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

Summary

The knotted1 (kn1) gene of maize is expressed in meristems and is absent from leaves, including the site of leaf initiation within the meristem. Recessive mutations of kn1 have been described that limit the capacity to make branches and result in extra carpels. Dominant mutations suggest that kn1 function plays a role in maintaining cells in an undifferentiated state. We took advantage of a Ds-induced dominant allele in order to screen for additional recessive alleles resulting from mobilization of the Ds element. Analysis of one such allele revealed a novel embryonic shoot phenotype in which the shoot initiated zero to few organs after the cotyledon was made, resulting in plants that arrested as seedlings. We refer to this phenotype as a limited shoot. The limited shoot phenotype reflected loss of kn1 function, but its penetrance was background dependent. We examined meristem size and found that plants lacking kn1 function had shorter meristems than non-mutant siblings. Furthermore, meristems of restrictive inbreds were significantly shorter than meristems of permissive inbreds, implying a correlation between meristem height and kn1 gene function in the embryo. Analysis of limited shoot plants during embryogenesis indicated a role for kn1 in shoot meristem maintenance. We discuss a model for kn1 in maintenance of the morphogenetic zone of the shoot apical meristem.

REFERENCES

    1. Abbe E. C.,
    2. Phinney B. O.,
    3. Baer D. F.
    (1951) The growth of the shoot apex in maize: internal features. Am. J. Bot 38, 744–751
    OpenUrlCrossRefWeb of Science
    1. Abbe E. C.,
    2. Stein O. L.
    (1954) The growth of the shoot apex in maize: embryogeny. Am. J. Bot 41, 285–293
    OpenUrlCrossRefWeb of Science
    1. Alleman M.,
    2. Kermicle J. L.
    (1993) Somatic variegation and germinal mutability reflect the position of transposable element Dissociation within the maize R gene. Genetics 135, 189–203
    OpenUrlAbstract/FREE Full Text
    1. Barton M. K.,
    2. Poethig R. S.
    (1993) Formation of the shoot apical meristem in Arabidopsisthaliana: an analysis of development in the wild type and in the shoot meristemless mutant. Development 119, 823–831
    OpenUrlAbstract/FREE Full Text
    1. Bharathan G.,
    2. Janssen B. J.,
    3. Kellog E.,
    4. Sinha N.
    (1999) Phylogenetic relationships and evolution of the KNOTTED class of plant homeodomain proteins. Mol. Biol. Evol 16, 553–563
    OpenUrlAbstract
    1. Brutnell T. P.,
    2. May B. P.,
    3. Dellaporta S. L.
    (1997) The Ac-st2 element of maize exhibits a positive dosage effect and epigenetic regulation. Genetics 147, 823–834
    OpenUrlAbstract/FREE Full Text
    1. Bryan A. A.,
    2. Sass J. E.
    (1941) Heritable characters in maize. J. Hered 32, 343–346
    OpenUrlFREE Full Text
    1. Cheng P. C.,
    2. Greyson R. I.,
    3. Walden D. B.
    (1983) Organ initiation and the development of unisexual flowers in the tassel and ear of Zea mays. Am. J. Bot 70, 450–462
    OpenUrlCrossRefWeb of Science
    1. Chuck G.,
    2. Lincoln C.,
    3. Hake S.
    (1996) Knat1 induces lobed leaves with ectopic meristems when overexpressed in Arabidopsis. Plant Cell 8, 1277–1289
    OpenUrlAbstract/FREE Full Text
    1. Endrizzi K.,
    2. Moussian B.,
    3. Haecker A.,
    4. Levin J. Z.,
    5. Laux T.
    (1996) The SHOOT MERISTEMLESS gene is required for maintenance of undifferentiated cells in Arabidopsis shoot and floral meristems and acts at a different regulatory level than the meristem genes WUSCHEL and ZWILLE. Plant J 10, 101–113
