American Journal of Botany最新文献

{"title":"Divergent respiration-trait relationships reveal a unique economic strategy in ferns.","authors":"Xueqin Li, Xiaofang Chen, Shudong Zhang, Dandan Hu, Quanlin Zhong, Dongliang Cheng","doi":"10.1002/ajb2.70188","DOIUrl":"10.1002/ajb2.70188","url":null,"abstract":"<p><strong>Premise: </strong>Leaf respiration is a key metabolic process controlling leaf carbon balance. However, empirical data on leaf respiration, particularly in the light (R_L), remain scarce for ferns, and no study has systematically compared respiration-trait relationships between ferns and seed plants.</p><p><strong>Methods: </strong>We measured seven leaf traits, including leaf respiration in the dark (R_D), R_L, light-saturated photosynthetic rate (A_sat), leaf N and P content, leaf dry mass per unit area (LMA), and leaf dry mass content (LDMC) in 19 ferns. These fern data were analyzed in comparison with seed plant data from the Glopnet data set.</p><p><strong>Results: </strong>Light inhibition of leaf respiration averaged 37%. Ferns had significantly lower LMA, A_sat, and R_D than seed plants. Standardized major axis analyses (SMA) revealed the slopes of R_D vs. LMA, A_sat, and P differed significantly between ferns and seed plants, while R_D-N relationships shared common slopes, but their intercept differed markedly. Generalized linear models identified LMA and R_D as the strongest predictors of R_L, jointly explaining 70.6% of its variation.</p><p><strong>Conclusions: </strong>The terrestrial understory ferns employ a distinct \"low-cost, slow-cycling\" strategy-characterized by a unique combination of low leaf construction cost (LMA) and low metabolic rates (photosynthesis and respiration), which deviates from the traditional fast-slow leaf economics spectrum. The divergent respiration-trait relationships suggest that applying trait-based models parameterized solely for seed plants to ferns may introduce uncertainty into ecosystem models. This highlights the value of incorporating fern-specific trait relationships to refine projections of the global carbon cycle.</p>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":" ","pages":"e70188"},"PeriodicalIF":2.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147626470","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":"Flower color polymorphism in the peacock anemone (Anemone pavonina) reflects spatiotemporal variation in pollinator abundance.","authors":"Jonathan Heinze, Casper J van der Kooi, Gerd Vogg, Udo Jäger, Johannes Spaethe","doi":"10.1002/ajb2.70189","DOIUrl":"10.1002/ajb2.70189","url":null,"abstract":"<p><strong>Premise: </strong>Flower color polymorphisms are found across angiosperms and are shaped by multiple environmental factors. We investigated Anemone pavonina, which displays flower color variation from red to purple along an elevational gradient on Mount Olympus, Greece. This species serves as a model for studying how elevation-associated shifts in biotic and abiotic factors shape floral trait variation.</p><p><strong>Methods: </strong>We examined the floral biology of A. pavonina in the field (Greece) and in greenhouse experiments (Germany). We studied plant breeding system and flowering phenology; quantified pollinator dependence, pollen limitation, and pollinator contribution to seed set; and investigated pollinator distribution and color preferences, linking these patterns to elevation.</p><p><strong>Results: </strong>Anemone pavonina is protogynous, partially self-compatible, but relies on pollinators for seed set. Both morphs experience pollen limitation, which increases with elevation in the red morph but not in the purple one. In polymorphic populations, the flowering of red morphs peaked 1-2 weeks after purple morphs. Field trapping of common flower-visitors showed that Pygopleurus beetles prefer red colors, whereas bees choose non-red colors. Beetle but not bee abundance decreased with elevation.</p><p><strong>Conclusions: </strong>Anemone pavonina shows clear pollinator dependence. Flower color and phenology differ among morphs, reflecting adaptation to their local environment. The purple morph is better adapted to high elevations and associated with bee pollination, whereas the red morph is tuned to beetle vision and activity patterns. These findings demonstrate how spatiotemporal pollinator dynamics drive pollinator-mediated selection, contributing to the origin and maintenance of flower color variation.</p>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":" ","pages":"e70189"},"PeriodicalIF":2.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13103634/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147632323","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":"Temporal analysis of reproduction distributed in space illuminates the climate-change resiliency of toyon (Heteromeles arbutifolia).","authors":"Daniel Dakduk, Jeremy B Yoder","doi":"10.1002/ajb2.70182","DOIUrl":"https://doi.org/10.1002/ajb2.70182","url":null,"abstract":"<p><strong>Premise: </strong>Toyon, Heteromeles arbutifolia (Rosaceae), is an iconic and ecologically important member of California chaparral and oak woodland communities. Its habitat faces changing wildfire regimes, widening variation in annual rainfall, and competition by introduced species. We used a new modeling method, temporal analysis of reproduction distributed in space (TARDIS), to examine how recent climate change alters habitat suitability for toyon.