Grass meristems I: Shoot apical meristem maintenance, axillary meristem determinacy and the floral transition

Plant and Cell Physiology

Volumn 54, Issue 3, 2013, Pages 302-312

  Pautler, Michael ^a,b   Tanaka, Wakana ^c   Hirano, Hiro Yuki ^c   Jackson, David ^a  

^a Howard Hughes Medical Institute Cold Spring Harbor Laboratory Cold Spring Harbor   (United States)

^b WATSON SCHOOL OF BIOLOGICAL SCIENCES   (United States)

^c UNIVERSITY OF TOKYO   (Japan)

Author keywords

Floral transition; Grass; Maize; Meristem maintenance; Rice; Tillering

Indexed keywords

CYTOKININ; PHYTOHORMONE; VEGETABLE PROTEIN;

ARABIDOPSIS; BIOLOGICAL MODEL; CYTOLOGY; FLOWER; GENE EXPRESSION REGULATION; GENETICS; GROWTH, DEVELOPMENT AND AGING; HOMEOSTASIS; MAIZE; MERISTEM; METABOLISM; PHYSIOLOGY; PLANT; POACEAE; REVIEW; RICE; SIGNAL TRANSDUCTION; TIME;

ARABIDOPSIS; CYTOKININS; FLOWERS; GENE EXPRESSION REGULATION, PLANT; HOMEOSTASIS; MERISTEM; MODELS, BIOLOGICAL; ORYZA SATIVA; PLANT GROWTH REGULATORS; PLANT PROTEINS; PLANT SHOOTS; POACEAE; SIGNAL TRANSDUCTION; TIME FACTORS; ZEA MAYS;

EID: 84874864415     PISSN: 00320781     EISSN: 14719053     Source Type: Journal    
DOI: 10.1093/pcp/pct025     Document Type: Review

References (108)

