Plant Cell Cycle


In plants, just like animals, proliferative cells divide mostly mitotically or sometimes meiotically, where chromosome number is either maintained or halved, respectively. This is achieved in the cell cycle, an ordered sequence of events that enables a healthy cell to divide. Cell‐cycle regulation is crucial for plant development due to the link between cell proliferation in meristems and differentiation or altered plane of division of descendants. Regulation of cell division is also a major way whereby plants are able to respond to an ever‐changing environment. While generic cyclin‐dependent kinase (CDK) regulation operates in the plant cell cycle, there are distinct differences from animals. Prominently these are very large cyclin families, the plant‐specific class of B‐type CDKs and the absence of phosphoregulation of CDKs by CDC25 and WEE1 except under checkpoint conditions. Cell division in meristems and gametophytes is regulated by feedback loops involving transcription factors, cell‐cycle activators and repressors.

Key Concepts

  • There are many more members in cell‐cycle regularity families in plants.
  • In an unperturbed cell cycle, phosphoregulation of higher plant CDKs does not require WEE1 or CDC25.
  • Plant cell‐cycle checkpoints lack CHK1 but engage WEE1 and KRPs.
  • MYB transcription factors promote and repress G2/M expressed genes.
  • Induction of DNA replication is similar in plants and animals but there are more E2F and RB‐related proteins in plants.
  • Negative feedback loops regulate organising centres in plant meristems.
  • Coordination between cell division and cell differentiation is spatially and temporally different in RAMs and SAMs.
  • Similar to cell growth, organ growth by cell proliferation can be subdivided into the proliferation rate, the direction of cell divisions determined by the orientation of the mitotic spindle and the duration of cell divisions.
  • ICK4/KRP6 and CDKA are major regulators of cell division in gametophytes.

Keywords: proliferation; endoreduplication; mitosis; meiosis; cell growth; cyclin‐dependent kinase; cyclins; checkpoints

