Collaborative Research - Phenotypic and genetic analysis of the thigmomorphogenetic developmental response in Arabidopsis

作者：Massimo Pigliucci1,2, Randy Small1， and Janet braam1作者：Massimo Pigliucci1,2, Randy Small1， and Janet braam1作者：Massimo Pigliucci1,2, Randy Small1， and Janet braam1田纳西州大学诺克斯维勒州立大学-斯石布鲁克州立大学莱斯大学自然（遗传）和养育（环境）的相对重要性一直是科学家，哲学家和一般人的好奇心和讨论的中心。在过去二十年左右的时间里，对自然-养育或技术上称为基因型-环境相互作用的科学研究已经成为一个突出的研究领域。科学家们正在寻求更好地了解生物体究竟是如何感知和应对不断变化的环境条件和施加在它们身上的新压力的。特别是，科学家们想知道哪些基因参与了这些复杂的反应，以及它们如何在不同的生物体中随着时间的推移而进化。该研究项目旨在研究植物对胁迫的一种特殊反应：thigmomorphogenesis，或对机械接触的反应。植物经历了各种各样的机械刺激，从风和雪施加的刺激，到邻近植物引起的接触（这表明其他植物的密度，从而表明对水和光等共同资源的竞争程度），再到准备攻击植物并将其作为食物的昆虫引起的接触。因此，触觉反应是对环境条件变化的一种常见反应，植物已经进化出了适当应对风、雪、昆虫等挑战的方法。这些反应包括改变开花时间表（以减少与其他植物的竞争），植物茎变粗（以更好地抵御昆虫攻击或风或雪的压力），以及改变树枝的产生（再次减少竞争的影响）。然而，究竟是什么基因使这一切成为可能，以及这些基因如何在植物发育和生命周期的更广泛背景下起作用，仍有许多有待发现。研究人员将进行几项实验，以阐明一种常见杂草鼠耳草（芥菜科的一员）的触摸反应的遗传基础，这种杂草在过去几十年里被广泛用于遗传和生态研究。该植物的不同遗传品系将暴露在不同的环境条件下（越来越强的风），并测量其对该植物形态和生活史的一系列关键特征的响应。同时，将测量一系列已经被怀疑影响这些植物对机械刺激的反应能力的基因的特征，以测试这些基因中有多少可能是活跃的，以及在遗传分析水平上的变化如何准确地对应于在生态现实环境下生长时整个植物所表现出的可观察到的变化。这个项目的结果将帮助生态学家、进化生物学家和分子生物学家更好地理解基因、环境和生物体外观和行为方式之间的复杂关系。这是全世界许多实验室正在追求的一个总体目标，这项研究将使科学界在这一领域取得进展，因为这里选择的特定植物和环境变化使他们能够对基因及其影响进行精确的定量分析。同样重要的是要注意，对机械刺激的反应被认为是一种方便地改变某些植物特性（例如，茎粗）以能够更好地抵御昆虫攻击的方法。这对人类有商业价值的植物有明显的实际应用。

Collaborative research: Phenotypic and Genetic Analyses of Thigmomorphogenetic Developmental Response in ArabidopsisBy Massimo Pigliucci1,2, Randy Small1, and Janet Braam31University of Tennessee, Knoxville2SUNY-Stony Brook3Rice University The relative importance of nature (genetics) and nurture (environment) has always been at the center of much curiosity and discussion among scientists, philosophers, and people in general. In the last two decades or so, the scientific study of nature-nurture or, as it is technically known, genotype-environment interactions, has become a prominent field of inquiry. Scientists are seeking a better understanding of how exactly organisms perceive and react to changing environmental conditions and to new stresses imposed upon them. In particular, scientists want to know what genes are involved in these complex responses, and how they evolve through time in different organisms. This research project aims at studying a particular kind of response to stress in plants: thigmomorphogenesis, or the reaction to mechanical contact. Plants experience all sorts of mechanical stimulation, from those exerted by wind and snow, to the contact elicited by neighboring plants (which indicates the density of other plants, and hence the degree of competition for common resources such as water and light), to that induced by insects poised to attack the plant, using it as food. Touch response, then, is a common reaction to changing environmental conditions, and plants have evolved ways of dealing appropriately with the challenges imposed by wind, snow, insects, etc. These responses include an alteration of the flowering schedule (to minimize competition with other plants), a thickening of the plant stems (to better withstand insect attacks or pressure from wind or snow), and an alteration in the production of branches (again to minimize the effects of competition). Much remains to be uncovered, however, on exactly what genes make all of this possible, and how such genes work within the broader context of plant development and life cycles. The investigators will conduct several experiments to elucidate the genetic basis of touch response in a common weed, the mouse-ear cress (a member of the mustard family), which has been extensively used for genetic and ecological research over the past decades. Different genetic strains of this plant will be exposed to varying environmental conditions (increasingly strong wind), and their response will be measured for a series of crucial characteristics representative of the morphology and life history of this plant. At the same time, characteristics will be measured of a series of genes already suspected to affect the ability of these plants to respond to mechanical stimulation, in order to test hypotheses about how many of these genes may be active, and how exactly variation at the genetic level of analysis corresponds to the observable variation exhibited by the whole plant when grown under ecologically realistic settings. Results from this project will help ecologists, evolutionary biologists, and molecular biologists better understand the complex relationship between genes, environments, and the way living organisms look and behave. This is a general goal being pursued by many laboratories throughout the world, and this research will allow the scientific community to make progress in this area because of the ease with which the particular plant and environmental change selected here lend themselves to precise quantitative analyses of genes and their effects. It is also important to note that response to mechanical stimulation has been implicated as one way to conveniently alter certain plant characteristics (e.g., stem thickness) to be able to better withstand attacks from insects. This has obvious practical applications for plants of commercial interest to humans.