Phytohormone cytokinin guides microtubule dynamics during cell progression from proliferative to differentiated stage. (15th July 2020)

• Record Type: Journal Article
• Authors: Montesinos, Juan Carlos; Abuzeineh, Anas; Kopf, Aglaja; Juanes‐Garcia, Alba; Ötvös, Krisztina; Petrášek, Jan; Sixt, Michael; Benková, Eva
• Is Part Of: EMBO journal. Volume 39:Number 17(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-07-15
• Subjects: cell differentiation -- cytokinin -- cytoskeleton -- microtubules -- microtubules dynamics; Molecular biology -- Periodicals; 572.805
• DOI: 10.15252/embj.2019104238
• Languages: English
• ISSNs: 0261-4189

Abstract

Abstract: Cell production and differentiation for the acquisition of specific functions are key features of living systems. The dynamic network of cellular microtubules provides the necessary platform to accommodate processes associated with the transition of cells through the individual phases of cytogenesis. Here, we show that the plant hormone cytokinin fine‐tunes the activity of the microtubular cytoskeleton during cell differentiation and counteracts microtubular rearrangements driven by the hormone auxin. The endogenous upward gradient of cytokinin activity along the longitudinal growth axis in Arabidopsis thaliana roots correlates with robust rearrangements of the microtubule cytoskeleton in epidermal cells progressing from the proliferative to the differentiation stage. Controlled increases in cytokinin activity result in premature re‐organization of the microtubule network from transversal to an oblique disposition in cells prior to their differentiation, whereas attenuated hormone perception delays cytoskeleton conversion into a configuration typical for differentiated cells. Intriguingly, cytokinin can interfere with microtubules also in animal cells, such as leukocytes, suggesting that a cytokinin‐sensitive control pathway for the microtubular cytoskeleton may be at least partially conserved between plant and animal cells. Synopsis: Phytohormones auxin and cytokinin play antagonistic roles in plant development, including root growth. Here, cytokinin is found to fine‐tune microtubule dynamics in Arabidopsis roots, as well as in animal cells. Cytokinin activity gradients in Arabidopsis thaliana roots correlate with gradual microtubule cytoskeleton reconfiguration along the longitudinal growth axis. Cytokinin promotes re‐orientation of microtubules and reduces microtubule growth rate in root epidermal cells progressing from the proliferative‐to‐differentiation stage. Cytokinin signalling pathway components contribute to microtubule cytoskeleton regulation. Cytokinin counteracts auxin‐driven microtubule rearrangements. Cytokinin can suppress microtubule growth in mammalian leukocytes. Abstract : The plant hormone cytokinin can regulate microtubule orientation and polymerization in the plant root epidermis as well as in mammalian leukocytes, indicating a conserved mode of action.