1. Abe, M., Kuroshita, H., Umeda, M., Itoh, J. and Nagato, Y. (2008) The rice flattened shoot meristem, encoding CAF-1 p150 subunit, is required for meristem maintenance by regulating the cell-cycle period. Dev. Biol. 319: 384-393.
2. Abe, M., Yoshikawa, T., Nosaka, M., Sakakibara, H., Sato, Y., Nagato, Y. et al. (2010) WAVY LEAF1, an ortholog of Arabidopsis HEN1, regulates shoot development by maintaining MicroRNA and trans-acting small interfering RNA accumulation in rice. Plant Physiol. 154: 1335-1346.
3. Aguilar-Martinez, J.A., Poza-Carrion, C. and Cubas, P. (2007) Arabidopsis BRANCHED1 acts as an integrator of branching signals within axillary buds. Plant Cell 19: 458-472.
4. Aichinger, E., Kornet, N., Friedrich, T. and Laux, T. (2012) Plant stem cell niches. Annu. Rev. Plant Biol. 63: 615-636.
5. Argueso, C.T., Raines, T. and Kieber, J.J. (2010) Cytokinin signaling and transcriptional networks. Curr. Opin. Plant Biol. 13: 533-539.
6. Arite, T., Umehara, M., Ishikawa, S., Hanada, A., Maekawa, M., Yamaguchi, S. et al. (2009) d14, a strigolactone-insensitive mutant of rice, shows an accelerated outgrowth of tillers. Plant Cell Physiol. 50: 1416-1424.
7. Betsuyaku, S., Takahashi, F., Kinoshita, A., Miwa, H., Shinozaki, K., Fukuda, H. et al. (2011) Mitogen-activated protein kinase regulated by the CLAVATA receptors contributes to shoot apical meristem homeostasis. Plant Cell Physiol. 52: 14-29.
8. Bolduc, N. and Hake, S. (2009) The maize transcription factor KNOTTED1 directly regulates the gibberellin catabolism gene ga2ox1. Plant Cell 21: 1647-1658.
9. Bolduc, N., Yilmaz, A., Mejia-Guerra, M.K., Morohashi, K., O'Connor, D., Grotewold, E. et al. (2012) Unraveling the KNOTTED1 regulatory network in maize meristems. Genes Dev. 26: 1685-1690.
10. Bommert, P., Lunde, C., Nardmann, J., Vollbrecht, E., Running, M., Jackson, D. et al. (2005a) thick tassel dwarf1 encodes a putative maize ortholog of the Arabidopsis CLAVATA1 leucine-rich repeat receptor-like kinase. Development 132: 1235-1245.
11. Bommert, P., Satoh Nagasawa, N. and Jackson, D. (2013) Quantitative variation in maize kernel row number is controlled by the FASCIATED EAR2 locus of maize. Nat. Genet (in press).
12. Bommert, P., Satoh-Nagasawa, N., Jackson, D. and Hirano, H.-Y. (2005b) Genetics and evolution of inflorescence and flower development in grasses. Plant Cell Physiol. 46: 69-78.
13. Brand, U., Fletcher, J.C., Hobe, M., Meyerowitz, E.M. and Simon, R. (2000) Dependence of stem cell fate in Arabidopsis on a feedback loop regulated by CLV3 activity. Science 289: 617-619.
14. Brown, P.J., Upadyayula, N., Mahone, G.S., Tian, F., Bradbury, P.J., Myles, S. et al. (2011) Distinct genetic architectures for male and female inflorescence traits of maize. PLoS Genet. 7 e1002383.
15. Chen, H., Banerjee, A.K. and Hannapel, D.J. (2004) The tandem complex of BEL and KNOX partners is required for transcriptional repression of ga20ox1. Plant J. 38: 276-284.
16. Chickarmane, V.S., Gordon, S.P., Tarr, P.T., Heisler, M.G. and Meyerowitz, E.M. (2012) Cytokinin signaling as a positional cue for patterning the apical-basal axis of the growing Arabidopsis shoot meristem. Proc. Natl Acad. Sci. USA 109: 4002-4007.
17. Chu, H., Qian, Q., Liang, W., Yin, C., Tan, H., Yao, X. et al. (2006) The FLORAL ORGAN NUMBER4 gene encoding a putative ortholog of Arabidopsis CLAVATA3 regulates apical meristem size in rice. Plant Physiol. 142: 1039-1052.