Figure 1. Mitotic and meiotic cell cycles. (a) When a proliferative G2 cell traverses mitosis to G1, it maintains the diploid number of chromosomes (2n) but nuclear DNA amount (C value) is halved (4C to 2C). When the G1 cell traverses synthetic (S)‐phase to G2, nuclear DNA amount is doubled. (b) A meiocyte cell traversing meiosis undergoes two divisions, meiosis I, where chromosome number and nuclear DNA amount are halved (2n to n and 4C to 2C) and meiosis II, where chromosome number is maintained as haploid (n) but nuclear DNA amount is halved again (2C to 1C). 1C is defined as the amount of nuclear DNA in the unreplicated haploid genome of a gamete.
Figure 2. Cell‐cycle control at G2/mitosis. (a) CDKA is repressed by ICK1. Activation of CDKA is through phosphorylation () by CAK and cyclin binding, and phosphorylation of ICK1 by CDKB, causing ICK1 to release CDKA. Based on model by Boudolf et al., 2006. (b) At metaphase, the cyclin is ubiquitinated by the APC/C (anaphase promotion complex/cycleosome CULLIN‐RINGfinger E3 ligase) complex and degraded en route to the 26S proteasome. Model based on observations by Weingartner et al., () that a nondegradable cyclin permits normal mitosis until metaphase followed by mitotic catastrophe and that M‐phase degradative complex colocalises with mitotic spindles at metaphase (Farras et al., ). CDK = cyclin‐dependent kinase; ICK1 = interactor/inhibitor of CDK; CAK = cyclin‐dependent activating kinase.
Figure 3. DNA repair and replication checkpoints in plants. In the repair pathway, ultraviolet light (UVB) or ionising radiation (IR) induces the formation of ATM that phosphorylates WEE1 that, in turn, represses CDKA. The omega form of 14‐3‐3 protein binds to and protects the phosphorylated site of WEE1. In the replication pathway, hydroxyurea (HU) or reactive oxygen species (ROS) activates ATR, which, in turn, upregulates SOG1 that itself activates SMR5/7. The latter complex then represses CDKA. ATR can also phosphorylate WEE1. ATM = ataxia telangiectasia mutated; ATR= ATM‐related; SOG1 = suppressor of γ1; SMR = Siamese/Siamese‐related. Based on Yi et al. () and Sorrell et al. ().
Figure 4. Activation of DNA replication. A CDKA‐cyclin D complex forms at G1/S and hyperphosphorylates RBR of the RBR/E2F complex. RBR releases three E2Fs, transcription factors that are stabilised by DPa and b. This complex, in turn, transcriptionally upregulates CDC6 that coordinates the activation of DNA replication at a replication origin. RBR = retinoblastoma‐related, E2F = DNA‐binding protein essential for E1A‐dependent activation of adeno virus E2 promoter; CDC = cell division cycle; DP = dimerisation protein.
Figure 5. A summary of cell cycles in meristems. (a) In the vegetative shoot apical meristem, three histological zones can be ascribed: the central zone (CZ), large vacuolated cells with long cell cycles (288 h), a peripheral zone (PZ), small cells with shorter cell cycles (157 h) and a pith rib meristem (PRM), with intermediate cell size and cell cycle times. WUS expression (which is positively regulated by STIP) occurs in the lower region of the CZ and confers stem‐cell identity on neighbouring cells above. CLV3 expression in apical cells of the CZ marks a stem cell region. CLV3 encodes a small polypeptide acting as a ligand for CLV1, which then negatively regulates WUS. MGO expression is restricted to the PZ while ANT, which promotes primordial outgrowth, is expressed solely in the new leaf primordium of rapidly cycling cells (20 h). In the youngest formed primordium, cell division stops with cells arresting in G1 or G2 or becoming endopolyploid (see shoot apical meristem). WUS = Wuschel, CLV = Clavata, STIP = Stimpy, MGO = Mgoun, ANT = Aintegumenta. Cell‐cycle data are from the vegative SAM of Sinapis alba (Bodson, ). (b) In the root apical meristem is the quiescent centre that locates at the very tip of the RAM. It comprises noncycling cells at its midpoint, surrounded by very slowly cycling stem cells (390 h). On the margins of the QC, are apical initials that cycle much more rapidly (18 h) and result in cell lineages forming. Subtending the distal apical initials is the root cap in which cells slowly cease proliferating and eventually slough off. A longitudinal file of cells is shown stretching along the epidermis. At the transition point, the cell elongates but exits the cell cycle, demarking the proximal limit of the meristem. SHR and SCR are transcription factors that are expressed in the quiescent centre to maintain the stem cell population. A feedback control of cell proliferation is depicted in the side box. Here, a close relative to CLV3, CLE40, is secreted from cap columella cells into the QC and represses WOX5 (related to WUS) via ACR4, which is expressed in the distal meristem and restricts cell division. SCR = Scarerow; SHR = short root; CLE = CLV3/Endosperm surrounding region; ACR = Arabidopsis crinkly; WOX = Wuschel‐related homoebox. Cell‐cycle data are from Clowes ().
Figure 6. Generic model of gametogenesis, and fertilisation in higher plants. In the reproductive organs of the sporophyte flower, diploid (2n) meiocyctes undergo meiosis to generate four haploid (n) spores. Each haploid male microspore undergoes a mitotic division, generating the vegetative and generative cell and the latter undergoes a further mitosis yielding two sperm cells/nuclei. The female meiocyte yields four haploid cells, three of which degenerate. The remaining haploid cell (megaspore) then undergoes three rounds of mitosis. Six of the resulting eight haploid nuclei cellularise to form three antipodals at one end and, a central cell flanked by two synergids at the other. Two polar nuclei localise in the centre. Fertilisation occurs when the pollen tube penetrates one of the synergids, which then degrades, allowing one of the male nuclei to fuse with the nucleus of the egg cell to form the diploid zygote (2n). The other male nucleus fuses with two polar nuclei of the female gametophyte. This is the triploid (3n) progenitor of the endosperm. See also: Plant Reproduction


Bisova K, Krylov DM and Umen JG (2005) Genome‐wide annotation and expression profiling of cell cycle regulatory genes in Chlamydomonas reinhardtii. Plant Physiology 137: 475–491.

