The epidermal cell layer of plants has important functions in regulating plant growth and development. We have studied the impact of an altered epidermal cytokinin metabolism on Arabidopsis shoot development. Increased epidermal cytokinin synthesis or breakdown was achieved through expression of the cytokinin synthesis gene LOG4 and the cytokinin-degrading CKX1 gene, respectively, under the control of the epidermis-specific AtML1 promoter. During vegetative growth, increased epidermal cytokinin production caused an increased size of the shoot apical meristem and promoted earlier flowering. Leaves became larger and the shoots showed an earlier juvenile-to-adult transition. An increased cytokinin breakdown had the opposite effect on these phenotypic traits indicating that epidermal cytokinin metabolism can be a factor regulating these aspects of shoot development. The phenotypic consequences of abbreviated cytokinin signaling in the epidermis achieved through expression of the ARR1-SRDX repressor were generally milder or even absent indicating that the epidermal cytokinin acts, at least in part, cell non-autonomously. Enhanced epidermal cytokinin synthesis delayed cell differentiation during leaf development leading to an increased cell proliferation and leaf growth. Genetic analysis showed that this cytokinin activity was mediated mainly by the AHK3 receptor and the transcription factor ARR1. We also demonstrate that epidermal cytokinin promotes leaf growth in a largely cell-autonomous fashion. Increased cytokinin synthesis in the outer layer of reproductive tissues and in the placenta enhanced ovule formation by the placenta and caused the formation of larger siliques. This led to a higher number of seeds in larger pods resulting in an increased seed yield per plant. Collectively, the results provide evidence that the cytokinin metabolism in the epidermis is a relevant parameter determining vegetative and reproductive plant growth and development.

Institute of Biology Applied Genetics Dahlem Centre of Plant Sciences Freie Universität Berlin Berlin Germany

Institute of Biology NAWI Graz University of Graz Graz Austria

Laboratory of Growth Regulators Faculty of Science Palacký University and Institute of Experimental Botany The Czech Academy of Sciences Olomouc Czechia

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Abràmoff M. D., Magalhães P. J., Ram S. J. (2004). Image processing with ImageJ.

Antoniadi I., Novák O., Gelova Z., Johnson A., Plíhal O., Simerský R., et al. (2020). Cell-surface receptors enable perception of extracellular cytokinins. PubMed DOI PMC

Argyros R. D., Mathews D. E., Chiang Y. H., Palmer C. M., Thibault D. M., Etheridge N., et al. (2008). Type B response regulators of PubMed DOI PMC

Arnaud D., Lee S., Takebayashi Y., Choi D., Choi J., Sakakibara H., et al. (2017). Cytokinin-mediated regulation of reactive oxygen species homeostasis modulates stomatal immunity in PubMed DOI PMC

Bartrina I., Jensen H., Novák O., Strnad M., Werner T., Schmülling T. (2017). Gain-of-function mutants of the cytokinin receptors AHK2 and AHK3 regulate plant organ size, flowering time and plant longevity. PubMed DOI PMC

Bartrina I., Otto E., Strnad M., Werner T., Schmülling T. (2011). Cytokinin regulates the activity of reproductive meristems, flower organ size, ovule formation, and thus seed yield in PubMed DOI PMC

Bencivenga S., Simonini S., Benkova E., Colombo L. (2012). The transcription factors BEL1 and SPL are required for cytokinin and auxin signaling during ovule development in PubMed DOI PMC

Bhargava A., Clabaugh I., To J. P., Maxwell B. B., Chiang Y. H., Schaller G. E., et al. (2013). Identification of cytokinin-responsive genes using microarray meta-analysis and RNA-seq in PubMed DOI PMC

Brenner W. G., Ramireddy E., Heyl A., Schmülling T. (2012). Gene regulation by cytokinin in PubMed DOI PMC

Cerbantez-Bueno V. E., Zúñiga-Mayo V. M., Reyes-Olalde J. I., Lozano-Sotomayor P., Herrera-Ubaldo H., Marsch-Martínez N., et al. (2020). Redundant and non-redundant functions of the AHK cytokinin receptors during gynoecium development. PubMed DOI PMC

Chickarmane V. S., Gordon S. P., Tarr P. T., Heisler M. G., Meyerowitz E. M. (2012). Cytokinin signaling as a positional cue for patterning the apical-basal axis of the growing PubMed DOI PMC