18. Clark, R.M., Wagler, T.N., Quijada, P. and Doebley, J. (2006) A distant upstream enhancer at the maize domestication gene tb1 has pleiotropic effects on plant and inflorescent architecture. Nat. Genet. 38: 594-597.
19. Clark, S.E., Williams, R.W. and Meyerowitz, E.M. (1997) The CLAVATA1 gene encodes a putative receptor kinase that controls shoot and floral meristem size in Arabidopsis. Cell 89: 575-585.
20. Cockram, J., Jones, H., Leigh, F.J., O'Sullivan, D., Powell, W., Laurie, D.A. et al. (2007) Control of flowering time in temperate cereals: genes, domestication, and sustainable productivity. J. Exp. Bot. 58: 1231-1244.
21. Colasanti, J. and Coneva, V. (2009) Mechanisms of floral induction in grasses: something borrowed, something new. Plant Physiol. 149: 56-62.
22. Colasanti, J., Yuan, Z. and Sundaresan, V. (1998) The indeterminate gene encodes a zinc finger protein and regulates a leaf-generated signal required for the transition to flowering in maize. Cell 93: 593-603.
23. Corbesier, L., Vincent, C., Jang, S., Fornara, F., Fan, Q., Searle, I. et al. (2007) FT protein movement contributes to long-distance signaling in floral induction of Arabidopsis. Science 316: 1030-1033.
24. Crawford, S., Shinohara, N., Sieberer, T., Williamson, L., George, G., Hepworth, J. et al. (2010) Strigolactones enhance competition between shoot branches by dampening auxin transport. Development 137: 2905-2913.
25. Doebley, J. (2004) The genetics of maize evolution. Annu. Rev. Genet. 38: 37-59.
26. Doebley, J., Stec, A. and Hubbard, L. (1997) The evolution of apical dominance in maize. Nature 386: 485-488.
27. Fletcher, J.C., Brand, U., Running, M.P., Simon, R. and Meyerowitz, E.M. (1999) Signaling of cell fate decisions by CLAVATA3 in Arabidopsis shoot meristems. Science 283: 1911-1914.
28. Gaiji, N., Cardinale, F., Prandi, C., Bonfante, P. and Ranghino, G. (2012) The computational-based structure of Dwarf14 provides evidence for its role as potential strigolactone receptor in plants. BMC Res. Notes 5: 307.
29. Gallavotti, A., Long, J.A., Stanfield, S., Yang, X., Jackson, D., Vollbrecht, E. et al. (2010) The control of axillary meristem fate in the maize ramosa pathway. Development 137: 2849-2856.
30. Gallavotti, A., Zhao, Q., Kyozuka, J., Meeley, R.B., Ritter, M.K., Doebley, J.F. et al. (2004) The role of barren stalk1 in the architecture of maize. Nature 432: 630-635.
31. Giulini, A., Wang, J. and Jackson, D. (2004) Control of phyllotaxy by the cytokinin-inducible response regulator homologue ABPHYL1. Nature 430: 1031-1034.
32. Gomez-Roldan, V., Fermas, S., Brewer, P.B., Puech-Pages, V., Dun, E.A., Pillot, J.P. et al. (2008) Strigolactone inhibition of shoot branching. Nature 455: 189-194.
33. Gordon, S.P., Chickarmane, V.S., Ohno, C. and Meyerowitz, E.M. (2009) Multiple feedback loops through cytokinin signaling control stem cell number within the Arabidopsis shoot meristem. Proc. Natl Acad. Sci. USA 106: 16529-16534.
34. Ha, C.M., Jun, J.H. and Fletcher, J.C. (2010) Shoot apical meristem form and function. Curr. Top. Dev. Biol. 91: 103-140.
35. Hamiaux, C., Drummond, R.S., Janssen, B.J., Ledger, S.E., Cooney, J.M., Newcomb, R.D. et al. (2012) DAD2 is an alpha/beta hydrolase likely to be involved in the perception of the plant branching hormone, strigolactone. Curr. Biol. 22: 2032-2036.
36. Hirano, H.-Y. (2008) Genetic regulation of meristem maintenance and organ specification in rice flower development. In Rice Biology in the Genomics Era. Edited by Hirano, H.-Y., Hirai, A., Sano, Y. and Sasaki, T pp. 69-79. Springer, Heidelberg.
