Myong-Suk Cho, Seon-Hee Kim, Philippe Danton, Seung-Chul Kim, Tod F. Stuessy, Daniel J. Crawford
Premise
Island plants have long interested biologists because of their distinctive morphological features and their isolation on small land areas in vast oceans. Studies of insular endemics may include identifying their ancestors, tracing their dispersal to islands, and describing their evolution on islands, including characters adaptive to island life. Thamnoseris is a monospecific genus endemic to the Desventuradas Islands, Chile. Its origins and relationships are unresolved, given the challenges of getting to the islands and accessing plants there.
Methods
Sequences from ITS of nrDNA and the complete chloroplast genome were employed to resolve phylogenetic relationships of Thamnoseris.
Results
Phylogenetic analyses of nuclear and chloroplast sequences showed Thamnoseris nested within or sister to Dendroseris, the largest endemic genus in the Juan Fernández Islands.
Conclusions
Thamnoseris evolved from a common ancestor of all or most species of Dendroseris prior to the diversification of Dendroseris in the Juan Fernández archipelago. The ancestor of Thamnoseris dispersed to the Desventuradas archipelago, which consists of the islands San Ambrosio and San Félix, within the past 3 Ma (the age of San Ambrosio). This is the only known example of possible plant dispersal between the Juan Fernández and Desventuradas Islands. We also mention two less likely biogeographic scenarios for the origin of Thamnoseris, which has features not seen in Dendroseris: small capitula with yellow florets; style branches barely divergent; and basally swollen subtending involucral bracts, all features associated with selfing and reduced dispersal. Goats and rabbits (now removed) reduced T. lacerata, once very abundant on the Desventuradas Islands, to several plants, making it of extreme conservation concern and worthy of further study.
前言长期以来，岛屿植物因其独特的形态特征以及在广阔海洋中与世隔绝的狭小陆地区域而引起生物学家的兴趣。对岛屿特有植物的研究包括确定它们的祖先、追踪它们向岛屿的传播以及描述它们在岛屿上的进化，包括适应岛屿生活的特征。Thamnoseris是智利德斯文图拉达斯群岛（Desventuradas Islands）特有的单种属。方法利用 nrDNA 的 ITS 序列和完整的叶绿体基因组来解析 Thamnoseris 的系统发育关系。结果核序列和叶绿体序列的系统进化分析表明，Thamnoseris与胡安-费尔南德斯群岛最大的特有属Dendroseris嵌套或姊妹。Thamnoseris的祖先在过去3Ma（San Ambrosio时代）内分散到由San Ambrosio岛和San Félix岛组成的Desventuradas群岛。这是胡安-费尔南德斯群岛和德斯文图拉达斯群岛之间可能存在植物分散的唯一已知例子。我们还提到了两种不太可能出现的关于Thamnoseris起源的生物地理学假设，它具有在Dendroseris中未见的特征：小头状花序具黄色小花；花柱分枝几乎不分叉；总苞片基部膨大，所有这些特征都与自交和减少散播有关。山羊和野兔（现已被移走）使德文图拉达斯群岛上曾经非常茂盛的 T. lacerata 减少到只有几株，使其成为极受保护的植物，值得进一步研究。
{"title":"Inter-archipelago dispersal, anagenetic evolution, and the origin of a rare, enigmatic plant genus on a remote oceanic archipelago","authors":"Myong-Suk Cho, Seon-Hee Kim, Philippe Danton, Seung-Chul Kim, Tod F. Stuessy, Daniel J. Crawford","doi":"10.1002/ajb2.16403","DOIUrl":"10.1002/ajb2.16403","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Island plants have long interested biologists because of their distinctive morphological features and their isolation on small land areas in vast oceans. Studies of insular endemics may include identifying their ancestors, tracing their dispersal to islands, and describing their evolution on islands, including characters adaptive to island life. <i>Thamnoseris</i> is a monospecific genus endemic to the Desventuradas Islands, Chile. Its origins and relationships are unresolved, given the challenges of getting to the islands and accessing plants there.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Sequences from ITS of nrDNA and the complete chloroplast genome were employed to resolve phylogenetic relationships of <i>Thamnoseris</i>.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Phylogenetic analyses of nuclear and chloroplast sequences showed <i>Thamnoseris</i> nested within or sister to <i>Dendroseris</i>, the largest endemic genus in the Juan Fernández Islands.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p><i>Thamnoseris</i> evolved from a common ancestor of all or most species of <i>Dendroseris</i> prior to the diversification of <i>Dendroseris</i> in the Juan Fernández archipelago. The ancestor of <i>Thamnoseris</i> dispersed to the Desventuradas archipelago, which consists of the islands San Ambrosio and San Félix, within the past 3 Ma (the age of San Ambrosio). This is the only known example of possible plant dispersal between the Juan Fernández and Desventuradas Islands. We also mention two less likely biogeographic scenarios for the origin of <i>Thamnoseris</i>, which has features not seen in <i>Dendroseris</i>: small capitula with yellow florets; style branches barely divergent; and basally swollen subtending involucral bracts, all features associated with selfing and reduced dispersal. Goats and rabbits (now removed) reduced <i>T. lacerata</i>, once very abundant on the Desventuradas Islands, to several plants, making it of extreme conservation concern and worthy of further study.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142185285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A key goal of evolutionary biologists is to understand how and why genetic variation is partitioned within species. In the yellow monkeyflower, Mimulus guttatus (syn. Erythranthe guttata), coastal perennial populations constitute a single genetically and morphologically differentiated ecotype compared to inland M. guttatus populations. While the coastal ecotype's distinctiveness has now been well documented, there is also environmental variation across the ecotype's range that could drive more continuous differentiation among its component populations.
