American Journal of Botany最新文献

{"title":"Phosphoproteomic analysis of distylous Turnera subulata identifies pathways related to endoreduplication that correlate with reciprocal herkogamy","authors":"Paige M. Henning,&nbsp;Benjamin B. Minkoff,&nbsp;Michael R. Sussman","doi":"10.1002/ajb2.16438","DOIUrl":"10.1002/ajb2.16438","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>A multi-omic approach was used to explore proteins and networks hypothetically important for establishing filament dimorphisms in heterostylous <i>Turnera subulata</i> (Sm.) as an exploratory method to identify genes for future empirical research.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Mass spectrometry (MS) was used to identify differentially expressed proteins and differentially phosphorylated peptides in the developing filaments between the L- and S-morphs. RNAseq was used to generate a co-expression network of the developing filaments, MS data were mapped to the co-expression network to identify hypothetical relationships between the <i>S</i>-gene responsible for filament dimorphisms and differentially expressed proteins.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Mapping all MS identified proteins to a co-expression network of the S-morph's developing filaments identified several clusters containing SPH1 and other differentially expressed or phosphorylated proteins. Co-expression analysis clustered CDKG2, a protein that induces endoreduplication, and SPH1—suggesting a shared biological function. MS analysis suggests that the protein is present and phosphorylated only in the S-morph, and thus active only in the S-morph. A series of CDKG2 regulators, including ATM1, and cell cycle regulators also correlated with the presence of reciprocal herkogamy, supporting our interest in the protein.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>This work has built a foundation for future empirical work, specifically supporting the role of CDKG2 and ATM1 in promoting filament elongation in response to SPH1 perception.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"111 12","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.16438","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142646712","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}

{"title":"Oomycete communities in lowland tropical forest soils vary in species abundance and comprise saprophytes and pathogens of seeds and seedlings of multiple plant species","authors":"Kirk D. Broders,&nbsp;Hernan D. Capador-Barreto,&nbsp;Gloria Iriarte,&nbsp;S. Joseph Wright,&nbsp;Hilario Espinosa,&nbsp;Moritz Baur,&nbsp;Mayra A. Lemus-Peralta,&nbsp;Enith Rojas,&nbsp;Erin R. Spear","doi":"10.1002/ajb2.16425","DOIUrl":"10.1002/ajb2.16425","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>The soils in lowland tropics are teeming with microbial life, which can impact plant community structure and diversity through plant–soil feedbacks. While bacteria and fungi have been the focus of most studies in the tropics, oomycetes may have an outsized effect on seed and seedling health and survival, given their affinity for moister, warmer environments.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We assessed the diversity and pathogenicity of oomycete species present in a lowland tropical forest in Panama. We used a culture-dependent leaf-baiting assay and culture-independent soil DNA metabarcoding methods to quantify zoospore abundance and species diversity. A subset of the isolates from the baiting assay were used to evaluate pathogenicity and symptom severity on seedlings of three tree species.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Oomycetes were ubiquitous and common members of the soil microbial community in lowland tropical forests, and zoospore abundance was far greater compared to similar studies from temperate and mediterranean forests. The various oomycete species also varied in the ability to infect host plants. Species of <i>Pythium</i> were more virulent, while species of <i>Phytopythium</i> caused less severe symptoms but were more diverse and commonly isolated from the soil. Finally, we found that individual hosts accumulated a distinct oomycete community and was the only factor that had an effect on community structure.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Collectively, these findings demonstrate that oomycetes are ubiquitous, host-generalist pathogens and saprophytes, that can impact seed and seedling survival in lowland tropical forests.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"111 12","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142612477","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}