37. Ikeda-Kawakatsu, K., Yasuno, N., Oikawa, T., Iida, S., Nagato, Y., Maekawa, M. et al. (2009) Expression level of ABERRANT PANICLE ORGANIZATION1 determines rice inflorescence form through control of cell proliferation in the meristem. Plant Physiol. 150: 736-747.
38. Itoh, H., Nonoue, Y., Yano, M. and Izawa, T. (2010) A pair of floral regulators sets critical day length for Hd3a florigen expression in rice. Nat. Genet. 42: 635-638.
39. Itoh, J.I., Hibara, K.I., Kojima, M., Sakakibara, H. and Nagato, Y. (2012) Rice DECUSSATE controls phyllotaxy by affecting the cytokinin signaling pathway. Plant J. (in press).
40. Itoh, J.I., Kitano, H., Matsuoka, M. and Nagato, Y. (2000) Shoot organization genes regulate shoot apical meristem organization and the pattern of leaf primordium initiation in rice. Plant Cell 12: 2161-2174.
41. Jackson, D. and Hake, S. (1999) Control of phyllotaxy in maize by the abphyl1 gene. Development 126: 315-323.
42. Jasinski, S., Piazza, P., Craft, J., Hay, A., Woolley, L., Rieu, I. et al. (2005) KNOX action in Arabidopsis is mediated by coordinate regulation of cytokinin and gibberellin activities. Curr. Biol. 15: 1560-1565.
43. Kawakatsu, T., Itoh, J., Miyoshi, K., Kurata, N., Alvarez, N., Veit, B. et al. (2006) PLASTOCHRON2 regulates leaf initiation and maturation in rice. Plant Cell 18: 612-625.
44. Kawakatsu, T., Taramino, G., Itoh, J., Allen, J., Sato, Y., Hong, S.K. et al. (2009) PLASTOCHRON3/GOLIATH encodes a glutamate carboxypeptidase required for proper development in rice. Plant J. 58: 1028-1040.
45. Kayes, J.M. and Clark, S.E. (1998) CLAVATA2, a regulator of meristem and organ development in Arabidopsis. Development 125: 3843-3851.
46. 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.
47. Kinoshita, A., Betsuyaku, S., Osakabe, Y., Mizuno, S., Nagawa, S., Stahl, Y. et al. (2010) RPK2 is an essential receptor-like kinase that transmits the CLV3 signal in Arabidopsis. Development 137: 3911-3920.
48. Kobayashi, K., Yasuno, N., Sato, Y., Yoda, M., Yamazaki, R., Kimizu, M. et al. (2012) Inflorescence meristem identity in rice is specified by overlapping functions of three AP1/FUL-like MADS box genes and PAP2, a SEPALLATA MADS box gene. Plant Cell 24: 1848-1859.
49. Komatsu, K., Maekawa, M., Ujiie, S., Satake, Y., Furutani, I., Okamoto, H. et al. (2003) LAX and SPA: major regulators of shoot branching in rice. Proc. Natl Acad. Sci. USA 100: 11765-11770.
50. Komiya, R., Yokoi, S. and Shimamoto, K. (2009) A gene network for long-day flowering activates RFT1 encoding a mobile flowering signal in rice. Development 136: 3443-3450.
51. Kondo, T., Sawa, S., Kinoshita, A., Mizuno, S., Kakimoto, T., Fukuda, H. et al. (2006) A plant peptide encoded by CLV3 identified by in situ MALDI-TOF MS analysis. Science 313: 845-848.
52. Kurakawa, T., Ueda, N., Maekawa, M., Kobayashi, K., Kojima, M., Nagato, Y. et al. (2007) Direct control of shoot meristem activity by a cytokinin-activating enzyme. Nature 445: 652-655.
53. Lazakis, C.M., Coneva, V. and Colasanti, J. (2011) ZCN8 encodes a potential orthologue of Arabidopsis FT florigen that integrates both endogenous and photoperiod flowering signals in maize. J. Exp. Bot. 62: 4833-4842.
54. Lee, B.H., Johnston, R., Yang, Y., Gallavotti, A., Kojima, M., Travencolo, B.A. et al. (2009) Studies of aberrant phyllotaxy1 mutants of maize indicate complex interactions between auxin and cytokinin signaling in the shoot apical meristem. Plant Physiol. 150: 205-216.
