Identification and characterization of a novel miR159 target not related to MYB in tomato.
MicroRNA 159 (miR159) is a highly conserved miRNA with roles in flowering under short days, anther development and seed germination via repression of GAMYB-like genes. In tomato, the function of miR159 (Sl-miR159) is currently unknown and target transcripts have not been experimentally validated. Here, we identified and characterized a new miR159 target gene (SGN-U567133) in Solanum lycopersicum (tomato) that is not related to MYB. SGN-U567133 is predominantly expressed in flowers and encodes a nuclear-localized protein that contains a unique NOZZLE-like domain at its N terminus. In tomato, SGN-U567133 represents a small gene family and orthologs have been identified in other plant species, all containing a conserved miR159 target site in their coding sequence. Accordingly, 5'-RACE cleavage assay supported miRNA-mediated cleavage of SGN-U567133 transcripts in vivo. Moreover, the SGN-U567133 transcript accumulated in P19-HA-expressing tomato leaves in which miRNA-mediated cleavage is inhibited. In addition, transgenic tomato plants expressing a miR159-resistant form of SGN-U567133 accumulated higher levels of the SGN-U567133 transcript and exhibited defects in leaf and flower development. Together, our results suggest that SGN-U567133 represents a novel class of miR159 targets in plants and raise the possibility that its post-transcriptional regulation by Sl-miR159 is essential for normal tomato development.
Buxdorf
Kobi
K
Institute of Plant Sciences, Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel.
Hendelman
Anat
A
Stav
Ran
R
Lapidot
Moshe
M
Ori
Naomi
N
Arazi
Tzahi
T
D000595:Amino Acid Sequence; D015139:Blotting, Southern; D035264:Flowers / Q000235:genetics / Q000254:growth & development / Q000378:metabolism / Q000648:ultrastructure; D018506:Gene Expression Regulation, Plant / Q000235:genetics; D018551:Solanum lycopersicum / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism / Q000648:ultrastructure; D035683:MicroRNAs / Q000235:genetics* / Q000502:physiology; D008855:Microscopy, Electron, Scanning; D008969:Molecular Sequence Data; D018515:Plant Leaves / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000502:physiology; D030821:Plants, Genetically Modified / Q000235:genetics / Q000254:growth & development / Q000378:metabolism / Q000648:ultrastructure; D018749:RNA, Plant / Q000235:genetics* / Q000502:physiology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid
D035683:MicroRNAs; D010940:Plant Proteins; D018749:RNA, Plant