Synthesis of very-long-chain fatty acids in the epidermis controls plant organ growth by restricting cell proliferation (April 10, 2013)
The epidermis functions as an important interface with the environment, but it is also essential in the establishment and maintenance of the plant body. Recent studies have shown that the epidermis participates in both driving and restricting growth via inter-cell-layer communication. However, it remains an open question whether the epidermis can send signals to internal tissue to control cell proliferation during development. Professor Masaaki Umeda in the Laboratory of Plant Growth Regulation, Graduate School of Biological Sciences, and coworkers found that synthesis of very-long-chain fatty acids (VLCFAs) in the epidermis is essential for proper development of Arabidopsis thaliana. Defects in VLCFA synthesis caused overproliferation of cells in the vasculature or in the rib zone of shoot apices. The decrease of VLCFA content elevated the synthesis of the phytohormone cytokinin in the vasculature. Vasculature-specific expression of cytokinin oxidase, which degrades active forms of cytokinin, suppressed the enhanced cell proliferation in internal tissue, implying that VLCFA synthesis in the epidermis is required to suppress cytokinin biosynthesis and overproliferation. These results demonstrate that shoot growth is controlled by interactions between the surface (epidermis) and the axis (vasculature) of the plant body (Fig. 1).
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Nobusawa T, Okushima Y, Nagata N, Kojima M, Sakakibara H, Umeda M.
Synthesis of very-long-chain fatty acids in the epidermis controls plant organ growth by restricting cell proliferation. PLoS Biol. 11(4): e1001531 (2013)