Eric H Roalson

Eric H Roalson
Washington State University | WSU · School of Biological Sciences

PhD

About

362
Publications
61,661
Reads
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5,192
Citations
Additional affiliations
August 2001 - present
Washington State University
Position
  • Professor (Full)
Education
July 1995 - July 2000
Claremont Graduate University
Field of study
  • Botany
August 1993 - July 1995
New Mexico State University
Field of study
  • Range Science

Publications

Publications (362)
Article
Full-text available
Background CINNAMYL ALCOHOL DEHYDROGENASE (CAD) catalyzes the NADPH-dependent reduction of cinnamaldehydes into cinnamyl alcohols and is a key enzyme found at the final step of the monolignol pathway. Cinnamyl alcohols and their conjugates are subsequently polymerized in the secondary cell wall to form lignin. CAD genes are typically encoded by mul...
Article
Full-text available
Premise Cleomaceae is an important model clade for studies of evolutionary processes including genome evolution, floral form diversification, and photosynthetic pathway evolution. Diversification and divergence patterns in Cleomaceae remain tangled as research has been restricted by its worldwide distribution, limited genetic sampling and species c...
Preprint
Full-text available
Background CINNAMYL ALCOHOL DEHYDROGENASE (CAD) catalyzes the NADPH-dependent reduction of cinnamaldehydes into cinnamyl alcohols and is a key enzyme found at the final step of the phenylpropanoid pathway. Cinnamyl alcohols and their conjugates are subsequently polymerized in the secondary cell wall to form lignin. CAD genes are typically encoded b...
Article
Full-text available
Model species continue to underpin groundbreaking plant science research. At the same time, the phylogenetic resolution of the land plant Tree of Life continues to improve. The intersection of these two research paths creates a unique opportunity to further extend the usefulness of model species across larger taxonomic groups. Here we promote the u...
Article
Full-text available
Model species continue to underpin groundbreaking plant science research. At the same time, the phylogenetic resolution of the land plant Tree of Life continues to improve. The intersection of these two research paths creates a unique opportunity to further extend the usefulness of model species across larger taxonomic groups. Here we promote the u...
Article
Full-text available
Here, we discover a player in root development. Recovered from a forward‐genetic screen in Brachypodium distachyon, the buzz mutant initiates root hairs but they fail to elongate. In addition, buzz roots grow twice as fast as wild‐type roots. Also, lateral roots show increased sensitivity to nitrate, whereas primary roots are less sensitive to nitr...
Article
Full-text available
Tragopogon (Asteraceae) includes two recently and repeatedly formed allopolyploids, T. mirus and T. miscellus, both of which formed in western North America following the human-mediated introduction of three diploids from Europe: T. dubius, T. porrifolius, and T. pratensis. We recently investigated the genetics of the introduction history to North...
Article
Full-text available
A majority of Turnera species (Passifloraceae) exhibit distyly, a reproductive system involving both self-incompatibility and reciprocal herkogamy. This system differs from self-incompatibility in Passiflora species. The genetic basis of distyly in Turnera is a supergene, restricted to the S-morph, and containing three S-genes. How supergenes and d...
Article
Broˇzov´a et al. (2022) present a study, “Toward finally unraveling the phylogenetic relationships of Juncaceae with respect to another cyperid family, Cyperaceae”, with the premise of revising the phylogenetic re-lationships in Juncaceae and Cyperaceae based on Sanger sequencing of one nuclear rDNA (ITS) and two plastid regions (the gene rbcL and t...
Article
Based on available molecular phylogenetic data, we describe four new Carex sections to accommodate 15 species from Asia, Europe and North America. All the sections form strongly supported monophyletic groups in the most recent phylogenetic hypotheses for the genus and are diagnosable by morphological characters, therefore distinct from closely rela...
Article
A taxonomic revision of the species currently circumscribed in Tarenaya Raf. (Cleomaceae) is presented here. Tarenaya comprises 38 species distributed from Mexico to Argentina (except for Chile) and the West Indies, and with one species disjunct in Central Africa. We present a new combination, 14 lectotypifications, and two neotypifications, and de...
Article
Carex subg. Uncinia (Cyperaceae) constitutes one of six currently recognized Carex subgenera. This subgenus is mainly distributed on the American continent and in the Pacific region, and it is the only subgenus almost entirely absent from the Old World and primarily diversified in the Southern Hemisphere. It includes some of the few Carex species w...