Methods
Based on previous observations of a potential cline within this ecotype, we quantified plant height, among other traits, across coastal perennial accessions from 74 populations in a greenhouse common garden experiment. To evaluate potential drivers of the relationship between trait variation and latitude, we regressed height against multiple climatic factors, including temperature, precipitation, and coastal wind speeds. We also accounted for exposure to the open ocean in all analyses.
Results
Multiple traits were correlated with latitude of origin, but none more than plant height. Height was negatively correlated with latitude, and plants directly exposed to the open ocean were shorter than those protected from coastal winds. Further analyses revealed that height was correlated with climatic factors (precipitation, temperature, and wind speeds) that were autocorrelated with latitude. We hypothesize that one or more of these climatic factors drove the evolution of latitudinal clinal variation within the coastal ecotype.
Conclusions
Overall, our study illustrates the complexity of how the distribution of environmental variation can simultaneously drive the evolution of both distinct ecotypes and continuous clines within those ecotypes.
{"title":"Ocean exposure and latitude drive multiple clines within the coastal perennial ecotype of the yellow monkeyflower, Mimulus guttatus","authors":"Thomas Zambiasi, David B. Lowry","doi":"10.1002/ajb2.16402","DOIUrl":"10.1002/ajb2.16402","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>A key goal of evolutionary biologists is to understand how and why genetic variation is partitioned within species. In the yellow monkeyflower, <i>Mimulus guttatus</i> (syn. <i>Erythranthe guttata</i>), coastal perennial populations constitute a single genetically and morphologically differentiated ecotype compared to inland <i>M. guttatus</i> populations. While the coastal ecotype's distinctiveness has now been well documented, there is also environmental variation across the ecotype's range that could drive more continuous differentiation among its component populations.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Based on previous observations of a potential cline within this ecotype, we quantified plant height, among other traits, across coastal perennial accessions from 74 populations in a greenhouse common garden experiment. To evaluate potential drivers of the relationship between trait variation and latitude, we regressed height against multiple climatic factors, including temperature, precipitation, and coastal wind speeds. We also accounted for exposure to the open ocean in all analyses.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Multiple traits were correlated with latitude of origin, but none more than plant height. Height was negatively correlated with latitude, and plants directly exposed to the open ocean were shorter than those protected from coastal winds. Further analyses revealed that height was correlated with climatic factors (precipitation, temperature, and wind speeds) that were autocorrelated with latitude. We hypothesize that one or more of these climatic factors drove the evolution of latitudinal clinal variation within the coastal ecotype.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Overall, our study illustrates the complexity of how the distribution of environmental variation can simultaneously drive the evolution of both distinct ecotypes <i>and</i> continuous clines within those ecotypes.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.16402","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142144960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ernesto C. Rodríguez-Ramírez, Frank Arroyo, Fressia N. Ames-Martínez, Agustina Rosa Andrés-Hernández
Premise
Understanding the responses of functional traits in tree species to climate variability is essential for predicting the future of tropical montane cloud forest (TMCF) tree species, especially in Andean montane environments where fog pockets act as moisture traps.
