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The California Pipevine, Aristolochia californica Torr., is the only endemic California species within the cosmopolitan birthwort family Aristolochiaceae. It occurs as an understory vine in riparian and chaparral areas and in forest edges and windrows. The geographic range of this plant species almost entirely overlaps with that of its major specialized herbivore, the California Pipevine Swallowtail Butterfly Battus philenor hirsuta. While this species pair is a useful, ecologically well-understood system to study co-evolution, until recently, genomic resources for both have been lacking. Here, we report a new, chromosome-level assembly of A. californica as part of the California Conservation Genomics Project (CCGP). Following the sequencing and assembly strategy of the CCGP, we used Pacific Biosciences HiFi long reads and Hi-C chromatin proximity sequencing technology to produce a de novo assembled genome. Our genome assembly, the first for any species in the genus, contains 531 scaffolds spanning 661 megabase (Mb) pairs, with a contig N50 of 6.53 Mb, a scaffold N50 of 42.2 Mb, and BUSCO complete score of 98%. In combination with the recently published B. philenor hirsuta reference genome assembly, the A. californica reference genome assembly will be a powerful tool for studying co-evolution in a rapidly changing California landscape.

In this review, we tried to summarize the results of all more or less noticeable works carried out in recent years and devoted to the search for ecological factors influencing the corolla color in flowering plants. The influence of various factors on corolla color has been established, including temperature, precipitation, soil characteristics, geographic latitude and longitude, distance from the place of species origin, interaction with pollinators, and in some cases the nature of such influence has been analyzed. However, it should be noted that the results obtained are rather scattered and relate to particular species, groups or phytocenoses. Significant efforts remain to be done to summarize the particular results into an overall picture, and we offer and justify our proposals for the direction of future research.

Abstract Background Horizontal gene transfer (HGT) events have rarely been reported in gymnosperms. Gnetum is a gymnosperm genus comprising 25‒35 species sympatric with angiosperms in West African, South American, and Southeast Asian rainforests. Only a single acquisition of an angiosperm mitochondrial intron has been documented to date in Asian Gnetum mitogenomes. We wanted to develop a more comprehensive understanding of frequency and fragment length distribution of such events as well as their evolutionary history in this genus. Results We sequenced and assembled mitogenomes from five Asian Gnetum species. These genomes vary remarkably in size and foreign DNA content. We identified 15 mitochondrion-derived and five plastid-derived (MTPT) foreign genes. Our phylogenetic analyses strongly indicate that these foreign genes were transferred from diverse eudicots—mostly from the Rubiaceae genus Coptosapelta and ten genera of Malpighiales. This indicates that Asian Gnetum has experienced multiple independent HGT events. Patterns of sequence evolution strongly suggest DNA-mediated transfer between mitochondria as the primary mechanism giving rise to these HGT events. Most Asian Gnetum species are lianas and often entwined with sympatric angiosperms. We therefore propose that close apposition of Gnetum and angiosperm stems presents opportunities for interspecific cell-to-cell contact through friction and wounding, leading to HGT. Conclusions Our study reveals that multiple HGT events have resulted in massive amounts of angiosperm mitochondrial DNA integrated into Asian Gnetum mitogenomes. Gnetum and its neighboring angiosperms are often entwined with each other, possibly accounting for frequent HGT between these two phylogenetically remote lineages.

The present review aims to explore the traditional plant knowledge and utilization practices among the local tribal communities in Yavatmal district, Maharashtra, India. To document ethnobotanical uses, the published literature including journals, floras and other online published sources was surveyed. A total of 370 taxa belonging to 290 genera and 82 families were identified. Local communities employ these plant species for various purposes. Traditional medicinal practices in local communities involve the use of both monoherbal and polyherbal remedies. Notably, this study indicated a higher prevalence of dermatological and gastrointestinal disorders in the district. Interestingly, research has also found that 34 invasive plant species are being utilized by the local tribal communities for healing various ailments. We have also computed the citation index (CI) and use index (UI) for each species. This study illuminates the rich traditional plant knowledge and its multifaceted applications within the local tribal communities of Yavatmal district of Maharashtra, India. The documentation of traditional plant knowledge in this region provides valuable insights into conservation efforts and the development of sustainable practices that respect the intricate bonds between people and nature. [ABSTRACT FROM AUTHOR]

Fossil woods are preserved as calcareous permineralizations in the Upper Cretaceous Northumberland Formation on Collishaw Point, Hornby Island, British Columbia, Canada. They are well preserved, often including peripheral tissues, and reveal the diversity and structure of vegetation in the region ca. 72 million years ago. We describe a new genus and species based on two specimens. Two specimens were cut using a rock saw to expose the fossil wood in transverse and longitudinal sections. Thin sections were prepared using the cellulose acetate peel technique. Peels were mounted on slides with Eukitt mounting medium. Anatomical description follows the IAWA guidelines. We compared the anatomy of the fossils with that of other plants using data available in the published literature and the InsideWood database. The combination of wide vessels and high vessel frequency given the narrow diameter of the stem, combined with the abrupt increase in vessel diameter near the pith indicates this plant had hydraulic properties typical of a climbing plant (liana). The anatomy of the rays, the arrangement of the vessels and their pitting, and the thickness of the bark are also consistent with the climbing habit, but not diagnostic of any extant family. This is the second species of liana to be described from the Hornby Island assemblage, providing new information about the composition of structurally complex mixed conifer–angiosperm forests in the Late Cretaceous of western North America. [ABSTRACT FROM AUTHOR]

Double fertilization in angiosperms results in the formation of a second zygote, the fertilized endosperm. Unlike its embryo sibling, the endosperm is a transient structure that eventually undergoes developmentally controlled programmed cell death (PCD) at specific time points of seed development or germination. The nature of endosperm PCD exhibits a considerable diversity, both across different angiosperm taxa and within distinct endosperm tissues. In endosperm-less species, PCD might cause central cell degeneration as a mechanism preventing the formation of a fertilized endosperm. In most other angiosperms, embryo growth necessitates the elimination of surrounding endosperm cells. Nevertheless, complete elimination of the endosperm is rare and, in most cases, specific endosperm tissues persist. In mature seeds, these persisting cells may be dead, such as the starchy endosperm in cereals, or remain alive to die only during germination, like the cereal aleurone or the endosperm of castor beans. In this review, we explore current knowledge surrounding the cellular, molecular, and genetic aspects of endosperm PCD, and the influence environmental stresses have on PCD processes. Overall, this review provides an exhaustive overview of endosperm PCD processes in angiosperms, shedding light on its diverse mechanisms and its significance in seed development and seedling establishment. [ABSTRACT FROM AUTHOR]

