Regulation of Root and Nodule Meristems By The LATD Gene and the Hormone Abscisic Acid in the Model Legume, Medicago Truncatula

与动物的情况不同，植物的大部分发育并不发生在胚胎中，而是在种子发芽后，并持续到植物的一生。所有新的生长最初都来自于茎尖和根尖的一个特殊区域，称为分生组织。 随着主根的发育，植物根系以两种方式扩大：第一，通过生长更长，第二，通过形成分支根，称为侧根，其从主根生长。此外，植物的根不是随机形成的，而是对环境和内在因素的差异做出反应，如化学信使或激素，协调植物的反应。本研究探讨了植物激素脱落酸（阿坝）对主根和侧根分生组织生长的影响。豆科植物的根形成了一个额外的结构，一个共生根瘤，这是与有益细菌根瘤菌相互作用的结果。这些结节的进化起源尚不清楚，但它们似乎与侧根共享一些特征。这个项目将研究M的作用。在豆科植物侧根和根瘤中，都发现了蒺藜LATD基因在阿坝反应中的作用。该项目的目的是克隆和测序LATD基因，并确定其在豆科植物根和根瘤的阿坝反应中的作用。这些发现将有助于人们更好地了解植物对共生根瘤的控制、豆类中的激素信号以及根瘤形成与根系生长的关系。更广泛的影响：豆类是世界粮食供应的重要组成部分。该项目将研究豆科植物的根系形成与其他植物的根系形成有何不同，并可能导致农业实践的改进。它还将有助于培训博士后，研究生和本科生研究人员，以及继续与当地小学开展外联活动，包括基于植物的根系生长科学实验和基于实验的预测发展。

Unlike the situation seen in animals, much of plant development does not occur in the embryo, but rather, after the seed germinates and continues for the lifetime of the plant. All new growth initially is derived from a special region at the tip of the shoot and root called the meristem. Following elaboration of the primary root, plant root systems enlarge in two ways: first, by growing longer, and second, by forming branch roots, called lateral roots, which grow from the main root. Furthermore, plant roots do not form randomly, but are responsive to differences in the environment and intrinsic factors such as the chemical messengers, or hormones, that coordinate the plant's response. This study examines the effect of a plant hormone, Abscisic Acid (ABA), on the growth of meristems of both primary and lateral roots. Legume roots form an additional structure, a symbiotic root nodule, that results from an interaction with a beneficial bacterium, Rhizobium. The evolutionary origin of these nodules is unknown, but they appear to share some features with lateral roots. This project will examine the role of the M. truncatula LATD gene in the ABA response both in legume lateral roots and in nodules. The aims of the project are to clone and sequence the LATD gene and to determine its role in the ABA response of legume roots and nodules. These findings will lead to increased understanding of plant control of symbiotic nodules, hormone signaling in legumes, and the relationship of nodule formation to growth of the root system.Broader Impacts: Legumes are an important part of the world's food supply. This project will examine how root system formation in legumes differs from that of other plants and may lead to improved agricultural practices. It will also contribute to the training of a postdoc, graduate student, and undergraduate researchers, as well as continuing outreach activities with a local elementary school, involving plant-based science experiments on root growth and the development of predictions based upon their experiments.