Abstract
We have isolated a cDNA clone encoding a homeobox sequence from rice. DNA sequence analysis of this clone, which was designated as Oryza sativa homeobox 1 (OSH1), and a genomic clone encoding the OSH1 sequence have shown that the OSH1 gene consists of five exons and encodes a polypeptide of 361 amino acid residues. Restriction fragment length polymorphism analysis has shown that OSH1 is a single-copy gene located near the phytochrome gene on chromosome 3. Introduction of the cloned OSH1 gene into rice resulted in altered leaf morphology, which was similar to that of the maize morphological mutant Knotted-1 (Kn1), indicating that OSH1 is a rice gene homologous to the maize Kn1 gene. RNA gel blot analysis has shown that the gene is primarily expressed in the shoot apices of young rice seedlings. This finding is supported by results of transformation experiments in which the 5' flanking region of the gene directed expression of a reporter gene in the shoot apex, particularly in stipules, of transgenic Arabidopsis. To elucidate the biological function of the OSH1 gene product, the coding region was introduced into Arabidopsis under the control of the cauliflower mosaic virus 35S promoter. Almost all transformants showed abnormal morphology. The typical phenotype was the formation of clumps of abundant vegetative and reproductive shoot apices containing meristems and leaf primordia, which did not form elongated shoots. Some transformants with a less severe phenotype formed elongated shoots but had abnormally shaped leaves and flowers with stunted sepals, petals, and stamens. The abnormal phenotypes were inherited, and the level of expression of the introduced OSH1 correlates with the severity of the phenotype. These findings indicate that the abnormal morphologies of the transgenic plants are caused by the expression of the OSH1 gene product and, therefore, that OSH1 is related to the plant development process.
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- Estruch J. J., Chriqui D., Grossmann K., Schell J., Spena A. The plant oncogene rolC is responsible for the release of cytokinins from glucoside conjugates. EMBO J. 1991 Oct;10(10):2889–2895. doi: 10.1002/j.1460-2075.1991.tb07838.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Falkner F. G., Zachau H. G. Correct transcription of an immunoglobulin kappa gene requires an upstream fragment containing conserved sequence elements. Nature. 1984 Jul 5;310(5972):71–74. doi: 10.1038/310071a0. [DOI] [PubMed] [Google Scholar]
- Gehring W. J. Homeo boxes in the study of development. Science. 1987 Jun 5;236(4806):1245–1252. doi: 10.1126/science.2884726. [DOI] [PubMed] [Google Scholar]
- Hake S. Unraveling the knots in plant development. Trends Genet. 1992 Mar;8(3):109–114. doi: 10.1016/0168-9525(92)90199-e. [DOI] [PubMed] [Google Scholar]
- Hayashi S., Scott M. P. What determines the specificity of action of Drosophila homeodomain proteins? Cell. 1990 Nov 30;63(5):883–894. doi: 10.1016/0092-8674(90)90492-w. [DOI] [PubMed] [Google Scholar]
- Ishii N., Hijikata M., Osumi T., Hashimoto T. Structural organization of the gene for rat enoyl-CoA hydratase:3-hydroxyacyl-CoA dehydrogenase bifunctional enzyme. J Biol Chem. 1987 Jun 15;262(17):8144–8150. [PubMed] [Google Scholar]
- Koob G. F., Dantzer R., Rodriguez F., Bloom F. E., Le Moal M. Osmotic stress mimics effects of vasopressin on learned behaviour. 1985 Jun 27-Jul 3Nature. 315(6022):750–752. doi: 10.1038/315750a0. [DOI] [PubMed] [Google Scholar]
