Annals of botany最新文献

{"title":"Why conserve genetic diversity? A perspective based on a case study with a European conifer.","authors":"Bruno Fady, Caroline Scotti-Saintagne","doi":"10.1093/aob/mcaf041","DOIUrl":"https://doi.org/10.1093/aob/mcaf041","url":null,"abstract":"<p><strong>Background: </strong>Biodiversity is the variability among living organisms that exists within species, between species and of ecosystems. Yet, genetic diversity, the within species component of biodiversity, is rarely considered as a conservation concern or goal in protected areas.</p><p><strong>Scope: </strong>In this perspective, we explore possible reasons why genetic diversity is poorly considered in conservation and ecological restoration. We also present the case study of a threatened forest conifer in France (Pinus nigra ssp. salzmannii (Dunal) Franco, Salzmann's pine) that we offer as proof of how straightforward implementation of genetic diversity conservation goals can be in protected areas.</p><p><strong>Conclusions: </strong>Scientific studies in the fields of either conservation or biodiversity consider genetics in less than 10% of scientific productions. While genetic tools are used for taxonomic delineation, concerns about diversity within species at population level appear comparatively rare in conservation and biodiversity science or management. The use of genetic tools for the conservation of genetic diversity of Salzmann's pine in France clarified its taxonomic status, identified populations relevant for in-situ conservation compatible with habitat conservation and made it possible to select genetically original individual trees that could be grafted as a core collection for dynamic ex-situ conservation. As threats on biodiversity increase worldwide, fully integrating genetic diversity in conservation demands that conservation adopts an evolutionary centered, nature for itself perspective, rather than either an anthropocentric, resource focused perspective or a bio-centered, emblematic species focused perspective.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143655971","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":"Morphological and developmental analysis of Plantago spp. seed capsules reveal key features of the dehiscence zones.","authors":"Lina Herliana, James M Cowley, Lisa A O'Donovan, Tina Bianco-Miotto, Rachel A Burton","doi":"10.1093/aob/mcaf044","DOIUrl":"https://doi.org/10.1093/aob/mcaf044","url":null,"abstract":"<p><strong>Background and aims: </strong>Shattering is a natural phenomenon displayed by dry fruits or capsules that dehisce at maturity to distribute seeds. This undesirable trait in commercially-important Plantago ovata can cause high yield losses, especially when triggered by weather events. However, the underlying internal and external triggers of capsule dehiscence are not well understood. This study aimed to characterise the morphological features of Plantago seed capsules, focusing on dehiscence zones (DZ) and structural components influencing capsule opening.</p><p><strong>Methods: </strong>Capsule development and dehiscence in P. ovata were examined using staining, immunolabelling, and electron microscopy, with particular emphasis on the dehiscence zone between the lid and base. Polysaccharide-directed antibodies and monosaccharide profiling were used to analyse cell wall composition. Findings were compared across three Plantago relatives ranked by manually-induced dehiscence propensity.</p><p><strong>Key results: </strong>Capsule walls are dominated by xylans and differentially-esterified pectins. The operculum (lid) shows a distinct lignification pattern absent in the capsule base. A key feature is the \"operculum hook\", a vertical cell layer with thickened walls enriched in xylans and lignin, connecting the lid to the base. The DZ contains two separation layers: the first formed by cuboidal cells lacking unesterified homogalacturonan with the second layer found at the junction between the operculum hook and the capsule base. Dehiscence occurs in two steps, involving abscission at these zones. Structural differences in the operculum hook, particularly cell wall thickness, vary across Plantago species and are correlated with ordinally ranked differences in manually-triggered dehiscence.</p><p><strong>Conclusions: </strong>Capsule dehiscence in Plantago involves two sequential separation events influenced by cell wall composition and structure. Cell wall dimensions at the operculum hook base could be critical in determining dehiscence ease. These findings provide new insights into capsule development and dehiscence, which could inform future breeding strategies to reduce yield losses in P. ovata and other crops.