</p><p><strong>Methods: </strong>As data for TARDIS, we annotated flowering and fruiting in images from 4105 observations of toyon contributed to the iNaturalist crowdsourcing platform. From these records, we trained Bayesian additive regression tree models relating weather to toyon flowering. We used a trained model to hindcast flowering each year back to 1900, and examined trends in the hindcast flowering. For comparison, we also modeled changing habitat suitability using a conventional species distribution model (SDM) relating toyon presence to 30-year climate averages.</p><p><strong>Results: </strong>Toyon flowering was associated with greater winter precipitation and warmer fall and winter temperatures. Our hindcast showed that mean flowering intensity has been stable to slightly increasing since 1900, with greater increases at higher elevations, but also at lower latitudes. Variation in flowering intensity also increased, especially at lower latitudes. Trends in flowering were positively correlated with changes in SDM-predicted suitability.</p><p><strong>Conclusions: </strong>TARDIS recovers biologically realistic predictors of toyon flowering, and hindcast changes in flowering intensity indicate the species' range remains suitable after 125 years of changing climate. Overall, our results indicate toyon populations remain healthy, but may have limited opportunity to migrate northward as climate change continues.</p>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":" ","pages":"e70182"},"PeriodicalIF":2.7,"publicationDate":"2026-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147572060","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":"Observing weak adaptation of duckweeds to their local microbiome depends on local pondwater","authors":"Ava M. Rose,&nbsp;Anna M. O'Brien","doi":"10.1002/ajb2.70165","DOIUrl":"10.1002/ajb2.70165","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Populations can locally adapt to the biotic and abiotic factors of environments. However, detecting adaptation to biotic factors can depend on the abiotic conditions in which the adaptation is tested, and vice versa. The microbiome is one important aspect of the biotic environment: Interactions between microbiomes and their hosts are critical for host fitness and trait expression. If hosts adapt to local microbiomes, they may therefore depend on interactions with local microbes to express trait values adapted to the local abiotic environment.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Using <i>Lemna minor</i> (duckweed) as a model host, we examined differences in host fitness when grown in local and nonlocal microbiomes and in local and nonlocal water. We experimentally recombined duckweeds, microbes, and water from four ponds around Durham, New Hampshire (United States) in well-plate microcosms in a growth chamber.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The source of duckweeds, microbes, and water all affected microbial growth, duckweed growth, and duckweed traits. However, weak, marginally significant local adaptation resulted in higher frond area only when duckweeds were paired with their local water and local microbes. Microbial growth was also marginally reduced when duckweeds were paired with microbes and water from their local site.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>While microbiome impacts on duckweed growth and traits varied across abiotic contexts, local microbiomes provided only limited growth benefits. Harnessing the effects of plant microbiomes is an exciting area of applied research. Despite our findings, bioprospecting in local microbiomes could still be fruitful: It may be ecologically safer, and other plants may locally adapt to microbiomes.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"113 3","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146130848","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":"Aging and longevity in decades-old genebanked seeds from U.S. endangered plant species: Assessments using survival and RNA integrity assays","authors":"Christina Walters,&nbsp;Katherine D. Heineman,&nbsp;Lisa Hill,&nbsp;Hannah Tetreault,&nbsp;Parker Tyler,&nbsp;Zoe Zingerman,&nbsp;Shaimaa Ibrahim,&nbsp;Joyce Maschinski","doi":"10.1002/ajb2.70169","DOIUrl":"10.1002/ajb2.70169","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Seed longevity is critical for successful genebanking, but it is hard to detect or predict. We examined survival of genebanked seeds from species native to the United States to estimate longevity. We tested whether RNA integrity (RIN) can be used to detect aging and predict mortality.