- Kosugi S., Suzuka I., Ohashi Y., Murakami T., Arai Y. Upstream sequences of rice proliferating cell nuclear antigen (PCNA) gene mediate expression of PCNA-GUS chimeric gene in meristems of transgenic tobacco plants. Nucleic Acids Res. 1991 Apr 11;19(7):1571–1576. doi: 10.1093/nar/19.7.1571. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Li Y., Hagen G., Guilfoyle T. J. Altered morphology in transgenic tobacco plants that overproduce cytokinins in specific tissues and organs. Dev Biol. 1992 Oct;153(2):386–395. doi: 10.1016/0012-1606(92)90123-x. [DOI] [PubMed] [Google Scholar]
- Luan S., Bogorad L. A rice cab gene promoter contains separate cis-acting elements that regulate expression in dicot and monocot plants. Plant Cell. 1992 Aug;4(8):971–981. doi: 10.1105/tpc.4.8.971. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mattsson J., Söderman E., Svenson M., Borkird C., Engström P. A new homeobox-leucine zipper gene from Arabidopsis thaliana. Plant Mol Biol. 1992 Mar;18(5):1019–1022. doi: 10.1007/BF00019223. [DOI] [PubMed] [Google Scholar]
- Miller A. M., MacKay V. L., Nasmyth K. A. Identification and comparison of two sequence elements that confer cell-type specific transcription in yeast. Nature. 1985 Apr 18;314(6012):598–603. doi: 10.1038/314598a0. [DOI] [PubMed] [Google Scholar]
- Oppenheimer D. G., Herman P. L., Sivakumaran S., Esch J., Marks M. D. A myb gene required for leaf trichome differentiation in Arabidopsis is expressed in stipules. Cell. 1991 Nov 1;67(3):483–493. doi: 10.1016/0092-8674(91)90523-2. [DOI] [PubMed] [Google Scholar]
- Romano C. P., Hein M. B., Klee H. J. Inactivation of auxin in tobacco transformed with the indoleacetic acid-lysine synthetase gene of Pseudomonas savastanoi. Genes Dev. 1991 Mar;5(3):438–446. doi: 10.1101/gad.5.3.438. [DOI] [PubMed] [Google Scholar]
- Ruberti I., Sessa G., Lucchetti S., Morelli G. A novel class of plant proteins containing a homeodomain with a closely linked leucine zipper motif. EMBO J. 1991 Jul;10(7):1787–1791. doi: 10.1002/j.1460-2075.1991.tb07703.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schena M., Davis R. W. HD-Zip proteins: members of an Arabidopsis homeodomain protein superfamily. Proc Natl Acad Sci U S A. 1992 May 1;89(9):3894–3898. doi: 10.1073/pnas.89.9.3894. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Smigocki A. C. Cytokinin content and tissue distribution in plants transformed by a reconstructed isopentenyl transferase gene. Plant Mol Biol. 1991 Jan;16(1):105–115. doi: 10.1007/BF00017921. [DOI] [PubMed] [Google Scholar]
- Smith L. G., Greene B., Veit B., Hake S. A dominant mutation in the maize homeobox gene, Knotted-1, causes its ectopic expression in leaf cells with altered fates. Development. 1992 Sep;116(1):21–30. doi: 10.1242/dev.116.1.21. [DOI] [PubMed] [Google Scholar]
- Treisman J., Gönczy P., Vashishtha M., Harris E., Desplan C. A single amino acid can determine the DNA binding specificity of homeodomain proteins. Cell. 1989 Nov 3;59(3):553–562. doi: 10.1016/0092-8674(89)90038-x. [DOI] [PubMed] [Google Scholar]
- Valvekens D., Van Montagu M., Van Lijsebettens M. Agrobacterium tumefaciens-mediated transformation of Arabidopsis thaliana root explants by using kanamycin selection. Proc Natl Acad Sci U S A. 1988 Aug;85(15):5536–5540. doi: 10.1073/pnas.85.15.5536. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Veit B., Vollbrecht E., Mathern J., Hake S. A tandem duplication causes the Kn1-O allele of Knotted, a dominant morphological mutant of maize. Genetics. 1990 Jul;125(3):623–631. doi: 10.1093/genetics/125.3.623. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Vollbrecht E., Veit B., Sinha N., Hake S. The developmental gene Knotted-1 is a member of a maize homeobox gene family. Nature. 1991 Mar 21;350(6315):241–243. doi: 10.1038/350241a0. [DOI] [PubMed] [Google Scholar]