fulltext.study @t Gmail

Brassinosteroids regulate the thylakoid membrane architecture and the photosystem II function

Paper ID Volume ID Publish Year Pages File Format Full-Text
30500 44482 2013 8 PDF Available
Title
Brassinosteroids regulate the thylakoid membrane architecture and the photosystem II function
Abstract

•Brassinosteroids control thylakoid membrane architecture and function.•Smaller PSII supercomplexes in BRI1OE, bri1-116 and cpd thylakoids.•BRI1OE, bri1-116 and cpd thylakoids exhibit impaired oxygen evolution.•Suboptimal BR level hampers the thylakoid structure and functionality.

Brassinosteroids (BRs) are plant steroid hormones known to positively affect photosynthesis. In this work we investigated the architecture and function of photosynthetic membranes in mature Arabidopsis rosettes of BR gain-of-function (overexpressing the BR receptor BR INSENSITIVE 1 (BRI1), BRI1OE) and loss-of-function (bri1-116 with inactive BRI1 receptor, and constitutive photomorphogenesis and dwarfism (cpd) deficient in BR biosynthesis) mutants. Data from atomic force microscopy, circular dichroism, fluorescence spectroscopy and polarographic determination of oxygen yields revealed major structural (enlarged thylakoids, smaller photosystem II supercomplexes) and functional (strongly inhibited oxygen evolution, reduced photosystem II quantum yield) changes in all the mutants with altered BR response compared to the wild type plants. The recorded thermal dependences showed severe thermal instability of the oxygen yields in the BR mutant plants. Our results suggest that an optimal BR level is required for the normal thylakoid structure and function.

Keywords
Brassinosteroids; Photosynthesis; Thylakoid membrane; Fluorescence spectroscopy; Photosystem II function; Oxygen yield
First Page Preview
Brassinosteroids regulate the thylakoid membrane architecture and the photosystem II function
Publisher
Database: Elsevier - ScienceDirect
Journal: Journal of Photochemistry and Photobiology B: Biology - Volume 126, 5 September 2013, Pages 97–104
Authors
, , , , , , , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering