Collaborative Research: Understanding the effects of ploidal level on responses to global change in plants

多倍体，或全基因组复制，发生在生物体所有染色体都有一个或多个额外拷贝的时候。这种现象在植物中特别普遍，最近的估计表明15-30%的植物是多倍体。多倍体物种包括大量具有经济和农业用途的作物和其他植物（如棉花、小麦、马铃薯、大豆）。多倍体影响植物广泛的遗传和生理特征，包括与水分利用和光合作用有关的生理性状。多倍体植物可以比二倍体植物更健壮，有更广泛的生态位，更广泛的地理分布，以及更强的入侵新栖息地的能力，所有这些都是由新的基因组合或基因表达模式驱动的，这些基因组合或基因表达模式可以在许多性状上产生广泛的变化。该项目将研究多倍体如何影响植物对温度升高和可用水减少（即干旱）的反应能力。将测量一组不同倍体水平（多倍体数量）的蕨类植物的基因表达和对干旱和温度的生理反应。了解倍体水平是否以及如何影响美国东部森林的这些重要组成部分，将有助于更好地预测温度和水的可用性变化将如何影响自然生态系统中的群落结构，并将为保护工作提供信息。有关耐旱性和温度升高的基因表达变化的信息有可能帮助作物育种计划。该项目的一个组成部分是培养博士后助理、研究生和本科生。这个项目的重点是在美国东部的森林中发现的一组蕨类植物。这是一个自然发生的植物系统，多倍体普遍存在，其成员在生态系统中具有重要的生态意义。在干旱和温度处理的多因子试验中，对6种毛蕨属植物的配子体进行了培养，其中包括多倍体及其亲本类群的两对配子体。将收集有关生殖和生理生态学的数据，以确定温度和水供应的变化如何影响人口统计学和配子体的孢子体招募以及从环境胁迫中恢复的能力。RNASeq将用于生成基因表达谱，以评估不同温度处理下非胁迫、脱水和复水配子体之间的差异。数据分析将使用新方法进行每细胞、每生物量和每转录组基础的差异基因表达分析。结果将为量化实验处理对不同倍性水平生物体（包括作物植物和非植物系统）基因表达的影响提供信息。这项工作的结果将提高对倍体水平如何影响物种对环境变化的反应的理解。关于如何有效和引人入胜地教授植物生命周期的研讨会将在美国植物学会的年度植物学会议上举行，并将使用数据驱动的方法，结合研究结果。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Polyploidy, or whole genome duplication, occurs when an organism has one or more extra copies of all its chromosomes. This phenomenon is particularly common in plants, and recent estimates suggest that 15-30% of plants are polyploid. Polyploid species include a vast number of crop and other plants with economic and agricultural uses (e.g., cotton, wheat, potato, soybean). Polyploidy is known to influence a wide range of genetic and physiological features of plants, including physiological traits related to water use and photosynthesis. Polyploid plants can be more vigorous than diploids, have broader ecological niches, wider geographic distributions, and increased ability to invade new habitats, all driven by novel genetic combinations or gene expression patterns that can produce extensive changes in many traits. This project will investigate how polyploidy affects plants' ability to respond to increases in temperature and decreases in available water (i.e., drought). Gene expression and physiological responses to drought and temperature will be measured for a set of fern species at different ploidal levels (amounts of polyploidy). Knowing whether and how ploidal level impacts these important components of the eastern forests of the United States will allow better prediction of how changes in temperature and water availability will influence community structure in natural ecosystems and will inform conservation efforts. Information on gene expression changes involved in tolerance of drought and increased temperatures has potential to assist crop breeding programs. An integral part of the project is to train postdoctoral associates, graduate students, and undergraduate students.This project focuses on a set of fern species found in forests throughout the eastern United States. This is a naturally occurring plant system where polyploidy is prevalent, and whose members are ecologically important in the ecosystems where they occur. Gametophytes of six Dryopteris species, including two pairs of a polyploid and its parent taxa, will be grown in a multifactorial experiment with drought and temperature treatments. Data will be collected on reproductive and physiological ecology to determine how changes in temperature and water availability influence demographics and sporophyte recruitment from gametophytes as well as ability to recover from environmental stress. RNASeq will be used to generate gene expression profiles to evaluate differences between unstressed, dehydrated, and rehydrated gametophytes in different temperature treatments. Data will be analyzed using new methods for performing differential gene expression analyses on per-cell, per-biomass, and per-transcriptome bases. Results will be informative in quantifying the effects of experimental treatment on gene expression in organisms at different ploidy levels, including in crop plants and non-plant systems. The results of this work will improve the understanding of how ploidal level may influence species' responses to environmental change. A workshop on how to effectively and engagingly teach plant life cycles will be held at the Botanical Society of America's annual Botany conference, and will use a data-driven approach that incorporates results from the research.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.