American Journal of Botany最新文献

{"title":"The intensity and spatial dispersion of within-plant herbivory drive trait-specific resistance and tolerance in wild cotton.","authors":"Víctor Hugo Ramírez-Delgado, Yeyson Briones-May, Juan Sánchez-Durán, Lucía Martín-Cacheda, Xoaquín Moreira, Ted C J Turlings, Luis Abdala-Roberts","doi":"10.1002/ajb2.70280","DOIUrl":"https://doi.org/10.1002/ajb2.70280","url":null,"abstract":"<p><strong>Premise: </strong>Herbivory induces complex plant defensive responses that may vary depending on the amount and spatial dispersion of damage on the plant; however, of the two variables, damage dispersion has received much less attention. To address this gap, we studied wild cotton (Gossypium hirsutum) defensive responses to different herbivory amounts and degrees of dispersion among leaves using the specialist caterpillar Alabama argillacea (Erebidae).</p><p><strong>Methods: </strong>Four herbivory treatments differing in the amount and spatial distribution were applied to 4-month-old plants: no herbivory (controls), low (two caterpillars: one on each of two leaves), high-concentrated (four caterpillars: one pair on each of two leaves), and high-dispersed (four caterpillars: one on each of four leaves). We measured extrafloral nectar (EFN) and phenolics, both resistance-related traits, and as a proxy for tolerance, regrowth capacity (new leaf biomass post-herbivory). To differentiate local from systemic induction, we measured EFN and phenolics separately for damaged and undamaged leaves.</p><p><strong>Results: </strong>EFN was significantly and more consistently induced in damaged leaves (i.e., stronger local induction) and in response to high-dispersed damage, but phenolics were unaffected by the treatment. Biomass of new leaves produced post herbivory was similar to that of controls for most treatment groups, except for high-concentrated damage (lower than controls), suggesting this damage treatment incurred higher costs.</p><p><strong>Conclusions: </strong>These results highlight the importance of studying induced plant defenses under various herbivory patterns and suggest that the spatial distribution of within-plant damage has contrasting effects on resistance- (namely EFN) versus tolerance-related induced responses of importance for wild cotton growth and ant-plant interactions.</p>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":" ","pages":"e70280"},"PeriodicalIF":2.8,"publicationDate":"2026-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149190612","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":"Modeling diseased xylem networks.","authors":"Nancy C Walker","doi":"10.1002/ajb2.70279","DOIUrl":"https://doi.org/10.1002/ajb2.70279","url":null,"abstract":"<p><p>Vascular wilt pathogens induce xylem blockages that disrupt plant water transport, posing critical threats to agricultural productivity and food security. Key processes including xylem transport, vessel blockage, and pathogen spread within the xylem remain poorly understood, largely due to our limited ability to internally monitor infected tissues. This review explores how complementary mathematical modeling alongside laboratory studies can elucidate features governing these critical processes. I first provide a brief history of xylem imaging and quantification, highlighting technological advances, and persistent limitations. I then review modeling approaches to describe xylem water transport and pathogen dynamics, emphasizing that different pathogens require fundamentally different modeling frameworks. Existing xylem flow models may provide suitable hydraulic conductivity estimates for healthy stems under idealized conditions; however, they lack explicit representation of pit membranes and lumen-occluding structures, limiting their applicability to diseased stems where these features are actively modified during infection. Previously described biofilm models can replicate bacterial colony growth in controlled experimental settings but are often too complex for integration with flow simulations and rely on parameters that are difficult to quantify experimentally. Finally, I highlight directions and challenges for modeling occlusion and spread at the local scale and discuss how these models might be scaled to network-level architecture. While these types of models remain computationally challenging, advances in multiscale imaging technologies and scaling approaches promise significant progress in the coming decades. Insights from such models stand to advance both our understanding of disease progression and the development of resilient crops for an uncertain climate future.</p>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":" ","pages":"e70279"},"PeriodicalIF":2.8,"publicationDate":"2026-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149190625","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":"Heterosis in crosses between remnant populations of the rare prairie forb Silene regia: Implications for restoration genetics.","authors":"Isabelle A Turner, Juan Diego Rojas-Gutierrez, Bob Easter, Christopher G Oakley","doi":"10.1002/ajb2.70278","DOIUrl":"https://doi.org/10.1002/ajb2.70278","url":null,"abstract":"<p><strong>Premise: </strong>Calls to adopt seed-sourcing strategies in biological restoration that preserve local adaptation while maximizing genetic variation (e.g., regional admixture provenancing) are increasingly common. Heterosis, the increased fitness of progeny from crosses between populations relative to progeny from crosses within populations, could provide an added benefit under such strategies.