Protein kinases that regulate root waving

蛋白激酶是存在于所有细胞类型中的调节酶。它们参与了对激素、营养、发育和环境刺激的一系列反应。这项工作的总体目标是阐明选定的蛋白激酶在幼苗发育中的作用。来自拟南芥的两种蛋白激酶WAG1和WAG2是本研究的重点。WAG1和WAG2的突变使这些基因的表达消失。然而，wag1和wag2单突变体对植物没有明显的影响。然而，当wag1单突变体通过基因杂交产生wag1/wag2双突变体时，与非突变体相比，它们确实表现出明显的差异。双突变体的幼苗在垂直方向的培养皿上生长时表现出明显的根生长缺陷：根具有波浪状图案。只有当培养皿从垂直方向向后倾斜（倾斜坡度小于90度）时，才能在正常幼苗中观察到这种类型的根波动。推测WAG1和WAG2是拟南芥根系波动的负调控因子。为了阐明WAG1和WAG2在根生长中的作用，本研究的具体目的是：(1)研究改变WAG1和WAG2的量或酶活性是否会影响转基因拟南芥幼苗的根波动响应。(2)探索wag1/wag2突变体波浪根表型的潜在机制，特别是重力对根系生长的影响以及植物生长激素生长素的转运和响应。更广泛的影响：该项目将为一名本科生、一名研究生和一名博士后提供培训机会。研究中的两个WAG基因编码蛋白激酶，当突变时，这些蛋白激酶会赋予幼苗根系一种不寻常的生长模式。了解WAG激酶的作用将为尚未定义的调节根发育的细胞途径提供基本的见解。根的摆动可以被看作是一种适应性反应，它可以增强根在土壤中遇到难以穿透的物体时导航的能力。因此，了解根摆动的过程和调控它的基因可能有助于其他研究领域，如生态生理学。此外，从基因上操纵根系摆动可能会提高幼苗在田间生根的能力，从而提供农业效益。

Protein kinases are regulatory enzymes found in all cell types. They are involved in a vast array of responses to hormonal, nutritional, developmental, and environmental stimuli. The overall goal of the work proposed is to elucidate the roles played by selected protein kinases in the development of young seedlings. Two protein kinases from Arabidopsis named WAG1 and WAG2 are the focus of this proposal. Mutations in both WAG1 and WAG2 abolish the expression of these genes. Nevertheless, the wag1 and wag2 single mutants exhibit no detectable affect on the plant. However, when the wag single mutants are genetically crossed to generate wag1/wag2 double mutants, they do show a readily observable difference compared to their non-mutant counterparts. Seedlings of the double mutants exhibit a pronounced root growth defect when grown on vertically-oriented Petri plates: the roots possess a wavy pattern. Root waving of this type is observed in normal seedlings only when the Petri plates are leaned backward from vertical (inclined at pitches less than 90). It is proposed that WAG1 and WAG2 are negative regulators of root waving in Arabidopsis. To elucidate the roles that WAG1 and WAG2 play in root growth, the specific aims of the proposed research are: (1) To ask whether altering the amount or enzymatic activity of WAG1 and WAG2 affects the root waving response in transgenic Arabidopsis seedlings. (2) To explore the underlying mechanisms for the wavy root phenotype in wag1/wag2 mutants, particularly with regard to the effect of gravity on root growth and the transport of and response to the plant growth hormone auxin.Broader Impacts:This project will provide training opportunities for an undergraduate student, a graduate student, and a postdoctoral associate. The two WAG genes under study encode protein kinases that when mutated confer an unusual growth pattern on seedling roots. Understanding the role of the WAG kinases will provide fundamental insight into the cellular pathways regulating root development that have not yet been defined. Root waving can be viewed as an adaptive response that may enhance the ability of a root to navigate its way around impenetrable objects encountered in the soil. As such, understanding the process of root waving and the genes that regulate it might contribute to other research areas, such as ecological physiology. Moreover, manipulating root waving genetically might improve a young seedlings ability to become established in the field, and thus provide agricultural benefits as well.