Main conclusion: In this review, we summarize how chlorophyll metabolism in angiosperm is affected by the environmental factors: light, temperature, metal ions, water, oxygen, and altitude. The significance of chlorophyll (Chl) in plant leaf morphogenesis and photosynthesis cannot be overstated. Over time, researchers have made significant advancements in comprehending the biosynthetic pathway of Chl in angiosperms, along with the pivotal enzymes and genes involved in this process, particularly those related to heme synthesis and light-responsive mechanisms. Various environmental factors influence the stability of Chl content in angiosperms by modulating Chl metabolic pathways. Understanding the interplay between plants Chl metabolism and environmental factors has been a prominent research topic. This review mainly focuses on angiosperms, provides an overview of the regulatory mechanisms governing Chl metabolism, and the impact of environmental factors such as light, temperature, metal ions (iron and magnesium), water, oxygen, and altitude on Chl metabolism. Understanding these effects is crucial for comprehending and preserving the homeostasis of Chl metabolism. [ABSTRACT FROM AUTHOR]

Background: Horizontal gene transfer (HGT) events have rarely been reported in gymnosperms. Gnetum is a gymnosperm genus comprising 25‒35 species sympatric with angiosperms in West African, South American, and Southeast Asian rainforests. Only a single acquisition of an angiosperm mitochondrial intron has been documented to date in Asian Gnetum mitogenomes. We wanted to develop a more comprehensive understanding of frequency and fragment length distribution of such events as well as their evolutionary history in this genus. Results: We sequenced and assembled mitogenomes from five Asian Gnetum species. These genomes vary remarkably in size and foreign DNA content. We identified 15 mitochondrion-derived and five plastid-derived (MTPT) foreign genes. Our phylogenetic analyses strongly indicate that these foreign genes were transferred from diverse eudicots—mostly from the Rubiaceae genus Coptosapelta and ten genera of Malpighiales. This indicates that Asian Gnetum has experienced multiple independent HGT events. Patterns of sequence evolution strongly suggest DNA-mediated transfer between mitochondria as the primary mechanism giving rise to these HGT events. Most Asian Gnetum species are lianas and often entwined with sympatric angiosperms. We therefore propose that close apposition of Gnetum and angiosperm stems presents opportunities for interspecific cell-to-cell contact through friction and wounding, leading to HGT. Conclusions: Our study reveals that multiple HGT events have resulted in massive amounts of angiosperm mitochondrial DNA integrated into Asian Gnetum mitogenomes. Gnetum and its neighboring angiosperms are often entwined with each other, possibly accounting for frequent HGT between these two phylogenetically remote lineages. [ABSTRACT FROM AUTHOR]

Aim Location Taxon Methods Results Main Conclusions Beta‐diversity quantifies the change in taxonomic and phylogenetic composition between areas, and is a scalar between local (α) and regional (γ) diversity. Geographic distance, which reflects dispersal limitation, and climatic distance, which reflects environmental filtering, are major drivers of β‐diversity. Here, we analyse a comprehensive data set of angiosperms in regional floras across Africa to assess the relationships of β‐diversity, and its components, to three major types of environmental variables (current climate, Quaternary climate change and topographic heterogeneity) thought to drive β‐diversity.Africa.Angiosperms.Africa was divided into 27 regions. Species lists of angiosperms for each region were collated. The relationships of both taxonomic and phylogenetic β‐diversity, and their respective turnover and nestedness components, with geographic and environmental distances were assessed.This study showed that (1) regions of the lowest β‐diversity are located in moist tropical climates, (2) the turnover and nestedness components of β‐diversity are negatively correlated with each other, (3) taxonomic β‐diversity is higher than phylogenetic β‐diversity across Africa, (4) variation in β‐diversity of angiosperms is more strongly associated with current climate than with Quaternary climate change and topographic heterogeneity and (5) the variation in taxonomic β‐diversity and its turnover component that is independently explained by geographic distance is much larger than that is independently explained by climatic distance for angiosperms in Africa.The finding that geographic distance explained more variation than climatic distance suggests that dispersal limitation plays a greater role than environmental filtering in shaping angiosperm β‐diversity in Africa. Of climatic factors, current climate plays a more important role than Quaternary climate change in shaping angiosperm β‐diversity in Africa. [ABSTRACT FROM AUTHOR]

The article titled "PRAXELIS CLEMATIDEA (GRISEB.) R.M. KING & H. ROB. (ASTERACEAE): A NEW ALLIEN INVASIVE ANGIOSPERMIC RECORD FOR BANGLADESH" discusses the discovery of a new species of plant, Praxelis clematidea, in Bangladesh. The article provides a comprehensive description of the species, including its physical characteristics and distribution. The plant is an annual or short-lived perennial herb that grows in waste areas, grasslands, and cultivated lands. It possesses various medicinal properties, such as anti-inflammatory and antioxidant activities. The article also discusses the taxonomic classification and invasive nature of Praxelis clematidea, highlighting its resemblance to other weed species and the potential threat it poses to native plant species in Bangladesh. [Extracted from the article]

Endemism of lineages lies at the core of understanding variation in community composition among geographic regions because it reflects how speciation, extinction, and dispersal have influenced current distributions. Here, we investigated geographic patterns and ecological drivers of taxonomic and phylogenetic endemism of angiosperm genera across the world. We identify centers of paleo-endemism and neo-endemism of angiosperm genera, and show that they are mostly located in the Southern Hemisphere in tropical and subtropical regions, particularly in Asia and Australia. Different categories of phylogenetic endemism centers can be differentiated using current climate conditions. Current climate, historical climate change, and geographic variables together explained ∼80% of global variation in taxonomic and phylogenetic endemism, while 42−46%, 1%, and 15% were independently explained by these three types of variables, respectively. Thus our findings show that past climate change, current climate, and geography act together in shaping endemism, which are consistent with the findings of previous studies that higher temperature and topographic heterogeneity promote endemism. Our study showed that many centers of phylogenetic endemism of angiosperms, including regions in Amazonia, Venezuela, and west-central tropical Africa that have not previously been identified as biodiversity hotspots, are missed by taxon-based measures of endemism, indicating the importance of including evolutionary history in biodiversity assessment.

AP2/ERF transcription factor family plays an important role in plant development and stress responses. Previous studies have shed light on the evolutionary trajectory of the AP2 and DREB subfamilies. However, knowledge about the evolutionary history of the ERF subfamily in angiosperms still remains limited. In this study, we performed a comprehensive analysis of the ERF subfamily from 107 representative angiosperm species by combining phylogenomic and synteny network approaches. We observed that the expansion of the ERF subfamily was driven not only by whole-genome duplication (WGD) but also by tandem duplication (TD) and transposition duplication events. We also found multiple transposition events in Poaceae, Brassicaceae, Poales, Brassicales, and Commelinids. These events may have had notable impacts on copy number variation and subsequent functional divergence of the ERF subfamily. Moreover, we observed a number of ancient tandem duplications occurred in the ERF subfamily across angiosperms, e.g., in Subgroup IX, IXb originated from ancient tandem duplication events within IXa. These findings together provide novel insights into the evolution of this important transcription factor family. [ABSTRACT FROM AUTHOR]

