Review: Cytokinin – A developing story (Trends Plant Sci) ($)

With its diverse chemical structures, the phytohormone cytokinin is significant from embryogenesis to the maturation of plants. In this review, Wybouw and De Rybel highlight in detail cytokinin signaling in multiple plant developmental process including shoot, flower, stomata, root and vascular development. The Type B-ARRs (ARABIDOPSIS RESPONSE REGULATORS) induce multiple cytokinin responsive genes like WUSHEL in shoot apical meristem development, AGAMOUS during flower development and SPEECHLESS during stomata development. Activation of these response genes triggers signaling cascade for organogenesis which is still being explored. Moreover the authors discuss tools for visualization of cytokinin levels as a limiting factor in understanding cytokinin function. Auxin and cytokinin interplay in organ development adds another level of complexity to understand how cytokinin responses are spatiotemporally regulated. Determining cytokinin response gene signaling and interaction with other hormones will help uncover its mechanism in development. (Summary by Suresh Damodaran) Trends Plant Sci. 10.1016/j.tplants.2018.10.012