Co-Regulation of Brassinosteroid Biosynthesis-Related Genes During Xylem Cell Differentiation

• DOI: 10.1093/pcp/pcl039
• Publication Date: 2006-11-29T02:52:54Z
• Authors: R. Yamamoto; S. Fujioka; K. Iwamoto; T. Demura; S. Takatsuto; S. Yoshida; H. Fukuda
• Keywords: Brassinosteroid; Brassinolide; Squalene monooxygenase

To understand the regulatory mechanisms of brassinosteroid (BR) biosynthesis in specific plant developmental processes, we first investigated accumulation profiles BRs and sterols xylem differentiation a Zinnia culture. The amounts many substances late C28 sterol biosynthetic pathway to campesterol (CR), such as episterol 24-methylenecholesterol, well those BR-specific from CR brassinolide (BL), were elevated close association with tracheary element differentiation. Among them, 6-deoxotyphasterol (6-deoxoTY) accumulated unusually high levels within cells cultured element-inductive medium, while castasterone (CS) was not either or outside cells. identify molecular basis this co-up-regulation sterols, isolated genes for key enzymes BR biosynthesis, ZeSTE1, ZeDIM, ZeDWF4, ZeCPD1 ZeCPD2. RNA gel blot analysis these indicated coordinated increase transcripts ZeDWF4 ZeCPD1, differentiation-specific ZeCPD1. In situ hybridization experiments mRNAs revealed their preferential procambium cells, immature parenchyma These results suggest that during may be regulated by regulation broad which occurs part transcript encoding enzymes, specifically data provide new insights into signaling development.