The transcription factor is an essential factor for regulating the responses of plants to external stimuli. The WRKY protein is a superfamily of plant transcription factors involved in response to various stresses (e.g., cold, heat, salt, drought, ions, pathogens, and insects). During angiosperm evolution, the number and function of WRKY transcription factors constantly change. After suffering from long-term environmental battering, plants of different evolutionary statuses ultimately retained different numbers of WRKY family members. The WRKY family of proteins is generally divided into three large categories of angiosperms, owing to their conserved domain and three-dimensional structures. The WRKY transcription factors mediate plant adaptation to various environments via participating in various biological pathways, such as ROS (reactive oxygen species) and hormone signaling pathways, further regulating plant enzyme systems, stomatal closure, and leaf shrinkage physiological responses. This article analyzed the evolution of the WRKY family in angiosperms and its functions in responding to various external environments, especially the function and evolution in Magnoliaceae plants. It helps to gain a deeper understanding of the evolution and functional diversity of the WRKY family and provides theoretical and experimental references for studying the molecular mechanisms of environmental stress. [ABSTRACT FROM AUTHOR]

Phylogenetic signal (PS) is the propensity of closely related species to resemble each other. PS has been tested across clades of terrestrial plants; however, insight for seagrasses is still lacking. Signatures of PS and models of niche (trait) evolution can help to detect phylogenetic niche conservatism (PNC), that is, close relatives live in comparable niches.The initial goal of this study was to assess the pattern of PS for the world's seagrasses, by testing the non‐independence of phylogenetic relatedness and seagrass species traits. A phylogeny of 49 seagrasses was constructed, together with a matrix of nine traits covering morphological, life‐history and reproductive attributes. PS of traits was tested through complementary indices (Pagel's λ, Blomberg's K, Moran's I and Abouheif's Cmean). Three models of niche evolution (Brownian Motion, BM; Ornstein–Uhlenbeck, OU; Early Burst, EB) were then fitted to each trait and the multivariate trait matrix.Results supported the existence of strong PS for seagrasses, with a particularly large effect size for seagrass reproductive traits, which followed an EB evolution model. Local Indicators of Phylogenetic Association (local autocorrelation metrics that can help to identify areas of large autocorrelation) supported the presence of PS across seagrass lineages/clades, supported by the dominance of OU as the most parsimonious trait evolution model.The pattern of strong PS seems to be a consequence of long‐term PNC of seagrass traits after initial radiation.Synthesis: Our study highlights the relevance of evolution from common ancestors and shared history underpinning large seagrass phylogenetic structuring. [ABSTRACT FROM AUTHOR]

Not all colours are perceived and interpreted equally. The electromagnetic spectrum is perceived differently by the distinct visual systems of animal species, resulting in differences in each species’ colour perception. Given the diverse colours found in flowering plants, it is interesting to consider the colour perception of insects and the co-evolution of flowering plants to attract pollinators. Here, we considered the differences between human visual systems and that of bees and flies—the two largest insect pollinator groups. We collected flower reflectance spectral data of 73 species across seven human-perceived colours using a spectrophotometer. Minimum of 3 different flowers were used to measure the reflectance properties of flower colours. The raw data can be used to visualize the different animals’ visual systems i.e. it can be processed and translated into known photoreceptors of human, bee, and fly visual systems. Overall, our data will help to compare how different animals see flower colours in the natural world and will also highlight the importance of understanding the interspecific communication in plant-pollinator communities. Thus, our data will assist scientists in the future to recognize the floral colour evolution in angiosperms.

Fruit functions in seed protection and dispersal and belongs to many dry and fleshy types, yet their evolutionary pattern remains unclear in part due to uncertainties in the phylogenetic relationships among several orders and families. Thus we used nuclear genes of 502 angiosperm species representing 231 families to reconstruct a well supported phylogeny, with resolved relationships for orders and families with previously uncertain placements. Using this phylogeny as a framework, molecular dating supports a Triassic origin of the crown angiosperms, followed by the emergence of most orders in the Jurassic and Cretaceous and their rise to ecological dominance during the Cretaceous Terrestrial Revolution. The robust phylogeny allowed an examination of the evolutionary pattern of fruit and ovary types, revealing a trend of parallel carpel fusions during early diversifications in eudicots, monocots, and magnoliids. Moreover, taxa in the same order or family with the same ovary type can develop either dry or fleshy fruits with strong correlations between specific types of dry and fleshy fruits; such associations of ovary, dry and fleshy fruits define several ovary‐fruit "modules" each found in multiple families. One of the frequent modules has an ovary containing multiple ovules, capsules and berries, and another with an ovary having one or two ovules, achenes (or other single‐seeded dry fruits) and drupes. This new perspective of relationships among fruit types highlights the closeness of specific dry and fleshy fruit types, such as capsule and berry, that develop from the same ovary type and belong to the same module relative to dry and fleshy fruits of other modules (such as achenes and drupes). Further analyses of gene families containing known genes for ovary and fruit development identified phylogenetic nodes with multiple gene duplications, supporting a possible role of whole‐genome duplications, in combination with climate changes and animal behaviors, in angiosperm fruit and ovary diversification. [ABSTRACT FROM AUTHOR]

The Australian genus Isopogon (Proteaceae) consists of approximately 39 species, most of which occur in southwestern Australia, a region of considerable endemism and biodiversity. Unresolved taxonomic issues exist for two species complexes (nine suspected taxa) allied to I. spathulatus and I. polycephalus. There is uncertainty in how to delimit species in these two complexes due to unclear or overlapping morphological characters, although recognition of four phrase‐named taxa provide starting hypotheses for potential new taxa. We used a genomic approach (ddRAD) to generate SNPs for 146 samples from 32 populations across the two complexes to evaluate the genomic distinction of taxa and delimit species. We used an optimised ipyrad assembly of the sequenced libraries, followed by custom filtering of samples and SNPs for ordination, genetic structure, distance and concatenation and coalescent phylogenetic analyses. Population genetic and phylogenetic analyses consistently supported three geographically overlapping yet genomically distinct groups, two of which showed additional genomic divergence consistent with multiple distinct species. Existing morphological hypotheses were congruent with genomic groupings in some cases but discordant in others, where genomic admixture suggested existing taxa were conspecific. Evaluating morphological characters, geographic distribution and genomic distinction, we recognise five species and three subspecies from nine original taxa. We provide a key to species in the complexes and related taxa, updated descriptions for existing taxa, and describe two new species, I. elatus sp. nov. and I. pallidus sp. nov., and two new subspecies, I. spathulatus subsp. obovatus stat. nov. and I. spathulatus subsp. elongatus subsp. nov. [ABSTRACT FROM AUTHOR]