Clough S. J., Bent A. F. (1998). Floral dip: a simplified method for PubMed DOI

Cortleven A., Nitschke S., Klaumünzer M., Abdelgawad H., Asard H., Grimm B., et al. (2014). A novel protective function for cytokinin in the light stress response is mediated by the ARABIDOPSIS HISTIDINE KINASE2 and ARABIDOPSIS HISTIDINE KINASE3 receptors. PubMed DOI PMC

Czesnick H., Lenhard M. (2015). Size control in plants – lessons from leaves and flowers. PubMed DOI PMC

Efroni I., Han S. K., Kim H. J., Wu M. F., Steiner E., Birnbaum K. D., et al. (2013). Regulation of leaf maturation by chromatin-mediated modulation of cytokinin responses. PubMed DOI PMC

Grandjean O., Vernoux T., Laufs P., Belcram K., Mizukami Y., Traas J. (2004). In vivo analysis of cell division, cell growth, and differentiation at the shoot apical meristem in PubMed DOI PMC

Gruel J., Landrein B., Tarr P., Schuster C., Refahi Y., Sampathkumar A., et al. (2016). An epidermis-driven mechanism positions and scales stem cell niches in plants. PubMed DOI PMC

Ha C. M., Jun J. H., Fletcher J. C. (2010). Shoot apical meristem form and function. PubMed DOI

Hemerly A. S., Ferreira P., Engler J. D., Van Montagu M., Engler G., Inzé D. (1993). PubMed DOI PMC

Heyl A., Ramireddy E., Brenner W. G., Riefler M., Allemeersch J., Schmülling T. (2008). The transcriptional repressor ARR1-SRDX suppresses pleiotropic cytokinin activities in PubMed DOI PMC

Higuchi M., Pischke M. S., Mähönen A. P., Miyawaki K., Hashimoto Y., Seki M., et al. (2004). PubMed DOI PMC

Hiratsu K., Matsui K., Koyama T., Ohme-Takagi M. (2003). Dominant repression of target genes by chimeric repressors that include the EAR motif, a repression domain, in PubMed DOI

Holst K., Schmülling T., Werner T. (2011). Enhanced cytokinin degradation in leaf primordia of transgenic PubMed DOI

Horiguchi G., Tsukaya H. (2011). Organ size regulation in plants: insights from compensation. PubMed DOI PMC

Hou B., Lim E. K., Higgins G. S., Bowles D. J. (2004). N-glucosylation of cytokinins by glycosyltransferases of PubMed DOI

Huijser P., Schmid M. (2011). The control of developmental phase transitions in plants. PubMed DOI

Hwang I., Sheen J. (2001). Two-component circuitry in PubMed DOI

Hwang I., Sheen J., Müller B. (2012). Cytokinin signaling networks. PubMed DOI

Ingram G. C. (2004). Between the sheets: inter-cell-layer communication in plant development. PubMed DOI PMC

Inoue T., Higuchi M., Hashimoto Y., Seki M., Kobayashi M., Kato T., et al. (2001). Identification of CRE1 as a cytokinin receptor from PubMed DOI

Ishida K., Yamashino T., Yokoyama A., Mizuno T. (2008). Three type-B response regulators, ARR1, ARR10 and ARR12, play essential but redundant roles in cytokinin signal transduction throughout the life cycle of PubMed DOI

Kakimoto T. (2001). Identification of plant cytokinin biosynthetic enzymes as dimethylallyl diphosphate:ATP/ADP isopentenyltransferases. PubMed DOI

Karimi M., De Meyer B., Hilson P. (2005). Modular cloning in plant cells. PubMed DOI

Karimi M., Inzé D., Depicker A. (2002). GATEWAY PubMed DOI

Kiba T., Takei K., Kojima M., Sakakibara H. (2013). Side-chain modification of cytokinins controls shoot growth in PubMed DOI

Kieber J. J., Schaller G. E. (2014). Cytokinins. PubMed DOI PMC

Kieber J. J., Schaller G. E. (2018). Cytokinin signaling in plant development. PubMed DOI

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. PubMed DOI

Kuroha T., Tokunaga H., Kojima M., Ueda N., Ishida T., Nagawa S., et al. (2009). Functional analyses of LONELY GUY cytokinin-activating enzymes reveal the importance of the direct activation pathway in PubMed DOI PMC

Li J., Nie X., Tan J. L., Berger F. (2013). Integration of epigenetic and genetic controls of seed size by cytokinin in PubMed DOI PMC

Lu P. Z., Porat R., Nadeau J. A., Oneill S. D. (1996). Identification of a meristem L1 layer-specific gene in PubMed DOI PMC

