Components of the Arabidopsis mRNA decapping complex are required for early seedling development.
To understand the mechanisms controlling vein patterning in Arabidopsis thaliana, we analyzed two phenotypically similar mutants, varicose (vcs) and trident (tdt). We had previously identified VCS, and recently, human VCS was shown to function in mRNA decapping. Here, we report that TDT encodes the mRNA-decapping enzyme. VCS and TDT function together in small cytoplasmic foci that appear to be processing bodies. To understand the developmental requirements for mRNA decapping, we characterized the vcs and tdt phenotypes. These mutants were small and chlorotic, with severe defects in shoot apical meristem formation and cotyledon vein patterning. Many capped mRNAs accumulated in tdt and vcs mutants, but surprisingly, some mRNAs were specifically depleted. In addition, loss of decapping arrested the decay of some mRNAs, while others showed either modest or no decay defects, suggesting that mRNAs may show specificity for particular decay pathways (3' to 5' and 5' to 3'). Furthermore, the severe block to postembryonic development in vcs and tdt and the accompanying accumulation of embryonic mRNAs indicate that decapping is important for the embryo-to-seedling developmental transition.
Goeres
David C
DC
Department of Biology, University of Utah, Salt Lake City, Utah 84112, USA.
Van Norman
Jaimie M
JM
Zhang
Weiping
W
Fauver
Nellie A
NA
Spencer
Mary Lou
ML
Sieburth
Leslie E
LE
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D022083:Cytoplasmic Structures / Q000378:metabolism; D004722:Endoribonucleases / Q000378:metabolism; D020869:Gene Expression Profiling; D020868:Gene Silencing; D005838:Genotype; D018519:Meristem / Q000166:cytology; D035683:MicroRNAs / Q000378:metabolism; D008954:Models, Biological; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D011485:Protein Binding; D012315:RNA Caps / Q000378:metabolism*; D020871:RNA Stability; D036226:Seedlings / Q000254:growth & development*; D017386:Sequence Homology, Amino Acid
D029681:Arabidopsis Proteins; D035683:MicroRNAs; D012315:RNA Caps; C483689:VARICOSE protein, Arabidopsis; D004722:Endoribonucleases