</p><p><strong>Methods: </strong>We quantified heterosis in crosses between three small remnant populations of the rare prairie forb Silene regia. We measured early fitness components (seed number per fruit, germination, and juvenile survival) in a greenhouse. Adult fitness components (survival and reproduction) were quantified over two flowering seasons in two different environments: in a field experiment simulating the initial stages of a restoration and in a greenhouse. Our approach is unique in estimating heterosis in an environment most relevant to the early stages of a restoration, and in comparing heterosis in the field and controlled conditions.</p><p><strong>Results: </strong>The consequences of between-population crosses for cumulative fitness in the field were strongly positive in two of the populations (281% and 50% heterosis) and nearly neutral in a third. Heterosis was generally stronger when measured in the field, and stage-specific patterns of heterosis varied among populations.</p><p><strong>Conclusions: </strong>Regional admixture provenancing in restorations should be beneficial for this species. We advocate for more research on heterosis in rare species, particularly for restorations. We also provide a cautionary note on how to calculate and report results for heterosis studies.</p>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":" ","pages":"e70278"},"PeriodicalIF":2.8,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149178876","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":"Experimental manipulation of floral display size does not affect the distribution of paternal diversity in Silene dioica.","authors":"Nina Joffard, Ihsen Lecat, Kate Ollier, Camille Jolivel, Eric Schmitt, Cécile Godé, Estelle Barbot, Mathilde Dufay, Isabelle De Cauwer","doi":"10.1002/ajb2.70276","DOIUrl":"https://doi.org/10.1002/ajb2.70276","url":null,"abstract":"<p><strong>Premise: </strong>Various factors, including pollinator visitation patterns and pollen carryover, govern paternal diversity and its distribution within maternal plants. Floral display size may have opposite effects on fruit- and plant-level paternal diversity, because plants with large displays may receive more pollinator visits but also more sequential probes per visit.</p><p><strong>Methods: </strong>To investigate the effect of floral display size on the distribution of paternal diversity in Silene dioica, we genotyped and assigned paternity for 1320 seeds sampled in several fruits per plant in control and manipulated females-whose flower number was artificially increased-in an experimental population exposed to natural pollination. We estimated within-fruit paternal diversity and sire profile dissimilarity among fruits and compared these metrics between control and manipulated plants. We then quantified pollen carryover using controlled pollinator visitation assays and pollen counts.</p><p><strong>Results: </strong>Most fruits were multiply sired, but we found no effect of floral display size on within-fruit paternal diversity. Sire profiles were more similar between fruits from the same than from different females, but not more so in manipulated than in control plants. The pollen deposition curve was steep, with an increasing carryover fraction throughout the visitation sequence.</p><p><strong>Conclusions: </strong>Our results suggest that the effect of floral display size on pollinator foraging behavior is too weak to affect paternal diversity and its distribution in S. dioica, or that other processes, such as limited pollen carryover and spatially restricted pollen dispersal, blur the effect of pollinator visitation patterns on sire profiles.</p>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":" ","pages":"e70276"},"PeriodicalIF":2.8,"publicationDate":"2026-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149178848","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":"Beyond the tangled bank: An evolving meta-ecosystems framework to integrate ecological and evolutionary perspectives.","authors":"Brandon M Lind, Ian N C Shuman, Linda A Deegan, Mary Heskel, Mark C Urban, Jill L Wegrzyn, Peter A H Westley","doi":"10.1002/ajb2.70274","DOIUrl":"https://doi.org/10.1002/ajb2.70274","url":null,"abstract":"","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":" ","pages":"e70274"},"PeriodicalIF":2.8,"publicationDate":"2026-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149163981","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":"Evolutionary relationship between organellar DNA inheritance patterns and traits of seed plants.","authors":"Takuya Konuma, Takashi Makino","doi":"10.1002/ajb2.70272","DOIUrl":"https://doi.org/10.1002/ajb2.70272","url":null,"abstract":"<p><strong>Premise: </strong>In plants, organellar DNA is predominantly maternally inherited, but biparental and paternal inheritance have also been observed. Specific mechanisms, such as plastid exclusion during pollen mitosis or genome degradation, ensure maternal inheritance. Certain factors, including low temperatures, disrupt cytoskeletal functions, thereby increasing paternal plastid transmission. Despite these findings, the ecological and evolutionary drivers of these inheritance modes remain unclear. We explored the traits associated with biparental and paternal inheritance to reveal the contributing ecological factors.