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Dry seeds from &gt;100 species were stored for 28 ± 7 yr at −18°C. A recently harvested sample (cohort) from the same population provides a zero-time reference. Germination and RIN were assessed and differences between cohorts were used to distinguish short-lived seeds from long-lived seeds.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>No differences in germination or RIN were detected between cohorts in about one-fourth of the species. Viability and/or RIN was lower in the stored cohort than in the recently harvested cohort in most species, and the size of the difference was used to infer aging rates. Differences in germination and RIN were correlated among the 100 samples tested; moderate correlation coefficients indicate that additional factors are involved in seed aging and its detection.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Overall, longevity in the genebank appears to be similar for seeds from wild and domesticated species. We identified species that appeared to produce quite long-lived and short-lived seeds. Seeds from wild species tend to germinate slowly and asynchronously, and this confounds comparisons across storage times; deterioration is detected mostly after severe mortality. By contrast, RIN values decline before viability loss is detected and appear to be unaffected by wild seed traits. RIN tests during early storage can help predict seed longevity.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"113 3","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13003721/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147281904","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":"Origin of subgenomes in the circumboreal, allopolyploid, carnivorous plant Drosera anglica","authors":"Rebekah A. Mohn,&nbsp;Ya Yang","doi":"10.1002/ajb2.70170","DOIUrl":"10.1002/ajb2.70170","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>The parentage of the widespread allopolyploid <i>Drosera anglica</i>, a member of the carnivorous sundew genus, remains uncertain despite over 100 years of morphological, cytological, and, more recently, molecular study.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Using transcriptomic and genomic data from 12 species of <i>Drosera</i> sect. <i>Drosera</i>, including four <i>D. anglica</i> populations and a population sometimes identified as disjunct <i>D. intermedia</i>, we assembled genes in HybPiper and phased sequences in HybPhaser. We estimated species relationships with phylogenetic and pairwise genetic distance methods and ploidy with heterozygosity and flow cytometry measurements. Additionally, we expanded represented taxa by analyzing new and previously published <i>rbcL</i> sequences.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Sequences from phased subgenomes of <i>D. anglica</i> were highly similar to <i>D. rotundifolia</i> (99.60–99.80%) and <i>D. linearis</i> (99.79–99.95%) and showed no evidence of multiple origins despite sampling across North America, Europe, and Hawaii. Additionally, the disjunct <i>D. intermedia</i> from Idaho had been misidentified and is <i>D. anglica</i>. <i>S</i>equences from the nuclear ribosomal region and <i>rbcL</i> of <i>D. anglica</i> were nearly identical to <i>D. linearis</i> despite their chromosomes mispairing during meiosis and counter to interpretations of limited Sanger sequencing. <i>Drosera anglica</i> is intermediate between its parental lineages in leaf shape and microhabitat; however, across <i>D</i>. sect. <i>Drosera</i>, neither leaf shape nor biogeographic distribution was a reliable indicator of phylogenetic relationships.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p><i>Drosera anglica</i> arose from allopolyploidy between the <i>D. linearis</i> lineage, representing the plastid and dominant ribosomal donor, and the <i>D. rotundifolia</i> lineage. Our study demonstrates the importance of taxon sampling and careful examination of complex phylogenomic data and presents an exemplar of analyzing allopolyploid relationships.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"113 3","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13003725/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147324472","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":"Spring ephemeral Erythronium umbilicatum may not be vulnerable to phenological mismatch with overstory trees","authors":"Melina Schopler,&nbsp;Anita Simha,&nbsp;Rebecca M. Dalton,&nbsp;Emma M. Wilson,&nbsp;Emmeline Redick,&nbsp;Elsa Youngsteadt,&nbsp;William K. Petry","doi":"10.1002/ajb2.70172","DOIUrl":"10.1002/ajb2.70172","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>The defining life history strategy of spring ephemeral wildflowers is their avoidance of shading by trees during the brief, high-light period before canopy leaf out. Studies suggest that spring ephemerals will experience increased light competition because canopy leaf out is more sensitive to warming than is the phenology of spring ephemerals. However, it remains unclear how longer durations of shade will alter the population dynamics of spring ephemerals and whether all populations are at risk.