Cytokinins Secreted by Agrobacterium Promote Transformation by Repressing a Plant Myb Transcription Factor

Abstract

Agrobacterium-mediated transformation is the most widely used technique for generating transgenic plants. However, many crops remain recalcitrant. We found that an Arabidopsis myb family transcription factor (MTF1) inhibited plant transformation susceptibility. Mutating MTF1 increased attachment of several Agrobacterium strains to roots and increased both stable and transient transformation in both susceptible and transformation-resistant Arabidopsis ecotypes. Cytokinins from Agrobacterium tumefaciens decreased the expression of MTF1 through activation of the cytokinin response regulator ARR3. Mutating AHK3 and AHK4, genes that encode cytokinin-responsive kinases, increased the expression of MTF1 and impaired plant transformation. Mutant mtf1 plants also had increased expression of AT14A, which encodes a putative transmembrane receptor for cell adhesion molecules. Plants overexpressing AT14A exhibited increased susceptibility to transformation, whereas at14a mutant plants exhibited decreased attachment of bacteria to roots and decreased transformation, suggesting that AT14A may serve as an anchor point for Agrobacteria. Thus, by promoting bacterial attachment and transformation of resistant plants and increasing such processes in susceptible plants, treating roots with cytokinins may help engineer crops with improved features or yield.

Department(s)

Mathematics and Statistics

Keywords and Phrases

Cell Adhesion Molecule; Cytokinin; Phosphotransferase; Protein Myb; Receptor; Arabidopsis Protein; ARR3 Protein, Arabidopsis; At14a Protein, Arabidopsis; Cell Surface Receptor; MYBC1 Protein, Arabidopsis; Protein Histidine Kinase; Protein Kinase; Protein-Histidine Kinase; Transcription Factor; Transcriptome; WOL Protein, Arabidopsis; Arabidopsis; Article; Bacterial Strain; Bacterium Transformation; Ecotype; Gene Expression; Gene Mutation; Gene Overexpression; Gene Repression; Genetic Transformation; Hormone Release; Nonhuman; Plant Root; Plant Transformation; Priority Journal; Protein Expression; Rhizobium Radiobacter; Transgenic Plant; Agrobacterium Tumefaciens; DNA Microarray; Gene Expression Regulation; Genetics; Metabolism; Mutation; Physiology; Reverse Transcription Polymerase Chain Reaction; RNA Interference; Secretion (Process); Signal Transduction; Agrobacterium Tumefaciens; Arabidopsis; Arabidopsis Proteins; Cytokinins; Gene Expression Regulation, Plant; Mutation; Oligonucleotide Array Sequence Analysis; Plants, Genetically Modified; Protein Kinases; Receptors, Cell Surface; Reverse Transcriptase Polymerase Chain Reaction; RNA Interference; Signal Transduction; Transcription Factors; Transcriptome

International Standard Serial Number (ISSN)

1945-0877

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2013 American Association for the Advancement of Science (AAAS), All rights reserved.

Publication Date

01 Jan 2013

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