Article
The name Cleome heptaphylla was published by Linnaeus in the second edition of Species plantarum and is still untypified. Analysis of the protologue and the associated pre‐Linnaean names indicated the absence of original material that could serve for lectotypification. A specimen from Miller’s herbarium at BM is designated as its neotype. The neoty...
Article
Eucnide (Loasaceae) consists of about 15 species distributed across Mexico, Guatemala, and the North American Southwest, a geographically complex landscape made up of floristically unique deserts, large mountain ranges, and a large, geographically isolated peninsula. This complex geography is credited for high levels of biodiversity and endemism in...
Article
Full-text available
Cyperaceae (sedges) are the third largest monocot family and are of considerable economic and ecological importance. Sedges represent an ideal model family to study evolutionary biology because of their species richness, global distribution, large discrepancies in lineage diversity, broad range of ecological preferences, and adaptations including m...
Article
This is the first work of a series of thorough studies into the taxonomy and systematics of Carex in South America. Here, we present the systematic placement, biogeographic insights, taxonomic accounts, formal typifications and summarized distributions for the 24 species of Carex subgenus Vignea with androgynous spikes in the continent. We performe...
Article
Full-text available
Carex section Phacocystis (Cyperaceae) is one of the most diverse and taxonomically complex groups of sedges (between 116‐147 spp.) with a worldwide distribution in a wide array of biomes. It has a very complicated taxonomic history, with numerous disagreements among different treatments. We studied the biogeography and niche evolution in a phyloge...
Article
Changes in chromosome number as a result of fission and fusion in holocentric chromosomes have direct and immediate effects on genome structure and recombination rates. These in turn may influence ecology and evolutionary trajectories profoundly. Sedges of the genus Carex (Cyperaceae) comprise ca. 2000 species with holocentric chromosomes that evol...
Article
Morphological characterizations of genera in Cyperaceae tribe Abildgaardieae have been highly problematic and the subject of much debate. Earlier molecular phylogenetic studies based on Sanger sequencing and a limited sampling have indicated that several generic circumscriptions are not monophyletic. Here, we provide the first phylogenetic hypothes...
Article
Full-text available
Phylogenetic studies of Carex L. (Cyperaceae) have consistently demonstrated that most subgenera and sections are para‐ or polyphyletic. Yet taxonomists continue to use subgenera and sections in Carex classification. Why? The Global Carex Group here takes the position that the historical and continued use of subgenera and sections serves to (1) org...
Article
Physostemon (Cleomaceae) includes 15 taxa in 10 species distributed from Mexico and the Caribbean south to Brazil and Paraguay. A full nomenclatural synonymy is presented including 7 lectotypes and 5 new combinations. Mitostylis species are moved to Physostemon based on morphological and molecular phylogenetic evidence. A table of characteristics f...
Article
Full-text available
Subcellular relocalization of proteins determines an organism’s metabolic repertoire and thereby its survival in unique evolutionary niches. In plants, the plastid and its various morphotypes import a large and varied number of nuclear-encoded proteins to orchestrate vital biochemical reactions in a spatiotemporal context. Recent comparative genomi...
Article
We present a taxonomic revision of Dactylaena and Haptocarpum as part of a series of generic revisions and delimitation of Neotropical Cleomaceae. Two new species are described, Dactylaena boliviensis and D. zmarztyae, one new combination is made, D. monandra, four lectotypes are designated in Dactylaena, and a key to all species is presented. This...
Article
The field of systematics is experiencing a new molecular revolution driven by the increased availability of high-throughput sequencing technologies. As these techniques become more affordable, the increased genomic resources have increasingly far-reaching implications for our understanding of the Tree of Life. With c. 2000 species, Carex (Cyperacea...
Article
The family Cleomaceae is represented in the Neotropics by nine native lineages, with some of them currently recognized as distinct genera and others in need of clear delimitation. We present here a new phylogenetic hypothesis for the New World Cleomaceae with a more comprehensive sampling, including samples of 62 species with emphasis on Tarenaya a...