{"title":"Importance of habit and environmental characteristics in shaping patterns of richness and range size of ferns and lycophytes in the Atlantic Forest","authors":"Amabily Bohn,&nbsp;Elivane S. Capellesso,&nbsp;Paulo H. Labiak,&nbsp;Andrés Lira-Noriega,&nbsp;Victor Zwiener,&nbsp;Marcia C. M. Marques","doi":"10.1002/ajb2.16437","DOIUrl":"10.1002/ajb2.16437","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Ferns and lycophytes, the two spore-bearing lineages of vascular plants, share a unique life cycle, and because of several morpho-ecophysiological similarities, are usually investigated as a unit, but they may have distinct ecological and environmental responses. Understanding the diversity and distribution patterns of ferns and lycophytes separately is essential for designing effective conservation strategies.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We assessed species richness and range sizes using range–diversity analyses and investigated environmental (climatic, edaphic) and ecological (endemism, habit diversity, specialization) predictors of these range and richness metrics using generalized linear models.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The central region of the Atlantic Forest primarily contained areas with fern and lycophyte species with high richness and small ranges; the northern and southern extremes of the forest had species with low richness and larger ranges. Fern richness was associated with a combination of environmental and ecological variables; lycophyte richness was associated only with ecological variables. Range sizes were positively related to habit diversity for both ferns and lycophytes, but the effect of environmental variables differed between the two lineages. Critical areas were primarily not within protected areas.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Fern range sizes and richness were influenced by a combination of ecological and environmental factors such as temperature, precipitation, and soil variables; only ecological variables influenced lycophyte richness and range sizes. The effects of these factors must be considered separately for the two lineages due to their different responses to stressors. Conservation efforts should increase in the species-rich–low-range areas that are outside protected areas to protect these low-range species.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"111 11","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142612468","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}

{"title":"Herbarium specimens reveal links between leaf shape of Capsella bursa-pastoris and climate","authors":"Asia T. Hightower,&nbsp;Daniel H. Chitwood,&nbsp;Emily B. Josephs","doi":"10.1002/ajb2.16435","DOIUrl":"10.1002/ajb2.16435","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Studies into the evolution and development of leaf shape have connected variation in plant form, function, and fitness. For species with consistent leaf margin features, patterns in leaf architecture are related to both biotic and abiotic factors. However, for species with inconsistent leaf shapes, quantifying variation in leaf shape and the effects of environmental factors on leaf shape has proven challenging.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>To investigate leaf shape variation in a species with inconsistently shaped leaves, we used geometric morphometric modeling and deterministic techniques to analyze approximately 500 digitized specimens of <i>Capsella bursa-pastoris</i> collected throughout the continental United States over 100 years. We generated a morphospace of the leaf shapes and modeled leaf shape as a function of environment and time.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Leaf shape variation of <i>C. bursa-pastoris</i> was strongly associated with temperature over its growing season, with lobing decreasing as temperature increased. While we expected to see changes in variation over time, our results show that the level of leaf shape variation was consistent over the 100 years.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our findings showed that species with inconsistent leaf shape variation can be quantified using geometric morphometric modeling techniques and that temperature is the main environmental factor influencing leaf shape variation.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"111 11","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11584044/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142581793","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}

{"title":"Local adaptation and phenotypic plasticity drive leaf trait variation in the California endemic toyon (Heteromeles arbutifolia)","authors":"Laurel G. Thomas,&nbsp;Rachel Prunier","doi":"10.1002/ajb2.16430","DOIUrl":"10.1002/ajb2.16430","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>To survive climate change and habitat loss, plants must rely on phenotypic changes in response to the environment, local adaptation, or migration. Understanding the drivers of intraspecific variation is critical to anticipate how plant species will respond to climate change and to inform conservation decisions. Here we explored the extent of local adaptation and phenotypic plasticity in <i>Heteromeles arbutifolia</i>, toyon, a species endemic to the California Floristic Province.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We collected leaves from 286 individuals across toyon's range and used seeds from 37 individuals to establish experimental gardens in the northern and southern parts of toyon's range. We measured leaf functional traits of the wild-collected leaves and functional and fitness traits of the offspring grown in the experimental gardens. We then investigated the relationships between traits and source environment.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Most traits we investigated responded plastically to the environment, and some traits in young seedlings were influenced by maternal effects. We found strong evidence that variation in leaf margins is a result of local adaptation to variation in temperature and temperature range. However, the source environment was not related to fitness traits or survival in the experimental gardens.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our findings reiterate the adaptive role of toothed leaf margins in colder and more seasonally variable environments. Additionally, we provide evidence that fitness of toyon is not dependent on where they are sourced, and thus toyon can be sourced across its range for restoration purposes.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"111 11","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11584042/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142589948","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}