Fire is a disturbance that serves to maintain the diverse mosaic of vegetation in the Eastern Deciduous Forest. However, our ability to reconstruct fire occurrence from hardwood tree scars still lags far behind our expertise in reconstructing fire history from conifers in the western United States. This study examines the fidelity of fire scaring in multiple tree species in the Big Oaks National Wildlife Refuge in Indiana, which is located in the central hardwood region of the Eastern Deciduous Forest. All 15 species, except for red oak, showed evidence of past fires, and most samples recorded multiple fire events. No fire scars were recorded in the latewood of the samples. Most of the fires scars occurred in the earlywood (May) suggesting the dormant season fires are likely associated with fires in March to April before the growing season begins. No synchronous fires were recorded across all sites, but fires occurred in 1981, 1982, 1984, 1985, and 1988 across multiple sites. This suggests that these were larger spreading fires. Establishment pulses were documented in association with fire events in 1981, 1984, and 1995, suggesting that fire may benefit the establishment or root sprouting of some hardwood species. Fourteen of the fifteen species that we sampled preserved fire scars, suggesting that the diverse suite of species in the Eastern Deciduous Forest is a viable sampling pool for examining fire history across this forest type. [ABSTRACT FROM AUTHOR]

Bee and angiosperm communities engage in myriad symbioses with microbial communities, conferring benefits, enduring costs, and exchanging fitness trade-offs. Microbiota facilitate bee development by processing, protecting, and preserving the pollen provisions of young bees, while suppressing pathogen establishment. For angiosperms, microbes influence floral attractancy, increase fertilization, and antagonize pathogens. Bee and angiosperm communities provide their microbial associates with vital resources, such as pollen, nectar, resins, transportation, and shelter. These microbial communities 'hitchhike' on bees and then feed upon the pollen–nectar provisions that bees curate within their hives/nests. Such microbes contribute significantly to the enduring success of their tripartite (three-way) mutualisms with bees and angiosperms. This ancient relationship has been profoundly influential across the major terrestrial ecosystems on Earth. Recognizing symbiotic microbes as true mutualists in this three-way partnership should recalibrate conservation strategies by widening the lens to include the vital, although inconspicuous, symbionts of bees and angiosperms. While bee–angiosperm mutualisms are widely recognized as foundational partnerships that have shaped the diversity and structure of terrestrial ecosystems, these ancient mutualisms have been underpinned by 'silent third partners': microbes. Here, we propose reframing the canonical bee–angiosperm partnership as a three-way mutualism between bees, microbes, and angiosperms. This new conceptualization casts microbes as active symbionts, processing and protecting pollen–nectar provisions, consolidating nutrients for bee larvae, enhancing floral attractancy, facilitating plant fertilization, and defending bees and plants from pathogens. In exchange, bees and angiosperms provide their microbial associates with food, shelter, and transportation. Such microbial communities represent co-equal partners in tripartite mutualisms with bees and angiosperms, facilitating one of the most important ecological partnerships on land. [ABSTRACT FROM AUTHOR]

Lauraceae have one of the oldest fossil records of angiosperms with the earliest known evidence from the mid-Cretaceous. However, most of these records are based on leaves, especially from the Cenozoic of Asia, which are often challenging to assign to extinct or extant genera or species. In contrast, fossils of reproductive organs are more informative, but remain scarce. We here described the first Cenozoic Lauraceae flower of Asia and confirmed the presence of Cryptocarya in the Miocene Zhangpu flora (Fujian Province, south-eastern China) based on an amber inclusion. We scanned the specimen using synchrotron radiation-based micro-computed tomography (SRμCT) and then compared the fossil with extant flowers of the genus. The present fossil flower is small, bisexual, and polysymmetric, with a whorled and trimerous perianth and androecium along with a hypanthium around the gynoecium. The perianth comprises six undifferentiated tepals, the androecium consists of nine stamens and three innermost staminodes, and the gynoecium of a single carpel with a superior, unilocular (and uniovulate) ovary. Our study also shows that the fossil shares an unusual position of the typical staminal glands and a short androecial tube on the rim of the hypanthium with at least one extant Australian species of Cryptocarya, which have not been reported before. Nowadays, Lauraceae are still present in tropical to subtropical regions, mostly in American and Asian rainforests. The discovery of many Lauraceae leaf fossils in Zhangpu, as well as the amber flower of this study, is consistent with the current reconstruction of the amber source environment as a megathermal seasonal rainforest during the Mid-Miocene. [ABSTRACT FROM AUTHOR]

In this review, we tried to summarize the results of all more or less noticeable works carried out in recent years and devoted to the search for ecological factors influencing the corolla color in flowering plants. The influence of various factors on corolla color has been established, including temperature, precipitation, soil characteristics, geographic latitude and longitude, distance from the place of species origin, interaction with pollinators, and in some cases the nature of such influence has been analyzed. However, it should be noted that the results obtained are rather scattered and relate to particular species, groups or phytocenoses. Significant efforts remain to be done to summarize the particular results into an overall picture, and we offer and justify our proposals for the direction of future research. [ABSTRACT FROM AUTHOR]

Argonaute (AGO) proteins are central players in RNA interference in eukaryotes. They associate with small RNAs (sRNA) and lead to transcriptional or posttranscriptional silencing of targets, thereby regulating diverse biological processes. The molecular and biological functions of AGO proteins have been extensively characterized, particularly in a few angiosperm species, leading to the recognition that the AGO family has expanded to accommodate diverse sRNAs thereby performing diverse biological functions. However, understanding of the expansion of AGO proteins in plants is still limited, due to a dearth of knowledge of AGO proteins in green algal groups. Here, we identified more than 2900 AGO proteins from 244 plant species, including green algae, and performed a large-scale phylogenetic analysis. The phylogeny shows that the plant AGO family gave rise to four clades after the emergence of hydrobiontic algae and prior to the emergence of land plants. Subsequent parallel expansion in ferns and angiosperms resulted in eight main clades in angiosperms: AGO2, AGO7, AGO6, AGO4, AGO1, AGO10a, AGO10b and AGO5. On the basis of this phylogeny, we identified two novel AGO4 orthologs that Arabidopsis does not have, and redefined AGO10, which is composed of AGO10a and AGO10b. Finally, we propose a hypothetical evolutionary model of AGO proteins in plants. Our studies provide a deeper understanding of the phylogenetic relationships of AGO family members in the green lineage, which would help to further reveal their roles as RNAi effectors.

Beta diversity (β-diversity) is the scalar between local (α) and regional (γ) diversity. Understanding geographic patterns of β-diversity is central to ecology, biogeography, and conservation biology. A full understanding of the origin and maintenance of geographic patterns of β-diversity requires exploring both taxonomic and phylogenetic β-diversity, as well as their respective turnover and nestedness components, and exploring phylogenetic β-diversity at different evolutionary depths. In this study, we explore and map geographic patterns of β-diversity for angiosperm genera in regional floras across the world. We examine both taxonomic and phylogenetic β-diversity and their constituent components, and both tip-weighted and basal-weighted phylogenetic β-diversity, and relate them to latitude. On the one hand, our study found that the global distribution of β-diversity is highly heterogeneous. This is the case for both taxonomic and phylogenetic β-diversity, and for both tip-weighted and basal-weighted phylogenetic β-diversity. On the other hand, our study found that there are highly consistent geographic patterns among different metrics of β-diversity. In most cases, metrics of β-diversity are negatively associated with latitude, particularly in the Northern Hemisphere. Different metrics of taxonomic β-diversity are strongly and positively correlated with their counterparts of phylogenetic β-diversity.

