Qiuyun Xiang

Overview������������������Collaborative Research: The Relative Roles of Historical Constraint, Local Adaptation, and Time in Shaping Diversity and Function of Co-distributed Plant and Microbial Communities Across an Ancient Biogeographic Disjunction. The mixed deciduous forests in eastern Asia (EA) and eastern North America (ENA) represent relics of once widespread Tertiary mesophytic forests that spanned the Northern Hemisphere; some of these relics are also present in western North America (WNA). As a result of this shared history, EA and ENA share many common floristic elements. Compared to eastern North America, eastern Asia has twice as many plant species, although the two areas are similar in size, geographic latitudes, and climate conditions. Accelerated net allopatric speciation in eastern Asia has been proposed to be a cause of this disparity. Intellectual merit ������������������ The disjunct forests in EA, ENA and WNA provide an excellent natural system to examine the link between biodiversity, within the context of a shared phylogenetic history, to ecological function. We have assembled an excellent international team with complementary expertise for the proposed research. A better understanding of biodiversity and ecosystem functioning requires knowledge from multiple spatial scales, multiple functions, and multiple measures of diversity. We address fundamental questions at the interface of plant and microbial phylogenetics and ecosystem function at multiple scales. For example, if historical constraint and local microevolutionary adaptation shape the phylogenomics of bacterial diazotrophs associated with plants across an ancient biogeographic disjunction, then the phylogenomic relationships between diazotrophs across the disjunction will reflect plant genotypes���������������. The corollary of this hypothesis is that divergence in soil edaphic variables associated with different regions will shape the genomic diversity of these bacterial taxa more so than plant genotype. Broader Impacts������������������ This project will provide modern interdisciplinary post-doc and graduate student training in next-generation sequencing, bioinformatics, large-scale phylogeny reconstruction, complex post-tree analyses including niche modeling and niche diversification, microbial phylogenomics. We will recruit underrepresented students and women. The project will enhance international collaboration with China in research and teaching through this project and reciprocal study abroad courses.

The Cornales - which includes both dogwoods and hydrangea - is the sister lineage to all other asterids and a high quality dogwood genome assembly, together with the forthcoming blueberry genome (Vaccinum corymbosum, Ericaceae, Ericales; http://www.vaccinium.org) will elucidate gene content and genome structure in the ancestors of all asterids and in turn all core eudicots. The strategic position of the Cornales in the angiosperm phylogeny makes the dogwood genome an ideal catalyst for advancing comparative genomics across all angiosperm woody ornamentals. The specific aims of the proposed two-year project include resource development for genome-enabled research in the dogwoods, across the Cornales and among all woody ornamentals: 1. Establish a flowering dogwood (Cornus florida) reference genome assembly and annotation as a foundation for Cornales, asterid and eudicot comparative genomics. We will generate a reference genome sequence and deep transcriptome sequence for Appalachian Spring, the most important cultivar in the horticultural dogwood trade. We will also employ gene capture to assess genetic variation and structure among natural populations. In addition will generate gene-space genome assemblies and transciptomes for Conus kousa and Hydrangea macrophylla. 2. Characterize genes and gene interactions contributing to powdery mildew resistance within flowering dogwood. RNA Seq data generated from infected and uninfected plantlets from resistant (including the Appalachian Spring cultivar and C. kousa) and non-resistant dogwood accessions. 3. Initiate a consortium for genomics research on woody ornamental in the horticultural industry. We will launch a web portal and database for genomics data from/for woody ornamentals including development of a set of conserved orthologous genes (COGs) for eudicot and other angiosperm woody ornamentals. We are already cultivating interest in such a web site and database (see letters) and we will generate further interest by hosting a conference to discuss the state-of-the-art and future of genomics and transcriptomics research in woody ornamentals. Finally we will work with the organizers of the Ornamentals session at the Plant and Animal Genome Conference (PAG) to include a set of presentations and discussions focused on woody ornamentals.

The rapid loss of biodiversity due to human activities has adversely affected ecosystem functions and services around the world, and is a pressing concern to all nations. The importance of better understanding and protecting biodiversity cannot be overstated. The United States and China occupy large areas of North America and eastern Asia at similar temperate latitudes. While both are rich in biodiversity, China harbors more species. Unfortunately, China is also losing its diversity at a higher rate. . The two regions offer many opportunities for comparative studies of biodiversity at all levels and in different dimensions, from the origin, evolution, and distribution of species to the community assembly and ecological functions. Recent increases in research funding from the Chinese government have greatly enhanced the research capacity in China and led to an enhancement of biodiversity studies and training of a younger generation of investigators in China. This provides the right timing for large-scale collaboration between researchers in the US and China in support of innovative and integrative research to address questions about biodiversity that are unique to these geographic regions which can greatly benefit the two countries and other geographic regions. To promote more collaboration on biodiversity research between the US and China, we proposed to hold two 3-day US-China collaborative workshops, one in the US and the other in China, to bring biologists from China and the US together to foster new research partnerships via presentations, discussions, and field visits to research sites. Intellectual merits: The workshops will integrate keynote talks from invited speakers, mini-talks of all participants in topical groups, discussion periods and three field trips. The invited talks will present the state of the science in biodiversity studies, successful examples of collaborations, discuss frontier issues on US-China biodiversity, and innovative approaches and new opportunities for collaborative studies. The mini-talks in topical groups will communicate expertise and interest of the participants and facilitate seeking appropriate partners by participants. The workshops will target leading scientists, including some who have received NSF dimensions awards as invited speakers to share their cutting-edge research, and recruit junior PIs, graduate students, and postdoctoral researchers from diverse fields including evolutionary biology, ecology, systematics, and bioinformatics, as participants from both countries. The group discussion and field trips to the to coastal, Piedmont, and mountain research sites will foster broad interactions seeking new research directions and inspiring new collaboration. Broader Impacts: The workshops will expose the younger generation of biologists to cutting-edge research on biodiversity and will engage participants from across diverse disciplines and institutions. A wiki website will be constructed to post the talks and relevant information. With respect to the North American meeting, through local news report, NESCent and NC Natural History Museum, the workshop event can outreach to local communities and increase the awareness of biodiversity research and education.

