Reactive Oxygen Species Tune Root Tropic Responses . Issue 2 (17th August 2016)
- Record Type:
- Journal Article
- Title:
- Reactive Oxygen Species Tune Root Tropic Responses . Issue 2 (17th August 2016)
- Main Title:
- Reactive Oxygen Species Tune Root Tropic Responses
- Authors:
- Krieger, Gat
Shkolnik, Doron
Miller, Gad
Fromm, Hillel - Abstract:
- Abstract : ROS accelerates gravitropism but attenuates hydrotropism of Arabidopsis roots. Abstract: 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, butAbstract : ROS accelerates gravitropism but attenuates hydrotropism of Arabidopsis roots. Abstract: 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 H2 O2, function in tuning root tropic responses by promoting gravitropism and negatively regulating hydrotropism. … (more)
- Is Part Of:
- Plant physiology. Volume 172:Issue 2(2016)
- Journal:
- Plant physiology
- Issue:
- Volume 172:Issue 2(2016)
- Issue Display:
- Volume 172, Issue 2 (2016)
- Year:
- 2016
- Volume:
- 172
- Issue:
- 2
- Issue Sort Value:
- 2016-0172-0002-0000
- Page Start:
- 1209
- Page End:
- 1220
- Publication Date:
- 2016-08-17
- Subjects:
- Plant physiology -- Periodicals
Botany -- Periodicals
Periodicals
Electronic journals
571.2 - Journal URLs:
- https://academic.oup.com/plphys/issue ↗
http://www.plantphysiol.org/ ↗
http://www.jstor.org/journals/00320889.html ↗
http://www.pubmedcentral.nih.gov/tocrender.fcgi?journal=69 ↗
http://www-us.ebsco.com/online/direct.asp?JournalID=101725 ↗
http://www.oxfordjournals.org/ ↗ - DOI:
- 10.1104/pp.16.00660 ↗
- Languages:
- English
- ISSNs:
- 0032-0889
- Deposit Type:
- Legaldeposit
- View Content:
- Available online (eLD content is only available in our Reading Rooms) ↗
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- British Library DSC - BLDSS-3PM
British Library HMNTS - ELD Digital store - Ingest File:
- 16618.xml