A new angiosperm is reported based on a leaf specimen from the Early Cretaceous Chijinpu Formation in Beishan area, Northwest China. The associated plants include abundant gymnosperms and ferns. The new angiosperm leaf, discovered for the first time in this region, has a cordate base and peltate excentric lamina attachment. Cluster analysis and morphological comparisons with other angiosperm leaves show that this specimen is more similar to peltate fossil leaves. However, the exact taxonomic position of this fossil leaf is uncertain due to limited characters, so that we established a new genus and species, Gansupeltata beishanensis gen. et sp. nov. The new finding adds to the diversity of early angiosperms, and further demonstrates that angiosperms have already evolved during the Early Cretaceous in the Beishan area, Northwest China. [ABSTRACT FROM AUTHOR]

Dinosaurs were the dominant megaherbivores during the Cretaceous when angiosperms, the flowering plants, emerged and diversified. How herbivorous dinosaurs responded to the increasing diversity of angiosperms is largely unknown due to the lack of methods that can reconstruct diet directly from body fossils. We applied dental microwear texture analysis (DMTA), an approach that quantifies microtopography of diet‐induced wear marks on tooth surfaces, to ornithopods, the dinosaur clade that includes taxa with the most sophisticated masticatory system. We found that Late Cretaceous ornithopods have significantly rougher dental microwear texture (DMT) compared to pre‐Late Cretaceous ornithopods, and DMT variation increased in hadrosaurids, a derived Late Cretaceous ornithopod clade. These changes indicate a likely temporal dietary shift towards more abrasive foodstuffs within ornithopods, probably due to the increased ingestion of phytoliths (amorphous silica bodies in plants). Phytoliths are a main source of rough DMT in modern herbivores, along with exogenous dust and grit, and were generally more concentrated in Late Cretaceous angiosperms than in other major plant groups. Our results show that DMTA of the occlusal enamel surface can be used to reconstruct the diets of herbivorous dinosaurs, with a resolution superior to conventional methods. [ABSTRACT FROM AUTHOR]

Fossil plants, including large trunks, stems, some branches, and twigs, were collected from the Maastrichtian (68.9 Ma), upper Dorotea Formation in the Magallanes–Austral Basin, 16 km north of the Cerro Guido–Las Chinas complex in the southern Chilean Magallanes region. These fossil trunks range from 0.2 to 2.2 m in length. Petrographic slides were made in three sections (transverse, radial and tangential) and analysed under a light microscope to study the permineralized fossils. The woods and stems belong to Austroginkgoxylon gen. et sp. nov., Agathoxylon antarcticum, Podocarpoxylon paradoxi sp. nov., Podocarpoxylon mazzonii, Palmoxylon subantarcticae and Notomalvaceoxylon magallanense gen. et sp. nov. The growth rings of gymnosperms and anatomical characters of angiosperms were analysed to obtain palaeoecological data. Interactions between gymnosperm roots growing into the secondary xylem of an angiosperm (nurse logs) are recorded. The data obtained from the fossil woods suggest warm and humid conditions in this southern South American locality during the Late Cretaceous, providing a unique opportunity to study continental environments at high southern latitudes, which are poorly represented on a global scale. [ABSTRACT FROM AUTHOR]

The population status and age distribution of Baobab (Adansonia digitata L.) trees in Zing Local Government Area of Taraba State, Nigeria, were studied. Six (6) wards cutting across 25 villages were purposely selected, and baobab clusters were randomly sampled. Data on the number of stands, stand density (SD) per cluster, height, CBH, crown cover (CC), number of branches (NB), and number of flowers or fruits (NF) were recorded. A total of 851 baobab stands were recorded in an area covering 751,105.56 m2 . Zing AI, AII, and B recorded 18 clusters (35.25%) and a total stand of 370 (43.46%), while Dingding, Monkin, and Yakoko recorded 33 clusters (54.71%) and a total stand of 481 (56.92%). Baobab clusters were more aggregated in Dingding, Monkin, and Yakoko than in Zing AI, AII, and B. Mean CBH (4.23+0.26), mean CC (3.78+0.48), mean NB (5.70+1.65), mean NF (18.94+13.94), and area of clusters (416,135.91m2 ) were highest in Zing AI, AII, and B, while total stand (481), SD (1.43E-3), and mean baobab height (13.94+1.63) were highest in Dingding, Monkin, and Yakoko, although not statistically significant (p>0.05). The results also revealed very low natural regeneration, as only 66 (7.76%) juveniles and 785 (92.24%) adults were recorded, with no single seedling sighted. We therefore, recommend that extensive research be conducted into unearthing the factors limiting natural regeneration and poor recruitment of young baobab trees. [ABSTRACT FROM AUTHOR]

Species diversity of angiosperms (flowering plants) varies greatly among regions. Geographic patterns of variation in species diversity are shaped by the interplay of ecological and evolutionary processes. Here, using a comprehensive data set for regional angiosperm floras across the world, we show geographic patterns of taxonomic (species) diversity, phylogenetic diversity, phylogenetic dispersion, and phylogenetic deviation (i.e., phylogenetic diversity after accounting for taxonomic diversity) across the world. Phylogenetic diversity is strongly and positively correlated with taxonomic diversity; as a result, geographic patterns of taxonomic and phylogenetic diversity across the world are highly similar. Areas with high taxonomic and phylogenetic diversity are located in tropical regions whereas areas with low taxonomic and phylogenetic diversity are located in temperate regions, particularly in Eurasia and North America, and in northern Africa. Similarly, phylogenetic dispersion is, in general, higher in tropical regions and lower in temperate regions. However, the geographic pattern of phylogenetic deviation differs substantially from those of taxonomic and phylogenetic diversity and phylogenetic dispersion. As a result, hotspots and coldspots of angiosperm diversity identified based on taxonomic and phylogenetic diversity and phylogenetic dispersion are incongruent with those identified based on phylogenetic deviations. Each of these metrics may be considered when selecting areas to be protected for their biodiversity.

Human activities have caused the exchange of species among different parts of the world. When introduced species become naturalized and invasive, they may cause great negative impacts on the environment and human societies, and pose significant threats to biodiversity and ecosystem structure. Knowledge on phylogenetic relatedness between native and non-native species and among non-native species at different stages of species invasion may help for better understanding the drivers of species invasion. Here, I analyze a comprehensive data set including both native and non-native angiosperm species in China to determine phylogenetic relatedness of introduced species across a full invasion continuum (from introduction through naturalization to invasion). This study found that (1) introduced plants are a phylogenetically clustered subset of overall (i.e. native plus non-native) angiosperm flora, (2) naturalized plants are a phylogenetically clustered subset of introduced plants, and (3) invasive plants are a phylogenetically clustered subset of naturalized plants. These patterns hold regardless of spatial scales examined (i.e. national versus provincial scale) and whether basal- or tip-weighted metric of phylogenetic relatedness is considered. These findings are consistent with Darwin's preadaptation hypothesis.

