A Root-to-Shoot Signaling Pathway Controls Plant Development and Requires BYPASS1

植物发育涉及根与芽之间的协调，根检测水分和营养水平，芽是植物的地上部分。 然而，根源信号的性质以及它们如何控制芽生长在很大程度上是未知的。 最近对一种名为bypass 1（bps 1）的拟南芥突变体的分析表明，在这种突变体中，根不断产生一种信号，这种信号在植物中移动，并能够阻止芽的生长。 这一结果表明，BYPASS 1（BPS 1）的功能是停止产生一种长距离信号，这种信号通常可用于控制植物生长。Sieburth实验室将开展旨在了解BPS 1控制的根到芽信号传导的实验。 研究将使用遗传、生物化学和细胞生物学方法来解决以下三个问题：（1）什么是移动的信号;（2）BPS 1通常与什么相互作用，抑制信号产生;（3）信号如何抑制芽生长？ 这些实验有望确定信号产生所需的类胡萝卜素的一个分支。 这项工作还有望确定与BPS 1相互作用的细胞蛋白质：可能有助于指导植物产生信号或功能以将环境信号传递给BPS 1的蛋白质。 最后，这项工作还有望确定如何控制芽生长（例如通过阻止细胞周期进展或抑制细胞扩增）。这项工作将提供深入了解根到芽信号，同时培训本科生，研究生和博士后学生。 此外，根到芽的信号被认为会大大降低农业生产力，特别是在应对干旱时。 深入了解BPS 1途径可能为工程植物提供合理的基础，改变对根源信号的反应，从而提高农业生产力。

Plant development involves coordination between roots, which detect water and nutrient levels and shoots, the above-ground portion of the plant. However, the nature of root-derived signals and how they work to control shoot growth is largely unknown. Recent analysis of an Arabidopsis mutant called bypass1 (bps1) showed that, in this mutant, the roots continually produced a signal that moved through the plant and was able to stop shoot growth. This result suggests that BYPASS1 (BPS1) functions to stop production of a long-distance signal that might normally be used to control plant growth. The Sieburth lab will carry out experiments directed toward understanding the root-to-shoot signaling controlled by BPS1. Research will use genetic, biochemical and cell biological approaches to address the following three questions: (1) what is the mobile signal; (2) what does BPS1 interact with normally that suppresses signal production; and (3) how does the signal inhibit shoot growth? The experiments are expected to identify a branch of the carotenoids that are required for signal production. The work is also expected to identify cellular proteins that interact with BPS1: proteins which might assist in directing the plant to generate the signal or function to transmit environmental signals to BPS1. Finally, the work is also expected to identify how shoot growth is controlled (e.g. by preventing cell cycle progression or by inhibiting cell expansion). This work will provide insight into root-to-shoot signaling while training undergraduate, graduate, and post-doctoral students. Moreover, root-to-shoot signals are believed to profoundly reduce agricultural productivity, especially in response to drought. Insight into the BPS1 pathway may provide a rational basis for engineering plants with altered responses to the root-derived signal, thus leading to boosts in agricultural productivity.