55. Leibfried, A., To, J.P., Busch, W., Stehling, S., Kehle, A., Demar, M. et al. (2005) WUSCHEL controls meristem function by direct regulation of cytokinin-inducible response regulators. Nature 438: 1172-1175.
56. Li, X., Qian, Q., Fu, Z., Wang, Y., Xiong, G., Zeng, D. et al. (2003) Control of tillering in rice. Nature 422: 618-621.
57. Lin, Q., Wang, D., Dong, H., Gu, S., Cheng, Z., Gong, J. et al. (2012) Rice APC/C(TE) controls tillering by mediating the degradation of MONOCULM 1. Nat. Commun. 3: 752.
58. Long, J.A., Moan, E.I., Medford, J.I. and Barton, M.K. (1996) A member of the KNOTTED class of homeodomain proteins encoded by the STM gene of Arabidopsis. Nature 379: 66-69.
59. Martin-Trillo, M. and Cubas, P. (2010) TCP genes: a family snapshot ten years later. Trends Plant Sci. 15: 31-39.
60. Matsubara, K., Yamanouchi, U., Wang, Z.X., Minobe, Y., Izawa, T. and Yano, M. (2008) Ehd2, a rice ortholog of the maize INDETERMINATE1 gene, promotes flowering by up-regulating Ehd1. Plant Physiol. 148: 1425-1435.
61. Mayer, K.F.X., Schoof, H., Haecker, A., Lenhard, M., Jürgens, G. and Laux, T. (1998) Role of WUSCHEL in regulating stem cell fate in the Arabidopsis shoot meristem. Cell 95: 805-815.
62. McSteen, P. and Leyser, O. (2005) Shoot branching. Annu. Rev. Plant Biol. 56: 353-374.
63. Meng, X., Muszynski, M.G. and Danilevskaya, O.N. (2011) The FT-like ZCN8 gene functions as a floral activator and is involved in photoperiod sensitivity in maize. Plant Cell 23: 942-960.
64. Miller, T., Muslin, E. and Dorweiler, J. (2008) A maize CONSTANS-like gene, conz1, exhibits distinct diurnal expression patterns in varied photoperiods. Planta 227: 1377-1388.
65. Minakuchi, K., Kameoka, H., Yasuno, N., Umehara, M., Luo, L., Kobayashi, K. et al. (2010) FINE CULM1 (FC1) works downstream of strigolactones to inhibit the outgrowth of axillary buds in rice. Plant Cell Physiol. 51: 1127-1135.
66. Miwa, H., Betsuyaku, S., Iwamoto, K., Kinoshita, A., Fukuda, H. and Sawa, S. (2008) The receptor-like kinase SOL2 mediates CLE signaling in Arabidopsis. Plant Cell Physiol. 49: 1752-1757.
67. Miyoshi, K., Ahn, B.O., Kawakatsu, T., Ito, Y., Itoh, J., Nagato, Y. et al. (2004) PLASTOCHRON1, a timekeeper of leaf initiation in rice, encodes cytochrome P450. Proc. Natl Acad. Sci. USA 101: 875-880.
68. Müller, R., Bleckmann, A. and Simon, R. (2008) The receptor kinase CORYNE of Arabidopsis transmits the stem cell-limiting signal CLAVATA3 independently of CLAVATA1. Plant Cell 20: 934-946.
69. Muszynski, M., Dam, T., Li, B., Shirbroun, D., Hou, Z., Bruggemann, E. et al. (2006) delayed flowering1 encodes a basic leucine zipper protein that mediates floral inductive signals at the shoot apex in maize. Plant Physiol. 142: 1523-1536.
70. Nagasaki, H., Itoh, J., Hayashi, K., Hibara, K., Satoh-Nagasawa, N., Nosaka, K. et al. (2007) The small interfering RNA production pathway is required for shoot meristem initiation in rice. Proc. Natl Acad. Sci. USA 104: 14867-14871.
71. Nagasawa, N., Miyoshi, M., Kitano, H., Satoh, H. and Nagato, Y. (1996) Mutations associated with floral organ number in rice. Planta 198: 627-633.
72. Nardmann, J. and Werr, W. (2006) The shoot stem cell niche in angiosperms: expression patterns of WUS orthologues in rice and maize imply major modifications in the course of mono- and dicot evolution. Mol. Biol. Evol. 23: 2492-2504.
73. Ogawa, M., Shinohara, H., Sakagami, Y. and Matsubayashi, Y. (2008) Arabidopsis CLV3 peptide directly binds CLV1 ectodomain. Science 319: 294.
