Plant responses to environmental cues: Novel roles for microtubule plus-end binding proteins.

植物是固着的，当条件变得不利时，不能改变位置。相反，它们通过改变自己的生长来回应环境刺激。植物生长反应涉及细胞水平的变化，进而影响植物的大小和形状以及叶、茎、根和花的位置。微管在许多相关的细胞过程中起着关键作用。尽管它们发挥着核心作用，但人们对信息如何通过微管传递以改变生长知之甚少。我的研究计划的长期目标是确定信息是如何传递到微管和从微管传递出来的，以影响植物生长和发育的变化。为了实现这一目标，我们正在研究+TIPS，这是一组庞大而多样的微管相关蛋白，与快速增长的微管的“+”端结合。+TIPS是可以在植物的微管和其他亚细胞组件之间传递信息的分子的主要候选者。特别是，末端结合1(EB1)家族的成员已经成为动物和真菌细胞中的核心调节+末端，因为它们结合并招募许多其他蛋白质到微管末端。我们发现EB1调节植物的发育过程；这些蛋白质抑制根对机械信号的反应，影响亚细胞结构，并在根毛中发挥作用。这些发现与EB1在植物细胞中的微管和其他成分之间传递信息的假设是一致的。这项研究旨在阐明EB1在根毛和根对机械信号的反应中的功能，并发现参与微管信息传递的新蛋白。根对机械信号的反应在植物适合性和影响作物生产力方面起着关键作用，因为它们决定了根系如何有效地穿透土壤寻找水分和养分。根毛对植物的生存和健康也是至关重要的，因为它们提供了吸收水分和养分的表面。从这些研究中获得的知识将影响旨在提高作物生产力的战略的制定。

Plants are sessile and cannot change locations when conditions become unfavorable. Instead they respond to environmental stimuli by modifying their growth. Plant growth responses involve changes at the cellular level that, in turn, affect the size and shape of the plant and the placement of leaves, stems, roots, and flowers. Microtubules play key roles in many of the relevant cellular processes. Despite their central role, little is known about how information is relayed through microtubules to alter growth. The long term goal of my research program is to determine how information is transmitted to and from microtubules to effect changes in plant growth and development. Towards this goal, we are studying +TIPs, a large and diverse group of microtubule associated proteins that bind to the rapidly growing "plus" ends of microtubules. +TIPS are prime candidates for molecules that could relay information between microtubules and other subcellular components in plants. In particular, members of the END BINDING 1 (EB1) family have emerged as core regulatory +TIPs in animal and fungal cells, since they bind and recruit many other proteins to microtubule ends. We discovered that EB1 regulates developmental processes in plants; the proteins suppress root responses to mechanical cues, affect subcellular architecture, and have roles in root hairs. These discoveries are consistent with the hypothesis that EB1 relays information between microtubules and other components in plant cells. The research proposed here aims to elucidate the functions of EB1 in root hairs and in roots responding to mechanical cues and to discover novel proteins involved in the relay of information to and from microtubules. Root responses to mechanical cues play key roles in plant fitness and affect productivity in crop plants because they determine how effectively the root system can penetrate through the soil in search of water and nutrients. Root hairs are also paramount for survival and fitness in plants, since they provide the surfaces across which water and nutrients are absorbed. The knowledge that is gained from these studies will impact the development of strategies aimed at improving productivity in crop plants.