Bodson M (1975) Variation in the rate of cell division in the apical meristem of Sinapis alba during transition to flowering. Annals of Botany 39: 547–554.

Boruc J, Van den Daele H, Hollunder J, et al. (2010) Functional modules in the Arabidopsis core cell cycle binary protein–protein interaction network. Plant Cell 22: 1264–1289.

Boudolf V, Inze D and De Veylder L (2006) What if plants lack a CDC25 phosphatase? Trends in Plant Science 11: 474–479.

Brownfield L, Hafidh S, Borg M, et al. (2009) A plant germline‐specific integrator of sperm specification and cell cycle progression. PLoS Genetics 5 (3): e1000430. DOI: 10.1371/journal.pgen.1000430.

Clowes FAL (1958) Development of quiescent centres in root meristems. New Phytologist 57: 85–88.

Dhondt S, Coppens F, De Winter F, et al. (2010) SHORT‐ROOT and SCARECROW regulate leaf growth in Arabidopsis by stimulating S‐Phase progression of the cell cycle. Plant Physiology 154: 1183–1195.

Dudits D, Cserháty M, Miskolczi P and Horvath V (2007) The growing family of plant cyclin‐dependent kinases with multiple functions in cellular and developmental regulation. In: Inze D (ed) Cell cycle control and plant development, pp. 1–30. Oxford: Blackwell Publishing.

Ebel C, Mariconti L and Gruissem W (2004) Plant retinoblastoma homologues control nuclear proliferation in the female gametophyte. Nature 429: 776–780.

Farras R, Ferrando A, Jasik J, et al. (2001) SKP1‐SnRK protein kinase interactions mediate proteosoomal binding of a plant SCF ubiquitin ligase. EMBO Journal 20: 2742–2756.

Gao XP, Francis D, Ormrod JC and Bennett MD (1992) Changes in cell number and cell division activity during endosperm development in allohexaploid wheat, Triticum aestivum L. Journal of Experimental Botany 257: 1603–1609.

Gendron JM, Liu J‐S, Fan M, et al. (2012) Brassinosteroids regulate organ boundary formation in the shoot apical meristem of Arabidopsis. Proceedings of the National Academy of Sciences of the United States of America 109: 21152–21157.

Howard A and Pelc SR (1953) Synthesis of DNA in normal and irradiated cells and its relation to chromosome breakage. Heredity 6 (Suppl. 6): 261–273.

Ito M, Araki S, Matsunaga S, et al. (2001) G2/M‐phase‐specific transcription during the plant cell cycle is mediated by c‐Myb‐like transcription factors. Plant Cell 13: 1891–1905.

Kim HJ, Oh SA, Brownfield L, Hong SH, et al. (2008) Control of plant germline proliferation by SCFFBL17 degradation of cell cycle inhibitors. Nature 455: 1134–1137.

Komaki S and Sugimoto K (2012) Control of the plant cell cycle by developmental and environmental Cues. Plant Cell Physiology 43: 953–964.

Liu J, Zhang Y, Qin G, et al. (2008) Targeted degradation of the cyclin‐dependent kinase inhibitor ICK4/KRP6 by RING‐Type E3 ligases is essential for mitotic cell cycle progression during Arabidopsis gametogenesis. Plant Cell 20: 1538–1554.

Nowack MK, Grini PE, Jakoby MJ, et al. (2006) A positive signal from the fertilization of the egg cell sets off endosperm proliferation in angiosperm embryogenesis. Nature Genetics 38: 63–67.

Orchard CB, Siciliano I, Sorrell DA, et al. (2005) Tobacco BY‐2 cells expressing fission yeast cdc25 bypass a G2/M block on the cell cycle. Plant Journal 44: 290–299.

Pribat A, Sormani R, Rousseau‐Gueutin M, et al. (2012) A novel class of PTEN protein in Arabidopsis displays unusual phosphoinositide phosphatase activity and efficiently binds phosphatidic acid. Biochemical Journal 444: 161–171.

Potters G, Horemans N, Bellone S, et al. (2014) Dehydroascorbate influences the plant cell cycle through a glutathione‐independent reduction mechanism. Plant Physiology 134: 1479–1487.