74. Ohmori, Y., Tanaka, W., Kojima, M., Sakakibara, H. and Hirano, H.-Y. (2013) WOX4 is required for meristem function to maintain the undifferentiated state and is negatively regulated by the CLE gene FCP1 in rice. Plant Cell (in press).
75. Ohyama, K., Shinohara, H., Ogawa-Ohnishi, M. and Matsubayashi, Y. (2009) A glycopeptide regulating stem cell fate in Arabidopsis thaliana. Nat. Chem. Biol. 5: 578-580.
76. Oikawa, T. and Kyozuka, J. (2009) Two-step regulation of LAX PANICLE1 protein accumulation in axillary meristem formation in rice. Plant Cell 21: 1095-1108.
77. Ongaro, V. and Leyser, O. (2008) Hormonal control of shoot branching. J. Exp. Bot. 59: 67-74.
78. Park, S.J., Kim, S.L., Lee, S., Je, B.I., Piao, H.L., Park, S.H. et al. (2008) Rice Indeterminate 1 (OsId1) is necessary for the expression of Ehd1 (Early heading date 1) regardless of photoperiod. Plant J. 56: 1018-1029.
79. Sakamoto, T., Kamiya, N., Ueguchi-Tanaka, M., Iwahori, S. and Matsuoka, M. (2001) KNOX homeodomain protein directly suppresses the expression of a gibberellin biosynthetic gene in the tobacco shoot apical meristem. Genes Dev. 15: 581-590.
80. Sakamoto, T., Sakakibara, H., Kojima, M., Yamamoto, Y., Nagasaki, H., Inukai, Y. et al. (2006) Ectopic expression of KNOTTED1-like homeobox protein induces expression of cytokinin biosynthesis genes in rice. Plant Physiol. 142: 54-62.
81. Schoof, H., Lenhard, M., Haecker, A., Mayer, K.F.X., Jürgens, G. and Laux, T. (2000) The stem cell population of Arabidopsis shoot meristems is maintained by a regulatory loop between the CLAVATA and WUSCHEL genes. Cell 100: 635-644.
82. Studer, A., Zhao, Q., Ross-Ibarra, J. and Doebley, J. (2011) Identification of a functional transposon insertion in the maize domestication gene tb1. Nat. Genet. 43: 1160-1163.
83. Suzaki, T., Ohneda, M., Toriba, T., Yoshida, A. and Hirano, H.Y. (2009) FON2 SPARE1 redundantly regulates floral meristem maintenance with FLORAL ORGAN NUMBER2 in rice. PLoS Genet. 5 e1000693.
84. Suzaki, T., Sato, M., Ashikari, M., Miyoshi, M., Nagato, Y. and Hirano, H.-Y. (2004) The gene FLORAL ORGAN NUMBER1 regulates floral meristem size in rice and encodes a leucine-rich repeat receptor kinase orthologous to Arabidopsis CLAVATA1. Development 131: 5649-5657.
85. Suzaki, T., Toriba, T., Fujimoto, M., Tsutsumi, N., Kitano, H. and Hirano, H.-Y. (2006) Conservation and diversification of meristem maintenance mechanism in Oryza sativa: function of the FLORAL ORGAN NUMBER2 gene Plant Cell Physiol. 47 1591-1602.
86. Suzaki, T., Yoshida, A. and Hirano, H.-Y. (2008) Functional diversification of CLAVATA3-related CLE proteins in meristem maintenance in rice. Plant Cell 20: 2049-2058.
87. Tabuchi, H., Zhang, Y., Hattori, S., Omae, M., Shimizu-Sato, S., Oikawa, T. et al. (2011) LAX PANICLE2 of rice encodes a novel nuclear protein and regulates the formation of axillary meristems. Plant Cell 23: 3276-3287.
88. Taguchi-Shiobara, F., Yuan, Z., Hake, S. and Jackson, D. (2001) The fasciated ear2 gene encodes a leucine-rich repeat receptor-like protein that regulates shoot meristem proliferation in maize. Genes Dev. 15: 2755-2766.
89. Takahashi, Y., Teshima, K.M., Yokoi, S., Innan, H. and Shimamoto, K. (2009) Variations in Hd1 proteins, Hd3a promoters, and Ehd1 expression levels contribute to diversity of flowering time in cultivated rice. Proc. Natl Acad. Sci. USA 106: 4555-4560.
90. Takeda, T., Suwa, Y., Suzuki, M., Kitano, H., Ueguchi-Tanaka, M., Ashikari, M. et al. (2003) The OsTB1 gene negatively regulates lateral branching in rice. Plant J. 33: 513-520.