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We experimentally shaded <i>Erythronium umbilicatum</i> for one to six additional weeks before canopy leaf out to test for immediate and lagged effects of early shading on the timing of senescence and the probability of survival and flowering. To predict the potential for earlier shading, we combined long-term time series of spring air temperature, remotely sensed tree leaf out, and <i>E. umbilicatum</i> flowering phenology in North Carolina, United States.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Early shading did not alter <i>E. umbilicatum</i> until the following year, when more-shaded plants senesced later. Year-to-year survival did not change, and the probability of flowering was reduced only when plants experienced extremely early shading. Moreover, <i>E. umbilicatum</i> phenology was more sensitive than tree leaf out to warming temperatures. We project that, under climate warming, <i>E. umbilicatum</i> is unlikely to experience shortened periods of high light.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our findings show that a plant species’ defining life history strategy does not necessarily predict their sensitivity to phenological mismatches. This incongruity complicates, but also underscores the importance of identifying the most vulnerable species and directing our research efforts accordingly.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"113 3","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13003714/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147347051","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":"Fitness consequences of trait-mediated plant–pollinator interactions","authors":"Christine S. Sheppard,&nbsp;Frank M. Schurr,&nbsp;Ingo Grass","doi":"10.1002/ajb2.70167","DOIUrl":"10.1002/ajb2.70167","url":null,"abstract":"&lt;p&gt;Most angiosperm species depend at least partly on animal pollinators; when pollinators are excluded, a third produce no seeds, and half produce at least 80% fewer seeds (Rodger et al., &lt;span&gt;2021&lt;/span&gt;). Simultaneously, many animal pollinators strongly depend on floral resources for survival and reproduction. Quantifying fitness consequences of plant–pollinator interactions holds great promise for understanding ecological and evolutionary dynamics and for assessments of global change impacts. To this end, we suggest a novel approach using fitness landscapes of plant–pollinator interactions, which we illustrate by using the example of human-mediated invasion by alien species.&lt;/p&gt;&lt;p&gt;Invasive alien species are a major threat to biodiversity. When alien plant species become dominant, they can fundamentally alter plant–pollinator interactions (Parra-Tabla and Arceo-Gómez, &lt;span&gt;2021&lt;/span&gt;) and thus provide a natural experiment to unravel the mechanisms governing fitness consequences of species interactions. Although many alien plants rely on local pollinators to invade new areas, pollinator limitation is not usually thought to limit invasions. In some cases, pollinators may be introduced with the plant invaders (e.g., fig wasp pollinators with alien &lt;i&gt;Ficus&lt;/i&gt; species), but more often the alien species will co-opt generalist pollinators of the same functional types as their pollinators in the native range (Stout and Tiedeken, &lt;span&gt;2017&lt;/span&gt;). Furthermore, floral traits of invasive plant populations may rapidly evolve in response to local pollinator pools (Schiestl, &lt;span&gt;2024&lt;/span&gt;).&lt;/p&gt;&lt;p&gt;Pollinators in turn may benefit from a new species that provides abundant floral resources (e.g., Chittka and Schürkens, &lt;span&gt;2001&lt;/span&gt;). On the other hand, the tendency of many invasive plants to form dense monocultures that provide only one type of floral resource can threaten pollinator diversity. The impacts of invasive plants on pollinators may also affect their indirect interactions with native plants (Morales and Traveset, &lt;span&gt;2009&lt;/span&gt;; Parra-Tabla et al., &lt;span&gt;2025&lt;/span&gt;). Pollinator-mediated facilitation of native plants occurs if the invader acts as a “magnet species”, attracting many pollinators and causing spillover effects on native plants. By contrast, pollinator-mediated competition occurs when invaders weaken mutualistic interactions between native plants and pollinators. Importantly, fitness of native plants at invaded sites may not just be lower because natives receive fewer pollinator visits, but also because the quality of visits declines with a lower ratio of conspecific to heterospecific pollen transfer (e.g., Parra-Tabla et al., &lt;span&gt;2025&lt;/span&gt;), an aspect that most studies focusing only on pollinator visitation rates do not consider.