Article

Gibberellins accumulate in the elongating endodermal cells of Arabidopsis root

Section of Cell and Developmental Biology, Departments of Pharmacology and Chemistry and Biochemistry, and Howard Hughes Medical Institute, University of California at San Diego, La Jolla, CA 92093.
Proceedings of the National Academy of Sciences (Impact Factor: 9.81). 02/2013; 110(12). DOI: 10.1073/pnas.1300436110
Source: PubMed

ABSTRACT Plant hormones are small-molecule signaling compounds that are collectively involved in all aspects of plant growth and development. Unlike animals, plants actively regulate the spatial distribution of several of their hormones. For example, auxin transport results in the formation of auxin maxima that have a key role in developmental patterning. However, the spatial distribution of the other plant hormones, including gibberellic acid (GA), is largely unknown. To address this, we generated two bioactive fluorescent GA compounds and studied their distribution in Arabidopsis thaliana roots. The labeled GAs specifically accumulated in the endodermal cells of the root elongation zone. Pharmacological studies, along with examination of mutants affected in endodermal specification, indicate that GA accumulation is an active and highly regulated process. Our results strongly suggest the presence of an active GA transport mechanism that would represent an additional level of GA regulation.

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    • "The contents of these hormones were dependent on low temperature, and exposure to variable low temperature treatments for 60 days could be used as the critical point for dormancy mediation in lily bulbs 'Siberia' and 'Tiber' (Hua et al., 2011). Chilling exposure of bulbs could lead to the production of growth promoting substances that were gibberellins-like (Shani et al., 2013) and auxin-like (Tsukamoto, 1971), and low temperature treatment promoted the translocation of gibberellins-like and auxin-like substances from the bulb scale to the shoot apex (Rodrigues-Pereira, 1964). Low temperature treatment promoted the breaking of bulb dormancy in L. hansoni, which was in accordance with the results of other studies that showed low temperature affects the carbohydrate contents and plant growth regulators that triggered shoot emergence. "
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    Horticulture, Environment and Biotechnology 08/2014; 55(4):257-262. DOI:10.1007/s13580-014-0143-1 · 0.49 Impact Factor
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    • "Application of Fl–GA 3 in Arabidopsis roots showed specic GA accumulation patterns in the endodermal cells of the elongation zone. In addition, REPRESSOR OF GA (RGA) marker (GFP:RGA), which encodes a DELLA protein that is degraded in the presence of active GA, showed decreasing signal in the endodermal cells, indicating that GA accumulates in these cells in wild-type plants (Shani et al., 2013). These new experimental approaches could be useful to further investigate a possible role of GA movement in owering time control of Arabidopsis. "
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    • "Thus, cell polarity is crucial from the start to the final stages of plant development. Cell polarity is also important for polar transport processes that induce asymmetric distribution of signaling molecules directing plant development, such as the plant hormones auxin and gibberellin (Grunewald and Friml 2010; Shani et al. 2013). "
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