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143623273","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":"Lipid metabolism improves salt tolerance of Salicornia europaea.","authors":"Lei Yang, Yanzhi Wang, Yang Bai, Jiahui Yang, Yunyan Gao, Chenxue Hou, Mengya Gao, Xinlu Gu, Weizhong Liu","doi":"10.1093/aob/mcae189","DOIUrl":"10.1093/aob/mcae189","url":null,"abstract":"<p><strong>Background and aims: </strong>Salicornia europaea L., a succulent euhalophyte plant, has been found to exhibit optimal reproductive capabilities under appropriate salinity concentrations. However, the underlying metabolic changes are not yet fully understood.</p><p><strong>Methods: </strong>In this study, we conducted a comprehensive analysis combining transcriptomic and lipidomic techniques to investigate the molecular mechanisms of lipid metabolism in response to different NaCl concentrations (0 and 200 mM).</p><p><strong>Results: </strong>Transcriptomic data demonstrated that salt treatment mainly affected processes including lipid biosynthesis, phosphatidylinositol signalling and glycerophospholipid metabolism. The expression levels of several key genes involved in salt tolerance, namely SeSOS1, SeNHX1, SeVHA-A, SeVP1 and SePSS, were found to be upregulated upon NaCl treatment. A total of 485 lipid compounds were identified, of which 27 changed in abundance during salt treatment, including the enrichment of phospholipids and sphingolipids. Moreover, the increase in the double-bond index was mainly attributable to phospholipids and sphingolipids. Comparing the acyl chain length showed that the acyl chain length coefficient of sphingosine-1-phosphate decreased significantly in the presence of 200 mM NaCl.</p><p><strong>Conclusions: </strong>This study suggests that S. europaea adapts to saline environments by altering phospholipids and sphingolipids to improve salt tolerance. The salinity response of S. europaea can provide important insights into the action of lipids and their salt adaptation mechanisms.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":" ","pages":"789-802"},"PeriodicalIF":3.6,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11904900/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142520802","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":"Carnivorous Nepenthes pitcher plants combine common developmental processes to make a complex epidermal trapping surface.","authors":"Oona C Lessware, Judith M Mantell, Ulrike Bauer","doi":"10.1093/aob/mcae147","DOIUrl":"10.1093/aob/mcae147","url":null,"abstract":"<p><strong>Background and aims: </strong>A hierarchical micro-topography of ridges and steps renders the trap rim of carnivorous Nepenthes pitcher plants unusually wettable, and slippery for insects when wet. This complex three-dimensional epidermis structure forms, hidden from plain sight, inside the still-closed developing pitcher bud. Here, we reveal the sequence of epidermal patterning events that shape the trap rim. By linking this sequence to externally visible markers of bud development, we provide a framework for targeting individual stages of surface development in future studies.</p><p><strong>Methods: </strong>We used cryo-scanning electron microscopy to investigate the detailed morphogenesis and epidermal patterning of the Nepenthes × hookeriana pitcher rim. In addition, we collected morphometric and qualitative data from developing pitcher traps including those sampled for microscopy.</p><p><strong>Key results: </strong>We identified three consecutive patterning events. First, strictly oriented cell divisions resulted in radially aligned rows of cells and established a macroscopic ridge-and-groove pattern. Next, conical papillate cells formed, and papillae elongated towards the trap interior, increasingly overlapping adjacent cells and eventually forming continuous microscopic ridges. In between these ridges, the flattened papillae formed acutely angled arched steps. Finally, the cells elongated radially, thereby establishing the convex collar shape of the rim. This general sequence of surface development also showed a spatial progression from the outer to the inner trap rim edge, with several consecutive developmental stages co-occurring at any given time.</p><p><strong>Conclusions: </strong>We demonstrate that the complex surface micro-topography of the Nepenthes pitcher rim develops by sequentially combining widespread, evolutionarily conserved epidermal patterning processes in a new way. This makes the Nepenthes trap rim an excellent model for studying epidermal patterning mechanisms in leaves.