91. Tamaki, S., Matsuo, S., Wong, H.L., Yokoi, S. and Shimamoto, K. (2007) Hd3a protein is a mobile flowering signal in rice. Science 316: 1033-1036.
92. Tanaka, W., Pautler, M., Jackson, D. and Hirano., H.Y. (2013) Grass meristems II: inflorescence architecture, flower development and meristem fate. Plant Cell Physiol. 54: 313-324.
93. Taoka, K., Ohki, I., Tsuji, H., Furuita, K., Hayashi, K., Yanase, T. et al. (2011) 14-3-3 proteins act as intracellular receptors for rice Hd3a florigen. Nature 476: 332-335.
94. Tsuda, K., Ito, Y., Sato, Y. and Kurata, N. (2011) Positive autoregulation of a KNOX gene is essential for shoot apical meristem maintenance in rice. Plant Cell 23: 4368-4381.
95. Tsuji, H., Taoka, K. and Shimamoto, K. (2011) Regulation of flowering in rice: two florigen genes, a complex gene network, and natural variation. Curr. Opin. Plant Biol. 14: 45-52.
96. Turck, F., Fornara, F. and Coupland, G. (2008) Regulation and identity of florigen: FLOWERING LOCUS T moves center stage. Annu. Rev. Plant Biol. 59: 573-594.
97. Umehara, M., Hanada, A., Yoshida, S., Akiyama, K., Arite, T., Takeda- Kamiya, N. et al. (2008) Inhibition of shoot branching by new terpenoid plant hormones. Nature 455: 195-200.
98. 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.
99. Wang, J.W., Schwab, R., Czech, B., Mica, E. and Weigel, D. (2008) Dual effects of miR156-targeted SPL genes and CYP78A5/KLUH on plastochron length and organ size in Arabidopsis thaliana. Plant Cell 20: 1231-1243.
100. Werner, T., Motyka, V., Laucou, V., Smets, R., Van Onckelen, H. and Schmulling, T. (2003) Cytokinin-deficient transgenic Arabidopsis plants show multiple developmental alterations indicating opposite functions of cytokinins in the regulation of shoot and root meristem activity. Plant Cell 15: 2532-2550.
101. Whipple, C.J., Hall, D.H., DeBlasio, S., Taguchi-Shiobara, F., Schmidt, R.J. and Jackson, D.P. (2010) A conserved mechanism of bract suppression in the grass family. Plant Cell 22: 565-578.
102. Whipple, C.J., Kebrom, T.H., Weber, A.L., Yang, F., Hall, D., Meeley, R. et al. (2011) grassy tillers1 promotes apical dominance in maize and responds to shade signals in the grasses. Proc. Natl Acad. Sci. USA 108: E506-E512.
103. Xu, C., Wang, Y., Yu, Y., Duan, J., Liao, Z., Xiong, G. et al. (2012) Degradation of MONOCULM 1 by APC/C(TAD1) regulates rice tillering. Nat. Commun. 3: 750.
104. Xue, W., Xing, Y., Weng, X., Zhao, Y., Tang, W., Wang, L. et al. (2008) Natural variation in Ghd7 is an important regulator of heading date and yield potential in rice. Nat. Genet. 40: 761-767.
105. Yadav, R.K., Perales, M., Gruel, J., Girke, T., Jönsson, H. and Reddy, G.V. (2011) WUSCHEL protein movement mediates stem cell homeostasis in the Arabidopsis shoot apex. Genes Dev. 25: 2025-2030.
106. Yamaki, S., Nagato, Y., Kurata, N. and Nonomura, K.-I. (2011) Ovule is a lateral organ finally differentiated from the terminating floral meristem in rice. Dev. Biol. 351: 208-216.
107. Yanai, O., Shani, E., Dolezal, K., Tarkowski, P., Sablowski, R., Sandberg, G. et al. (2005) Arabidopsis KNOXI proteins activate cytokinin biosynthesis. Curr. Biol. 15: 1566-1571.
108. Yano, M., Katayose, Y., Ashikari, M., Yamanouchi, U., Monna, L., Fuse, T. et al. (2000) Hd1, a major photoperiod sensitivity quantitative trait locus in rice, is closely related to the Arabidopsis flowering time gene CONSTANS. Plant Cell 12: 2473-2484.