Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

Apical meristem exhaustion during determinate primary root growth in the moots koom 1 mutant of Arabidopsis thaliana


An indeterminate developmental program allows plant organs to grow continuously by maintaining functional meristems over time. The molecular mechanisms involved in the maintenance of the root apical meristem are not completely understood. We have identified a new Arabidopsis thaliana mutant named moots koom 1 (mko1) that showed complete root apical meristem exhaustion of the primary root by 9 days post-germination. MKO1 is essential for maintenance of root cell proliferation. In the mutant, cell division is uncoupled from cell growth in the region corresponding to the root apical meristem. We established the sequence of cellular events that lead to meristem exhaustion in this mutant. Interestingly, the SCR and WOX5 promoters were active in the mko1 quiescent center at all developmental stages. However, during meristem exhaustion, the mutant root tip showed defects in starch accumulation in the columella and changes in auxin response pattern. Therefore, contrary to many described mutants, the determinate growth in mko1 seedlings does not appear to be a consequence of incorrect establishment or affected maintenance of the quiescent center but rather of cell proliferation defects both in stem cell niche and in the rest of the apical meristem. Our results support a model whereby the MKO1 gene plays an important role in the maintenance of the root apical meristem proliferative capacity and indeterminate root growth, which apparently acts independently of the SCR/SHR and WOX5 regulatory pathways.

This is a preview of subscription content, log in to check access.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7



Confocal Laser Scanning Microscopy


Days after germination


Dimethyl sulfoxide


Ethyl methanesulfonate


Green fluorescent protein


Murashige and Skoog medium


Quiescent center


Root apical meristem


Simple Sequence Length Polymorphism

mko1 :

moots koom 1


  1. Aida M, Beis D, Heidstra R, Willemsen V, Blilou I, Galinha C, Nussaume L, Noh Y-S, Amasino R, Scheres B (2004) The PLETHORA genes mediate patterning of the Arabidopsis root stem cell niche. Cell 119:109–120

  2. Azpeitia E, Benitez M, Vega I, Villarreal C, Alvarez-Buylla ER (2010) Single-cell and coupled GRN models of cell patterning in the Arabidopsis thaliana root stem cell niche. BMC Syst Biol 4:134

  3. Barlow PW (1976) Towards an understanding of the behaviour of root meristems. J Theor Biol 57:433–451

  4. Baum SF (1996) The developmental organization of the root apical meristem in Arabidopsis thaliana CV WS. Ph.D. dissertation, University of California, Davis, CA, USA

  5. Baum SF, Rost TL (1996) Root apical organization in Arabidopsis thaliana 1. Root cap and protoderm. Protoplasma 192:178–188

  6. Baum SF, Dubrovsky JG, Rost TL (2002) Apical organization and maturation of the cortex and vascular cylinder in Arabidopsis thaliana (Brassicaceae) roots. Am J Bot 89:908–920

  7. Benfey P, Linstead PJ, Roberts K, Schiefelbein JW, Hauser MT, Aeschbacher RA (1993) Root development in Arabidopsis: four mutants with dramatically altered root morphogenesis. Development 119:57–70

  8. Benková E, Ivanchenko MG, Friml J, Shishkova S, Dubrovsky JG (2009) A morphogenetic trigger: is there an emerging concept in plant developmental biology? Trends Plant Sci 14:189–193

  9. Bennett T, Scheres B (2010) Root development-two meristems for the price of one? Curr Top Dev Biol 91:67

  10. Blilou I, Frugier F, Folmer S, Serralbo O, Willemsen V, Wolkenfelt H, Eloy NB, Ferreira PCG, Weisbeek P, Scheres B (2002) The Arabidopsis HOBBIT gene encodes a CDC27 homolog that links the plant cell cycle to progression of cell differentiation. Genes Dev 16:2566–2575

  11. Blilou I, Xu J, Wildwater M, Willemsen V, Paponov I, Friml I, Heidstra R, Aida M, Palme K, Scheres B (2005) The PIN auxin efflux facilitator network controls growth and patterning in Arabidopsis roots. Nature 433:39–44

  12. Cheng JC, Seeley KA, Sung ZR (1995) RML1 and RML2, Arabidopsis genes required for cell proliferation at the root tip. Plant Physiol 107:365–376

  13. Colón-Carmona A, You R, Haimovitch-Gal T, Doerner P (1999) Technical advance: spatio-temporal analysis of mitotic activity with a labile cyclin–GUS fusion protein. Plant J 20:503–508

