Brassinosteroid-Driven Stimulation of Shoot Formation and Elongation: Application in Micropropagation
Pp. 26-34 (9)
A. B. Pereira-Netto, L. R. Galagovsky and J. A. Ramirez
Brassinosteroids (BRs) comprise a specific class of low-abundance, natural polyhydroxy
steroidal lactones and ketones now recognized as a new class of phytohormones. These steroids of
ubiquitous occurrence in plants are known to stimulate stem elongation and to control apical dominance
as well. In this chapter, we describe the use of BRs to significantly improve protocols for
micropropagation of woody species, more specifically, the marubakaido apple rootstock and a clone of
Eucalyptus, through the stimulation of shoot elongation and formation of new shoots. It is also shown in
this chapter that these BR-induced changes in shoot architecture do not result from changes in the
endogenous levels of any single metabolite and do not rely on broad changes in the metabolite profile,
22-hydroxylated BRs, 5F-28-homocastasterone, brz220, E. grandis X E. urophylla hybrid,
marubakaido, metabolomics, multiplication rate.
Department of Botany-SCB, Centro Politecnico-Parana Federal University, C.P. 19031 Curitiba, PR, 81531-970, Brazil.