Article
Full-text available
Plastids are morphologically and functionally diverse organelles that are dependent on nuclear-encoded, plastid-targeted proteins for all biochemical and regulatory functions. However, how plastid proteomes vary temporally, spatially, and taxonomically has been historically difficult to analyze at a genome-wide scale using experimental methods. A b...
Article
Full-text available
Background Genetic pathways involved with flower color and shape are thought to play an important role in the development of flowers associated with different pollination syndromes, such as those associated with bee, butterfly, or hummingbird pollination. Because pollination syndromes are complex traits that are orchestrated by multiple genes and p...
Preprint
Full-text available
Plastids are morphologically and functionally diverse organelles that are dependent on nuclear-encoded, plastid-targeted proteins for all biochemical and regulatory functions. However, how plastid proteomes vary temporally, spatially, and taxonomically has been historically difficult to analyze at a genome-wide scale using experimental methods. A b...
Cover Page
Full-text available
Carex (Cyperaceae) is a megadiverse genus which ranks among the five largest angiosperm genera, with about 2000 species. The authors investigated the main biogeographic and lineage diversification history in the genus using a global phylogenetic sampling comprising 66% of accepted species. The study suggests that there may not be just one answer to...
Article
Full-text available
The megadiverse genus Carex (c. 2000 species, Cyperaceae) has a nearly cosmopolitan distribution, displaying an inverted latitudinal richness gradient with higher species diversity in cold‐temperate areas of the Northern Hemisphere. Despite great expansion in our knowledge of the phylogenetic history of the genus and many molecular studies focusing...
Preprint
Full-text available
Background. Genetic pathways involved with flower color and shape are thought to play an important role in the development of floral forms associated with different pollination syndromes, such as those associated with bee, butterfly, or hummingbird pollination. Because pollination syndromes are complex traits that are orchestrated by multiple genes...
Article
A recent study included the genus Nemum into Bulbostylis. The combinations made for Nemum spadiceum and Nemum megastachyum resulted in illegitimate names. Here, the epithet of the homotypic name Scirpus briziformis is used to make nomenclaturally correct combinations for both subspecies of Nemum spadiceum in Bulbostylis. Furthermore, Bulbostylis br...
Article
Full-text available
Tarenaya longicarpa, commonly known as “mussambe,ˆ ” is a new species from South America. Iltis previously recognized it as a subspecies of Cleome spinosa Jacq. but never published the name. Molecular phylogenetic studies have confirmed this taxon as a distinct lineage from T. spinosa. In addition, the results of a revision of Tarenaya, now underwa...
Article
Full-text available
Cyrtandra (Gesneriaceae) is a genus of flowering plants with over 800 species distributed throughout Southeast Asia and the Pacific Islands. On the Hawaiian Islands, 60 named species and over 89 putative hybrids exist, most of which are identified on the basis of morphology. Despite many previous studies on the Hawaiian Cyrtandra lineage, questions...
Article
While the limits of Fimbristylis Vahl (1805: 285) are contentious (Goetghebeur & Coudijzer 1984, Gordon-Gray 1971, Lye 1971, 1973), particularly with regard to the inclusion of Abildgaardia Vahl (1805: 296) within Fimbristylis, all current data support the derivation of Crosslandia W.Fitzg. (1906: 9) from within Fimbristylis (Ghamkhar et al. 2007;...
Article
Phylogenetic hypotheses and morphological characterizations of genera in the Abildgaardieae have suggested that current generic circumscriptions are not monophyletic. We here provide an updated phylogenetic hypothesis of the Abildgaardieae using nrDNA ITS sequences that continues to support the derivation of Nemum from within the Bulbostylis lineag...
Article
Full-text available
Premise of research. Recently diverged taxa may not exhibit strong morphological or DNA sequence differences, making evaluating species boundaries difficult. Finer-scale markers and alternate analytical methods can be used to address species status in these closely related taxa. The dwarf milkweeds have been variably treated as including between on...
Poster
Full-text available
Carex in South America Representative diversity. 201 taxa (about 10% of the whole genus), belonging to the four major clades and 33 sections. At least 2 introduced spp. (+ other 3 spp.?). Multiple origins. Carex has colonized South America several independent times and via different colonization routes. Ecology. Neotropical Carex grow in cold--...
