Polyamines are also important modulators of a variety of ion channels , including NMDA receptors and AMPA receptors . They block inward-rectifier potassium channels so that the currents of the channels are inwardly rectified, thereby the cellular energy, . K +
ion gradient across the cell membrane, is conserved. In addition, polyamine participate in initiating the expression of SOS response of Colicin E7 operon and down-regulate proteins that are essential for colicin E7 uptake, thus conferring a survival advantage on colicin-producing E. coli under stress conditions. 
In conclusion, we have developed a new strategy for synthesizing minor constituents of the class of BS phytohormones which is based on the use of readily available brassinosteroids of this class. Its advantage is that it allows preparing a full set of A-ring units (Δ 2 -, 2α,3α- and 2β,3β-epoxy-, 2α,3β-, 2β,3α-, and 2β,3β-dihydroxy-, 3-keto-, 3α- and 3β-hydroxy-, 2α-hydroxy-3-keto-) which are characteristic for biosynthetic precursors/metabolites of BS. The 2α,3α-diol function of ergostane BS was shown to be transformable into the required functionalities in only two to four standard chemical transformations.
Title: Crosstalk of the brassinosteroid signalosome with phytohormonal and stress signaling components maintains a balance between the processes of growth and stress tolerance
Author: Damian Gruszka
Affiliation: Department of Genetics, Faculty of Biology and Environment Protection, University of Silesia
Abstract: Brassinosteroids (BRs) are a class of phytohormones, which regulate various processes during plant life cycle. Intensive studies conducted with genetic, physiological and molecular approaches allowed identification of various components participating in the BR signaling - from the ligand perception, through cytoplasmic signal transduction, up to the BR-dependent gene expression, which is regulated by transcription factors and chromatin modifying enzymes. The identification of new components of the BR signaling is an ongoing process, however an emerging view of the BR signalosome indicates that this process is interconnected at various stages with metabolic pathways of other phytohormones. This molecular network of interdependencies allows a balance in homeostasis of the various hormones to be maintained. Moreover, the components of the BR signalosome interact with factors regulating plant reactions to environmental cues and stress conditions. This intricate network of interactions enables a rapid adaptation to constantly changing environmental conditions.