Methods
We studied the distribution of Magnolia gentryi, measured its spatial arrangement, identified local hotspots, and evaluated the extent to which climate-related factors are associated with its distribution. We then analyzed the variation in 13 functional traits of M. gentryi and the relationship with climate.
Results
Andean TMCF climatic factors constrain M. gentryi spatial distribution with significant patches or gaps that are associated with high precipitation and mean minimum temperature. The functional traits of M. gentryi are limited by the Andean TMCF climatic factors, resulting in reduced within-species variation in traits associated with water deficit.
Conclusions
The association between functional traits and climate oscillation is crucial for understanding the growth conditions of relict-endemic species and is essential for conservation efforts. Forest trait diversity and species composition change because of fluctuations in hydraulic safety-efficiency gradients.
{"title":"Tracking climate vulnerability across spatial distribution and functional traits in Magnolia gentryi in the Peruvian tropical montane cloud forest","authors":"Ernesto C. Rodríguez-Ramírez, Frank Arroyo, Fressia N. Ames-Martínez, Agustina Rosa Andrés-Hernández","doi":"10.1002/ajb2.16400","DOIUrl":"10.1002/ajb2.16400","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Understanding the responses of functional traits in tree species to climate variability is essential for predicting the future of tropical montane cloud forest (TMCF) tree species, especially in Andean montane environments where fog pockets act as moisture traps.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We studied the distribution of <i>Magnolia gentryi</i>, measured its spatial arrangement, identified local hotspots, and evaluated the extent to which climate-related factors are associated with its distribution. We then analyzed the variation in 13 functional traits of <i>M</i>. <i>gentryi</i> and the relationship with climate.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Andean TMCF climatic factors constrain <i>M. gentryi</i> spatial distribution with significant patches or gaps that are associated with high precipitation and mean minimum temperature. The functional traits of <i>M</i>. <i>gentryi</i> are limited by the Andean TMCF climatic factors, resulting in reduced within-species variation in traits associated with water deficit.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The association between functional traits and climate oscillation is crucial for understanding the growth conditions of relict-endemic species and is essential for conservation efforts. Forest trait diversity and species composition change because of fluctuations in hydraulic safety-efficiency gradients.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.16400","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142139038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Theresa C. Saunders, Isabel Larridon, William J. Baker, Russell L. Barrett, Félix Forest, Elaine Françoso, Olivier Maurin, Saba Rokni, Eric H. Roalson
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 coverage, and a lack of definitive fossil calibration points.
Methods
We used target sequence capture and the Angiosperms353 probe set to perform a phylogenetic study of Cleomaceae. We estimated divergence times and biogeographic analyses to explore the origin and diversification of the family. Seed morphology across extant taxa was documented with multifocal image-stacking techniques and morphological characters were extracted, analyzed, and compared to fossil records.
Results
We recovered a well-supported and resolved phylogenetic tree of Cleomaceae generic relationships that includes 236 (~86%) species. We identified 11 principal clades and confidently placed Cleomella as sister to the rest of the family. Our analyses suggested that Cleomaceae and Brassicaceae diverged ~56 mya, and Cleomaceae began to diversify ~53 mya in the Palearctic and Africa. Multiple transatlantic disjunct distributions were identified. Seeds were imaged from 218 (~80%) species in the family and compared to all known fossil species.
Conclusions
Our results represent the most comprehensive phylogenetic study of Cleomaceae to date. We identified transatlantic disjunctions and proposed explanations for these patterns, most likely either long-distance dispersals or contractions in latitudinal distributions caused by climate change over geological timescales. We found that seed morphology varied considerably but mostly mirrored generic relationships.
