Brassinosteroids (BRs) are a group of steroidal hormones involved in plant development. Although the BR biosynthesis pathways are well characterized, the BR inactivation process, which contributes to BR homeostasis, is less understood. Here, we show that a member of the BAHD (for benzylalcohol O-acetyltransferase, anthocyanin O-hydroxycinnamoyltransferase, anthranilate N-hydroxycinnamoyl/benzoy...

This paper presents evidence that plant brassinosteroid (BR) hormones play a role in promoting germination. It has long been recognized that seed dormancy and germination are regulated by the plant hormones abscisic acid (ABA) and gibberellin (GA). These two hormones act antagonistically with each other. ABA induces seed dormancy in maturing embryos and inhibits germination of seeds. GA breaks ...

The production of H2O2 is critical for brassinosteroid (BR)- and abscisic acid (ABA)-induced stress tolerance in plants. In this study, the relationship between BR and ABA in the induction of H2O2 production and their roles in response to heat and paraquat (PQ) oxidative stresses were studied in tomato. Both BR and ABA induced increases in RBOH1 gene expression, NADPH oxidase activity, apoplast...

The regulation of innate immunity and plant growth, along with the trade-off between them, affects the defense and recovery mechanisms of the plant after it is attacked by pathogens. Although it is known that hormonal crosstalk plays a major role in regulating interaction of plant growth and PAMP-triggered immunity, the relationship between plant growth and effector-triggered immunity (ETI) rem...

Storage proteins in cotyledons of legume plants are degraded by proteinases after germination. We examined whether abscisic acid (ABA), gibberellin (GA) and brassinosteroid (BR) are involved in the expression of cysteine proteinases in cotyledons of common bean seeds with RNA blotting using cDNAs for five papain-like proteinases, EP-C1, CP1, CP2, CP3, CP4 and two legumain-like proteinases, LLP1...

The receptor kinase BRI1 (BRASSINOSTEROID-INSENSITIVE 1) is a key component in BR (brassinosteroid) perception and signal transduction, and has a broad impact on plant growth and development. In the present study, we demonstrate that Arabidopsis CaM (calmodulin) binds to the recombinant cytoplasmic domain of BRI1 in a Ca2+-dependent manner in vitro. In silico analysis predicted binding to Helix...

The effect of 24-epibrassinolide (EBR) on glucosinolate biosynthesis in Arabidopsis thaliana was investigated in the present study by using mutants and transgenic plants involved in brassinosteroid (BR) biosynthesis and signal transduction, as well as glucosinolate biosynthesis. The results showed that EBR significantly decreased the contents of major aliphatic glucosinolates including glucoibe...

Basic helix-loop-helix (bHLH) proteins are highly conserved transcription factors critical for cell proliferation and differentiation. Recent studies have implicated bHLH proteins in many plant signaling processes, including brassinosteroid (BR) signaling. Here, we report identification of two families of atypical bHLH proteins capable of modulating BR signaling. We found that activation-tagged...

The brassinosteroid (BR) signaling module is a central regulator of plant morphogenesis, as indicated by the large number of BR-responsive cell wall-related genes and the severe growth defects of BR mutants. Despite a detailed knowledge of the signaling components, the logic of this auto-/paracrine signaling module in growth control remains poorly understood. Recently, extensive cross-talk with...

Signal transduction involves posttranslational modifications and protein-protein interactions, which can be studied by proteomics. In Arabidopsis, the steroid hormone (brassinosteroid (BR)) binds to the extracellular domain of a receptor kinase (BRI1) to initiate a phosphorylation/dephosphorylation cascade that controls gene expression and plant growth. Here we detected early BR signaling event...