Brassinosteroid hormone

Asami, T., Nakano, T. and Fujioka, S. (2005) Plant brassinosteroid hormones. Vitam. Horm., 72, 479-504. 

Turk EM, Fujioka S, Seto H, Shimada Y, Takat-suto S, Yoshida S, Denzel MA, Torres QI, Neff MM (2003) CYP72B1 inactivates brassinosteroid hormones an intersection between photomorphogenesis and plant steroid signal transduction. Plant Physiol 133 1643-1653... 

Brassinosteroids (BR) are a group of plant steroid hormones that help to regulate many aspects of plant growth and development. Several P450s have been... 

CLOUSE, S.D., FELDMANN, K.A., Molecular genetics of brassinosteroid action. In Brassinosteroids Steroidal Plant Hormones, (A. Sakurai, T. Yokota, and S.D. Clouse, eds,), Springer Verlag, Tokyo, 1999, pp 163-190. 

Isoprenoids that have hormonal and signaling functions form an important group. These include steroid hormones (1 = 6) and retinoate (the anion of retinoic acid 1 = 3) in vertebrates, and juvenile hormone (1 =3) in arthropods. Some plant hormones also belong to the isoprenoids—e.g., the cytokinins, absci-sic acid, and brassinosteroids. 

The kinds of compounds that elicit signals in plants are similar to certain signaling molecules in mammals (Fig. 12-28). Instead of prostaglandins, plants have jas-monate instead of steroid hormones, brassinosteroids. 

Adam, G. Schneider, B. In Brassinosteroids Steroidal Plant Hormones.-, Sakurai, A Yokota, T Clouse, S.D. Eds. Springer-Verlag Tokyo, 1999 p. 113-136... 

T. Yokota, Brassinosteroids. In Biochemistry and Molecular Biology of Plant Hormones P. J. J. Hooykaas, K. R. Libbenga,... 

A. Sakurai T. Yokota S. D. Clouse, Eds., Brassinosteroids Steroidal Plant Hormones Springer-Verlag Tokyo, 1999. 

Adam, G. and Schneider, B. (1999) Uptake, transport and metabolism, in Brassinosteroids - Steroidal Plant Hormones (eds A. Sakurai, T. Yokota and S. Clouse). Springer, Tokyo, Japan, pp. 113-36. 

Bishop, G.J. and Koncz, C. (2002) Brassinosteroids and plant steroid hormone signaling. Plant Cell, 14, 97-110. 

Yokota, T. (1999) Brassinosteroids, in Biochemistry and Molecular Biology of Plant Hormones (eds P. Hooykaas, M. Hall and K. Libbenga). Elsevier, Amsterdam. 

In 1979, a novel plant growth regulating steroidal substance called brassinolide was isolated from rape (Brassica napus) pollen. Brassinosteroids are thought by some to be a new class of plant hormones. The evidences are ... 

J.H. Yopp, Southern Illinois University, Carbondale, became interested in the brassins project in its early stages (36) and he conducted cooperative brassins studies with both Mitchell and Mandava. Yopp et al. (37, 38) evaluated brassins responses in a number of auxin, gibberellin, and cytokinin bioassays and showed that brassins responded similarly to some of the known hormones in certain systems but not in others. These studies led to more cooperative investigation of brassinolide and other brassinosteroids (39, 40). 

Brassinosteroids are steroidal plant hormones which promote plant growth. To date the presence of over sixty kinds of brassinosteroids has been verified from various plant sources and thirty one of them fully characterized. In this chapter, the distribution and structural characteristics of the naturally-occurring brassinosteroids are discussed. 

Generally, immature seeds have been demonstrated to be one of the richest sources of plant hormones. Thus, Yokota et al. examined brassinosteroids in immature seeds ofDolichos lablab (12-15). As a result, two brassinosteroids with a 24-exomethylene [ dolicholide (2) and dolichosterone (4) ] two Cs brassinosteroids with a 24(E>ethylidene [ homodolicholide (10) and homodolichosterone (11) ] and two 6-deoxodihydro brassinosteroids [ 6-deoxodihydrocastasterone (5) and 6-deoxodihydrodolichosterone (6) ] were unequivocally identified and later the presence of brassinolide and castasterone were determined. The content of the major brassinosteroid, dolicholide, was 200 ig/kg, which paralleled the concentration of brassinolide in rape pollens. 

Different Activities of Several Brassinosteroids in Two Bean Internode Tests. It is a well-known phenomenon that structurally closely related plant growth regulators exhibit different orders of activity in different bioassays. This makes it difficult to define the criteria of specificity of their hormonal action. The same situation exists in the case of BRst, and it can be documented by the comparison of different BRst in the two bioassays. 

Effects of Plant Hormones on Production of Brassinosteroids in Cell Cultures... 

Brassinosteroids (BSs) represent a new group of plant hormones that possess a broad spectrum of physiological activities (1,2). A most Intriguing property of BSs Is their capacity to Increase stress resistance In plants, but the mechanism of such an antistress activity still remains unknown (1). As cell stress resistance Is usually associated with stress protein synthesis (3 4) our aim was to study the BS effect on protein synthesis and ultrastructure of wheat leaf cells at normal temperature and under heat shock conditions. We have also studied the Influence of BSs on mesophyll cell ultrastructure under saline stress. 

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