</p><p><strong>Methods: </strong>Plastid inheritance data were compiled for 378 species (302 genera and 112 families) and 12 functional traits obtained from the TRY database were analyzed. Missing values were filled according to Bayesian hierarchical modeling. On the basis of phylogenetic logistic regression, we investigated the relationships between inheritance patterns and plant traits, accounting for evolutionary history.</p><p><strong>Results: </strong>Our models identified plant height, leaf area, and stem conduit density as traits associated with inheritance modes, with the strongest support for leaf area and limited support for the other traits. Coefficient directions indicated greater plant height, smaller leaves, and higher stem conduit density in species with non-maternal inheritance. Excluding gymnosperms yielded similar tendencies, which suggests that similar ecological factors may be associated with plastid inheritance patterns in both groups.</p><p><strong>Conclusions: </strong>Functional traits were associated with organelle inheritance patterns, with ecological and evolutionary implications. Similar ecological factors may be associated with the independent occurrence of paternal inheritance across lineages. Future work integrating molecular and ecological data will help elucidate the mechanisms underlying organelle inheritance and their adaptive significance.</p>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":" ","pages":"e70272"},"PeriodicalIF":2.8,"publicationDate":"2026-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149164678","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":"Palatability of geophyte underground storage organs partially explains their depth in the Cape Floristic Region, geophyte capital of the world.","authors":"Tineke Kraaij, Elzanne Singels, Félix Forest, Karen J Esler, Richard M Cowling","doi":"10.1002/ajb2.70271","DOIUrl":"https://doi.org/10.1002/ajb2.70271","url":null,"abstract":"<p><strong>Premise: </strong>The soil depth of underground storage organs (USOs) of geophytes involves cost-benefit trade-offs and may relate to USO age, size, and disturbances such as fire and herbivory. Yet determinants of USO depth are poorly studied. We posit that belowground mammalian predation of USOs is a selective force for the positive relationship between USO size and depth.</p><p><strong>Methods: </strong>We tested the mammalian predation hypothesis using USO depth, mass, type (bulb, corm, tuber, rhizome) and palatability to human foragers for 1828 geophyte individuals (153 species, 54 genera, 22 families) from the lowlands of the Cape Floristic Region (South Africa) which harbors the world's highest concentration of geophytes.</p><p><strong>Results: </strong>USOs were found at depths of 0-34 cm, but depth had no consistent relationship with mass. The depth-mass relationship was instead related to USO type: Compared with smaller counterparts, larger bulbs were at shallower depths, and larger corms were deeper. USO palatability affected the depth-mass relationship; palatability was generally associated with deeper burial across USO types: Palatable corms, tubers, and rhizomes mostly had positive depth-mass relationships, and unpalatable types had no relationship. Palatable bulbs had negative relationships that were less significant than for unpalatable bulbs. The phylogenetic signal in the study species was only moderate.</p><p><strong>Conclusions: </strong>USO type and palatability explained some variation in their depth-mass relationship in accordance with the mammalian predation hypothesis. USO age and shape, soil type, and predation strategy and intensity should be explored as potential additional correlates of USO depth and size.