{"title":"Tangled webs and spider-flowers: Phylogenomics, biogeography, and seed morphology inform the evolutionary history of Cleomaceae","authors":"Theresa C. Saunders, Isabel Larridon, William J. Baker, Russell L. Barrett, Félix Forest, Elaine Françoso, Olivier Maurin, Saba Rokni, Eric H. Roalson","doi":"10.1002/ajb2.16399","DOIUrl":"10.1002/ajb2.16399","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>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 coverage, and a lack of definitive fossil calibration points.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We used target sequence capture and the Angiosperms353 probe set to perform a phylogenetic study of Cleomaceae. We estimated divergence times and biogeographic analyses to explore the origin and diversification of the family. Seed morphology across extant taxa was documented with multifocal image-stacking techniques and morphological characters were extracted, analyzed, and compared to fossil records.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>We recovered a well-supported and resolved phylogenetic tree of Cleomaceae generic relationships that includes 236 (~86%) species. We identified 11 principal clades and confidently placed <i>Cleomella</i> as sister to the rest of the family. Our analyses suggested that Cleomaceae and Brassicaceae diverged ~56 mya, and Cleomaceae began to diversify ~53 mya in the Palearctic and Africa. Multiple transatlantic disjunct distributions were identified. Seeds were imaged from 218 (~80%) species in the family and compared to all known fossil species.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our results represent the most comprehensive phylogenetic study of Cleomaceae to date. We identified transatlantic disjunctions and proposed explanations for these patterns, most likely either long-distance dispersals or contractions in latitudinal distributions caused by climate change over geological timescales. We found that seed morphology varied considerably but mostly mirrored generic relationships.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.16399","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142103575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Cenozoic Macquarie Harbour Formation (MHF) hosts one of the oldest and southernmost post-Cretaceous fossil plant assemblages in Australia. Coinciding with the Early Eocene Climatic Optimum (EECO) and predating the breakup of Australia from Antarctica, it offers critical data to study the diversity and extent of the Austral Polar Forest Biome, and the floristic divergence between Australasia and South America resulting from the Gondwana breakup.
Methods
The micromorphology and macromorphology of new fossil plant compressions from the MHF were described and systematically analyzed. Previously published non-flowering plant records were reviewed and revised. Macrofossil abundance data were provided. The flora was compared with other early Paleogene assemblages from across the Southern Hemisphere.
Results
Twelve species of non-flowering plants were identified from the macrofossil record. Conifers include Araucariaceae (Araucaria macrophylla, A. readiae, A. timkarikensis sp. nov., and Araucarioides linearis), Podocarpaceae (Acmopyle glabra, Dacrycarpus mucronatus, Podocarpus paralungatikensis sp. nov., and Retrophyllum sp.), and Cupressaceae (Libocedrus microformis). Dacrycarpus linifolius was designated a junior synonym of D. mucronatus. Further components include a cycad (Bowenia johnsonii, Zamiaceae), a pteridosperm (Komlopteris cenozoicus, Umkomasiaceae), and a fern (Lygodium dinmorphyllum, Schizaeaceae).
Conclusions
The fossil assemblage represents a mixed near-polar forest with a high diversity of conifers. The morphology and preservation of several species indicate adaptations to life at high latitudes. The coexistence of large- and small-leaved conifers implies complex, possibly open forest structures. Comparisons with contemporaneous assemblages from Argentina support a circumpolar biome during the EECO, reaching from southern Australia across Antarctica to southern South America.
{"title":"The non-flowering plants of a near-polar forest in East Gondwana, Tasmania, Australia, during the Early Eocene Climatic Optimum","authors":"Miriam A. Slodownik","doi":"10.1002/ajb2.16398","DOIUrl":"10.1002/ajb2.16398","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>The Cenozoic Macquarie Harbour Formation (MHF) hosts one of the oldest and southernmost post-Cretaceous fossil plant assemblages in Australia. Coinciding with the Early Eocene Climatic Optimum (EECO) and predating the breakup of Australia from Antarctica, it offers critical data to study the diversity and extent of the Austral Polar Forest Biome, and the floristic divergence between Australasia and South America resulting from the Gondwana breakup.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>The micromorphology and macromorphology of new fossil plant compressions from the MHF were described and systematically analyzed. Previously published non-flowering plant records were reviewed and revised. Macrofossil abundance data were provided. The flora was compared with other early Paleogene assemblages from across the Southern Hemisphere.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Twelve species of non-flowering plants were identified from the macrofossil record. Conifers include Araucariaceae (<i>Araucaria macrophylla</i>, <i>A. readiae</i>, <i>A. timkarikensis</i> sp. nov., and <i>Araucarioides linearis</i>), Podocarpaceae (<i>Acmopyle glabra</i>, <i>Dacrycarpus mucronatus</i>, <i>Podocarpus paralungatikensis</i> sp. nov., and <i>Retrophyllum</i> sp.), and Cupressaceae (<i>Libocedrus microformis</i>). <i>Dacrycarpus linifolius</i> was designated a junior synonym of <i>D. mucronatus</i>. Further components include a cycad (<i>Bowenia johnsonii</i>, Zamiaceae), a pteridosperm (<i>Komlopteris cenozoicus</i>, Umkomasiaceae), and a fern (<i>Lygodium dinmorphyllum</i>, Schizaeaceae).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The fossil assemblage represents a mixed near-polar forest with a high diversity of conifers. The morphology and preservation of several species indicate adaptations to life at high latitudes. The coexistence of large- and small-leaved conifers implies complex, possibly open forest structures. Comparisons with contemporaneous assemblages from Argentina support a circumpolar biome during the EECO, reaching from southern Australia across Antarctica to southern South America.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.16398","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142078894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jade Stryker, Elizabeth White, Erika Díaz-Almeyda, Brian Sidoti, Brad Oberle
Premise: Up to half of tropical forest plant species grow on other plants. Lacking access to soils, vascular epiphytes have unique adaptations for mineral nutrition. Among the most distinctive is the tank growth form of certain large bromeliads, which absorb nutrients that are cycled by complex microbial communities in water trapped among their overlapping leaf bases. However, tanks form only after years of growth by juvenile plants, which must acquire nutrients differently. Understanding how nutrient dynamics change during tank bromeliad development can provide key insights into the role of microorganisms in the maintenance of tropical forest biodiversity.
