Brassinosteroid signaling in plant development and adaptation to stress

Abstract

Brassinosteroids (BRs) are steroid hormones that are essential for plant growth and development. These hormones control the division, elongation and differentiation of various cell types throughout the entire plant life cycle. Our current understanding of the BR signaling pathway has mostly been obtained from studies using Arabidopsis thaliana as a model. In this context, the membrane steroid receptor BRI1 (BRASSINOSTEROID INSENSITIVE 1) binds directly to the BR ligand, triggering a signal cascade in the cytoplasm that leads to the transcription of BR-responsive genes that drive cellular growth. However, recent studies of the primary root have revealed distinct BR signaling pathways in different cell types and have highlighted cell-specific roles for BR signaling in controlling adaptation to stress. In this Review, we summarize our current knowledge of the spatiotemporal control of BR action in plant growth and development, focusing on BR functions in primary root development and growth, in stem cell self-renewal and death, and in plant adaption to environmental stress.

Visualizing protein-protein interactions in plants by rapamycin-dependent delocalization

“…We prove that KPS is feasible for interactions holding diverse physiological roles in distinct biological processes. We successfully reproduced previously demonstrated interactions of the transcription factors SACL3 and LHW (Vera-Sirera et al, 2015),interplay of TPLATE and TML, subunits of endocytic TPLATE complex, (Gadeyne et al, 2014) and interaction between the brassinosteroid signaling proteins BIN2 and BES1 (Anwar et al, 2018;Planas-Riverola et al, 2019). Likewise, homodimerization of MAP65-1 (Tulin et al, 2012;Van Damme et al, 2004), could be identified using our system.…”

“…To investigate the required timing for KSP to occur in N. benthamiana, leaves coexpressing BES1-GFP, BIN2-mCherry-FKBP and MITO-TagBFP2-FRB* were treated with rapamycin and the delocalization was monitored at different time points. Interaction through delocalization was visible as soon as five minutes after rapamycin treatment (Supplemental Knocksideways does not stabilize protein-protein interactions KSP allowed to reproduce interactions reported before (Anwar et al, 2018;De Rybel et al, 2013;Gadeyne et al, 2014;Ohashi-Ito and Bergmann, 2007;Planas-Riverola et al, 2019;Tulin et al, 2012;Vera-Sirera et al, 2015). However, we also encountered protein pairs, which did not interact in our system.…”

Robotic Assay for Drought (RoAD): An Automated Phenotyping System for Brassinosteroid and Drought Response

“…On the other hand, the growth of BR gain-of-function BRI1P-BRI1-OX plants showed less inhibition in response to drought compared to WT. These phenotypes of BRI1P-BRI1-OX are interesting in light of the recent findings showing that overexpression of the vascular BR receptor BRL3, a homolog of BRI1, allows for increased drought survival without compromising plant growth (Fàbregas et al, 2018;Planas-Riverola et al, 2019). Our findings suggest additional complexity in BR-mediated control of drought responses.…”

Soybean Resistance to Soybean Mosaic Virus

“…Levels of other hormones such as cytokinins and brassinosteroids and expression levels of their related genes were mildly elevated in response to infection by SMV-G5H or SMV-G7H. Cytokinins and brassinosteroids have various functions in plant growth and development and also increase plant tolerance to infection by some viruses [16,18,132].…”