</p>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":" ","pages":"e70271"},"PeriodicalIF":2.8,"publicationDate":"2026-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149126524","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":"A practical prioritization strategy for vegetation-focused restoration of anthropogenic wastelands.","authors":"Erika Stewart, Joshua B Grinath, Kathryn G Turner","doi":"10.1002/ajb2.70273","DOIUrl":"https://doi.org/10.1002/ajb2.70273","url":null,"abstract":"","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":" ","pages":"e70273"},"PeriodicalIF":2.8,"publicationDate":"2026-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149102989","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":"From ice age to present: Clonal expansion and genetic variation in the world's oldest conifer stand.","authors":"James R Marthick, Andrew J Phipps, Gregory J Jordan, Daiki Takahashi, Yoshihisa Suyama, James R P Worth","doi":"10.1002/ajb2.70269","DOIUrl":"https://doi.org/10.1002/ajb2.70269","url":null,"abstract":"<p><strong>Premise: </strong>Clonality is widespread among plants, yet the processes governing genetic diversity within the most ancient clones remains understudied. We investigated these dynamics using a reputed 10,500-year-old clonal stand of one of the world's longest-lived tree species, the paleoendemic conifer Lagarostrobos franklinii at Mt Read in Western Tasmania.</p><p><strong>Methods: </strong>To quantify the clone's spatial extent and map its underlying genetic structure and gain insights into its origin, we used unmanned aerial vehicle (UAV) photogrammetry and two complementary genetic data sets including nuclear simple sequence repeats (nSSRs) and multiplexed intersimple sequence repeat genotyping by sequencing (MIG-seq), a reduced representation SNP discovery method.</p><p><strong>Results: </strong>The putative clonal stand at Mt Read has been severely impacted by fire, with living stems occupying approximately 5260 m², a ~65% reduction in the stand's previously estimated size. Contrary to the hypothesis that a single clone endures at Mt Read, both data sets revealed multiple, circumscribed patches, each with fixed multilocus genotypes (MLGs).</p><p><strong>Conclusions: </strong>The Mt Read stand comprises three closely related MLGs, with the two largest clones being 3350 m² and 1861 m², respectively, they remain some of the largest conifer clones known. Although extremely low allelic diversity in the stand meant that nSSRs could not exclude a somatic origin for these MLGs, higher resolution MIG-seq markers indicate an inbreeding origin. Overall, this study demonstrates how ancient clones previously regarded as single genets can harbor cryptic diversity. Accounting for this hidden structure is crucial to accurately estimate clone size and longevity and unravel their evolutionary history.</p>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":" ","pages":"e70269"},"PeriodicalIF":2.8,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149102955","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":"Placing very long branch taxa in the plant tree of life: A case study with Dioscoreales mycoheterotrophs.","authors":"Marybel Soto Gomez, Qianshi Lin, Nathaniel J Klimpert, Vivienne K Y Lam, Juan Viruel, Vincent S F T Merckx, Paula J Rudall, Sean W Graham","doi":"10.1002/ajb2.70267","DOIUrl":"https://doi.org/10.1002/ajb2.70267","url":null,"abstract":"<p><strong>Premise: </strong>The inclusion of heterotrophic plants in broader systematic studies is challenging due to substantial morphological modification, gene loss, and accelerated substitution rates following photosynthesis loss. In particular, inclusion of very long branch (VLB) taxa with highly elevated rates may lead to phylogenomic misinference.</p><p><strong>Methods: </strong>We explored how rapidly evolving plastomes behave in model-based phylogenetic inferences in the yam order Dioscoreales, which experienced convergent photosynthesis losses. Our taxon sampling included mycoheterotrophic lineages displaying a broad range of substitution rates and all photosynthetic genera.</p><p><strong>Results: </strong>When only moderately rapidly evolving heterotrophs are included, relationships within Dioscoreales are congruent with recent mitochondrial analysis, and generally strongly supported. Photosynthetic Stenomeris (represented by only three genes) is moderately supported as sister to Dioscoreaceae. Notably, Burmanniaceae and Thismiaceae, two mycoheterotrophic families including highly reduced plastomes, are strongly supported as distantly related within Dioscoreales. Constrained analysis rejects combining Thismiaceae with Burmanniaceae, conflicting with current angiosperm classification. Including a subset of VLB mycoheterotrophs in phylogenetic inference results in localized or broad reduction in branch support-substantially so for Afrothismiaceae, a family placing in disparate locations in Dioscoreales (and beyond) in variant analyses, with no ability to differentiate among its alternative placements.</p><p><strong>Conclusions: </strong>Inclusion of highly rate-elevated taxa in analyses of Dioscoreales phylogeny can depress branch support. Inferred relationships in the order are otherwise congruent with studies based on mitochondrial data; the family-level classification needs updating. The extraordinarily rapidly evolving family Afrothismiaceae places inconsistently in diverse plastid analyses, pointing to probable analytical limits for plastid-based phylogenomic analyses of VLB heterotrophs.</p>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":" ","pages":"e70267"},"PeriodicalIF":2.8,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149102981","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}