  14. Cui H, Levesque MP, Vernoux T, Jung JW, Paquette AJ, Gallagher KL, Wang JY, Blilou I, Scheres B, Benfey PN (2007) An evolutionarily conserved mechanism delimiting SHR movement defines a single layer of endodermis in plants. Science 316:421–425

  15. Ding Z, Friml J (2010) Auxin regulates distal stem cell differentiation in Arabidopsis roots. Proc Natl Acad Sci USA 107:12046–12051

  16. Dolan L, Janmaat K, Willemsen V, Linstead P, Poethig S, Roberts K, Scheres B (1993) Cellular organisation of the Arabidopsis thaliana root. Development 119:71–84

  17. Drenkard E, Richter BG, Rozen S, Stutius LM, Angell NA, Mindrinos M, Cho RJ, Oefner PJ, Davis RW, Ausubel FM (2000) A simple procedure for the analysis of single nucleotide polymorphisms facilitates map-based cloning in Arabidopsis. Plant Physiol 124:1483–1492

  18. Dubrovsky JG (1997) Determinate primary-root growth in seedlings of Sonoran Desert Cactaceae; its organization, cellular basis, and ecological significance. Planta 203:85–92

  19. Dubrovsky JG, Soukup A, Napsucialy-Mendivil S, Jeknic Z, Ivanchenko MG (2009) The lateral root initiation index: an integrative measure of primordium formation. Ann Bot 103:807–817

  20. Friml J, Vieten A, Sauer M, Weijers D, Schwarz H, Hamann T, Offringa R, Jürgens G (2003) Efflux-dependent auxin gradients establish the apical–basal axis of Arabidopsis. Nature 426:147–153

  21. Galinha C, Hofhuis H, Luijten M, Willemsen V, Blilou I, Heidstra R, Scheres B (2007) PLETHORA proteins as dose-dependent master regulators of Arabidopsis root development. Nature 449:1053–1057

  22. Hamann T, Mayer U, Jürgens G (1999) The auxin-insensitive bodenlos mutation affects primary root formation and apical-basal patterning in the Arabidopsis embryo. Development 126:1387–1395

  23. Hamann T, Benková E, Bäurle I, Kientz M, Jürgens G (2002) The Arabidopsis BODENLOS gene encodes an auxin response protein inhibiting MONOPTEROS-mediated embryo patterning. Genes Dev 16:1610–1615

  24. Hardtke CS, Ckurshumova W, Vidaurre DP (2004) Overlapping and non- redundant functions of the Arabidopsis auxin response factors MONOPTEROS and NONPHOTOTROPIC HYPOCOTYL 4. Development 131:1089–1100

  25. Helariutta Y, Fukaki H, Wysocka-Diller J, Nakajima K, Jung J, Sena G, Hauser MT, Benfey PN (2000) The SHORT-ROOT gene controls radial patterning of the Arabidopsis root through radial signaling. Cell 101:555–567

  26. Ivanov VB (1974) Kletochnye Osnovy Rosta Rastenii (Cellular Bases of Plant Growth). Nauka, Moscow (in Russian)

  27. Ivanov VB (1994) Root growth responses to chemicals. Sov Sci Rev D Physicochem Biol 13:1–70

  28. Ivanov VB, Dobrochaev AE, Baskin TI (2002) What the distribution of cell lengths in the root meristem does and does not reveal about cell division. J Plant Growth Regul 21:60–67

  29. Jiang K, Meng YL, Feldman LJ (2003) Quiescent center formation in maize roots is associated with an auxin-regulated oxidizing environment. Development 130:1429–1438

  30. Jiang K, Zhu T, Diao Z, Huang H, Feldman LJ (2010) The maize root stem cell niche: a partnership between two sister cell populations. Planta 231:411–424

  31. Kidner C, Sundaresan V, Roberts K, Dolan L (2000) Clonal analysis of the Arabidopsis root confirms that position, not lineage, determines cell fate. Planta 211:191–199

  32. Koprivova A, Mugford ST, Kopriva S (2010) Arabidopsis root growth dependence on glutathione is linked to auxin transport. Plant Cell Rep 29:1157–1167

  33. Lukowitz W, Gillmor CS, Scheible WR (2000) Positional cloning in Arabidopsis. Why it feels good to have a genome initiative working for you. Plant Physiol 123:795–805

  34. Nakajima K, Sena G, Nawy T, Benfey PN (2001) Intercellular movement of the putative transcription factor SHR in root patterning. Nature 413:307–311

  35. Overvoorde P, Fukaki H, Beeckman T (2010) Auxin control of root development. Cold Spring Harb Perspect Biol 2:a001537

