Co-Authors:
Buxdorf, K., Institute of Plant Sciences, Agricultural Research Organization, The Volcani Center, PO Box 6, Bet Dagan 50250, Israel
Hendelman, A., Institute of Plant Sciences, Agricultural Research Organization, The Volcani Center, PO Box 6, Bet Dagan 50250, Israel
Stav, R., Institute of Plant Sciences, Agricultural Research Organization, The Volcani Center, PO Box 6, Bet Dagan 50250, Israel
Lapidot, M., Institute of Plant Sciences, Agricultural Research Organization, The Volcani Center, PO Box 6, Bet Dagan 50250, Israel
Ori, N., The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
Arazi, T., Institute of Plant Sciences, Agricultural Research Organization, The Volcani Center, PO Box 6, Bet Dagan 50250, Israel
Abstract:
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. © 2010 Springer-Verlag.