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":" ","pages":"643-654"},"PeriodicalIF":3.6,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11904891/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142139069","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":"Exploring silica accumulation in bamboo leaves: a study on phytolith morphology and epidermal patterning in the tropical giant bamboo Dendrocalamus copelandii.","authors":"Naritsa Rotmuenwai, Ketsara Aryuyo, Nuttida Kruethaworn, Witoon Wattananit, Nimnara Yookongkaew","doi":"10.1093/aob/mcae209","DOIUrl":"10.1093/aob/mcae209","url":null,"abstract":"<p><strong>Background and aims: </strong>Bamboo is a grass in the Poaceae family with various applications. Bamboo leaves can accumulate high silica. However, silica deposition in bamboo has received limited study. Therefore, this research investigated silica accumulation in Dendrocalamus copelandii leaves. The study includes the localization of silica through phytolith morphology, examination of the distribution patterns of phytoliths in epidermal tissues, analysis of silica accumulation within specialized silica cells (short cells) and analysis of silicon concentration across various leaf developmental stages.</p><p><strong>Methods: </strong>We used imaging techniques, including differential interference contrast and a scanning electron microscope incorporating an energy-dispersive X-ray spectrometer, to investigate silica accumulation in bamboo leaves. We also analysed the silicon concentration using inductively coupled plasma-optical emission spectroscopy.</p><p><strong>Key results: </strong>Leaves of D. copelandii exhibited 11 phytolith morphotypes, namely Bilobate, Polylobate, Saddle, Acute, Acute bulbosus, Microhair, Stomata, Bulliform flabellate, Elongate sinuate, Elongate entire and Tracheary. Most of these phytoliths were found in short cells (Bilobate, Polylobate and Saddle) of epidermal tissues. The short cells were arranged transversely along the leaf length. Bilobate phytoliths were found in both the abaxial and adaxial epidermis, whereas the Saddle morphotype was found only in the abaxial epidermis. Silica accumulation in the short cells of unexpanded leaves begins at the leaf apex, spreads to the middle and base positions, and accumulates initially in the abaxial epidermis, then the adaxial epidermis. Moreover, bamboo leaves accumulate a higher silicon concentration as they age.</p><p><strong>Conclusions: </strong>Phytolith morphotypes and silica accumulation in epidermal short cells are key factors in understanding silica deposition. Leaf age and climate significantly impact the silicon concentration in bamboo leaves. Our findings are informative for archaeological studies and for plant taxonomical classification. The results are also applicable for biotechnological applications.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":" ","pages":"757-768"},"PeriodicalIF":3.6,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11904895/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142823864","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":"Molecular genetic regulation of the vegetative-generative transition in wheat from an environmental perspective.","authors":"Tibor Kiss, Ádám D Horváth, András Cseh, Zita Berki, Krisztina Balla, Ildikó Karsai","doi":"10.1093/aob/mcae174","DOIUrl":"10.1093/aob/mcae174","url":null,"abstract":"<p><p>The key to the wide geographical distribution of wheat is its high adaptability. One of the most commonly used methods for studying adaptation is investigation of the transition between the vegetative-generative phase and the subsequent intensive stem elongation process. These processes are determined largely by changes in ambient temperature, the diurnal and annual periodicity of daylength, and the composition of the light spectrum. Many genes are involved in the perception of external environmental signals, forming a complex network of interconnections that are then integrated by a few integrator genes. This hierarchical cascade system ensures the precise occurrence of the developmental stages that enable maximum productivity. This review presents the interrelationship of molecular-genetic pathways (Earliness per se, circadian/photoperiod length, vernalization - cold requirement, phytohormonal - gibberellic acid, light perception, ambient temperature perception and ageing - miRNA) responsible for environmental adaptation in wheat. Detailed molecular genetic mapping of wheat adaptability will allow breeders to incorporate new alleles that will create varieties best adapted to local environmental conditions.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":" ","pages":"605-628"},"PeriodicalIF":3.6,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11904908/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142370815","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":"Climatic and edaphic niche shifts during plant radiation in the Mediterranean biodiversity hotspot.","authors":"Mario Fernández-Mazuecos, Beverley J Glover","doi":"10.1093/aob/mcae205","DOIUrl":"10.1093/aob/mcae205","url":null,"abstract":"<p><strong>Background and aims: </strong>Ecological speciation is frequently invoked as a driver of plant radiation, but the behaviour of environmental niches during radiation is contentious, with patterns ranging from niche conservatism to niche divergence. Here, we investigated climatic and edaphic niche shifts during radiation in a western Mediterranean lineage of the genus Linaria (Plantaginaceae).