Collaborative Research: Dimensions: Desiccation and Diversity in Dryland Mosses

合作研究：维度：旱地苔藓的干燥和多样性

• 批准号: 1638955
• 负责人: Kirsten Coe
• 金额: $ 13.01万
• 依托单位: St Mary's College of Maryland
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-01-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1638955&HistoricalAwards=false
• 关键词: Collaborative; Research; Dimensions; Desiccation; Diversity

Mosses are the second most diverse group of land plants and they play important ecological roles in terrestrial ecosystems. Since an early divergence from other land plants some 450 million years ago, mosses took a different path than vascular plants to solving the challenges to survival and reproduction posed by terrestrial environments. One important trait that is well developed in mosses is the capability of drying without dying, known as desiccation tolerance (DT). This critical trait allows many mosses to survive and reproduce even in drylands, and may be the key to their survival in the face of current, rapid climate change. Syntrichia is a large and diverse genus of mosses occurring worldwide and generally in dryland habitats. Despite their dominance in certain communities such as biological soil crusts, surprisingly little is known about the drivers of biodiversity in this clade. This interdisciplinary project integrates research from genomic, organismal, population, and community levels of organization in order to build a robust understanding of past and present dimensions of biodiversity in Syntrichia. The overall goals are to understand the evolutionary and ecological mechanisms that have produced and maintained functional diversity at these different levels of organization, and promote training, teaching, and learning via: (1) formal education through field and laboratory research; (2) informal education involving a classroom module, short-film series featuring mosses and biocrusts transitioning from desiccation dormancy, a citizen science program "Citizens of the Crust," and a series of free public workshops.The research will examine tradeoffs between asexual and sexual reproduction, and between phenotypic plasticity and canalization into specialized genotypes, by examining the mechanisms underlying traits (including phenotypic plasticity) that drive diversification, reproduction, habitat selection, and physiological trait evolution in environments with varying degrees of water stress. Specific methods to be employed include: (1) sequencing the full genomes of S. caninervis and S. ruralis; (2) using next generation sequencing (NGS) to develop genotypic markers for population-level genetic variation studies, signature transcriptome tools for phenotypic analyses (related to ecophysiological and ecosystem investigations), and multiple single-copy genes for phylogenetic analysis; (3) transcriptomics experiments comparing different development stages and sexes of both species in response to desiccation stress and reproductive state; (3) ecophysiological experiments on multiple populations of S. caninervis and S. ruralis, and all 15 species of N. American Syntrichia, to assess phenotypic plasticity in the key trait of DT; (5) population genetic studies of S. caninervis and S. ruralis in different environments; (6) building a robust phylogeny for Syntrichia and using it to understand evolutionary trends and correlations among the traits under study, as well as to produce a refined classification; (7) examining the role of genetic, functional, and phylogenetic diversity in the resilience to climate change of biocrust communities that are dominated by Syntrichia (with co-occurring mosses, lichens, and cyanobacteria) in field and greenhouse experiments.

藓类植物是陆地植物中第二大类群，在陆地生态系统中发挥着重要的生态作用。自从大约4.5亿年前从其他陆地植物中分化出来以来，苔藓采取了与维管植物不同的道路来解决陆地环境对生存和繁殖带来的挑战。苔藓中发育良好的一个重要特征是干燥而不死亡的能力，称为脱水耐受性（DT）。这一关键特性使许多苔藓即使在旱地也能生存和繁殖，可能是它们在当前快速气候变化中生存的关键。Syntrichia是一个大而多样的藓类植物属，分布于世界各地，通常生长在干旱地区。尽管它们在生物土壤结皮等某些群落中占据主导地位，但令人惊讶的是，人们对这一分支中生物多样性的驱动因素知之甚少。这个跨学科的项目整合了从基因组，有机体，人口和组织的社区层面的研究，以建立一个强大的理解过去和现在的Syntrichia生物多样性的尺寸。总体目标是了解在这些不同组织层次上产生和维持功能多样性的进化和生态机制，并通过以下方式促进培训、教学和学习：（1）通过实地和实验室研究进行正规教育;（2）非正式教育，包括课堂单元、以苔藓和生物壳从干燥休眠状态过渡为主题的短片系列，一个公民科学项目“地壳公民”，以及一系列免费的公共研讨会。这项研究将通过研究特征的潜在机制，研究无性生殖和有性生殖之间的权衡，以及表型可塑性和特殊基因型之间的权衡。（包括表型可塑性），在不同程度的水分胁迫的环境中驱动多样化、繁殖、栖息地选择和生理性状进化。具体方法包括：（1）对S. caninervis和S. ruralis;（2）利用下一代测序技术（NGS）开发用于群体水平遗传变异研究的基因型标记，用于表型分析的签名转录组工具，（3）转录组学实验，比较两个物种不同发育阶段和性别对干旱胁迫和生殖状态的反应;（3）多种群的生理生态试验。caninervis和S. ruralis和N.美国合毛藻的群体遗传学研究，以评估DT关键性状的表型可塑性; caninervis和S.不同环境下的ruralis;（6）建立一个强有力的Syntrichia的系统发生学，并利用它来了解所研究的性状之间的进化趋势和相关性，以及产生一个精确的分类;（7）研究遗传、功能和系统发育多样性在以合毛纲为主的生物结壳群落对气候变化的适应性中的作用（与共同发生的苔藓，地衣，和蓝藻）在田间和温室实验。