Methods: We evaluated variations in plant morphology, growth, foliar nitrogen physiology, and phyllosphere bacterial communities along a size gradient spanning the transition to tank formation in the threatened species Tillandsia utriculata.
Results: Sequential morphological and growth phases coincided with the transition to tank formation when the longest leaf on plants was between 14 and 19 cm. Before this point, foliar ammonium concentrations were very high, but after, leaf segments absorbed significantly more nitrate. Leaf-surface bacterial communities tracked ontogenetic changes in plant morphology and nitrogen metabolism, with less-diverse communities in tankless plants distinguished by a high proportion of taxa implicated in ureolysis, nitrogen fixation, and methanotrophy, whereas nitrate reduction characterized communities on individuals that could form a tank.
Conclusions: Coupled changes in plant morphology, physiology, and microbiome function facilitate the transition between alternative nutritional modes in tank bromeliads. Comparing bromeliads across life stages and habitats may illuminate how nitrogen-use varies across scales.
{"title":"Tank formation transforms nitrogen metabolism of an epiphytic bromeliad and its phyllosphere bacteria.","authors":"Jade Stryker, Elizabeth White, Erika Díaz-Almeyda, Brian Sidoti, Brad Oberle","doi":"10.1002/ajb2.16396","DOIUrl":"https://doi.org/10.1002/ajb2.16396","url":null,"abstract":"<p><strong>Premise: </strong>Up to half of tropical forest plant species grow on other plants. Lacking access to soils, vascular epiphytes have unique adaptations for mineral nutrition. Among the most distinctive is the tank growth form of certain large bromeliads, which absorb nutrients that are cycled by complex microbial communities in water trapped among their overlapping leaf bases. However, tanks form only after years of growth by juvenile plants, which must acquire nutrients differently. Understanding how nutrient dynamics change during tank bromeliad development can provide key insights into the role of microorganisms in the maintenance of tropical forest biodiversity.</p><p><strong>Methods: </strong>We evaluated variations in plant morphology, growth, foliar nitrogen physiology, and phyllosphere bacterial communities along a size gradient spanning the transition to tank formation in the threatened species Tillandsia utriculata.</p><p><strong>Results: </strong>Sequential morphological and growth phases coincided with the transition to tank formation when the longest leaf on plants was between 14 and 19 cm. Before this point, foliar ammonium concentrations were very high, but after, leaf segments absorbed significantly more nitrate. Leaf-surface bacterial communities tracked ontogenetic changes in plant morphology and nitrogen metabolism, with less-diverse communities in tankless plants distinguished by a high proportion of taxa implicated in ureolysis, nitrogen fixation, and methanotrophy, whereas nitrate reduction characterized communities on individuals that could form a tank.</p><p><strong>Conclusions: </strong>Coupled changes in plant morphology, physiology, and microbiome function facilitate the transition between alternative nutritional modes in tank bromeliads. Comparing bromeliads across life stages and habitats may illuminate how nitrogen-use varies across scales.</p>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142071827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Michael S. Barker, Yuannian Jiao, Kelsey L. Glennon
All flowering plants are now recognized as diploidized paleopolyploids (Jiao et al., 2011; One Thousand Plant Transcriptomes Initiative, 2019), and polyploid species comprise approximately 30% of contemporary plant species (Wood et al., 2009; Barker et al., 2016a). A major implication of these discoveries is that, to appreciate the evolution of plant diversity, we need to understand the fundamental biology of polyploids and diploidization. This need is broadly recognized by our community as there is a continued, growing interest in polyploidy as a research topic. Over the past 25 years, the sequencing and analysis of plant genomes has revolutionized our understanding of the importance of polyploid speciation to the evolution of land plants.
