Investigating the regulatory role of brassinosteroids in gibberellic acid homeostasis

油菜素内酯（BRs）是调节细胞分裂、细胞分化和细胞模式的植物类固醇。BRs控制着种子萌发、光暗发育、维管分化、开花、果实发育和衰老等基本生物学过程。由于另一类植物激素赤霉素酸在高度相似的发育程序和生长过程中起作用，长期以来人们一直怀疑赤霉素酸和赤霉素酸之间存在串扰。然而，最新的研究结果表明，这种串扰仅限于信号水平，两种途径的贡献因子相互作用来调节共同靶基因的转录。这一建议是基于新的发现，这些发现首次证明了BRs在控制拟南芥GA稳态中的中心调控功能。该研究旨在阐明潜在的分子模式，从而提高我们对植物生长调节原理的理解。

Brassinosteroids (BRs) are plant steroids that regulate cell division, cell differentiation and cellular patterning. The BRs control fundamental biological processes including germination, development in the light and dark, vascular differentiation, flowering, fruit development and senescence. Since another class of plant hormones, the gibberellic acids (GAs), function in highly similar developmental programs and growth processes, a cross talk of BRs and GAs has long been suspected. However, up to date results had suggested that this cross talk is restricted to the signaling level with both pathways contributing factors that interact to modulate transcription of common target genes.This proposal is based on novel findings, which provide first evidence for a central regulatory function of BRs in the control of GA homeostasis in Arabidopsis thaliana. The research is conceived to elucidate the underlying molecular modes, and thereby intends to improve our understanding of principles of growth regulation in plants.