BRL1 and BRL3 are novel brassinosteroid receptors that function in vascular differentiation in Arabidopsis
BRL1 and BRL3 are novel brassinosteroid receptors that function in vascular differentiation in Arabidopsis
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DOI：
10.1242/dev.01403
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发表时间：
2004-11-01
期刊：
影响因子：
4.6
通讯作者：
Chory, J
中科院分区：
文献类型：
--
作者：
Caño-Delgado, A;Yin, YH;Chory, J
植物类固醇激素，油菜素类固醇（BR），是由质膜定位的富含亮氨酸重复序列受体激酶BRI1感知。基于序列相似性，我们已经鉴定了BRI1家族的三个成员，分别命名为BRL 1、BRL 2和BRL 3。BRL 1和BRL 3，而不是BRL 2，编码功能性BR受体，其以高亲和力结合油菜素酶，最活跃的BR。一致地，当在BRIJ启动子的控制下表达时，只有BRL1和BRL3可以拯救bril突变体。虽然BRI1在生长细胞中普遍表达，但BRL 1和BRL 3的表达限于血管细胞的非重叠亚群。bri1基因功能缺失导致韧皮部木质部分化率异常并增强弱bril突变体的维管缺陷。brl1 brl1 brl3三重突变体增强了bri1侏儒症，并且还表现出异常的维管分化。因此，拟南芥含有少量BR受体，这些受体在细胞生长和血管分化中具有特定功能。
Plant steroid hormones, brassinosteroids (BRs), are perceived by the plasma membrane-localized leucine-rich-repeat-receptor kinase BRI1. Based on sequence similarity, we have identified three members of the BRI1 family, named BRL1, BRL2 and BRL3. BRL1 and BRL3, but not BRL2, encode functional BR receptors that bind brassinolide, the most active BR, with high affinity. In agreement, only BRL1 and BRL3 can rescue bril mutants when expressed under the control of the BRIJ promoter. While BRI1 is ubiquitously expressed in growing cells, the expression of BRL1 and BRL3 is restricted to non- overlapping subsets of vascular cells. Loss-of-function of bri1 causes abnormal phloemxylem differentiation ratios and enhances the vascular defects of a weak bril mutant. brl1 brl1 brl3 triple mutants enhance bri1 dwarfism and also exhibit abnormal vascular differentiation. Thus, Arabidopsis contains a small number of BR receptors that have specific functions in cell growth and vascular differentiation.