Malamy J. E., Benfey P. N. (1997). Organization and cell differentiation in lateral roots of PubMed

Maloof J. N., Nozue K., Mumbach M. R., Palmer C. M. (2013). LeafJ: an ImageJ plugin for semi-automated leaf shape measurement. PubMed DOI PMC

Marcotrigiano M. (2010). A role for leaf epidermis in the control of leaf size and the rate and extent of mesophyll cell division. PubMed DOI

Marsch-Martínez N., Ramos-Cruz D., Reyes-Olalde J. I., Lozano-Sotomayor P., Zúñiga-Mayo V. M., de Folter S. (2012). The role of cytokinin during PubMed DOI

Mason M. G., Li J., Mathews D. E., Kieber J. J., Schaller G. E. (2004). Type-B response regulators display overlapping expression patterns in PubMed DOI PMC

Matías-Hernández L., Aguilar-Jaramillo A. E., Cigliano R. A., Sanseverino W., Pelaz S. (2016). Flowering and trichome development share hormonal and transcription factor regulation. PubMed DOI

Michniewicz M., Kamieńska A. (1965). Flower formation induced by kinetin and vitamin E treatment in long-day plant (

Miyawaki K., Tarkowski P., Matsumoto-Kitano M., Kato T., Sato S., Tarkowska D., et al. (2006). Roles of PubMed DOI PMC

Morcuende R., Bari R., Gibon Y., Zheng W. M., Pant B. D., Bläsing O., et al. (2007). Genome-wide reprogramming of metabolism and regulatory networks of PubMed DOI

Niemann M. C., Bartrina I., Ashikov A., Weber H., Novák O., Spíchal L., et al. (2015). PubMed DOI PMC

Nishimura C., Ohashi Y., Sato S., Kato T., Tabata S., Ueguchi C. (2004). Histidine kinase homologs that act as cytokinin receptors possess overlapping functions in the regulation of shoot and root growth in PubMed DOI PMC

Nobusawa T., Okushima Y., Nagata N., Kojima M., Sakakibara H., Umeda M. (2013). Synthesis of very-long-chain fatty acids in the epidermis controls plant organ growth by restricting cell proliferation. PubMed DOI PMC

Novák O., Hauserová E., Amakorová P., Doležal K., Strnad M. (2008). Cytokinin profiling in plant tissues using ultra-performance liquid chromatography-electrospray tandem mass spectrometry. PubMed DOI

Ohta M., Matsui K., Hiratsu K., Shinshi H., Ohme-Takagi M. (2001). Repression domains of class II ERF transcriptional repressors share an essential motif for active repression. PubMed DOI PMC

Osugi A., Kojima M., Takebayashi Y., Ueda N., Kiba T., Sakakibara H. (2017). Systemic transport of trans-zeatin and its precursor have differing roles in PubMed DOI

Poethig R. S. (2013). Vegetative phase change and shoot maturation in plants. PubMed DOI PMC

Riefler M., Novak O., Strnad M., Schmülling T. (2006). PubMed DOI PMC

Romanov G. A., Lomin S. N., Schmülling T. (2006). Biochemical characteristics and ligand-binding properties of PubMed DOI

Sakai H., Aoyama T., Oka A. (2000). PubMed DOI

Sakai H., Honma T., Aoyama T., Sato S., Kato T., Tabata S., et al. (2001). ARR1, a transcription factor for genes immediately responsive to cytokinins. PubMed DOI

Savaldi-Goldstein S., Chory J. (2008). Growth coordination and the shoot epidermis. PubMed DOI PMC

Savaldi-Goldstein S., Peto C., Chory J. (2007). The epidermis both drives and restricts plant shoot growth. PubMed DOI

Schnablovà R., Herben T., Klimešova J. (2017). Shoot apical meristem and plant body organization: a cross-species comparative study. PubMed DOI PMC

Schwarz I., Scheirlinck M. T., Otto E., Bartrina I., Schmidt R. C., Schmülling T. (2020). Cytokinin regulates the activity of the inflorescence meristem and components of seed yield in oilseed rape. PubMed DOI

Sessions A., Weigel D., Yanofsky M. F. (1999). The PubMed DOI

Skalák J., Vercruyssen L., Claeys H., Hradilová J., Cerny M., Novák O., et al. (2019). Multifaceted activity of cytokinin in leaf development shapes its size and structure in PubMed DOI