{"title":"Structural changes in Nelumbo flower petals during opening and closing","authors":"Fumiko Ishizuna,&nbsp;Ukin Yo,&nbsp;Natsumi Yoshimura,&nbsp;Atsushi Shirai,&nbsp;Toshihiro Aono,&nbsp;Nobuhiro Tsutsumi,&nbsp;Shin-Ichi Arimura,&nbsp;Hideki Takanashi","doi":"10.1002/ajb2.16433","DOIUrl":"10.1002/ajb2.16433","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p><i>Nelumbo nucifera</i> is one of several plant species with flowers that typically open in the early morning and close by noon. This movement normally repeats for 3 days, with all petals falling off on day 4. However, detailed observations of flower movement in <i>Nelumbo</i> species are limited.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Movement of flowers on plants in growth chambers were observed using time-lapse photography. Petals were examined with scanning electron microscopy or fixed and sectioned for light microscopy to determine whether changes in cell size contribute to petal elongation during flowering.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>This study is the first to microscopically observe petal cells of a <i>Nelumbo</i> species during flowering in controlled conditions. Petals elongated during the 4-day flowering period. Inner petals were more elongated than the outer petals. Among the basal, central, and tip regions of a single petal, the cells in the basal region enlarged the most. Outer and inner epidermal cells in the basal region of the inner petals, on both adaxial and abaxial sides, gradually enlarged during the flowering period through cycles of repeated increases as the petals opened and decreases as they closed.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Petals opened and closed repeatedly as they elongated, primarily in their basal region. Cells in the basal region of the petal on the adaxial and abaxial sides periodically fluctuated in size, increased during flower opening and decreased during closing, but differences in these patterns were observed between the two sides, suggesting that one of the driving forces behind the opening and closing of flowers of <i>Nelumbo</i> species is the increase and decrease in the size of the petal cells.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"111 11","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142581773","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}

{"title":"Ceanothus: Taxonomic patterns in life history responses to fire","authors":"Jon E. Keeley,&nbsp;V. Thomas Parker,&nbsp;Paul H. Zedler,&nbsp;R. Brandon Pratt","doi":"10.1002/ajb2.16434","DOIUrl":"10.1002/ajb2.16434","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p><i>Ceanothus</i> (Rhamnaceae) is a large genus of shrubs that dominate California chaparral and are resilient to fires. Persistence is ensured by resprouting and/or seedling recruitment from dormant seed banks. Some species do both and others, the obligate seeders, are entirely dependent on seedling recruitment. The distribution of these two modes within the genus is poorly documented.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We used all available publications that document species responses to fire and filled most gaps in the literature based on extensive field studies of more than 60 recent wildfires in California.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The genus is divided into two subgenera, <i>Ceanothus</i> and <i>Cerastes</i>. <i>Ceanothus</i> is widely considered to comprise mostly resprouting species and <i>Cerastes</i> to consist of only obligate seeders. The subgenus <i>Ceanothus</i> includes resprouting species throughout their range from the eastern United States and Midwest to western United States. Within the California Floristic Province (CFP), a few species are unique in producing massive lignotubers that develop from repeated fires; however, within the CFP, the majority of species in this subgenus do not resprout and are obligate seeders. Two have disjunct subspecies that are facultative seeders or obligate seeders.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Previously, speciation in this genus was contended to have occurred in the late Miocene within the CFP. The syndrome of obligate seeding is most strongly represented in this region, and we hypothesize that evolution of this syndrome was a response to increased predictability of fire driven by the Mediterranean climate and the long interval between fires.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"111 11","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142581657","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}

{"title":"Historic breeding practices contribute to germplasm divergence in leaf specialized metabolism and ecophysiology in cultivated sunflower (Helianthus annuus)","authors":"Jordan A. Dowell,&nbsp;Alan W. Bowsher,&nbsp;Amna Jamshad,&nbsp;Rahul Shah,&nbsp;John M. Burke,&nbsp;Lisa A. Donovan,&nbsp;Chase M. Mason","doi":"10.1002/ajb2.16420","DOIUrl":"10.1002/ajb2.16420","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>The use of hybrid breeding systems to increase crop yields has been the cornerstone of modern agriculture and is exemplified in the breeding and improvement of cultivated sunflower (<i>Helianthus annuus)</i>. However, it is poorly understood what effect supporting separate breeding pools in such systems, combined with continued selection for yield, may have on leaf ecophysiology and specialized metabolite variation.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We analyzed 288 lines of cultivated <i>H. annuus</i> to examine the genomic basis of several specialized metabolites and agronomically important traits across major heterotic groups.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Heterotic group identity supports phenotypic divergences between fertility restoring and cytoplasmic male-sterility maintainer lines in leaf ecophysiology and specialized metabolism. However, the divergence is not associated with physical linkage to nuclear genes that support current hybrid breeding practices in cultivated <i>H. annuus</i>. Additionally, we identified four genomic regions associated with leaf ecophysiology and specialized metabolism that colocalize with previously identified QTLs for quantitative self-compatibility traits and with S-protein homolog (SPH) proteins, a recently discovered family of proteins associated with self-incompatibility and self/nonself recognition in <i>Papaver rhoeas</i> (common poppy) with suggested conserved downstream mechanisms among eudicots.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Further work is necessary to confirm the self-incompatibility mechanisms in cultivated <i>H. annuus</i> and their relationship to the integrative and polygenic architecture of leaf ecophysiology and specialized metabolism in cultivated sunflower. However, because self-compatibility is a derived quantitative trait in cultivated <i>H. annuus</i>, trait linkage to divergent phenotypic traits may have partially arisen as a potential unintended consequence of historical breeding practices and selection for yield.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"111 11","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142556955","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}

