The Mechanisms of Adaptive Shifts in Allocation among Growth, Reproduction, and Defense

生命的基本规则之一是，有机体适应不同的环境条件是有权衡的。这些权衡阻止了单个生物物种主宰每一个栖息地和气候条件。然而，虽然这些权衡是普遍存在的，但对导致这些权衡的遗传和生理机制的了解很少。确定植物中潜在的权衡机制将为进化如何运作提供知识，并为作物物种的改良提供指导。这项研究的重点是了解为什么黄猴花(Mimulus Guttatus)在适应加利福尼亚州高度不同的沿海和内陆气候条件时会出现权衡。这一地区的沿海栖息地在夏季的几个月里被凉爽的海洋雾淹没，这使得植物能够全年存活，但也意味着有更多的食草动物吃它们。相比之下，内陆栖息地在夏天非常炎热和干燥。猴子花适应这些不同气候的方式涉及到强烈的权衡，这项研究将建立潜在的机制。这项研究将涉及对研究生、博士后和少数族裔本科生的指导。此外，该奖项将支持研究人员与密歇根州立大学教育学院之间正在进行的合作，为密歇根州弗林特的低收入中学教室创建一个基于探究的学习模块，重点是猴花系统。将开发一个网站，将这一教育模块分发到全国各地的教室。是否将资源分配给繁殖、生长和/或防御是所有植物物种面临的根本两难境地。这项研究将集中在沿海和内陆斑节对虾在快速繁殖、长期生长和食草动物抗性方面的进化差异。内陆人口主要将资源分配给快速生长和繁殖，以躲避季节性干旱，而对草食动物的抗性投资很少。由于更高的食草动物压力和更长的生长季节，沿海人口已经进化成更多地投资于营养生长和对草食动物的抗性。研究的目的1将评估与沿海和内陆种群的适应性分化有关的两个基因座(DIV1和DIV2)如何影响赤霉素(GA)生长激素和防御激素茉莉酸(JA)的前体和生物活性形式的浓度。这两个基因座对防御性苯丙素苷(PPG)的诱导和组成水平的影响将被评估。目的2将阐明在快速繁殖、长期营养生长和草食动物抗性之间分配的适应性变化的分子机制。将进行赤霉素生物合成和信号基因的功能分子研究，以评估它们在权衡进化中的作用。目标3将在实地使用激素应用，以评估这些激素在气候条件下资源分配的适应性变化中的作用。植物将在操纵性的相互移植实验中生长，以评估GA和JA途径在沿海和内陆生境的开花时间、生物量和适合性方面的作用。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

One of the fundamental rules of life is that there are trade-offs associated with the adaptation of organisms to different environmental conditions. These trade-offs prevent individual biological species from dominating every habitat and climatic condition. However, while these trade-offs are prevalent, the understanding of what genetic and physiological mechanisms cause them is poor. Identifying the mechanisms underlying trade-offs in plants will provide knowledge of how evolution works and guidance for the improvement of crop species. This research focuses on understanding why trade-offs occur for adaptations of the yellow monkeyflower (Mimulus guttatus) to highly divergent coastal and inland climatic conditions in California. The coastal habitats of this region are inundated by a cool ocean fog during the summer months, which allows plants to survive year-round, but also means that there are more herbivores which eat them. In contrast, inland habitats are very hot and dry in the summer. The ways in which monkeyflowers have adapted to these different climates involves strong trade-offs, for which this research will establish the underlying mechanisms. The research will involve the mentorship of graduate students, postdocs, and underrepresented minority undergraduate students. Further, this award will support an ongoing partnership between investigators and the Michigan State University College of Education to create an inquiry-based learning module, focused on the monkeyflower system, for low-income middle school classrooms in Flint, MI. A website will be developed for distribution of this education module to classrooms nationwide. Whether to allocate resources to reproduction, growth, and/or defense is a fundamental dilemma faced by all plant species. This research will focus on the evolutionary divergence in allocation to rapid reproduction, long-term growth, and herbivore resistance between coastal and inland M. guttatus. Inland populations allocate resources primarily to rapid growth and reproduction to escape from seasonal drought while investing little in herbivore resistance. Coastal populations have evolved to invest more in vegetative growth and herbivore resistance as a result of higher herbivore pressure and a longer growing season. Aim 1 of the research will evaluate how two previously identified loci (DIV1 and DIV2) involved in adaptive divergence between coastal and inland populations contribute to concentrations of precursor and bioactive forms of the Gibberellin (GA) growth hormone and the defense hormone Jasmonic Acid (JA). The effects of the two loci on induced and constitutive levels of defensive phenylpropanoid glycosides (PPGs) will be evaluated. Aim 2 will elucidate the molecular mechanisms underlying adaptive variation in allocation among rapid reproduction, long-term vegetative growth, and herbivore resistance. Functional molecular studies of gibberellin biosynthesis and signaling genes will be conducted to evaluate their role in the evolution of trade-offs. Aim 3 will use hormone applications in the field to evaluate the role of those hormones in adaptive shifts in resource allocation across climatic conditions. Plants will be grown in manipulative reciprocal transplant experiments to assess the roles of GA and JA pathways on flowering time, biomass, and fitness in coastal and inland habitats.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.