Cargando…

Wortmannin-induced vacuole fusion enhances amyloplast dynamics in Arabidopsis zigzag1 hypocotyls

Gravitropism in Arabidopsis shoots depends on the sedimentation of amyloplasts in the endodermis, and a complex interplay between the vacuole and F-actin. Gravity response is inhibited in zigzag-1 (zig-1), a mutant allele of VTI11, which encodes a SNARE protein involved in vacuole fusion. zig-1 seed...

Descripción completa

Detalles Bibliográficos
Autores principales: Alvarez, Ashley Ann, Han, Sang Won, Toyota, Masatsugu, Brillada, Carla, Zheng, Jiameng, Gilroy, Simon, Rojas-Pierce, Marcela
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Oxford University Press 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5181587/
https://www.ncbi.nlm.nih.gov/pubmed/27816929
http://dx.doi.org/10.1093/jxb/erw418
_version_ 1782485735945797632
author Alvarez, Ashley Ann
Han, Sang Won
Toyota, Masatsugu
Brillada, Carla
Zheng, Jiameng
Gilroy, Simon
Rojas-Pierce, Marcela
author_facet Alvarez, Ashley Ann
Han, Sang Won
Toyota, Masatsugu
Brillada, Carla
Zheng, Jiameng
Gilroy, Simon
Rojas-Pierce, Marcela
author_sort Alvarez, Ashley Ann
collection PubMed
description Gravitropism in Arabidopsis shoots depends on the sedimentation of amyloplasts in the endodermis, and a complex interplay between the vacuole and F-actin. Gravity response is inhibited in zigzag-1 (zig-1), a mutant allele of VTI11, which encodes a SNARE protein involved in vacuole fusion. zig-1 seedlings have fragmented vacuoles that fuse after treatment with wortmannin, an inhibitor of phosphatidylinositol 3-kinase, and underscore a role of phosphoinositides in vacuole fusion. Using live-cell imaging with a vertical stage microscope, we determined that young endodermal cells below the apical hook that are smaller than 70 μm in length are the graviperceptive cells in dark-grown hypocotyls. This result was confirmed by local wortmannin application to the top of zig-1 hypocotyls, which enhanced shoot gravitropism in zig-1 mutants. Live-cell imaging of zig-1 hypocotyl endodermal cells indicated that amyloplasts are trapped between juxtaposed vacuoles and their movement is severely restricted. Wortmannin-induced fusion of vacuoles in zig-1 seedlings increased the formation of transvacuolar strands, enhanced amyloplast sedimentation and partially suppressed the agravitropic phenotype of zig-1 seedlings. Hypergravity conditions at 10 g were not sufficient to displace amyloplasts in zig-1, suggesting the existence of a physical tether between the vacuole and amyloplasts. Our results overall suggest that vacuole membrane remodeling may be involved in regulating the association of vacuoles and amyloplasts during graviperception.
format Online
Article
Text
id pubmed-5181587
institution National Center for Biotechnology Information
language English
publishDate 2016
publisher Oxford University Press
record_format MEDLINE/PubMed
spelling pubmed-51815872016-12-27 Wortmannin-induced vacuole fusion enhances amyloplast dynamics in Arabidopsis zigzag1 hypocotyls Alvarez, Ashley Ann Han, Sang Won Toyota, Masatsugu Brillada, Carla Zheng, Jiameng Gilroy, Simon Rojas-Pierce, Marcela J Exp Bot Research Paper Gravitropism in Arabidopsis shoots depends on the sedimentation of amyloplasts in the endodermis, and a complex interplay between the vacuole and F-actin. Gravity response is inhibited in zigzag-1 (zig-1), a mutant allele of VTI11, which encodes a SNARE protein involved in vacuole fusion. zig-1 seedlings have fragmented vacuoles that fuse after treatment with wortmannin, an inhibitor of phosphatidylinositol 3-kinase, and underscore a role of phosphoinositides in vacuole fusion. Using live-cell imaging with a vertical stage microscope, we determined that young endodermal cells below the apical hook that are smaller than 70 μm in length are the graviperceptive cells in dark-grown hypocotyls. This result was confirmed by local wortmannin application to the top of zig-1 hypocotyls, which enhanced shoot gravitropism in zig-1 mutants. Live-cell imaging of zig-1 hypocotyl endodermal cells indicated that amyloplasts are trapped between juxtaposed vacuoles and their movement is severely restricted. Wortmannin-induced fusion of vacuoles in zig-1 seedlings increased the formation of transvacuolar strands, enhanced amyloplast sedimentation and partially suppressed the agravitropic phenotype of zig-1 seedlings. Hypergravity conditions at 10 g were not sufficient to displace amyloplasts in zig-1, suggesting the existence of a physical tether between the vacuole and amyloplasts. Our results overall suggest that vacuole membrane remodeling may be involved in regulating the association of vacuoles and amyloplasts during graviperception. Oxford University Press 2016-12 2016-11-05 /pmc/articles/PMC5181587/ /pubmed/27816929 http://dx.doi.org/10.1093/jxb/erw418 Text en © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology. http://creativecommons.org/licenses/by/3.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Research Paper
Alvarez, Ashley Ann
Han, Sang Won
Toyota, Masatsugu
Brillada, Carla
Zheng, Jiameng
Gilroy, Simon
Rojas-Pierce, Marcela
Wortmannin-induced vacuole fusion enhances amyloplast dynamics in Arabidopsis zigzag1 hypocotyls
title Wortmannin-induced vacuole fusion enhances amyloplast dynamics in Arabidopsis zigzag1 hypocotyls
title_full Wortmannin-induced vacuole fusion enhances amyloplast dynamics in Arabidopsis zigzag1 hypocotyls
title_fullStr Wortmannin-induced vacuole fusion enhances amyloplast dynamics in Arabidopsis zigzag1 hypocotyls
title_full_unstemmed Wortmannin-induced vacuole fusion enhances amyloplast dynamics in Arabidopsis zigzag1 hypocotyls
title_short Wortmannin-induced vacuole fusion enhances amyloplast dynamics in Arabidopsis zigzag1 hypocotyls
title_sort wortmannin-induced vacuole fusion enhances amyloplast dynamics in arabidopsis zigzag1 hypocotyls
topic Research Paper
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5181587/
https://www.ncbi.nlm.nih.gov/pubmed/27816929
http://dx.doi.org/10.1093/jxb/erw418
work_keys_str_mv AT alvarezashleyann wortmannininducedvacuolefusionenhancesamyloplastdynamicsinarabidopsiszigzag1hypocotyls
AT hansangwon wortmannininducedvacuolefusionenhancesamyloplastdynamicsinarabidopsiszigzag1hypocotyls
AT toyotamasatsugu wortmannininducedvacuolefusionenhancesamyloplastdynamicsinarabidopsiszigzag1hypocotyls
AT brilladacarla wortmannininducedvacuolefusionenhancesamyloplastdynamicsinarabidopsiszigzag1hypocotyls
AT zhengjiameng wortmannininducedvacuolefusionenhancesamyloplastdynamicsinarabidopsiszigzag1hypocotyls
AT gilroysimon wortmannininducedvacuolefusionenhancesamyloplastdynamicsinarabidopsiszigzag1hypocotyls
AT rojaspiercemarcela wortmannininducedvacuolefusionenhancesamyloplastdynamicsinarabidopsiszigzag1hypocotyls