</p><p><strong>Methods: </strong>Detailed distributional, phylogenomic and environmental data were integrated to analyse changes in climatic and edaphic niches in a spatiotemporal context, including calculation of niche overlap, niche equivalency and similarity tests, maximum entropy modelling, phylogenetic comparative methods and biogeographical analyses.</p><p><strong>Key results: </strong>Active divergence of climatic and edaphic niches within a limited subset of available conditions was detected among the eight study species and particularly between sister species. Speciation and niche divergence are estimated to have happened in the southern Iberian Peninsula in Mediterranean conditions, followed by waxing and waning of distribution ranges resulting from the Quaternary climatic cycles.</p><p><strong>Conclusions: </strong>The results support the idea that the prevalence of niche conservatism or niche divergence patterns is a matter of phylogenetic scale. Habitat isolation pertaining to both climatic and soil conditions appears to have played a role in plant speciation in the western Mediterranean biodiversity hotspot, most probably in combination with pollinator isolation and some degree of geographical isolation. These findings are in agreement with an adaptive radiation scenario incorporating certain non-adaptive features.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":" ","pages":"717-734"},"PeriodicalIF":3.6,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11904899/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142823862","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":"Functional biogeography of the thermal thresholds for post-dispersal embryo growth in Conopodium majus.","authors":"Cristina Blandino, Brith Natlandsmyr, Sylvi M Sandvik, Hugh W Pritchard, Eduardo Fernández-Pascual","doi":"10.1093/aob/mcae204","DOIUrl":"10.1093/aob/mcae204","url":null,"abstract":"<p><strong>Background and aims: </strong>Plant regeneration by seeds is driven by a set of physiological traits, many of which show functional intraspecific variation along biogeographical gradients. In many species, germination phenology depends on a germination delay imposed by the need for post-dispersal embryo growth (a.k.a. morphological dormancy). Such growth occurs as a function of environmental temperatures and shows base, optimum and ceiling temperatures (i.e. cardinal temperatures or thermal thresholds). However, the biogeographical variation in such thresholds has not been tested.</p><p><strong>Methods: </strong>We used a thermal time approach and field experiments to assess intraspecific variation at the continental scale in the embryo growth thermal thresholds of the geophyte Conopodium majus (Apiaceae) across its distribution from the Iberian Peninsula to Scandinavia.</p><p><strong>Key results: </strong>Thermal thresholds for embryo growth varied across the latitudinal gradient, with estimated optimum temperatures between 2.5 and 5.2 °C, ceiling temperatures between 12 and 20.5 °C, and base temperatures between -6.6 and -2.7 °C. Germination in the field peaked in January and February. The limiting factor for embryo growth was the ceiling temperature, which was negatively correlated with latitude and the bioclimatic environment of each population. In contrast, the optimal and base temperature were independent of local climate.</p><p><strong>Conclusions: </strong>These results indicate that thermal thresholds for embryo growth are functional ecophysiological traits that drive seed germination phenology and seed responses to the soil climatic environment. Therefore, post-dispersal embryo growth can be a key trait impacting climate change effects on phenology and species distributions.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":" ","pages":"707-716"},"PeriodicalIF":3.6,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11904901/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142692689","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":"Evolutionary diversification of C2 photosynthesis in the grass genus Homolepis (Arthropogoninae).","authors":"Joyce Pereira Alvarenga, Matt Stata, Rowan F Sage, Ria Patel, Ane Marcela das Chagas Mendonca, Felipe Della Torre, Hongbing Liu, Shifeng Cheng, Samantha Weake, Emile J Watanabe, Pedro Lage Viana, Iago Augusto de Castro Arruda, Martha Ludwig, João Paulo Rodrigues Alves Delfino Barbosa, Tammy L Sage","doi":"10.1093/aob/mcae214","DOIUrl":"10.1093/aob/mcae214","url":null,"abstract":"<p><strong>Background and aims: </strong>To better understand C4 evolution in monocots, we characterized C3-C4 intermediate phenotypes in the grass genus Homolepis (subtribe Arthropogoninae).