin Transport Inhibitors. , 1977, Plant physiology.

[31]  E. KostShelton,et al.  Growth and development. , 1951, Ciba clinical symposia.

[32]  Howard C. Berg,et al.  Genetic analysis , 1957, Nature Biotechnology.