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| [PMID]: | 27535793 |
| [Au] Autor: | Krieger G; Shkolnik D; Miller G; Fromm H |
| [Ad] Endereço: | Department of Molecular Biology and Ecology of Plants, Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel (G.K., D.S., H.F.); andMina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel (G.M.). |
| [Ti] Título: | Reactive Oxygen Species Tune Root Tropic Responses. |
| [So] Source: | Plant Physiol;172(2):1209-1220, 2016 Oct. | | [Is] ISSN: | 1532-2548 |
| [Cp] País de publicação: | United States |
| [La] Idioma: | eng |
| [Ab] Resumo: | The default growth pattern of primary roots of land plants is directed by gravity. However, roots possess the ability to sense and respond directionally to other chemical and physical stimuli, separately and in combination. Therefore, these root tropic responses must be antagonistic to gravitropism. The role of reactive oxygen species (ROS) in gravitropism of maize and Arabidopsis (Arabidopsis thaliana) roots has been previously described. However, which cellular signals underlie the integration of the different environmental stimuli, which lead to an appropriate root tropic response, is currently unknown. In gravity-responding roots, we observed, by applying the ROS-sensitive fluorescent dye dihydrorhodamine-123 and confocal microscopy, a transient asymmetric ROS distribution, higher at the concave side of the root. The asymmetry, detected at the distal elongation zone, was built in the first 2 h of the gravitropic response and dissipated after another 2 h. In contrast, hydrotropically responding roots show no transient asymmetric distribution of ROS Decreasing ROS levels by applying the antioxidant ascorbate, or the ROS-generation inhibitor diphenylene iodonium attenuated gravitropism while enhancing hydrotropism. Arabidopsis mutants deficient in Ascorbate Peroxidase 1 showed attenuated hydrotropic root bending. Mutants of the root-expressed NADPH oxidase RBOH C, but not rbohD, showed enhanced hydrotropism and less ROS in their roots apices (tested in tissue extracts with Amplex Red). Finally, hydrostimulation prior to gravistimulation attenuated the gravistimulated asymmetric ROS and auxin signals that are required for gravity-directed curvature. We suggest that ROS, presumably H O , function in tuning root tropic responses by promoting gravitropism and negatively regulating hydrotropism. |
| [Mh] Termos MeSH primário: |
Arabidopsis/fisiologia
Gravitropismo/fisiologia
Raízes de Plantas/crescimento & desenvolvimento
Espécies Reativas de Oxigênio/metabolismo
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| [Mh] Termos MeSH secundário: |
Antioxidantes/farmacologia
Arabidopsis/genética
Arabidopsis/metabolismo
Ácido Ascórbico/farmacologia
Gravitropismo/efeitos dos fármacos
Gravitropismo/genética
Isoenzimas/genética
Isoenzimas/metabolismo
Microscopia Confocal
Mutação
NADPH Oxidases/genética
NADPH Oxidases/metabolismo
Oniocompostos/farmacologia
Raízes de Plantas/genética
Raízes de Plantas/metabolismo
Tropismo/efeitos dos fármacos
Tropismo/genética
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| [Pt] Tipo de publicação: | JOURNAL ARTICLE |
[Nm] Nome de substância:
| 0 (Antioxidants); 0 (Isoenzymes); 0 (Onium Compounds); 0 (Reactive Oxygen Species); 6HJ411TU98 (diphenyleneiodonium); EC 1.6.3.- (NADPH Oxidases); PQ6CK8PD0R (Ascorbic Acid) |
| [Em] Mês de entrada: | 1710 |
| [Cu] Atualização por classe: | 171116 |
[Lr] Data última revisão:
| 171116 |
| [Sb] Subgrupo de revista: | IM |
| [Da] Data de entrada para processamento: | 160819 |
| [St] Status: | MEDLINE |
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