Article
Full-text available
A comprehensive understanding of wheat responses to environmental stress will contribute to the long-term goal of feeding the planet. ALERNATIVE OXIDASE (AOX) genes encode proteins involved in a bypass of the electron transport chain and are also known to be involved in stress tolerance in multiple species. Here, we report the identification and ch...
Data
Accessions numbers of AOX proteins used in this study. RC in the wheat sequences refers to sequences which had high sequence similarity in the reverse complement from which the protein was translated. (XLSX)
Data
Bayesian phylogenetic tree generated for select AOX sequences in order to determine clades. The number of splice variant isomers for a protein are denoted in the dark gray circle when applicable. Colored boxes distinguish the different AOX clades. (PDF)
Data
Select AOX protein sequences used in this study. (PDF)
Data
Nucleotide sequences of AOX from hexaploid and diploid wheat. (PDF)
Data
Alignment of coding sequence of high-confidence hexaploid TaAOX1d-2AL.2.sv1 wheat with the non-expressed coding sequences. (PDF)
Data
Alignment of high-confidence protein sequence of hexaploid TaAOX1d-2AL.2.sv1 protein sequence with the non-expressed protein sequences. (PDF)
Data
Alignment and phylogeny of Waox1a and Waox1c proteins with closest hexaploid wheat relatives used in this study. (PDF)
Data
Expression data of high-confidence TaAOX gene family over multiple developmental stages, biotic and abiotic stress. (XLSX)
Data
Summary of ratios of hydrophobic, polar, and cyclic residues in the hydrophobic domain of wheat AOX proteins. (XLSX)
Data
Alignment of wheat AOX sequences with A. thaliana AOX1a in order to determine classification. Blue indicates presence of Type 1 residues. Red indicates a Type 2 residue. Green indicates residues for monocot Type 1(d). Yellow indicates Type 1(a-c/e). Purple represents amino acid residues that did not match either classification. Black represents res...
Data
Distribution of select TaAOX genes on the respective chromosomes. Diagram not to scale. (PDF)
Data
Regulators and motifs in AOX expression. *Denotes negative regulators of AOX expression. (PDF)
Data
Summary of TaAOX 3-D structures obtained with Phyre2. The model used was c3vvaD. *Models to c3rylB. (PDF)
Data
Summary of diploid AOX 3-D structures (TuAOX and AetAOX) obtained with Phyre2. The model used was c3vvaD. (PDF)
Data
Comparison of active site diiron residues between TbAOX and wheat AOX. *Denotes diploid AOX proteins. (PDF)
Data
Critical TbAOX residues known to cause reduction in activity when mutagenized. The residues that are not highlighted are from Moore et al. 2013; red highlights are residues from Shiba et al. 2013; green highlights are residues from Young et al. 2014 and Crichton et al. 2010. (PDF)
Data
Summary of residues of wheat AOX proteins in the context of AOX residues which have been experimentally determined to have reduced activity when mutagenized. The residues that are not highlighted are from Moore et al. 2013; red highlights are residues from Shiba et al. 2013; green highlights are residues from Young et al. 2014 and Crichton et al. 2...
Data
Summary of wheat AOX residues in the dimerization domain. (PDF)
Data
Comparison of TbAOX internal mitochondrial targeting peptide sequence with TaAOX residues in similar regions. The “reg” proteins were not analyzed due to absence of the amino acids within this region. (PDF)
Data
Conserved AOX motifs in the wheat protein isoforms. The highlighted residues in the motif are critical in the active site diiron center. X indicates presence of motifs. *Indicates diploid wheat isoforms. (PDF)
Data
Sequences of putative wheat AOX regulatory motifs. The nucleotide sequence in bold indicates cases where the motif YTTGNNNNNVAMV has a single nucleotide deviation (site of change underlined) from the MDM motif CTTGNNNNNCAMG. *Denotes negative regulators of AOX expression. (XLSX)
Data
Percent identities between the transcripts of all expressed wheat genes identified in this study. (XLSX)
Data
Putative post-translational modification sites in wheat AOX proteins. (XLSX)
Data
Summary of wheat AOX residues in the hydrophobic cavity. (PDF)
Data
Summary of percent identities within the wheat AOX isoforms. (XLSX)
Data
Wheat protein modeling files generated from Phyre2. (ZIP)
Article
Proposal to conserve Bulbostylis, nom. cons. (Cyperaceae) against an additional name, Nemum
Article
Cleomaceae is a diverse group well-suited to addressing fundamental genomic and evolutionary questions as the sister group to Brassicaceae, facilitating transfer of knowledge from the model Arabidopsis thaliana. Phylogenetic and taxonomic revisions provide a framework for examining the evolution of substantive morphological and physiology diversity...