AP2/ERF transcription factor family plays an important role in plant development and stress responses. Previous studies have shed light on the evolutionary trajectory of the AP2 and DREB subfamilies. However, knowledge about the evolutionary history of the ERF subfamily in angiosperms still remains limited. In this study, we performed a comprehensive analysis of the ERF subfamily from 107 representative angiosperm species by combining phylogenomic and synteny network approaches. We observed that the expansion of the ERF subfamily was driven not only by whole-genome duplication (WGD) but also by tandem duplication (TD) and transposition duplication events. We also found multiple transposition events in Poaceae, Brassicaceae, Poales, Brassicales, and Commelinids. These events may have had notable impacts on copy number variation and subsequent functional divergence of the ERF subfamily. Moreover, we observed a number of ancient tandem duplications occurred in the ERF subfamily across angiosperms, e.g., in Subgroup IX, IXb originated from ancient tandem duplication events within IXa. These findings together provide novel insights into the evolution of this important transcription factor family.

The transcription factor is an essential factor for regulating the responses of plants to external stimuli. The WRKY protein is a superfamily of plant transcription factors involved in response to various stresses (e.g., cold, heat, salt, drought, ions, pathogens, and insects). During angiosperm evolution, the number and function of WRKY transcription factors constantly change. After suffering from long-term environmental battering, plants of different evolutionary statuses ultimately retained different numbers of WRKY family members. The WRKY family of proteins is generally divided into three large categories of angiosperms, owing to their conserved domain and three-dimensional structures. The WRKY transcription factors mediate plant adaptation to various environments via participating in various biological pathways, such as ROS (reactive oxygen species) and hormone signaling pathways, further regulating plant enzyme systems, stomatal closure, and leaf shrinkage physiological responses. This article analyzed the evolution of the WRKY family in angiosperms and its functions in responding to various external environments, especially the function and evolution in Magnoliaceae plants. It helps to gain a deeper understanding of the evolution and functional diversity of the WRKY family and provides theoretical and experimental references for studying the molecular mechanisms of environmental stress.

SUMMARY: Photorespiration is an essential metabolic mechanism associated with photosynthesis; however, little is known about the photorespiratory pathway of conifer gymnosperms. Metabolite analyses of the leaves of 27 tree species showed that the mean glycerate content in conifer leaves was lower than that in angiosperm leaves. We performed experiments where [13C]‐serine was fed to detached shoots of a conifer (Cryptomeria japonica), via the transpiration stream, and compared the labeling patterns of photorespiratory metabolites with those of an angiosperm tree (Populus nigra), because glycerate is produced from serine via hydroxypyruvate in peroxisomes. In P. nigra, hydroxypyruvate, glycerate and glycine were labeled with 13C, whereas in C. japonica, glycolate and a non‐canonical photorespiratory metabolite, formate, were also labeled, suggesting that an H2O2‐mediated non‐enzymatic decarboxylation (NED) reaction occurs in C. japonica. We analyzed changes in the metabolite contents of leaves kept in the dark and leaves exposed to illuminated photorespiration‐promoting conditions: a positive relationship between formate and serine levels in C. japonica implied that the active C1‐metabolism pathway synthesizes serine from formate. Leaf gas exchange analyses revealed that CO2 produced through NED was recaptured by chloroplasts. Database analysis of the peroxisomal targeting signal motifs of an H2O2‐scavenging enzyme, catalase, derived from various species, including nine coniferous species, as well as analyses of peroxisomal fractions isolated from C. japonica and P. nigra leaves indicated that conifer peroxisomes had less catalase activity. These results suggest that NED and the subsequent C1 metabolism are involved in the photorespiratory pathway of conifer leaves, where peroxisomes have intrinsically low catalase activity. Significance Statement: Photorespiration is a crucial metabolism that has a significant impact on the net CO2 fixation rates and energy‐use efficiencies of plants. It is thought that the photorespiratory pathway is identical among tree species; however, this study demonstrates that conifer gymnosperms have a different photorespiratory mechanism than that of angiosperm trees. [ABSTRACT FROM AUTHOR]

The dominance of angiosperms, achieved around the late Cretaceous-early Palaeogene time, can be observed through multiple well-preserved fossil flowers and fruits described from the early Palaeogene sediments of Bikaner and Barmer (Rajasthan, India). Here, we report twelve pentamerous fossil flowers categorized into three morphotypes mainly based on their petal's shape and pattern. Fossil pollen Rhoipites anacardioides Ramanujam, extracted from the preserved androecium of one of the fossil flowers, has shown strong affinity with the modern pollen of Anacardiaceae. The pentamerous fossil fruit encompassing a single whorl of five carpels alternating with petals is similar to the extinct genus Chaneya Wang and Manchester. These fossils provide a cinematic picture of the beautiful flowering and fruiting phases during the early Palaeogene, well known for the major diversification of angiosperms. [ABSTRACT FROM AUTHOR]

The morphologically complex and charismatic genus Geleznowia (Rutaceae) is endemic to south-western Australia and faces existing and potential conservation issues associated with land clearing, climate change and commercial harvesting. Two species are currently recognised in the genus, but horticulturally recognised forms and phrase-named taxa reflect additional suspected species diversity. The genus exhibits complicated and subtle patterns of morphological variation that have historically inhibited delimitation of taxonomic entities and, as a result, precluded effective conservation assessments. Here we used ddRAD data from 25 populations across the range of Geleznowia to elucidate genomic diversity in the group in conjunction with morphological re-assessment so as to delimit species and revise the taxonomy. Our analyses consistently identified seven entities that maintain genomic distinctiveness even in sympatry with other entities, supporting the inference of reproductive barriers and lineage divergence. Morphological assessment of more than 300 specimens corroborated these seven taxa. Consequently, we recognise seven species of Geleznowia in Western Australia, retaining G. amabilis K.A.Sheph. & A.D.Crawford, recircumscribing G. verrucosa Turcz., reinstating G. calycina (J.Drumm. ex Harv.) Benth., and naming four new species as G. eximia K.A.Sheph. & A.D.Crawford, G. narcissoides K.A.Sheph. & A.D.Crawford, G. occulta K.A.Sheph. & A.D.Crawford, and G. uberiflora K.A.Sheph. & A.D.Crawford. Geleznowia species are charismatic yellow-flowered shrubs found only in south-western Australia, where their habitats are under threat from human activity. To support their conservation, we sought to clarify how many species there are by using thousands of sequences from their genomes. We uncovered unrecognised diversity and increased the number of species in the genus from two to seven. [ABSTRACT FROM AUTHOR]

