Cargando…
Phytochrome A Mediates Blue-Light Enhancement of Second-Positive Phototropism in Arabidopsis
Hypocotyl phototropism of etiolated Arabidopsis seedlings is primarily mediated by the blue-light receptor kinase phototropin 1 (phot1). Phot1-mediated curvature to continuous unilateral blue light irradiation (0.5 μmol m(−2) s(−1)) is enhanced by overhead pre-treatment with red light (20 μmol m(−2)...
Autores principales: | , , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Frontiers Media S.A.
2016
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4786545/ https://www.ncbi.nlm.nih.gov/pubmed/27014313 http://dx.doi.org/10.3389/fpls.2016.00290 |
_version_ | 1782420561474879488 |
---|---|
author | Sullivan, Stuart Hart, Jaynee E. Rasch, Patrick Walker, Catriona H. Christie, John M. |
author_facet | Sullivan, Stuart Hart, Jaynee E. Rasch, Patrick Walker, Catriona H. Christie, John M. |
author_sort | Sullivan, Stuart |
collection | PubMed |
description | Hypocotyl phototropism of etiolated Arabidopsis seedlings is primarily mediated by the blue-light receptor kinase phototropin 1 (phot1). Phot1-mediated curvature to continuous unilateral blue light irradiation (0.5 μmol m(−2) s(−1)) is enhanced by overhead pre-treatment with red light (20 μmol m(−2) s(−1) for 15 min) through the action of phytochrome (phyA). Here, we show that pre-treatment with blue light is equally as effective in eliciting phototropic enhancement and is dependent on phyA. Although blue light pre-treatment was sufficient to activate early phot1 signaling events, phot1 autophosphorylation in vivo was not found to be saturated, as assessed by subsequently measuring phot1 kinase activity in vitro. However, enhancement effects by red and blue light pre-treatment were not observed at higher intensities of phototropic stimulation (10 μmol m(−2) s(−1)). Phototropic enhancement by red and blue light pre-treatments to 0.5 μmol m(−2) s(−1) unilateral blue light irradiation was also lacking in transgenic Arabidopsis where PHOT1 expression was restricted to the epidermis. Together, these findings indicate that phyA-mediated effects on phot1 signaling are restricted to low intensities of phototropic stimulation and originate from tissues other than the epidermis. |
format | Online Article Text |
id | pubmed-4786545 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2016 |
publisher | Frontiers Media S.A. |
record_format | MEDLINE/PubMed |
spelling | pubmed-47865452016-03-24 Phytochrome A Mediates Blue-Light Enhancement of Second-Positive Phototropism in Arabidopsis Sullivan, Stuart Hart, Jaynee E. Rasch, Patrick Walker, Catriona H. Christie, John M. Front Plant Sci Plant Science Hypocotyl phototropism of etiolated Arabidopsis seedlings is primarily mediated by the blue-light receptor kinase phototropin 1 (phot1). Phot1-mediated curvature to continuous unilateral blue light irradiation (0.5 μmol m(−2) s(−1)) is enhanced by overhead pre-treatment with red light (20 μmol m(−2) s(−1) for 15 min) through the action of phytochrome (phyA). Here, we show that pre-treatment with blue light is equally as effective in eliciting phototropic enhancement and is dependent on phyA. Although blue light pre-treatment was sufficient to activate early phot1 signaling events, phot1 autophosphorylation in vivo was not found to be saturated, as assessed by subsequently measuring phot1 kinase activity in vitro. However, enhancement effects by red and blue light pre-treatment were not observed at higher intensities of phototropic stimulation (10 μmol m(−2) s(−1)). Phototropic enhancement by red and blue light pre-treatments to 0.5 μmol m(−2) s(−1) unilateral blue light irradiation was also lacking in transgenic Arabidopsis where PHOT1 expression was restricted to the epidermis. Together, these findings indicate that phyA-mediated effects on phot1 signaling are restricted to low intensities of phototropic stimulation and originate from tissues other than the epidermis. Frontiers Media S.A. 2016-03-11 /pmc/articles/PMC4786545/ /pubmed/27014313 http://dx.doi.org/10.3389/fpls.2016.00290 Text en Copyright © 2016 Sullivan, Hart, Rasch, Walker and Christie. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. |
spellingShingle | Plant Science Sullivan, Stuart Hart, Jaynee E. Rasch, Patrick Walker, Catriona H. Christie, John M. Phytochrome A Mediates Blue-Light Enhancement of Second-Positive Phototropism in Arabidopsis |
title | Phytochrome A Mediates Blue-Light Enhancement of Second-Positive Phototropism in Arabidopsis |
title_full | Phytochrome A Mediates Blue-Light Enhancement of Second-Positive Phototropism in Arabidopsis |
title_fullStr | Phytochrome A Mediates Blue-Light Enhancement of Second-Positive Phototropism in Arabidopsis |
title_full_unstemmed | Phytochrome A Mediates Blue-Light Enhancement of Second-Positive Phototropism in Arabidopsis |
title_short | Phytochrome A Mediates Blue-Light Enhancement of Second-Positive Phototropism in Arabidopsis |
title_sort | phytochrome a mediates blue-light enhancement of second-positive phototropism in arabidopsis |
topic | Plant Science |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4786545/ https://www.ncbi.nlm.nih.gov/pubmed/27014313 http://dx.doi.org/10.3389/fpls.2016.00290 |
work_keys_str_mv | AT sullivanstuart phytochromeamediatesbluelightenhancementofsecondpositivephototropisminarabidopsis AT hartjayneee phytochromeamediatesbluelightenhancementofsecondpositivephototropisminarabidopsis AT raschpatrick phytochromeamediatesbluelightenhancementofsecondpositivephototropisminarabidopsis AT walkercatrionah phytochromeamediatesbluelightenhancementofsecondpositivephototropisminarabidopsis AT christiejohnm phytochromeamediatesbluelightenhancementofsecondpositivephototropisminarabidopsis |