Riou‐Khamlichi C, Huntley R, Jacqmard A and Murray JA (1999) Cytokinin activation of Arabidopsis cell division through a D‐type cyclin. Science 283: 1541–1544.

Schnittger A, Schobinger U, Bouyer D, et al. (2002) Ectopic D‐type cyclin expression induces not only DNA replication but also cell division in Arabidopsis trichomes. Proceedings of the National Academy of Sciences of the United States of America 99: 6410–6415.

Sorrell DA, Marchbank AM, Chrimes DA, et al. (2003) The Arabidopsis 14‐3‐3 protein, GF14ω, binds to the Schizosaccharomyces pombe Cdc25 phosphatase and rescues checkpoint defects in the rad24− mutant. Planta 218: 50–57.

Spadafora ND, Doonan JH, Herbert RJ, et al. (2011) Arabidopsis T‐DNA insertional lines for CDC25 are hypersensitive to hydroxyurea but not to zeocin or salt stress. Annals of Botany 107: 1183–1192.

Wang H, Qi Q, Schorr P, et al. (1998) ICK1, a cyclin‐dependent kinase inhibitor from Arabidopsis thaliana interacts with both Cdc2a and Cdc2b and its expression is induced by abscisic acid. Plant Journal 15: 501–510.

Weingartner M, Criqui MC, Meszaros T, et al. (2004) Expression of nondegradable cyclin B1 affects plant development and leads to endomitosis by inhibiting the formation of the phragmoplast. Plant Cell 1: 634–657.

Wildwater M, Campilho A, Perez‐Perez JM, et al. (2005) The RETINOBLASTOMA‐RELATED gene regulates stem cell maintenance in Arabidopsis roots. Cell 123: 1337–1349.

Yi D, Kamei CLA, lvim CE, Cools T, et al. (2014) The Arabidopsis SIAMESE‐RELATED cyclin‐dependent kinase inhibitors SMR5 and SMR7 regulate the DNA damage checkpoint in response to reactive oxygen species. Plant Cell 26: 296–309.

Further Reading

Bitonti MB and Chiapetta A (2010) Root apical meriste pattern: hormone circuitry and transcriptional networks. In: Lüttge U, Beyshschlag W, Büdel B and Francis D (eds) Progress in Botany, vol. 72, pp. 37–71. Berlin, Heidelberg: Springer‐Verlag.

Capron A, Okresz L and Genschik P (2003) First glance at the plant APC/C, a highly conserved ubiquitin‐protein ligase. Trends in Plant Science 8: 83–89.

Deveshwar P, Bovill W, Sharma R, Able JA and Kapoor S (2011) Analysis of anther transcriptomes to identify genes contributing to meiosis and male gametophyte development in rice. BMC Plant Biology 11: 78.

Eichmann R and Schäfer P (2015) Growth versus immunity – a redirection of the cell cycle? Current Opinion in Plant Biology 26: 106–112.

Francis D (2011) A commentary on the G2/M transition of the plant cell cycle. Annals of Botany 107: 1065–1070.

Gaillochet C, Daum G and Lohmann JU (2015) O cell, where art thou? The mechanism of shoot meristem patterning. Current Opinion in Plant Biology 32: 91–97.

Jürgens G (2005) Plant cytokinesis:fission by fusion. Trends in Cell Biology 5: 277–283.

Polyn S, Willems A and De Veylder L (2015) Cell cycle entry, maintenance, and exit during plant development. Current Opinion in Plant Biology 23: 1–7.

Sprunk S and Groß‐Hardt R (2011) Nuclear behaviour, cell polarity and cell specification in the female gametophyte. Sexual Plant Reproduction 24: 123–136.

Thomann A, Dieterle M and Genschik P (2005) Plant CULLIN‐based E3s: phytohormones come first. FEBS Letters 579: 3239–3245.

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Francis, Dennis(Dec 2015) Plant Cell Cycle. In: eLS. John Wiley & Sons Ltd, Chichester. [doi: 10.1002/9780470015902.a0020111.pub2]