Variation in floral display (inflorescence) affects the success of plant reproduction and the yield of a crop by influencing seed number and dispersal/harvest ability. Despite its importance, little progress has been made in understanding how developmental and genetic changes have shaped inflorescence architectures in angiosperm evolution, in part because existing model organisms exhibit little variation in these traits. Species of Dogwood (Cornus L.) are popular ornamental trees in American landscapes due to their spectacular inflorescences often associated with large showy (petaloid) bracts. The genus offers us a unique opportunity to tackle this important problem. Cornus exhibits a wide variation in inflorescence structure, including heads, umbels and compound cymes. A recent breakthrough in our laboratory has resulted in successful regeneration and transformation of a key species of the genus. This new ability along with our recent achievements in phylogenetic reconstruction and nearly completed comparative developmental studies, now provides a timely opportunity to develop a model for investigating the molecular mechanisms shaping inflorescence architectures in a non-model plant lineage. In this proposal, we aim to test four hypotheses to gain insights into the changes in developmental and genetic mechanisms that may have led to alteration of inflorescence forms in dogwoods. Hypotheses: 1. Differences in early development processes lay the ground for divergence of inflorescence architectures in dogwood species. 2. Spatial, temporal, and quantitative variation of expression of conserved key inflorescence regulatory genes are essential for the changes of inflorescence architecture. 3. Expression of petal identity genes in bracts is essential for the origin of the petaloidy of bracts in dogwoods. 4. Spatial, temporal, and quantitative variation of expression of other genes are essential for the modification of inflorescence architecture and origin of petaloid bracts in dogwoods. Objectives: 1. Complete the comparative developmental characterization of four Cornus inflorescence types. 2. Comparative characterization of the expression of conserved key inflorescence regulators and petal identity genes in different inflorescence types. 3. Identify new genes regulating inflorescence development and bract petaloidy in dogwood. 4. Optimize the existing transformation system of Cornus canadensis and test the function of conserved key inflorescence regulatory genes Intellectual merits: This project represents the first study investigating the molecular controls of inflorescence development and evolution using a comparative approach on multiple closely related woody species from a non-model plant lineage. Although the proposal has technical challenges, we have overcome the most significant hurdles and achieving of our objectives would offer novel insights into the genetic basis underlying the evolutionary transitions of floral display strategies, of which the knowledge is presently lacking. The transformation system has tremendous potentials for future research of genetic controls of other plant traits including resistance to fungal diseases and drought, and flowering time divergence among species. By providing a transformation system in a non-model plant, this study will potentially provide a new tool for genetic analysis in other plants that are more closely related to the dogwoods than to the few existing model species. Broader impact: The project will not only enhance our understanding of inflorescence development and evolution in angiosperms, but also hold promise in breeding and bioengineering of dogwoods. Biotechnological improvement of Cornus species in display, disease and drought resistance holds tremendous industrial potential. Thus the results of this project will have broad interests to the scientific, biotechnolgical, and industrial communities. Perfection of the transformation system will immediately benefit the research of identifying genes resistant to the dogwood anthracnose disease that

Fothergilla (Hamamelidacea) is a small genus of uncommon, deciduous shrubs found exclusively in the Southeastern United States. The objectives of this research are to: 1) complete a taxonomic/systematic assessment of Fothergilla including molecular, cytogenetic, morphological, and ecological approaches, and 2) establish a representative germplasm collection for long-term ex situ conservation. These efforts will elucidate the diversity and evolutionary relationships among species within Fothergilla, providing essential data to help guide future conservation efforts. On a broader scale, this study will provide further insights into the phytogeoraphic patterns and history of Southeastern flora.

The objectives of this research are to: 1) establish a comprehensive germplasm collection for long-term ex situ conservation and utilization to be maintained at the Mt. Cuba Center, USDA GRIN system, and shared with public gardens and commercial nurseries, and 2) complete a taxonomic/systematic assessment of Fothergilla including molecular, cytogenetic, morphological, and ecological approaches. This germplasm collection will provide a valuable resource for plant breeders and commercial nurseries for further selection and improvement of Fothergilla. These efforts will also help elucidate the diversity and evolutionary relationships among species within Fothergilla, providing essential data to help guide future conservation efforts. On a broader scale, this study will provide further insights into the phytogeoraphic patterns and history of Southeastern flora.

