Requirements for Arabidopsis ATARP2 and ATARP3 during epidermal development.
Plant cells employ the actin cytoskeleton to stably position organelles, as tracks for long distance transport, and to reorganize the cytoplasm in response to developmental and environmental cues. While diverse classes of actin binding proteins have been implicated in growth control, the mechanisms of cytoskeletal reorganization and the cellular functions of specific actin filament arrays are unclear. Arabidopsis trichome morphogenesis includes distinct requirements for the microtubule and actin filament cytoskeletons. It also is a genetically tractable process that is providing new knowledge about cytoskeleton function in plants. The "distorted group" of mutants defines a class of at least eight genes that are required during the actin-dependent phase of trichome growth. Using map-based cloning and a candidate gene approach, we identified mutations in ARP3 (ATARP3) and ARP2 (ATARP2) genes as the cause of the distorted1 (dis1) and wurm (wrm) phenotypes, respectively. ARP2 and ARP3 are components of the evolutionarily conserved ARP2/3 complex that nucleates actin filament polymerization [3]. Mutations in DIS1 and WRM caused severe trichome growth defects but had relatively mild effects on shoot development. DIS1 rescued the phenotype of Deltaarp3 when overexpressed in S. cerevisiae. Developing dis1 trichomes had defects in cytoplasmic actin bundle organization and reduced relative amounts of cytoplasmic actin filaments in developing branches.
Le
Jie
J
Agronomy Department, Purdue University, Lily Hall, 915 West State Street, West Lafayette, IN 47907-2054, USA. dszyman@purdue.edu
El-Assal
Salah El-Din
Sel-D
Basu
Dipanwita
D
Saad
Mohamed E
ME
Szymanski
Daniel B
DB
D008841:Actin Cytoskeleton / Q000378:metabolism*; D051377:Actin-Related Protein 2; D051376:Actin-Related Protein 2-3 Complex; D051378:Actin-Related Protein 3; D000199:Actins / Q000235:genetics*; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics*; D017931:DNA Primers; D005455:Fluorescent Antibody Technique; D008840:Microfilament Proteins / Q000235:genetics*; D010641:Phenotype; D019441:Plant Epidermis / Q000235:genetics / Q000254:growth & development*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA
C512742:ARP2 protein, Arabidopsis; D051377:Actin-Related Protein 2; D051376:Actin-Related Protein 2-3 Complex; D051378:Actin-Related Protein 3; D000199:Actins; D029681:Arabidopsis Proteins; C478027:DIS1 protein, Arabidopsis; D017931:DNA Primers; D008840:Microfilament Proteins; C478980:WURM protein, Arabidopsis