Summary: In 1962 Carlquist published "A Theory of Paedomorphosis in Dicotyledonous Woods" based on his observations that some species of non-tree growth forms such as stem succulents, lianas, woody herbs, and tree rosettes exhibit, in their secondary xylem, cellular characteristics more commonly associated with primary xylem. He considered the appearance of these characters an expression of protracted juvenility, and that they reflected paedomorphosis. Since then, many others have observed similar suites of traits across multiple plant lineages, as these traits also characterize secondary and insular woodiness, and have used 'paedomorphic' and 'juvenile' to describe these traits. In this essay, it is argued that the use of the term paedomorphosis should be restricted to cases where ancestor/descendant relationships are known or used in a comparative sense among closely related taxa, to retain its significance as a descriptor of an evolutionary pattern. Second, it is argued that primary growth, and therefore primary xylem, should not be considered 'juvenile' because it is not characteristic only of the young, pre-reproductive phases of plant growth but instead persists for the life of the plant. Because both the concepts of juvenility and paedomorphosis possess more or less well-accepted modern meanings that differ in important ways from Carlquist's use of the terms, a different approach is suggested that focuses on the functional significance of this suit of traits, in addition to their cellular characteristics. [ABSTRACT FROM AUTHOR]

Diversification rates are critically important for understanding patterns of species richness among clades. However, the effects of climatic niche width on plant diversification rates remain to be elucidated. Based on the phylogenetic, climatic, and distributional information of angiosperms in China, a total of 26 906 species from 182 families were included in this study. We aimed to test relationships between diversification rate and climatic niche width and climatic niche width related variables (including climatic niche divergence, climatic niche position, geographic extent, and climatic niche evolutionary rate) using phylogenetic methods. We found that climatic niche divergence had the largest unique contribution to the diversification rate, while the unique effects of climatic niche width, climatic niche position, geographic extent, and climatic niche evolutionary rate on the diversification rate were negligible. We also observed that the relationship between diversification rate and climatic niche divergence was significantly stronger than the null assumption (artefactual relationship between diversification and clade‐level climatic niche width by sampling more species). Our study supports the hypothesis that wider family climatic niche widths explain faster diversification rates through a higher climatic niche divergence rather than through higher geographic extent, higher climatic niche evolutionary rate, or separated climatic niche position. Hence, the results provide a potential explanation for large‐scale diversity patterns within families of plants. [ABSTRACT FROM AUTHOR]

Premise: The Lower Cretaceous Crato Konservat‐Lagerstätte (CKL) preserves a rich flora that includes early angiosperms from northern Gondwana. From this area, the recently described fossil genus Santaniella was interpreted as a ranunculid (presumably Ranunculaceae). However, based on our examination of an additional specimen and a new phylogenetic analysis, we offer an alternative interpretation. Methods: The new fossil was collected from an active quarry for paving stones in the state of Ceará, northeastern Brazil. We assessed support for alternative phylogenetic hypotheses using a combined analysis of morphological data and DNA sequence data using Bayesian inference. We used a consensus network to visualize the posterior distribution of trees, and we used RoguePlot to illustrate the support for alternative positions on a scaffold tree. Results: The new material includes a flower‐like structure not present in the original material and also includes follicles preserved at early stages of development. The flower‐like structure is a compact terminal cluster of elliptical sterile laminar organs surrounding internal filamentous structures that occur on flexuous axes. Phylogenetic analyses did not support the fossil placement among eudicots. Instead, Santaniella appears to belong in the magnoliid clade. Conclusions: The presence of seeds in a marginal‐linear placentation and enclosed in a follicle supports the fossil as an angiosperm. However, even though most characters are clearly recognizable, its combination of characters does not provide strong support for a close relationship to any extant order of flowering plants. Its position in the magnoliid clade is intriguing and, based on plicate carpels, it is definitely a mesangiosperm. [ABSTRACT FROM AUTHOR]

Orphan genes (OGs) may evolve from noncoding sequences or be derived from older coding material. Some shares of OGs are present in all sequenced genomes, participating in the biochemical and physiological pathways of many species, while many of them may be associated with the response to environmental stresses and species-specific traits or regulatory patterns. However, identifying OGs is a laborious and time-consuming task. This paper presents an automated predictor, XGBoost-A2OGs (identification of OGs for angiosperm based on XGBoost), used to identify OGs for seven angiosperm species based on hybrid features and XGBoost. The precision and accuracy of the proposed model based on fivefold cross-validation and independent testing reached 0.90 and 0.91, respectively, outperforming other classifiers in cross-species validation via other models, namely, Random Forest, AdaBoost, GBDT, and SVM. Furthermore, by analyzing and subdividing the hybrid features into five sets, it was proven that different hybrid feature sets influenced the prediction performance of OGs involving eudicot and monocot groups. Finally, testing of small-scale empirical datasets of each species separately based on optimal hybrid features revealed that the proposed model performed better for eudicot groups than for monocot groups. [ABSTRACT FROM AUTHOR]

Typical cockroaches are flat, broad, with large pronotum and wings covering the body. This conserved morphotype dates back to the Carboniferous, during which the ancestral cockroaches, or roachoids, originated. On the other hand, the ovipositor of cockroaches gradually reduced during the Mesozoic, coupled with a major shift of reproductive strategy. By the Cretaceous, long external ovipositors became rare, most cockroaches used very short or even hidden internal ovipositors to fabricate egg cases (oothecae), which is an innovation for egg protection. Here, we describe two cockroaches from mid-Cretaceous Myanmar amber: Ensiferoblatta oecanthoides gen. et sp. nov. (Ensiferoblattidae fam. nov.) and Proceroblatta colossea gen. et sp. nov. They are slim, elongate, fusiform, with longitudinal pronotum, and have long external ovipositors. The combination of these traits represents a unique morphotype, which resembles crickets and katydids (Ensifera) more than general cockroaches. Ensiferoblatta and Proceroblatta may be arboreal, feeding on and/or laying eggs into certain angiosperms that newly emerged. Their open habit causes latent impairment to viability, and may contribute to their extinction. These new taxa are the youngest members of the ancient, extinct group of cockroaches, namely Eoblattodea, which are characterized by long ovipositors. We speculate that the extinction of certain gymnosperm hosts almost ended the 200-My triumph of Eoblattodea. Despite an attempt to adapt to angiosperm hosts, Ensiferoblatta, Proceroblatta and suchlike cockroaches as an evolutionary dead end failed to save Eoblattodea from extinction. The lack of protection for eggs (maternal care in particular) might accelerate the extinction of Eoblattodea as a whole. [ABSTRACT FROM AUTHOR]

Fire is a disturbance that serves to maintain the diverse mosaic of vegetation in the Eastern Deciduous Forest. However, our ability to reconstruct fire occurrence from hardwood tree scars still lags far behind our expertise in reconstructing fire history from conifers in the western United States. This study examines the fidelity of fire scaring in multiple tree species in the Big Oaks National Wildlife Refuge in Indiana, which is located in the central hardwood region of the Eastern Deciduous Forest. All 15 species, except for red oak, showed evidence of past fires, and most samples recorded multiple fire events. No fire scars were recorded in the latewood of the samples. Most of the fires scars occurred in the earlywood (May) suggesting the dormant season fires are likely associated with fires in March to April before the growing season begins. No synchronous fires were recorded across all sites, but fires occurred in 1981, 1982, 1984, 1985, and 1988 across multiple sites. This suggests that these were larger spreading fires. Establishment pulses were documented in association with fire events in 1981, 1984, and 1995, suggesting that fire may benefit the establishment or root sprouting of some hardwood species. Fourteen of the fifteen species that we sampled preserved fire scars, suggesting that the diverse suite of species in the Eastern Deciduous Forest is a viable sampling pool for examining fire history across this forest type.