    1. Foster T.,
    2. Yamaguchi J.,
    3. Wong B.,
    4. Veit B.,
    5. Hake S.
    (1999) Gnarley1 is a dominant mutation in the knox4 homeobox gene that affects cell identity and cell shape. Plant Cell 11, 1239–1252
    OpenUrlAbstract/FREE Full Text
    1. Freeling M.,
    2. Hake S.
    (1985) Developmental genetics of mutants that specify Knotted leaves in maize. Genetics 111, 617–634
    OpenUrlAbstract/FREE Full Text
    1. Freeling M.,
    2. Schwartz D.
    (1973) Genetic relationships between the multiple alcohol dehydrogenases of maize. Genetics 8, 27–36
    OpenUrl
    1. Gelinas D.,
    2. Postlethwaite S. N.,
    3. Nelson O. E.
    (1969) Characterization of development in maize through the use of mutants. II. The abnormal growth conditioned by the Knotted mutant. Am. J. Bot 56, 671–678
    OpenUrlCrossRefWeb of Science
    1. Goldberg R. B.,
    2. de Paiva G.,
    3. Yadegari R.
    (1994) Plant embryogenesis: zygote to seed. Science 266, 605–614
    OpenUrlAbstract/FREE Full Text
    1. Greenblatt I. M.
    (1984) A chromosome replication pattern deduced from pericarp phenotypes resulting from movements of the transposable element Modulator in maize. Genetics 108, 471–485
    OpenUrlAbstract/FREE Full Text
    1. Greene B.,
    2. Walko R.,
    3. Hake S.
    (1994) Mutator insertions in an intron of the maize knotted1 gene result in dominant suppressible mutations. Genetics 138, 1275–1285
    OpenUrlAbstract/FREE Full Text
    1. Hake S.,
    2. Vollbrecht E.,
    3. Freeling M.
    (1989) Cloning Knotted, the dominant morphological mutant in maize using Ds2 as a transposon tag. EMBO J 8, 15–22
    OpenUrlPubMedWeb of Science
    1. Jackson D.,
    2. Veit B.,
    3. 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
    OpenUrlAbstract
    1. Kaplan D. R.,
    2. Cooke T. J.
    (1997) Fundamental concepts in the embryogenesis of dicotyledons: a morphological interpretation of embryo mutants. Plant Cell 9, 1903–1919
    OpenUrlFREE Full Text
    1. Kerstetter R.,
    2. Vollbrecht E.,
    3. Lowe B.,
    4. Veit B.,
    5. Yamaguchi J.,
    6. Hake S.
    (1994) Sequence analysis and expression patterns divide the maize knotted1 -like homeobox genes into two classes. Plant Cell 6, 1877–1887
    OpenUrlAbstract/FREE Full Text
    1. Kerstetter R. A.,
    2. Laudencia-Chingcuanco D.,
    3. Smith L. G.,
    4. Hake S.
    (1997) Loss of function mutations in the maize homeobox gene, knotted1, are defective in shoot meristem maintenance. Development 124, 3045–3054
    OpenUrlAbstract
    1. Laufs P.,
    2. Grandjean O.,
    3. Jonak C.,
    4. Kieu K.,
    5. Traas J.
    (1998) Cellular parameters of the shoot apical meristem in Arabidopsis. Plant Cell 10, 1375–1389
    OpenUrlAbstract/FREE Full Text
    1. Ledin R. B.
    (1954) The vegetative shoot apex of Zea mays. Am. J. Bot 41, 11–17
    OpenUrlCrossRef
    1. Lynn K.,
    2. Fernandez A.,
    3. Aida M.,
    4. Sedbrook J.,
    5. Tasaka M.,
    6. Masson P.,
    7. Barton M. K.
    (1999) The PINHEAD/ZWILLE gene acts pleiotropically in Arabidopsis development and has overlapping functions with the ARGONAUTE1 gene. Development 126, 469–81