{"title":"Doubling down on polyploid discoveries: Global advances in genomics and ecological impacts of polyploidy","authors":"Michael S. Barker, Yuannian Jiao, Kelsey L. Glennon","doi":"10.1002/ajb2.16395","DOIUrl":"10.1002/ajb2.16395","url":null,"abstract":"<p>All flowering plants are now recognized as diploidized paleopolyploids (Jiao et al., 2011; One Thousand Plant Transcriptomes Initiative, 2019), and polyploid species comprise approximately 30% of contemporary plant species (Wood et al., 2009; Barker et al., 2016a). A major implication of these discoveries is that, to appreciate the evolution of plant diversity, we need to understand the fundamental biology of polyploids and diploidization. This need is broadly recognized by our community as there is a continued, growing interest in polyploidy as a research topic. Over the past 25 years, the sequencing and analysis of plant genomes has revolutionized our understanding of the importance of polyploid speciation to the evolution of land plants.</p>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.16395","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142008135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Houyin Deng, Rong Huang, Ruping Wei, Runhui Wang, Shu Yan, Yousry A. El-Kassaby, Yuhan Sun, Yun Li, Huiquan Zheng
Premise
The impact of inbreeding on biological processes is well documented in individuals with severe inbreeding depression. However, the biological processes influencing the adaptive growth of normal selfed individuals are unknown. Here, we aimed to investigate how inbreeding affects gene expression for adaptive growth of normal selfed seedlings from a self-fertilizing parent in Chinese fir (Cunninghamia lanceolata).
Methods
Using RNA-seq data from above- and underground tissues of abnormal and normal selfed seedlings, we analyzed GO biological processes network. We also sequenced small RNAs in the aboveground tissues and measured the copy number variations (CNV) of the hub genes.
Results
Phenotypic fitness analysis revealed that the normal seedlings were better adapted than their abnormal counterparts. Upregulated differentially expressed genes (DEGs) were associated with development processes, and downregulated DEGs were mainly enriched in fundamental metabolism and stress response. Results of mRNA-miRNA parallel sequencing revealed that upregulated target genes were predominantly associated with development, highlighting their crucial role in phosphorylation in signal transduction networks. We also discovered a moderate correlation (0.1328 < R2 < 0.6257) between CNV and gene expression levels for three hub genes (TMKL1, GT2, and RHY1A).
Conclusions
We uncovered the key biological processes underpinning the growth of normal selfed seedlings and established the relationship between CNV and the expression levels of hub genes in selfed seedlings. Understanding the candidate genes involved in the growth of selfed seedlings will help us comprehend the genetic mechanisms behind inbreeding depression in the evolutionary biology of plants.
{"title":"Inbreeding in Chinese fir: Insights into the adaptive growth traits of selfed progeny from mRNA, miRNA, and copy number variation","authors":"Houyin Deng, Rong Huang, Ruping Wei, Runhui Wang, Shu Yan, Yousry A. El-Kassaby, Yuhan Sun, Yun Li, Huiquan Zheng","doi":"10.1002/ajb2.16393","DOIUrl":"10.1002/ajb2.16393","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>The impact of inbreeding on biological processes is well documented in individuals with severe inbreeding depression. However, the biological processes influencing the adaptive growth of normal selfed individuals are unknown. Here, we aimed to investigate how inbreeding affects gene expression for adaptive growth of normal selfed seedlings from a self-fertilizing parent in Chinese fir (<i>Cunninghamia lanceolata</i>).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Using RNA-seq data from above- and underground tissues of abnormal and normal selfed seedlings, we analyzed GO biological processes network. We also sequenced small RNAs in the aboveground tissues and measured the copy number variations (CNV) of the hub genes.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Phenotypic fitness analysis revealed that the normal seedlings were better adapted than their abnormal counterparts. Upregulated differentially expressed genes (DEGs) were associated with development processes, and downregulated DEGs were mainly enriched in fundamental metabolism and stress response. Results of mRNA-miRNA parallel sequencing revealed that upregulated target genes were predominantly associated with development, highlighting their crucial role in phosphorylation in signal transduction networks. We also discovered a moderate correlation (0.1328 < <i>R</i><sup>2</sup> < 0.6257) between CNV and gene expression levels for three hub genes (<i>TMKL1</i>, <i>GT2</i>, and <i>RHY1A</i>).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>We uncovered the key biological processes underpinning the growth of normal selfed seedlings and established the relationship between CNV and the expression levels of hub genes in selfed seedlings. Understanding the candidate genes involved in the growth of selfed seedlings will help us comprehend the genetic mechanisms behind inbreeding depression in the evolutionary biology of plants.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142008136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jessie A. Pelosi, Bethany A. Zumwalde, Weston L. Testo, Emily H. Kim, J. Gordon Burleigh, Emily B. Sessa
Premise
Reticulate evolution, often accompanied by polyploidy, is prevalent in plants, and particularly in the ferns. Resolving the resulting non-bifurcating histories remains a major challenge for plant phylogenetics. Here, we present a phylogenomic investigation into the complex evolutionary history of the vining ferns, Lygodium (Lygodiaceae, Schizaeales).