&lt;/p&gt;&lt;p&gt;Given the contradictory evidence on how invasive alien plants impact the fitness of pollinators and co-occurring native plant species, a trait-based approach is a promising avenue bec","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"113 3","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13003716/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146257057","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":"Characterizing the causes and consequences of calcium oxalate crystal presence in Vitis riparia","authors":"Carolyn D. K. Graham,&nbsp;Samantha Molino,&nbsp;Addison L. Yerks,&nbsp;Marjorie Weber","doi":"10.1002/ajb2.70173","DOIUrl":"10.1002/ajb2.70173","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Calcium oxalate biomineralization in plants is phylogenetically widespread and morphologically diverse, but the function of these inorganic crystals is an area of active debate. The variety of environmental conditions that produce the crystals, as well as the inconsistent evidence that they provide antiherbivore defense across plant and herbivore species, suggests that different crystal morphologies might have different functions.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Using <i>Vitis riparia</i>, or riverbank grape, we experimentally investigated the environmental influence of excess calcium and simulated herbivory on the formation of calcium oxalate druse and raphide crystals in leaves. We also investigated the putative defensive function of these crystals by using a no-choice herbivore bioassay manipulating herbivore diet composition to test for impacts of crystal shape on herbivore growth, both on its own and with plant chemistry.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>We found that the addition of calcium to soil increased the density of both raphide and druse crystals in <i>V. riparia</i> leaves. Contrary to expectations, the herbivory treatment decreased the density of raphides in leaves, and <i>V. riparia</i>-derived crystals did not impact weight gain, time to pupation, or survival of moth larvae.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our multifaceted test of the formation and function of calcium oxalate crystals in riverbank grape demonstrates that an abiotic factor (i.e., soil calcium) is a relatively stronger determinant of crystal production and that, contrary to hundreds of years of speculation on their function, these crystals do not seem to mediate plant-insect herbivory in all plant taxa. Instead, the alternative hypothesis of calcium regulation was supported by our experimental evidence.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"113 3","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13003718/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147389203","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":"Linking environmental and pollination-related factors to touch-sensitive stigma closure dynamics in Mazus miquelii","authors":"Xiao-Fang Jin,&nbsp;Tian Luo,&nbsp;Chun-Feng Yang,&nbsp;Zhong-Ming Ye","doi":"10.1002/ajb2.70174","DOIUrl":"10.1002/ajb2.70174","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Touch-sensitive stigmas (TSSs), specialized receptive structures in angiosperms, dynamically respond to mechanical stimulation or pollen deposition. The typical sequence comprises temporary closure, reopening, and permanent closure, which optimize pollen capture, retention, and fertilization success. However, the specific environmental and pollination-related factors regulating these phases are unexplored.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Here we systematically investigated the association of environmental (temperature and humidity) and pollination-related factors (amount of pollen deposited [load], position of pollen tube, and growth rate of pollen tube) with the temporal dynamics of stigma movements in <i>Mazus miquelii</i>, a species with TSS.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Temporary closure and reopening were primarily associated with temperature and were independent of the pollen load. In contrast, permanent closure was strongly correlated with the pollen load and position and growth rate of pollen tube. Furthermore, temporary closure and reopening time were negatively correlated, although neither were significantly correlated with permanent closure time.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Rapid temporary closure and reopening events were primarily associated with environmental cues, whereas irreversible permanent closure was associated with pollination-related signals. These advances in our understanding of the ecological regulation of TSS behavior provide a foundation for future studies into the physiological and molecular mechanisms of touch sensitivity of stigmas.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":"113 3","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147375831","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}