NASA/NSF Collaborative Research: Analysis of Stimulus- Response Systems in Roots of Arabidopsis

9416015 Evans在玉米根的向性反应中有一个特殊的细胞区，具有突出的作用。 这一区域是“有丝分裂后等直径生长”（PIG）区，位于分生组织和伸长区（EZ）之间。 重力刺激诱导该区域的快速膜电位变化，与EZ不同，生长素刺激这些细胞的伸长。 先前的工作已经表明，重力诱导的不对称增强PIG区的伸长不是由生长素介导的。 本项目拟确定拟南芥中是否存在类似的PIG区，并测试它是否在拟南芥的向地性和向触性中起作用。 这项工作将1）使用一种新的生长分析系统进行局部生长速率分析，2）将曲率分析系统与局部组织方向的反馈控制结合联合收割机，以研究重力感应区的限制，3）研究电信号在协调根向重力和向触反应中的作用。 这项工作可能会提供新的详细信息的性质，植物感知环境信号的方式，这种感知导致协调的生长反应。 ***

9416015 Evans There is a specialized zone of cells with a prominent role in the tropistic responses of maize roots. This zone the "postmitotic isodiametric growth" (PIG) zone is located between the meristem and the elongation zone (EZ). Gravistimulation induces rapid membrane potential changes in this zone and, unlike the EZ, auxin stimulates elongation in these cells. Prior work has shown that gravity-induced asymmetric enhancement of elongation in the PIG zone is not mediated by auxin. This project proposes to determine whether a comparable PIG zone exists in Arabidopsis and to test whether it plays a role in root gravitropism and thigmotropism in Arabidopsis. The work will 1) use a new growth analysis system for localized growth rate analyses, 2) combine a curvature analysis system with feedback control of localized tissue orientation in order to investigate the limits of the zone of gravity sensing, and 3) investigate the role of electrical signaling in the coordination of root gravitropic and thigmotropic responses. This work may provide new detailed information on the nature of plant sensing of environmental signals and the manner in which this sensing leads to a coordinated growth response. ***