Methods
Using a targeted enrichment approach with the GoFlag 408 flagellate land plant probe set, we generated large nuclear and plastid sequence datasets for nearly all taxa in the genus and constructed the most comprehensive phylogeny of the family to date using concatenated maximum likelihood and coalescence approaches. We integrated this phylogeny with cytological and spore data to explore karyotype evolution and generate hypotheses about the origins of putative polyploids and hybrids.
Results
Our data and analyses support the origins of several putative allopolyploids (e.g., L. cubense, L. heterodoxum) and hybrids (e.g., L. ×fayae) and also highlight the potential prevalence of autopolyploidy in this clade (e.g., L. articulatum, L. flexuosum, and L. longifolium).
Conclusions
Our robust phylogenetic framework provides valuable insights into dynamic reticulate evolution in this clade and demonstrates the utility of target-capture data for resolving these complex relationships.
{"title":"All tangled up: Unraveling phylogenetics and reticulate evolution in the vining ferns, Lygodium (Schizaeales)","authors":"Jessie A. Pelosi, Bethany A. Zumwalde, Weston L. Testo, Emily H. Kim, J. Gordon Burleigh, Emily B. Sessa","doi":"10.1002/ajb2.16389","DOIUrl":"10.1002/ajb2.16389","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Reticulate evolution, often accompanied by polyploidy, is prevalent in plants, and particularly in the ferns. Resolving the resulting non-bifurcating histories remains a major challenge for plant phylogenetics. Here, we present a phylogenomic investigation into the complex evolutionary history of the vining ferns, <i>Lygodium</i> (Lygodiaceae, Schizaeales).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Using a targeted enrichment approach with the <i>GoFlag 408</i> flagellate land plant probe set, we generated large nuclear and plastid sequence datasets for nearly all taxa in the genus and constructed the most comprehensive phylogeny of the family to date using concatenated maximum likelihood and coalescence approaches. We integrated this phylogeny with cytological and spore data to explore karyotype evolution and generate hypotheses about the origins of putative polyploids and hybrids.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Our data and analyses support the origins of several putative allopolyploids (e.g., <i>L. cubense, L. heterodoxum</i>) and hybrids (e.g., <i>L.</i> ×<i>fayae</i>) and also highlight the potential prevalence of autopolyploidy in this clade (e.g., <i>L. articulatum, L. flexuosum</i>, and <i>L. longifolium</i>).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our robust phylogenetic framework provides valuable insights into dynamic reticulate evolution in this clade and demonstrates the utility of target-capture data for resolving these complex relationships.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.16389","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142003416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jean H. Burns, Katharine L. Stuble, Juliana S. Medeiros
<p>Combining ecological questions with evolutionary context generates novel insight into both ecology and evolution. However, our ability to draw broad inferences can be limited by the taxonomic diversity present within and across species at a site. Public gardens (including botanical gardens and arboreta) may focus solely on aesthetics in developing their gardens, but some public gardens include scientific inquiry and conservation at the core of their missions (Hohn, <span>2022</span>). These scientifically oriented public gardens follow community standards of excellence (Hohn, <span>2022</span>) to provide unique access to curated plant collections specifically designed to gather high levels of biodiversity, both among and within species, at a single geographic location. These research-grade collections include long-lived species cared for over many decades. Such public gardens have long histories of conducting and supporting research harnessing the power inherent in these diverse collections, including explorations of systematics, ecophysiology, and ecology. By bringing together species, as well as individuals within species, from across broad spatial ranges into a single site, these collections offer living repositories of diversity ripe for scientific exploration as de facto common gardens (Dosmann, <span>2006</span>; Dosmann and Groover, <span>2012</span>; Primack et al., <span>2021</span>).</p><p>The biodiversity curated by public gardens can offer a unique context for addressing questions at the intersection of ecology and evolution, such as <i>how does phylogenetic history shape plant trait evolution?