PubMed · 9121728
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
S Fujioka, A Sakurai. 1997. Brassinosteroids.. https://doi.org/10.1039/np9971400001
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
Brassinolide and related brassinosteroids are a novel group of steroids which appear to be ubiquitous in plants. There is compelling evidence, particularly from recent genetic studies, that these steroids are essential for normal plant growth and development. Synthesis of brassinosteroids and aspects of their biochemistry are reviewed.
In the field of brassinosteroids, which are potent plant growth regulators, we have developed a quantitative structure-activity relationship study to develop knowledge from a structural point of view and to find out new requirement definitions. This will help identify other suitable active brassinosteroid derivatives with a good activity/synthetic cost ratio for further application in agriculture. The methodology used to achieve this goal represents a multidisciplinary study involving synthesis, molecular modeling calculations, and bioactivity evaluation. The influence of different molecular properties in the bioactivity of a set of synthetic compounds (i.e., molecular electrostatic potential and the ability to form H bonds) is discussed. The molecular electrostatic potential is expressed in terms of the electrostatic Carbó similarity index (CI) between brassinolide (1) and other brassinosteroids. We have found that the electrostatic charges of the functional groups play an important role in the description of the activity, as evidenced by its good correlation with the CI in most cases. Deviation from this rule could be explained by the H bonding abilities of some of these compounds, which we believe may play an essential role in binding to the natural receptors.
To elucidate the involvement of brassinosteroids in the progression of tracheary element differentiation in cultured Zinnia cells, we analyzed the effects of uniconazole, an inhibitor of brassinosteroid synthesis, and brassinolide, a biologically active brassinosteroid, on the accumulation of mRNAs for various genes that were expressed in different stages of differentiation. Uniconazole specifically suppressed the accumulation of transcripts for genes that were induced in the final stage of differentiation in association with secondary wall formation and cell death. This suppression was recovered with the addition of brassinolide. These results strongly suggest that endogenous brassinosteroids induce entry into the final stage of differentiation.