Article
Systematically quantifying diversity across landscapes is necessary to understand how clade history and ecological heterogeneity contribute to the origin, distribution, and maintenance of biodiversity. Here, we chart the spatial structure of diversity among all species in the sedge family (Cyperaceae) throughout the USA and Canada. We first identif...
Article
Full-text available
Premise of the Study The Neotropical Gesneriaceae is a lineage known for its colorful and diverse flowers, as well as an extensive history of intra‐ and intergeneric hybridization, particularly among Achimenes (the magic flowers) and other members of subtribe Gloxiniinae. Despite numerous studies seeking to elucidate the evolutionary relationships...
Article
Full-text available
Differentiating sieve elements in the phloem of angiosperms produce abundant phloem-specific proteins before their protein synthesis machinery is degraded. These P-proteins initially form dense bodies, which disperse into individual filaments when the sieve element matures. In some cases, however, the dense protein agglomerations remain intact and...
Data
Examples of non-dispersive P-protein bodies (NPBs) that do not respond to wounding of sieve elements by puncturing with micro-pipettes. The CLSM micrographs were taken after a sieve element had been severed with a micro-pipette; arrowheads point to unresponsive NPBs. In all cases, the NPBs are located close to a sieve plate (compare Fig. 5). (A) Th...
Data
Comparison of the putative promoter sequences of the P. trichocarpa genes Potri.001G430200.1 and Potri.017G071000.1, the PtSEOR1 gene. Identical bases appear in blue, different bases and gaps are shown in red. The 100-bp sequence that confers phloem-specificity to the Potri.001G340200.1 promoter (Nguyen et al., 2017) and the corres-ponding sequence...
Data
Comparison of the hypothetical product of gene Potri.017G071000.1 (from Populus trichocarpa v3.0, https://phytozome.jgi.doe.gov/pz/portal.html), PtSEOR1, and AtSEOR1. Positions in which Potri.017G071000.1 and PtSEOR1 differ show in red, residues that are identical in the two are shown in blue. Positions in which AtSEOR1 matches the consensus of the...
Data
TEM micrographs of a sieve element in an Arabidopsis leaf with bundles of SEOR protein filaments in longitudinal and perpendicular section. (A) cross-section of a sieve element with two slime masses consisting of filaments of SEOR protein (arrows). (B) zoom into one of the protein masses, showing longitudinal or oblique sections of the winding SEOR...
Data
Amino acid sequences of the proteins analyzed in Fig. 7.
Article
Full-text available
Tarenaya clade includes 37 species based on phylogenetic relationships and on the stipular spine synapomorphy, however only 10 species thought to belong to the genus have had names established in Tarenaya. Besides the two new species are being described, we present 25 new combinations for the species and refine the typification of 13 species. Ten l...
Article
Full-text available
Two new endemic species of Tarenaya from Brazil are described and illustrated here. These species have been previously recognized, but their names were never validly published. They resemble each other by the armed petioles, corymbiform racemes, small flowers and sessile to subsessile mature capsules with deflexed and persistent sepals. Tarenaya cu...
Article
Full-text available
Cleome, as traditionally defined, is not monophyletic and we here work towards taxonomic revisions for the Cleomaceae where genera reflect morphologically diagnosable monophyletic groups based on previous phylogenetic studies. We provide morphological characters to distinguish eight genera of predominantly African distribution, four of which are ne...
Article
Full-text available
Cleoserrata is a small genus of Cleomaceae that currently includes only two species. We describe here a new species of the genus that is endemic to eastern Brazil, propose two new combinations, review the nomenclature of the species already circumscribed, propose the lectotypification and synonymization associated with those species, and present co...
Article
Three new combinations are proposed in the genus Pyankovia (Chenopodiaceae), of which one at the section level, Pyankovia sect. Brachyphylla comb. nov., and two at the species level, P. affinis comb. nov. and P. roborowskii comb. nov. The FULL-TEXT PDF is available upon request.