{"title":"Widespread male sterility and trioecy in androdioecious Mercurialis annua: Its distribution, genetic basis, and estimates of morph-specific fitness components","authors":"Mai Thu Nguyen,&nbsp;Thomas Martignier,&nbsp;John R. Pannell","doi":"10.1002/ajb2.16429","DOIUrl":"10.1002/ajb2.16429","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Angiosperms range in sexual system from hermaphroditism through gynodioecy and androdioecy to dioecy. Trioecy, where females and males coexist with hermaphrodites, is rare. Recently, trioecy was documented in hexaploid populations of the wind-pollinated herb <i>Mercurialis annua</i> in Spain.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We surveyed the frequency of males, hermaphrodites, and females in <i>M. annua</i> across its distribution in the Iberian Peninsula, tracked sex-ratio variation in several populations over consecutive generations, and assessed evidence for pollen limitation. In a common garden, we estimated male, female, and hermaphroditic fitness. We used controlled crosses to infer the genetic basis of male sterility. Finally, we compared predictions of a deterministic model with the distribution of observed sex ratios in the field based on our fitness estimates and the inferred genetics of sex determination.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Trioecy is widespread in Spanish and Portuguese populations of <i>M. annua</i>. Males are determined by a dominant (Y-linked) allele, and female expression results from the interaction between cytoplasmic male sterility and multiple nuclear male sterility restorers partially linked to the male determiner. Male pollen production is approximately 12 times that of hermaphrodites, while female seed production is less than 1.12 times the observed hermaphroditic levels. The distribution of sex ratios in natural populations conforms with predictions of our deterministic simulations.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our study documents and accounts for a clear case of trioecy in which sex is determined by both maternally and biparentally inherited genes.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"111 11","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11584041/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142556956","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}

{"title":"The landscape genetics of a mass-flowering fire-ephemeral plant","authors":"Mira Jordan,&nbsp;Jason Bragg,&nbsp;Mark Ooi,&nbsp;Marlien van der Merwe,&nbsp;Maurizio Rossetto,&nbsp;Will Cornwell","doi":"10.1002/ajb2.16432","DOIUrl":"10.1002/ajb2.16432","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Obligate fire ephemerals are annual plants that have germination and reproduction cued by fire occurrence, persisting between fire events in a long-lived soil seed bank. Within these species, gene flow is restricted not only geographically but also temporally because individuals are limited to reproducing with others affected by the same fire event. The patchwork-like distribution of fires may therefore promote population isolation. In contrast to past fires, the Australian fires of 2019–2020 were of unprecedented extent, providing an opportunity to investigate the landscape genetics of a fire ephemeral, <i>Actinotus forsythii</i>, across multiple populations and to compare it to a common congener, <i>Actinotus helianthi</i>.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>For both species, we used single nucleotide polymorphisms to infer patterns of population structure and calculate measures of genetic diversity. We also estimated a phylogeny of <i>Actinotus forsythii</i> to understand the differentiation of a geographically isolated population.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>For <i>A. forsythii</i>, the within-population diversity (allelic richness = 1.56) was greater, and the among-population differentiation (<i>F</i>_ST = 0.30) was lower than that observed for <i>A. helianthi</i> (allelic richness = 1.33, <i>F</i>_ST = 0.57). <i>Actinotus forsythii</i> had distinct geographic groupings, and a geographically isolated population of this species was genetically highly differentiated.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Despite the fire-dependent, asynchronous gene flow, predicted between site disconnect, and possible within-site homogeneity, our results suggest that burn mosaic could be influencing gene flow patterns and fire-triggered mass flowering may promote genetic diversity within <i>Actinotus forsythii</i>.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"111 11","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142543138","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}