</i> For example, Mason et al. (<span>2020</span>) explored seasonal trait shifts across 25 species of <i>Cornus</i> at the Arnold Arboretum (Boston, Massachusetts, USA) to ask whether there are tradeoffs among ecophysiological traits and how those traits correlate with home environment. They measured traits such as leaf chlorophyll content and leaf water content. By measuring plant traits across many species, they answered questions about ecophysiological trait evolution within a comparative phylogenetic framework. By doing so in a common garden, they controlled for much of the environmental variation that would otherwise confound a study across so many species, that occur in different habitats and locations in their native ranges. Their new analytical approaches simultaneously incorporated phylogenetic methods and within-species variation over time (Mason et al., <span>2020</span>). With this comparison, they demonstrated that traditional phylogenetic comparative approaches, which analyze a single trait mean per species, might come to erroneous conclusions about trait–trait correlations. For example, leaf nitrogen mostly declines through the growing season in <i>Cornus</i>, leading to changes in sign of correlations across the season (Mason et al., <span>2020</span>).</p><p>Plant–soil interactions are another growing area of research that
{"title":"Living collections: Biodiversity cultivated at public gardens has the power to connect ecological questions and evolutionary context","authors":"Jean H. Burns, Katharine L. Stuble, Juliana S. Medeiros","doi":"10.1002/ajb2.16394","DOIUrl":"10.1002/ajb2.16394","url":null,"abstract":"<p>Combining ecological questions with evolutionary context generates novel insight into both ecology and evolution. However, our ability to draw broad inferences can be limited by the taxonomic diversity present within and across species at a site. Public gardens (including botanical gardens and arboreta) may focus solely on aesthetics in developing their gardens, but some public gardens include scientific inquiry and conservation at the core of their missions (Hohn, <span>2022</span>). These scientifically oriented public gardens follow community standards of excellence (Hohn, <span>2022</span>) to provide unique access to curated plant collections specifically designed to gather high levels of biodiversity, both among and within species, at a single geographic location. These research-grade collections include long-lived species cared for over many decades. Such public gardens have long histories of conducting and supporting research harnessing the power inherent in these diverse collections, including explorations of systematics, ecophysiology, and ecology. By bringing together species, as well as individuals within species, from across broad spatial ranges into a single site, these collections offer living repositories of diversity ripe for scientific exploration as de facto common gardens (Dosmann, <span>2006</span>; Dosmann and Groover, <span>2012</span>; Primack et al., <span>2021</span>).</p><p>The biodiversity curated by public gardens can offer a unique context for addressing questions at the intersection of ecology and evolution, such as <i>how does phylogenetic history shape plant trait evolution?</i> For example, Mason et al. (<span>2020</span>) explored seasonal trait shifts across 25 species of <i>Cornus</i> at the Arnold Arboretum (Boston, Massachusetts, USA) to ask whether there are tradeoffs among ecophysiological traits and how those traits correlate with home environment. They measured traits such as leaf chlorophyll content and leaf water content. By measuring plant traits across many species, they answered questions about ecophysiological trait evolution within a comparative phylogenetic framework. By doing so in a common garden, they controlled for much of the environmental variation that would otherwise confound a study across so many species, that occur in different habitats and locations in their native ranges. Their new analytical approaches simultaneously incorporated phylogenetic methods and within-species variation over time (Mason et al., <span>2020</span>). With this comparison, they demonstrated that traditional phylogenetic comparative approaches, which analyze a single trait mean per species, might come to erroneous conclusions about trait–trait correlations. For example, leaf nitrogen mostly declines through the growing season in <i>Cornus</i>, leading to changes in sign of correlations across the season (Mason et al., <span>2020</span>).</p><p>Plant–soil interactions are another growing area of research that ","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.16394","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142003417","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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