Related Experiment Video
Updated: Jun 5, 2026

Pattern-Triggered Oxidative Burst and Seedling Growth Inhibition Assays in Arabidopsis thaliana
Published on: May 21, 2019
A fast brassinolide-regulated response pathway in the plasma membrane of Arabidopsis thaliana
Katharina Caesar1, Kirstin Elgass, Zhonghua Chen
1Center for Plant Molecular Biology, Department of Plant Physiology, University of Tübingen, Auf der Morgenstelle 1, 72076 Tübingen, Germany.
Abstract:
To understand molecular processes in living plant cells, quantitative spectro-microscopic technologies are required. By combining fluorescence lifetime spectroscopy with confocal microscopy, we studied the subcellular properties and function of a GFP-tagged variant of the plasma membrane-bound brassinosteroid receptor BRI1 (BRI1-GFP) in living cells of Arabidopsis seedlings. Shortly after adding brassinolide, we observed BRI1-dependent cell-wall expansion, preceding cell elongation. In parallel, the fluorescence lifetime of BRI1-GFP decreased, indicating an alteration in the receptor's physico-chemical environment. The parameter modulating the fluorescence lifetime of BRI1-GFP was found to be BL-induced hyperpolarization of the plasma membrane. Furthermore, for induction of hyperpolarization and cell-wall expansion, activation of the plasma membrane P-ATPase was necessary. This activation required BRI1 kinase activity, and was mediated by BL-modulated interaction of BRI1 with the P-ATPase. Our results were used to develop a model suggesting that there is a fast BL-regulated signal response pathway within the plasma membrane that links BRI1 with P-ATPase for the regulation of cell-wall expansion.
Related Concept Videos
Cell Signaling in Plants
Diversity in Cell Signaling Responses
Graded and Abrupt Responses
Some signaling systems generate...
Short-distance Transport of Resources
C4 Pathway and CAM
C4 Pathway
The C4 pathway is used by plants such as...
Transcription
Transcription is the process of synthesizing RNA from a DNA sequence by RNA polymerase. It is the first step in producing a protein from a gene sequence. Additionally, many other proteins and regulatory sequences are involved in the proper synthesis of messenger RNA (mRNA). Regulation of transcription is responsible for the differentiation of all the different types of cells and often for the proper cellular response to environmental signals.
Transcription Can Produce Different Kinds...
Biological Clocks and Seasonal Responses

