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knox genes

XOur laboratory is interested in plant morphology. We are taking a genetic approach to understand the processes that regulate form and function. We are primarily interested in how shoot meristems initiate organs. The knotted1 gene and related knox (knotted1-like homeobox) genes appear to play a critical role in this process. We are studying what regulates knox genes and what genes are regulated by KNOX proteins.
XTo learn more about our work on knox genes look at some of our Related Manuscripts.

Immuno file KN1 protein localization in maize seedling. The kn1 gene is expressed in the meristem and is down-regulated prior to leaf initiation. (image courtesy of Angela Hay)
Knots file kn1 was originally identified by a dominant leaf phenotype. When the meristem-specific gene is expressed in leaves, the cells continue to grow, resulting in these protrusions or knots. (image courtesy of Sarah Hake)
leaf file kn1 alters leaf morphology when it is expressed in Arabidopsis leaves (leaf on left). A normal Arabidopsis leaf is in the center and a leaf expressing the Arabidopsis gene, BP (KNAT1), is on the right. (image courtesy of Cindy Lincoln)
PNY, a BELL protein, interacts with BP. Double mutant plants have aberrant internode patterning.
BP regulates the lignin pathway. The bp mutant has increased lignin in the stem and overexpression of BP causes decreased lignin.

Related Manuscripts:

Smith, H. M. S., Campbell, B. C. and Hake, S. (2004) The competence to respond to floral induction signals requires the homeobox genes PENNYWISE and POUND-FOOLISH. Current Biology, 14:812-817.

Running MP, Lavy M, Sternberg H, Galichet A, Gruissem W, Hake S, Ori N, Yalovsky S. (2004) Enlarged meristems and delayed growth in plp mutants result from lack of CaaX prenyltransferases. Proc Natl Acad Sci U S A. 101:7815-20.

Foster, T. Hay, A., Johnston, R. and Hake S. (2004) The establishment of axial patterning in the maize leaf. Development 131:3921-9.

Hake, S. Smith, H. M. S., Magnani, E., Holtan, H., Mele, G., and Ramirez, J. (2004) The role of knox genes in plant development. Annual Review of Cell and Developmental Biology. 20:125-151.

Hay, A., and Hake, S. (2004). The dominant mutant Wavy auricle in Blade1 disrupts patterning in a lateral domain of the maize leaf. Plant Physiology 135: 300-308.

Smith, H. M. S. and Hake, S. (2003). The interaction of two homeobox genes, BREVIPEDICELLUS and PENNYWISE, regulates internode patterning in the Arabidopsis inflorescence. Plant Cell 15:1-12.

Mele, G. and Hake, S. (2003) Expression profiling of plant development. Genome Biology 4:215.

Mele, G. Ori, N., Sato, Y. and Hake, S. (2003). The knotted1-like homeobox gene, BREVIPEDICELLUS, regulates cell differentiation by modulating metabolic pathways. Genes and Development 17:2088-2093.

Holtan, H. E, and Hake, S. (2003) Quantitative Trait Locus Analysis of Leaf Dissection in Tomato Using Lycopersicon pennellii Segmental Introgression Lines. Genetics. 2003 165:1541-50.

Hay, A. Jackson, D. Ori, N. and Hake, S. (2003). Analysis of the competence to respond to KNOTTED1 activity in Arabidopsis leaves using a steroid induction system. Plant Physiol. 131:1671-1680.

Hay, A. Kaur, H. Phillips, A. Hedden, P., Hake, S. and Tsiantis, M. (2002) The gibberellin pathway mediates KNOTTED1-type homeobox function in plants with different body plans. Current Biology 12:1557-1565.

Smith, H. M., Boschke, I. And Hake, S. (2002) Selective interaction of plant homeodomain proteins mediates high DNA-binding affinity. Proc Natl Acad Sci U S A.99:9579-84.

Hake, S. and Ori, N. (2002) Plant morphogenesis and KNOX genes. Nature Genetics 31:121-122.

Ori, N., Eshed, Y., Chuck, G., Bowman, J. L. and Hake, S. (2000) Mechanisms that control knox gene expression in the Arabidopsis shoot. Development 127:5523-32.

Vollbrecht, E, Reiser, L., and Hake, S. (2000) Shoot meristem size is dependent on inbred background and presence of the maize homeobox gene, knotted1 Development 127:3161-3172

Reiser, L., Sanchez-Baracaldo, P., and Hake, S. (2000) Knots in the family tree: Evolutionary relationships and functions of knox homeobox genes. Plant Molecular Biology 42: 151-66.

Foster, T. Yamaguchi, J., Wong, B. C., Veit, B., and Hake, S. (1999) Gnarley is a dominant mutation in the knox4 homeobox gene affecting cell shape and identity. Plant Cell 11: 1239-1252.

Ori, N. Juarez, M. T., Jackson, D., Yamaguchi, J., Banowetz, G. M., and Hake, S. (1999) Leaf senescence is delayed in tobacco plants expressing the maize homeobox gene, knotted1, under the control of a senescence-activated promoter. Plant Cell 11: 1073-1080.

Foster, T. Veit, B. and Hake, S. (1999) Mosaic analysis of the dominant mutant, Gnarley1-R, reveals distinct lateral and transverse signaling pathways during maize leaf development. Development 126:305-313.

Williams, R., Lie, Y., Hake, S., and Lemaux, P. (1997) Ectopic expression of knotted1 phenocopies the barley Hooded mutant. Development 124:3737-3745.

Mathern, J. and Hake, S. (1997) Mu element-generated gene conversions at Kn1-0 attenuate the dominate knotted phenotype. Genetics 147:305-314.

Kerstetter, R.A., Laudencia-Chingcuanco, D., Smith, L.G., and Hake, S. (1997) Loss of function mutations in the maize homeobox gene, knotted1, are defective in shoot meristem maintenance. Development 124:3045-3054.

Chuck, G., Lincoln, C. and Hake, S. (1996) KNAT1 induces lobed leaves with ectopic meristems when overexpressed in Arabidopsis. Plant Cell 8:1277-1289.

Lucas, W. J., Bouché-Pillon, Jackson, D. P., Nguyen, Lynda, Baker, Lucian, Ding, B., and Hake, S. (1995) Selective trafficking of the KNOTTED1 homeodomain protein and its mRNA through plasmodesmata. Science, 270:1980-1983.

Richard Schneeburger, Becraft, P. Hake, S. and Freeling, M. (1995) Ectopic expression of the knox homeobox gene rough sheath1 transforms cell fate in maize leaves. Genes and Development 9: 2292-2304.

Smith, L. G., Jackson, D. and Hake, S. (1995) The expression of knotted1 marks shoot meristem formation during maize embryogenesis. Developmental Genetics 16:344-348.

Lincoln. C., Long. J., Yamaguchi, J., Serikawa, K. and Hake, S. (1994) A knotted-like homeobox gene in Arabidopsis is expressed in the vegetative meristem and dramatically alters leaf morphology when overexpressed in transgenic plants. Plant Cell 6: 1859-1876.

Kerstetter, R., Vollbrecht, E., Lowe, B., Veit, B., Yamaguchi, J. and Hake, S. (1994) Sequence analysis and expression patterns divide the maize kn1-like homeobox genes into two classes. Plant Cell 6: 1877-1887.

Greene, B., Walko, R. and Hake, S. (1994) Mutator insertions in an intron of the maize knotted1 gene result in dominant suppressible mutations. Genetics 138: 1275-1285.
Sinha, N. & Hake, S. 1994. The knotted1 leaf blade is a mosaic of blade, sheath and auricle identities. Developmental Genetics 15: 401-414.

Jackson, D., Veit, B. and Hake, S. 1994. Expression of maize knotted1 related homeobox genes in the shoot apical meristem predicts patterns of morphogenesis in the vegetative shoot. Development 120: 405-413.

Smith, L. & Hake, S. 1993. Molecular genetic approaches to leaf development: Knotted and beyond. Can. J. Bot. 72: 617-625.

Sinha, N., Williams, R. and Hake, S. 1993. Overexpression of the maize homeo box gene, Knotted-1, causes a switch from determinate to indeterminate cell fates. Genes & Development 7:787-795.

Smith, L., Greene, B., Veit, B. and Hake, S. 1992. A dominant mutation in the maize homeobox gene, Knotted-1, causes its ectopic expression in leaf cells with altered fates. Development, 116:21-30.

Lowe, B., Mathern, J. and Hake, S. 1992. Active Mutator elements suppress the knotted phenotype and increase recombination at the Kn1-O tandem duplication. Genetics, 132:813-822.

Vollbrecht, E., Veit, B., Sinha, N. and Hake, S. 1991. The developmental gene Knotted is a member of a maize homeobox gene family. Nature 350, 241-243.

Sinha, Neelima and Hake, S. 1990. Mutant characters in knotted1 maize leaves are determined in the innermost tissue layers. Developmental Biology 141, 203-210.

Veit, B., Vollbrecht, E., Mathern, J. and Hake, S. 1990. A tandem duplication causes the Kn1-O allele of Knotted, a dominant morphological mutant of maize. Genetics 125, 623-631.

Hake, S., Vollbrecht, E. and Freeling, M. Cloning Knotted, the dominant morphological mutant in maize using Ds2 as a transposon tag. 1989. EMBO: 8, 15-22.

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