    OpenUrlAbstract
    1. Moreno M. A.,
    2. Chen J.,
    3. Greenblatt I.,
    4. Dellaporta S. L.
    (1992) Reconstitutional mutagenesis of the maize P gene by short range Ac transpositions. Genetics 131, 939–956
    OpenUrlAbstract/FREE Full Text
    1. Moussian B.,
    2. Schoof H.,
    3. Haecker A.,
    4. Jurgens G.,
    5. Laux T.
    (1998) Roleof the ZWILLE gene in the regulation of central shoot meristem cell fate during Arabidopsis embryogenesis. EMBO J 17, 1799–1809
    OpenUrlAbstract/FREE Full Text
    1. Nourgarede A.
    (1967) Experimental cytology of the shoot apical cells during vegetative growth and flowering. Intern. Rev. Cytol 21, 203–351
    OpenUrlPubMed
    1. Randolph L. F.
    (1936) Developmental morphology of the caryopsis in maize. J. Ag. Res 53, 881–916
    OpenUrl
    1. Reiser L.,
    2. Sanchez-Baracaldo P.,
    3. Hake S.
    (2000) Knots in the family tree: Evolutionary relationships and functions of knox homeobox genes. Plant Mol. Biol 42, 151–66
    OpenUrlCrossRefPubMedWeb of Science
    1. Schneeberger R. G.,
    2. Becraft P. W.,
    3. Hake S.,
    4. Freeling M.
    (1995) Ectopic expression of the knox homeo box gene roughsheath1 alters cell fate in the maize leaf. Genes Dev 9, 2292–2304
    OpenUrlAbstract/FREE Full Text
    1. Scott L.,
    2. LaFoe D.,
    3. Weil C. F.
    (1996) Adjacent sequences influence DNA repair accompanying transposon excision in maize. Genetics, 142, 237–246
    OpenUrlAbstract/FREE Full Text
    1. Sentoku N.,
    2. Sato Y.,
    3. Kurata N.,
    4. Ito Y.,
    5. Kitano H.,
    6. Matsuoka M.
    (1999) Regional expression of the rice KN1-type homeobox gene family during embryo, shoot, and flower development. Plant Cell 11, 1651–1664
    OpenUrlAbstract/FREE Full Text
    1. Sinha N. R.,
    2. Williams R. E.,
    3. Hake S.
    (1993) Overexpression of the maize homeo box gene, KNOTTED-1, causes a switch from determinate to indeterminate cell fates. Genes Dev 7, 787–795
    OpenUrlAbstract/FREE Full Text
    1. Smith L.,
    2. Greene B.,
    3. Veit B.,
    4. 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
    OpenUrlAbstract
    1. Smith L. G.,
    2. Jackson D.,
    3. Hake S.
    (1995) The expression of Knotted1 marks shoot meristem formation during maize embryogenesis. Dev. Gen 16, 344–348
    OpenUrlCrossRefWeb of Science
    1. Timmermans M. C.,
    2. Hudson A.,
    3. Becraft P. W.,
    4. Nelson T.
    (1999) ROUGH SHEATH2: a Myb protein that represses knox homeobox genes in maize lateral organ primordia. Science 284, 151–153
    OpenUrlAbstract/FREE Full Text
    1. Tsiantis M.,
    2. Schneeberger R.,
    3. Golz J. F.,
    4. Freeling M.,
    5. Langdale J. A.
    (1999) The maize rough sheath2 gene and leaf development programs in monocot and dicot plants. Science 284, 154–156
    OpenUrlAbstract/FREE Full Text
    1. Vollbrecht E.,
    2. Veit B.,
    3. Sinha N.,
    4. Hake S.
    (1991) The developmental gene Knotted-1 is a member of a maize homeobox gene family. Nature 350, 241–243
    OpenUrlCrossRefPubMedWeb of Science
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JOURNAL ARTICLES
Shoot meristem size is dependent on inbred background and presence of the maize homeobox gene, knotted1
E. Vollbrecht, L. Reiser, S. Hake
Development 2000 127: 3161-3172;
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