Brassinosteroids regulate vacuolar morphology in root meristem cells of Arabidopsis thaliana

Ayumi Yamagami; Saito Chieko; Masaaki Sakuta; Kazuo Shinozaki; Hiroyuki Osada; Akihiko Nakano; Tadao Asami; Takeshi Nakano

doi:10.1080/15592324.2017.1417722

Brassinosteroids regulate vacuolar morphology in root meristem cells of Arabidopsis thaliana

Plant Signal Behav. 2018 Apr 3;13(4):e1417722. doi: 10.1080/15592324.2017.1417722. Epub 2018 Apr 16.

Authors

Ayumi Yamagami¹, Saito Chieko^{2

3}, Masaaki Sakuta⁴, Kazuo Shinozaki¹, Hiroyuki Osada⁵, Akihiko Nakano^{2

3

6}, Tadao Asami^{1

7

8

9}, Takeshi Nakano^{1

9}

Affiliations

¹ a Gene Discovery Research Group, RIKEN Center for Sustainable Resource Science, Wako , Saitama , Japan.
² b Molecular Membrane Biology Laboratory, RIKEN, Wako , Saitama , Japan.
³ c Department of Biological Sciences , Graduate School of Science, The University of Tokyo, Hongo , Bunkyo-ku, Tokyo , Japan.
⁴ d Department of Biological Sciences , Ochanomizu University, Ohtsuka , Bunkyo-ku, Tokyo , Japan.
⁵ e Chemical Biology Research Group, RIKEN Center for Sustainable Resource Science, Wako , Saitama , Japan.
⁶ f Live Cell Super-Resolution Imaging Research Team, RIKEN Center for Advanced Photonics, Wako , Saitama , Japan.
⁷ g Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences , The University of Tokyo, Yayoi, Bunkyo-ku , Tokyo , Japan.
⁸ h Department of Biochemistry, Faculty of Science , King Abdulaziz University, Department of Biochemistry , Jeddah , Saudi Arabia.
⁹ i CREST, JST (Japan Science and Technology Agency) , Kawaguchi, Saitama , Japan.

Abstract

Brassinosteroids (BRs) are plant hormones that regulate plant development and environmental response. Brz-insensitive-long hypocotyl4 (BIL4) was identified as a positive regulator of BR signaling that interacts with the BR receptor, BRASSINOSTEROID INSENSITIVE 1 (BRI1), and inhibits vacuolar degradation of BRI1 in Arabidopsis thaliana. Although BIL4 also localizes to the vacuolar membrane, the possible vacuolar function of BIL4 remains unknown. Here, we studied the effect of BIL4 and BR signaling on vacuole shape in root meristem cells using genetic and pharmacological approaches. In BIL4-deficient plants, vacuoles assumed a smaller luminal structure. Treatment with brassinolide (BL), the most active BR, resulted in visibly larger vacuoles, whereas treatment with the BR biosynthesis inhibitor Brz resulted in substantially smaller luminal vacuolar structures. In the bri1 mutant, vacuolar shapes exhibited small and fragmented structures. Our results suggest that BR signaling impacts vacuolar shape.

Keywords: Arabidopsis; BIL4; BRI1; Brz; VAM3/SYP22; brassinosteroid; chemical biology; signaling; vacuolar morphogenesis; vacuole.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Arabidopsis / metabolism
Arabidopsis Proteins / metabolism*
Brassinosteroids / metabolism*
Gene Expression Regulation, Plant
Meristem / metabolism*
Plant Roots / metabolism*
Vacuoles / metabolism*

Substances

Arabidopsis Proteins
Brassinosteroids

Grants and funding

This work was supported by a grant from the Program for Promotion of Basic Research Activities for Innovative Biosciences (PROBRAIN) to T.N. and T.A., a grant from CREST, Japan Science and Technology Agency, to T.N. and T.A., a grant from the RIKEN Bioarchitect Research Project to A.N. T.A. T.N. and C.S., and a grant from the RIKEN Extreme Photonics Research Project to A.N. and C.S.