  36. Pérez-Pérez JM, Serralbo O, Vanstraelen M, González C, Criqui MC, Genschik P, Kondorosi E, Scheres B (2008) Specialization of CDC27 function in the Arabidopsis thaliana anaphase-promoting complex (APC/C). Plant J 53:78–89

  37. Reddy GV, Heisler MG, Ehrhardt DW, Meyerowitz EM (2004) Real-time lineage analysis reveals oriented cell divisions associated with morphogenesis at the shoot apex of Arabidopsis thaliana. Development 131:4225–4237

  38. Rodríguez-Rodríguez JF, Shishkova S, Napsucialy-Mendivil S, Dubrovsky JG (2003) Apical meristem organization and lack of establishment of the quiescent center in Cactaceae roots with determinate growth. Planta 217:849–857

  39. Sabatini S, Beis D, Wolkenfelt H, Murfett J, Guilfoyle T, Malamy J, Benfey J, Leyser O, Bechtold N, Weisbeek P, Scheres B (1999) An auxin-dependent distal organizer of pattern and polarity in the Arabidopsis root. Cell 99:463–472

  40. Sabatini S, Heidstra R, Wildwater M, Scheres B (2003) SCARECROW is involved in positioning the stem cell niche in the Arabidopsis root meristem. Genes Dev 17:354–358

  41. Sarkar AK, Luijten M, Miyashima S, Lenhard M, Hashimoto T, Nakajima K, Scheres R, Heidstra R, Laux T (2007) Conserved factors regulate signalling in Arabidopsis thaliana shoot and root stem cell organizers. Nature 446:811–814

  42. Scheres B, Wolkenfelt H, Willemsen V, Terlouw M, Lawson E, Dean C, Weisbeek P (1994) Embryonic origin of the Arabidopsis primary root and root meristem initials. Development 120:2475–2487

  43. Serralbo O, Pérez-Pérez JM, Heidstra R, Scheres B (2006) Non-cell-autonomous rescue of anaphase-promoting complex function revealed by mosaic analysis of HOBBIT, an Arabidopsis CDC27 homolog. Proc Natl Acad Sci USA 103:13250–13255

  44. Shishkova S, Dubrovsky JG (2005) Developmental programmed cell death in primary roots of Sonoran Desert Cactaceae. Am J Bot 92:1590–1594

  45. Shishkova S, Rost TL, Dubrovsky JG (2008) Determinate root growth and meristem maintenance in angiosperms. Ann Bot 101:319–340

  46. Stahl Y, Wink RH, Ingram GC, Simon R (2009) A signaling module controlling the stem cell niche in Arabidopsis root meristems. Curr Biol 19:909–914

  47. Truernit E, Bauby H, Dubreucq B, Grandjean O, Runions J, Barthelemy J, Palauqui JC (2008) High-resolution whole-mount imaging of three-dimensional tissue organization and gene expression enables the study of phloem development and structure in Arabidopsis. Plant Cell 20:1494–1503

  48. Ueda M, Matsui K, Ishiguro S, Sano R, Wada T, Paponov I, Palme K, Okada K (2004) The HALTED ROOT gene encoding the 26S proteasome subunit RPT2a is essential for the maintenance of Arabidopsis meristems. Development 131:2101–2111

  49. van den Berg C, Willemsen V, Hage W, Weisbeek P, Scheres B (1995) Cell fate in the Arabidopsis root meristem determined by directional signalling. Nature 378:62–65

  50. van den Berg C, Willemsen W, Hendriks G, Weisbeek P, Scheres B (1997) Short-range control of cell differentiation in the Arabidopsis root meristem. Nature 390:287–289

  51. Vanneste S, Friml J (2009) Auxin: a trigger for change in plant development. Cell 136:1005–1016

  52. Vanstraelen M, Baloban M, Da Ines O, Cultrone A, Lammens T, Boudolf V, Brown SC, De Veylder L, Mergaert P, Kondorosi E (2009) APC/C −CCS52A complexes control meristem maintenance in the Arabidopsis root. Proc Natl Acad Sci USA 106:11806–11811

  53. Vernoux T, Wilson RC, Seeley KA, Reichheld JP, Muroy S, Brown S, Maughan SC, Cobbett CS, Van Montagu M, Inzé D, May MJ, Sung ZR (2000) The ROOT MERISTEMLESS1/CADMIUM SENSITIVE2 gene defines a glutathione-dependent pathway involved in initiation and maintenance of cell division during postembryonic root development. Plant Cell 12:97–110

  54. Von Guttenberg H (1960) Grundzüge der Histogenese höherer Pflanzen. I. Die Angiospermen. Gebruder Borntraeger, Berlin