Habitat loss, fragmentation, and altered disturbance regimes are among the greatest threats to biodiversity and species conservation. These situations can be ameliorated with appropriate management, but only when there is sufficient information on which to base this management. Unfortunately, it is often necessary to implement management strategies with an incomplete understanding of the demography and natural history of the target species. We propose population and community studies to provide this information for five species (Amorpha georgiana var. georgiana, Astragalus michauxii, Lilium pyrophilum, Pyxidanthera brevifolia, Stylisma pickeringii) selected for intensive study at Ft. Bragg. For L. pyrophilum, we also propose a population genetics study to quantify genetic structure, outcrossing rates, and level of genetic differentiation in relation to its sister species.

Variation in inflorescence architectures of flowering plants affects the success of plant reproduction and the yield of a crop by influencing seed number and dispersal/harvest ability. During angiosperm evolution, innovation of inflorescences has repeatedly occurred in different lineages. Despite the importance of inflorescence innovation in angiosperm evolution and crop production, we know little about the genetic basis of inflorescence development and the molecular changes that have altered inflorescence constructions in different plant lineages. This is partly due to the complexity of inflorescence development pathway and partly due to the lack of comparative studies between closely related species from an evolutionary perspective. Identifying genes responsible for heritable phenotypic differences between species represents the central challenge in evolutionary developmental genetics (EDG), a subdiscipline in biology that is among the most rapidly growing. It requires the use of diverse research strategies and a combination of technical advances from multidisciplines, from phylogenetics, developmental biology to molecular genetics and molecular biology. Previous EDG studies in plants often lacked data from one or more of these areas due to the lack of expertise in the multidisciplines of a single investigator, which hampered a clear understanding of the causal molecular changes of morphological evolution. The proposed study will combine the strength of three young faculty members with expertise in the following areas: plant developmental genetics (Franks), molecular biology, tissue culture, and transformation (Xie), and evolutionary biology, molecular systematics and evolution of dogwoods (Xiang), to unravel what changes in what genes have contributed to the condensation and petaloid bracts of inflorescences in different dogwood species. The dogwood genus Cornus L., containing our state flower C. florida, is a common element in eastern US forests, critically important to forest ecology and horticulture. The genus is an excellent model for EDG study of inflorescence due to the striking differences of inflorescence architectures displayed among species. Identification of genetic changes leading to the condensation and origin of petal-like bracts of inflorescences in Cornus will not only increase our understanding of inflorescence development and evolution at the molecular level in flowering plants, but also hold a promise in bioengineering of dogwoods to produce plants with novel inflorescence forms for ornamental purposes.

PROJECT SUMMARY The order Cornales (the dogwoods and close relatives), widely considered the first-branching lineage within the most diverse group of flowering plants, the asterid clade, are critically important to understanding the early evolution and diversification of asterids. The order, as currently defined, is a morphologically heterogeneous group with an excellent fossil record from the late Cretaceous and Tertiary, and provides an exceptional system to study macroevolution. The purpose of this project is to complete the reconstruction of a robust phylogeny for Cornales to allow for definitive tests of hypotheses surrounding: 1) key morphological transformations, 2) the biogeographic origin and radiation of early cornalean lineages, and 3) patterns of molecular diversification associated with morphological differentiation and speciation. Intellectual Merit: The proposed research provides a model study for integrating molecular, morphological, and palaeontological evidence to reconstruct phylogeny and test evolutionary hypotheses. Several important evolutionary questions within Cornales will be addressed, including the origin and times of diversification for a major lineage of flowering plants, and characterization of major events in the history of the radiation -- including morphological differentiation, molecular evolution in multiple nuclear and organellar loci, and intercontinental migration. The study will also help to resolve several outstanding systematic problems in Cornales, including the monophyly of - and relationships within- Cornaceae, the phylogenetic placement of enigmatic genera from Africa (Hydrostachys, Curtisia, and Grubbia), and the position of several recently discovered fossil genera (e.g., Amerisinia, Hironoia, Hartzielia). Broader Impact: In addition to its phylogenetic significance as the oldest asterid lineage, Cornales is also critically important to forest ecology, horticulture (e.g., many dogwood species) and medicine (e.g., Camptotheca acuminata contains a natural anti-cancer drug, camptothecin, considered second to taxol, in its importance to humans). A robust, predictive, phylogenetic hypothesis including these economically important plants provides a basis guiding other biological and horticultural studies in these plants. The proposed research provides training for a graduate student, a post-doc, and several undergraduate students, and adds key information to the ?Tree of Life? for flowering plants. The gene sequences from eight regions will contribute significantly to the existing molecular data pool of angiosperms, facilitating comparative evolutionary studies at higher taxonomic levels.

I propose to conduct metapopulation and plant community studies in support of research on appropriate management for five rare plant species that occur on Fort Bragg Military Reservation.