title: Brassinosteroid's multi-modular interaction with the general stress network customizes stimulus-specific responses in Arabidopsis.
abstract: Adaptation to fluctuating environmental conditions is a universal feature of plant life, governed by fundamental mechanisms optimizing resource allocation. This balance is achieved in part through tightly regulated communication networks among growth and stress response signaling pathways. Understanding the communication modules between brassinosteroids (BRs), the ubiquitous hormones known to control growth and stress adaptation, and the general stress response (GSR), a rapid and transient transcriptional output in response to perturbations, provides an optimal platform to unravel new facet(s) of plant stress adaptation. Here, we explore communication facets of BR with GSR via in planta quantification of the GSR in Arabidopsis expressing luciferase driven by a functional GSR cis-element, the Rapid Stress Response Element (4xRSRE:LUC). We establish that application of exogenous BR suppresses microbe-associated molecular pattern-activated GSR, but enhances the wound-triggered GSR. The enhanced wound-activated GSR in BR-treated plants results in a greater wound-induced resistance to Botrytis cinerea. A combination of molecular genetics using BR signaling mutants and application of an activator of BR signaling, bikinin, confirms these results and places the chief point of BR-GSR interaction downstream of potential membrane receptor circuitry. These results support a multi-modular interaction between BRs and stress signaling, instrumental in customizing stimulus-specific responses in Arabidopsis.
authors.affiliation: Department of Plant Sciences, University of California, Davis, CA, USA; Department of Plant Biology, University of California, Davis, CA, USA.
authors.forename: Marta
authors.initials: M
authors.lastname: Bjornson
authors.affiliation: Department of Plant Biology, University of California, Davis, CA, USA.
authors.forename: Abhaya M
authors.initials: AM
authors.lastname: Dandekar
authors.affiliation: Howard Hughes Medical Institute and Plant Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, USA.
authors.forename: Joanne
authors.initials: J
authors.lastname: Chory
authors.affiliation: Department of Plant Sciences, University of California, Davis, CA, USA. Electronic address: kdehesh@ucdavis.edu.
authors.forename: Katayoon
authors.initials: K
authors.lastname: Dehesh
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D060406:Brassinosteroids / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D010937:Plant Growth Regulators / Q000378:metabolism*; D020218:Response Elements; D015398:Signal Transduction; D013312:Stress, Physiological
chemical_list: D029681:Arabidopsis Proteins; D060406:Brassinosteroids; D010937:Plant Growth Regulators
keywords: Brassinosteroid (BR); Cross-hormonal communication; General stress response (GSR); Hypoxia; Microbe-associated molecular pattern (MAMP); Wound-induced resistance