Stolz A., Riefler M., Lomin S. N., Achazi K., Romanov G. A., Schmülling T. (2011). The specificity of cytokinin signalling in PubMed DOI

Suzuki T., Miwa K., Ishikawa K., Yamada H., Aiba H., Mizuno T. (2001). The PubMed DOI

Tajima Y., Imamura A., Kiba T., Amano Y., Yamashino T., Mizuno T. (2004). Comparative studies on the type-B response regulators revealing their distinctive properties in the His-to-Asp phosphorelay signal transduction of PubMed DOI

Takada S., Jürgens G. (2007). Transcriptional regulation of epidermal cell fate in the PubMed DOI

Takada S., Takada N., Yoshida A. (2013). PubMed DOI

Takei K., Sakakibara H., Sugiyama T. (2001). Identification of genes encoding adenylate isopentenyltransferase, a cytokinin biosynthesis enzyme, in PubMed DOI

Takei K., Yamaya T., Sakakibara H. (2004). PubMed DOI

Tanaka Y., Suzuki T., Yamashino T., Mizuno T. (2004). Comparative studies of the AHP histidine-containing phosphotransmitters implicated in His-to-Asp phosphorelay in PubMed DOI

Telfer A., Bollman K. M., Poethig R. S. (1997). Phase change and the regulation of trichome distribution in PubMed

To J. P. C., Haberer G., Ferreira F. J., Deruere J., Mason M. G., Schaller G. E., et al. (2004). Type-A PubMed DOI PMC

Tokunaga H., Kojima M., Kuroha T., Ishida T., Sugimoto K., Kiba T., et al. (2012). PubMed DOI

Vandesompele J., De Preter K., Pattyn F., Poppe B., Van Roy N., De Paepe A., et al. (2002). Accurate normalization of real-time quantitative RT-PCR data by geometric averaging of multiple internal control genes. PubMed DOI PMC

Vaseva I., Qudeimat E., Potuschak T., Du Y., Genschik P., Vandenbussche F., et al. (2018). The plant hormone ethylene restricts PubMed DOI PMC

Vatén A., Soyars C. L., Tarr P. T., Nimchuk Z. L., Bergmann D. C. (2018). Modulation of asymmetric division diversity through cytokinin and SPEECHLESS regulatory interactions in the PubMed DOI PMC

Werner T., Köllmer I., Bartrina I., Holst K., Schmülling T. (2006). New insights into the biology of cytokinin degradation. PubMed DOI

Werner T., Motyka V., Laucou V., Smets R., Van Onckelen H., Schmülling T. (2003). Cytokinin-deficient transgenic PubMed DOI PMC

Werner T., Motyka V., Strnad M., Schmülling T. (2001). Regulation of plant growth by cytokinin. PubMed DOI PMC

Werner T., Schmülling T. (2009). Cytokinin action in plant development. PubMed DOI

Wulfetange K., Lomin S. N., Romanov G. A., Stolz A., Heyl A., Schmülling T. (2011). The cytokinin receptors of PubMed DOI PMC

Yadav R. K., Tavakkoli M., Xie M., Girke T., Reddy G. V. (2014). A high-resolution gene expression map of the PubMed DOI

Yamada H., Suzuki T., Terada K., Takei K., Ishikawa K., Miwa K., et al. (2001). The PubMed DOI

Yeats T. H., Rose J. K. (2013). The formation and function of plant cuticles. PubMed DOI PMC

Yoshida S., Mandel T., Kuhlemeier C. (2011). Stem cell activation by light guides plant organogenesis. PubMed DOI PMC

Zubo Y. O., Blakley I. C., Yamburenko M. V., Worthen J. M., Street I. H., Franco-Zorrilla J. M., et al. (2017). Cytokinin induces genome-wide binding of the type-B response regulator ARR10 to regulate growth and development in PubMed DOI PMC

Zúñiga-Mayo V. M., Baños-Bayardo C. R., Díaz-Ramírez D., Marsch-Martínez N., De Folter S. (2018). Conserved and novel responses to cytokinin treatments during flower and fruit development in PubMed DOI PMC

Zúñiga-Mayo V. M., Gómez-Felipe A., Herrera-Ubaldo H., De Folter S. (2019). Gynoecium development: networks in PubMed DOI

Cytokinin depends on GA biosynthesis and signaling to regulate different aspects of vegetative phase change in Arabidopsis

Dynamic changes of endogenous phytohormones and carbohydrates during spontaneous morphogenesis of Centaurium erythraea Rafn