Collaborative Research: EAGER: Mapping small molecules in the root meristem

众所周知，植物的根具有许多基本功能，例如在结构上支持植物和从土壤中吸收养分以促进植物的生长。但目前尚不清楚的是不同根室的化学成分，以及这些化学物质是如何用来指示植物生长的。研究小组希望通过绘制这些化合物在根结构中的位置的化学图来发现这些化合物的身份和功能。他们将引导一股微小的液滴流到根部的切割部分，然后让产生的液滴溅入质谱仪，这是一种可以确定在分散的液滴中溶解的每种化合物的身份和数量的设备。通过将根切片贴在上下左右移动的载玻片上，根中化合物的二维图谱就会被记录下来。他们相信，这种方法将提供与植物根系功能有关的新信息。代谢物和脂质信号分子对多细胞生物发育的适当调节至关重要。这些小分子的化学性质使它们能够跨越细胞膜，作为蛋白质受体的高度特异性配体，并在短时间内在不同的分子物种之间动态转换。这些能力促进了组织间发育线索的快速交流。这些化合物的生物合成、感知或代谢缺陷可导致异常的组织形成和疾病。尽管小分子至关重要，但我们对它们功能的了解大多来自对这些化合物的间接测量。研究人员将利用解吸电喷雾电离质谱成像（DESI-MSI）直接测量根组织不同发育区域的小分子。根分生组织是这项工作的一个很好的模型，因为细胞是沿着纵向发育梯度组织的，多能干细胞位于根的尖端，分化细胞位于茎的方向。这种方法正在产生新的小分子发育调节剂的鉴定。将DESI-MSI与传统的分子生物学方法相结合，将能够表征代谢物和脂质信号化合物在干细胞决策中的新作用，这对植物和人类研究都有意义。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

It is well appreciated that plants have roots which serve many essential functions, such as structurally supporting the plant and taking up nutrients from the soil to promote the growth of the plant. But what is not clear is the chemical composition of different root compartments and how these chemicals are used to signal the growth of the plant. The research team hopes to discover the identity and function of these chemical compounds by making a chemical map of where these chemical compounds are located in the root structure. They will do that by directing a stream of tiny droplets onto a cut section of the root and letting the resulting droplet splash enter a mass spectrometer, a device that can determine the identity and the amount of each compound dissolved in the scattered droplets. By mounting the root section on a slide that be moved right and left as well as up and down, a two-dimensional map will be recorded of the compounds present in the root. They believe this approach will provide new information related to how roots of plants function.Metabolite and lipid signaling molecules are critical for proper regulation of development in multicellular organisms. The chemical properties of these small molecules enable them to cross cell membranes, function as highly specific ligands to protein receptors, and dynamically convert between different molecular species on short time scales. These abilities facilitate rapid communication of developmental cues across tissues. Defects in the biosynthesis, perception, or metabolism of these compounds can lead to aberrant tissue formation and disease. Despite the critical importance of small molecules, most of our understanding of their function is derived from indirect measurements of these compounds. The investigators will utilize desorption electrospray ionization mass spectrometry imaging (DESI-MSI) to directly measure small molecules in distinct developmental regions of root tissue. The root meristem is an excellent model for this work because cells are organized along a longitudinal developmental gradient, with pluripotent stem cells located at the tip of the root, and differentiated cells localized towards the direction of the shoot. This approach is yielding the identification of novel small molecule regulators of development. Combining DESI-MSI with traditional molecular biology approaches will enable characterization of new roles of metabolite and lipid signaling compounds in stem cell decisions, with implications in both plant and human research.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.