</p><p><strong>Methods: </strong>Carbon isotope ratio (δ13C), leaf gas exchange, mesophyll (M) and bundle sheath (BS) tissue characteristics, organelle size and numbers in M and BS tissue, and tissue distribution of the P-subunit of glycine decarboxylase (GLDP) were determined for five Homolepis species and the C4 grass Mesosetum loliiforme from a phylogenetic sister clade. We generated a transcriptome-based phylogeny for Homolepis and Mesosetum species to interpret physiological and anatomical patterns in an evolutionary context, and to test for hybridization.</p><p><strong>Key results: </strong>Homolepis contains two C3 species (H. glutinosa, H. villaricensis), one species with a weaker form of C2 termed sub-C2 (H. isocalycia), and two C2 species (H. longispicula, H. aturensis). Homolepis longispicula and H. aturensis express over 85 % of leaf glycine in centripetal mitochondria within the BS, and have increased fractions of leaf chloroplasts, mitochondria and peroxisomes within the BS relative to H. glutinosa. Analysis of leaf gas exchange, cell ultrastructure and transcript expression show M. loliiforme is a C4 plant of the NADP-malic enzyme subtype. Homolepis comprises two sister clades, one containing H. glutinosa and H. villaricensis and the second H. longispicula and H. aturensis. Homolepis isocalycia is of hybrid origin, its parents being H. aturensis and a common ancestor of the C3  Homolepis clade and H. longispicula.</p><p><strong>Conclusions: </strong>Photosynthetic activation of BS tissue in the sub-C2 and C2 species of Homolepis is similar to patterns observed in C3-C4 intermediate eudicots, indicating common evolutionary pathways from C3 to C4 photosynthesis in these disparate clades. Hybridization can diversify the C3-C4 intermediate character state and should be considered in reconstructing putative ancestral states using phylogenetic analyses.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":" ","pages":"769-788"},"PeriodicalIF":3.6,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11904902/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142833774","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":"A modified petal and stamen dimorphism interact to enhance pollen placement by a buzz-pollinated flower.","authors":"Thainã R Monteiro, Rogério V S Gonçalves, Francismeire J Telles, Gudryan J Barônio, Anselmo Nogueira, Vinícius L G Brito","doi":"10.1093/aob/mcae210","DOIUrl":"10.1093/aob/mcae210","url":null,"abstract":"<p><strong>Background: </strong>Floral adaptations supposedly help pollen grains to cross the numerous barriers faced during their journey to stigmas. Stamen dimorphism and specialized petals, like the cucculus in the Cassieae tribe (Fabaceae), are commonly observed in flowers that offer only pollen as a resource for bee pollinators. Here, we experimentally investigated whether stamen dimorphism and the cucculus enhance pollen placement on the bee's body.</p><p><strong>Methods: </strong>We used 3-D-printed bee models to apply artificial vibrations to the flowers of Chamaechrista latistipula with their cucculus deflected or maintained in its original position and their anther pores manipulated. After each simulated flower visit, we captured photographs of the artificial bee from four distinct angles. Employing digital imaging techniques, we documented the presence and location of pollen and stigma on the bee's body.</p><p><strong>Key results: </strong>Our findings reveal that the cucculus redistributes pollen grains on the bee's body. There is a remarkable increase in pollen density (~10-fold) on the lateral side adjacent to the cucculus, precisely where the stigma contacts the bee when the cucculus is unmanipulated. Furthermore, the cucculus also enhances pollen placement on the ventral region of the bee, indicating its additional function. The cucculus also increases the accuracy of pollen grains on the adjacent lateral region of the bee's body, irrespective of the pollen grains released by small or large anthers.</p><p><strong>Conclusions: </strong>Floral specialized traits, such as modified petals and stamen dimorphism, can modify the fate of pollen grains and ultimately contribute to male reproductive performance in pollen flowers with poricidal anthers. The cucculus exhibits a dual role by promoting pollen placement in optimal regions for pollination and probably supporting pollen grains for bee feeding. These findings provide valuable insights into the adaptive significance of floral traits and their impact on the reproductive success of pollen flowers.</p>","PeriodicalId":8023,"journal":{"name":"Annals of botany","volume":" ","pages":"669-680"},"PeriodicalIF":3.6,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11904892/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142826524","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}