  55. Willemsen V, Wolkenfelt H, de Vrieze G, Weisbeek P, Scheres B (1998) The HOBBIT gene is required for formation of the root meristem in the Arabidopsis embryo. Development 125:521–531

  56. Wysocka-Diller JW, Helariutta Y, Fukaki H, Malamy JE, Benfey PN (2000) Molecular analysis of SCARECROW function reveals a radial patterning mechanism common to root and shoot. Development 127:595–603

Download references


We thank J. M. Hurtado-Ramírez, S. Ainsworth, E. López, P, Gaitan, M. E. Salas-Ocampo, G. Zavala-Padilla, and A. M. Saralegui for excellent technical help, P. Doerner, B. Scheres, J. Friml, and K. Okada for seed donation and A. Colón-Carmona for critical reading of a previous version of the manuscript. The research was supported by the Dirección General de Asuntos del Personal Académico (DGAPA)—Programa de Apoyo a Proyectos de Investigación e Innovación Tecnológica, Universidad Nacional Autónoma de México (grant IN212509 to S.S. and grants IN225906 and IN212009 to J.G.D.), Consejo Nacional de Ciencia y Technología (CONACyT), Mexico (grant 79736 to S.S. and grants 49267 and 127957 to J.G.D.). Doctorate fellowship to A.H.-B. from CONACyT and postdoctoral fellowship from DGAPA-UNAM (to G.D., V.L.-R., A.S., and Y.U.-C.) are gratefully acknowledged.

Author information

Correspondence to Joseph G. Dubrovsky.

Additional information

A. Hernández-Barrera and Y. Ugartechea-Chirino contributed equally to this work.

Electronic supplementary material

Below is the link to the electronic supplementary material.

Suppl. Material S1. Map location of mko1. The MKO1 locus is positioned on the lower arm of chromosome IV between SSLP markers CER453190 and CER460296. The mapped interval includes 2.7 Mb. The number of recombination events per the number of scored chromosomes for each marker and marker position are shown. The open circle indicates the centromere. The CCS52A2 (7.1 Mb), RML1 (12.1 Mb) and SHR (17. 6 Mb) loci are outside the mapping region. (TIFF 429 kb)

Suppl. Material S2 (DOC 63 kb)

Suppl. Material S3 Representative morphological features of cell differentiation in mko1 primary RAM with completely exhausted RAM. Median longitudinal sections of cleared (a, b) and pseudo-Schiff-stained (c, d) roots. Scanning electron microscopy image of the root apex (e). The mko1 exhausted meristem is characterized by the following features: mature xylem strands (arrowheads in a and b) and root hairs (white arrows in a, b, and e) or root hair bulges (yellow arrow in b) near the root apex; swollen or abnormally elongated epidermal cells (c, d). Mutant root tips with exhausted RAM can maintain a remnant root cap (c) or consist of elongated cells in the position of the root cap (d). Scale bar 20 μm (a, b) and 50 μm (c-e) (TIFF 6449 kb)

Suppl. Material S4 pWOX5::GFP expression is not restricted to the QC in wild-type and the mko1 mutant. Median longitudinal sections of pWOX5::GFP (a, b) and mko1 pWOX5::GFP (c, d) stem cell niche. GFP signal capture was obtained at the same conditions in 3- and 6-dag seedlings, and the images were enhanced post-capture using ImageJ software to facilitate visualization of the GFP distribution. When pWOX5::GFP is expressed at 3 dag in the wild-type background, GFP signal is mainly restricted to the QC (a) and is subsequently expanded to the surrounding initials by 6 dag (b). In the mko1 background, the GFP signal is relatively less restricted to the QC in 3- (c) and 6 (d)-dag seedlings (corresponding to stages I and II of the RAM exhaustion). Scale bar 20 μm (TIFF 788 kb)

Suppl. Material S5 Cell growth impairment in mko1 mutant cortex cells early after germination (1 dag). Cortical cell length at fixed cell positions within the meristematic region; cell number one is a daughter cell of the cortex-endodermis initial. Mean ± SE, n = 5 (wild type) and 7 (mko1) roots with two cells measured per root at each position (TIFF 1189 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Hernández-Barrera, A., Ugartechea-Chirino, Y., Shishkova, S. et al. Apical meristem exhaustion during determinate primary root growth in the moots koom 1 mutant of Arabidopsis thaliana . Planta 234, 1163–1177 (2011). https://doi.org/10.1007/s00425-011-1470-4

Download citation


  • Arabidopsis
  • Determinate growth
  • Meristem organization
  • Root apical meristem maintenance
  • Stem cells