How repeated epiphylly correlates with gene expression of resident knox1 in the leaves of tobacco epiphyllous shoots
- 29 Downloads
The tobacco knox1 genes tokn1 and tokn2 were isolated and their neomorphic capacities were tested while expressed in tobacco and potato. In addition, their neomorphic capacities were compared to barley bkn3 transgenic plant material. While tokn2 and bkn3 induced epiphylly in tobacco and supercompound leaves in potato, tokn1 failed to produce such prominent knox1 specific phenotypes. In wild type tobacco, alleles of the tokn genes were found to be expressed within distinct zones of the shoot apical meristem (SAM), leaving out regions that correlated with leaf founder cells . In contrast, the expression of the tokn genes was detected throughout the meristem and in leaf primordia of epiphyllous shoots that developed in tobacco over-expressing the barley hooded gene bkn3. It was determined that such extended expression domains of resident tobacco knox1 genes were mediated through an enhanced expression domain of bkn3 within the tissue confined to the epiphylls, and this contributed to “repeated epiphylly”, i.e. an iterated development of epiphyllous shoots on leaves of progenitor epiphylls.
KeywordsLeaf development epiphylly compound leaf plant unit iteration Hooded
Unable to display preview. Download preview PDF.
- D. Jackson, B. Veit and S. Hake: “Expression of maize KNOTTED-1 related homeobox genes in the shoot apical meristem predicts patterns of morphogenesis in the vegetative shoot”, Development, Vol. 120, (1994), pp. 405–413Google Scholar
- S.P. Venglat, T. Dumonceaux, K. Rozwadowski, L. Parnell, V. Babic, W. Keller, R. Martienssen, G. Selvaraj and R. Datla: “The homeobox gene BREVIPEDICELLUS is a key regulator of inflorescence architecture in Arabidopsis”, Proc. Nat. Acad. Sci. U.S.A., Vol. 99, (2002), pp. 4730–4735.CrossRefGoogle Scholar
- N.R. Sinha, R.E. Williams and S. Hake: “Overexpression of the maize homeobox gene, KNOTTED-1, causes a switch from determinate to indeterminate cell fates”, Genes & Dev., Vol. 7, (1993), pp. 787–795.Google Scholar
- K.J. Müller: Die Homöoboxgene der Knox-Familie in Gerste (Hordeum vulgare L.): Molekulare Charakterisierung, transgene Expression und Assoziationsversuche mit homöotischen Mutationen, Thesis (Ph.D), University of Cologne, 1997.Google Scholar
- M. Bevan: “Binary Agrobacterium vectors for plant transformation”, Nucl. Acid Res., Vol. 12, (1984), pp. 8711–8721.Google Scholar