Department of Biology, University of Utah, Salt Lake City, UT 94112, USA.
Development. 2012 Feb;139(4):805-15. doi: 10.1242/dev.077313.
Development is often coordinated by biologically active mobile compounds that move between cells or organs. Arabidopsis mutants with defects in the BYPASS1 (BPS1) gene overproduce an active mobile compound that moves from the root to the shoot and inhibits growth. Here, we describe two related Arabidopsis genes, BPS2 and BPS3. Analyses of single, double and triple mutants revealed that all three genes regulate production of the same mobile compound, the bps signal, with BPS1 having the largest role. The triple mutant had a severe embryo defect, including the failure to properly establish provascular tissue, the shoot meristem and the root meristem. Aberrant expression of PINFORMED1, DR5, PLETHORA1, PLETHORA2 and WUSCHEL-LIKE HOMEOBOX5 were found in heart-stage bps triple-mutant embryos. However, auxin-induced gene expression, and localization of the PIN1 auxin efflux transporter, were intact in bps1 mutants, suggesting that the primary target of the bps signal is independent of auxin response. Thus, the bps signal identifies a novel signaling pathway that regulates patterning and growth in parallel with auxin signaling, in multiple tissues and at multiple developmental stages.
发育通常由在细胞或器官之间移动的生物活性移动化合物协调。BYPASS1 (BPS1) 基因缺陷的拟南芥突变体过度产生一种活跃的移动化合物，从根部移动到芽部并抑制生长。在这里，我们描述了两个相关的拟南芥基因，BPS2 和 BPS3。对单突变体、双突变体和三突变体的分析表明，这三个基因都调节相同的移动化合物的产生，即 bps 信号，其中 BPS1 起主要作用。三突变体具有严重的胚胎缺陷，包括不能正确建立维管束组织、芽分生组织和根分生组织。在心脏期 bps 三突变体胚胎中发现 PINFORMED1、DR5、PLETHORA1、PLETHORA2 和 WUSCHEL-LIKE HOMEOBOX5 的异常表达。然而，在 bps1 突变体中，生长素诱导的基因表达和 PIN1 生长素外排转运蛋白的定位是完整的，这表明 bps 信号的主要靶标独立于生长素反应。因此，bps 信号确定了一条新的信号通路，该通路与生长素信号平行调节模式和生长，在多种组织和多个发育阶段。