Abstract Leaf anatomical features are widely used to better understand angiosperm taxonomy. However, such information is scarce for the family Myrtaceae. Aiming to fill this knowledge gap, we studied anatomical and micromorphological leaf characters of ten species of Psidium: P. cattleyanum, P. cauliflorum, P. corynanthum, P. guajava, P. guineense, P. macahense, P. myrtoides, P. oligospermum, P. ovale and P. sartorianum. Uniseriate epidermis, paracytic stomata, secretory cavities, and adaxial hypodermis are common among the studied species and are typical characteristics of Myrtaceae. The presence of three or more layers of palisade parenchyma and the absence of sclerenchyma are diagnostic characters of P. guajava. The abaxial epidermis of Psidium cattleyanum and P. macahense possess curved walls. Psidium corynanthum and P. macahense are the only species with sinuous anticlinal walls on both sides of the epidermis, with all other species having straight or curved walls. Open bicollateral vascular bundles are present in all the studied species except P. guineense. With the exception of P. cauliflorum, all the studied species possess druses. The absence of collenchyma in the adaxial face is exclusive to P. ovale. The leaf anatomy of P. macahense, P. corynanthum, P. oligospermum and P. ovale are described for the first time here.

The impact of low-dose-rate radiation on genetics is largely unknown, particularly in natural environments. The Fukushima Dai-ich Nuclear Power Plant disaster resulted in the creation of contaminated natural lands. In this study, de novo mutations (DNMs) in germ line cells were surveyed from double-digest RADseq fragments in Japanese cedar and flowering cherry trees exposed to ambient dose rates ranging from 0.08 to 6.86 μGy h−1. These two species are among the most widely cultivated Japanese gymnosperm and angiosperm trees for forestry and horticultural purpose, respectively. For Japanese flowering cherry, open crossings were performed to produce seedlings, and only two candidate DNMs were detected from uncontaminated area. For Japanese cedar, the haploid megagametophytes were used as next generation samples. The use of megagametophytes from open crossing for next generation mutation screening had many advantages such as reducing exposure to radiation in contaminated areas because artificial crossings are not needed and the ease of data analysis owing to the haploid nature of megagametophytes. A direct comparison of the nucleotide sequences of parents and megagametophytes revealed an average of 1.4 candidate DNMs per megagametophyte sample (range: 0–40) after filtering procedures were optimized based on the validation of DNMs via Sanger sequencing. There was no relationship between the observed mutations and the ambient dose rate in the growing area or the concentration of 137Cs in cedar branches. The present results also suggest that mutation rates differ among lineages and that the growing environment has a relatively large influence on these mutation rates. These results suggested there was no significant increase in the mutation rate of the germplasm of Japanese cedar and flowering cherry trees growing in the contaminated areas.

Seagrasses create three-dimensional habitats (i.e. meadows) of paramount conservation relevance, which are distributed across large spatial scales, under varying environmental conditions. Cymodocea nodosa (Ucria) Ascherson is a warm-temperate seagrass, distributed along the entire Mediterranean and the adjacent Atlantic Ocean. As with many seagrasses, this species shows an annual (seasonal) pattern in canopy vitality, with maximums in leaf canopy structure (e.g. shoot density and leaf length) in spring-summer, while canopy leaf structure is reduced in winter. Since this seagrass experiences varying environmental (e.g. thermal) scenarios across its distribution range, we tested whether annual (seasonal) variation in the leaf canopy structure, in terms of shoot density, leaf length and above-ground biomass, are modulated by local environmental (here, thermal) variation. Annual variation in the shoot density of C. nodosa across its distribution range was not predicted by local environmental regimes (thermal regimes, in terms of variation in sea surface temperature, SST). However, annual variation in leaf length and biomass was significantly predicted by variation in local thermal regimes. A larger annual environmental variation, here in terms of SST, was connected with a more marked seasonal variation in leaf canopy structure, both in terms of leaf length and biomass. If a major effect of climate change is an increase in environmental variation, an increase in the annual leaf canopy variation for C. nodosa meadows along its distribution range might be expected. [ABSTRACT FROM AUTHOR]

Mixing tree species can lead to more productive forests, but how belowground productivity is affected by mixtures of trees of diverse phylogenetic and eco‐evolutionary histories is unclear. Here, we examine how species origin and phylogeny affect belowground productivity in tree communities of varied richness and functional diversity. We measured standing fine‐root biomass and annual fine‐root production across 41 assemblages of 12 tree species, representing both angiosperms and gymnosperms originating from North America and Europe. Increasing functional diversity of mixtures stimulated overyielding of annual production but did not affect standing biomass. In general, annual productivity of mixtures of species that were less productive in monoculture had neutral (angiosperms) to positive (North American species: +16%) responses to mixing, whereas annual productivity of mixtures of species that were more productive in monoculture had neutral (European species) to negative (gymnosperms: −6%) responses to mixing. These differences translated into angiosperm mixtures overyielding in standing biomass by 16% but no effects of mixing on gymnosperm mixtures. The trends we observed between North American and European species annual production were reversed when considering standing biomass. European mixtures had 14% more standing biomass and North American mixtures had 10% less standing biomass than expected from monocultures. Our study offers a rare examination of the combined roles of origin and phylogeny in forest fine‐root productivity, and suggests varied consequences of biodiversity change for forest belowground productivity based on composition. In North America, belowground productivity of young forests composed of angiosperms and native tree species may be more tightly linked to diversity than that of forests dominated by gymnosperms or European species. This suggests that increased diversity may lead to the greatest enhancement of belowground productivity in native, North American forests dominated by angiosperms, but also that declines in diversity may be felt most strongly in these forests as well. [ABSTRACT FROM AUTHOR]

Leaf anatomical features are widely used to better understand angiosperm taxonomy. However, such information is scarce for the family Myrtaceae. Aiming to fill this knowledge gap, we studied anatomical and micromorphological leaf characters of ten species of Psidium: P. cattleyanum, P. cauliflorum, P. corynanthum, P. guajava, P. guineense, P. macahense, P. myrtoides, P. oligospermum, P. ovale and P. sartorianum. Uniseriate epidermis, paracytic stomata, secretory cavities, and adaxial hypodermis are common among the studied species and are typical characteristics of Myrtaceae. The presence of three or more layers of palisade parenchyma and the absence of sclerenchyma are diagnostic characters of P. guajava. The abaxial epidermis of Psidium cattleyanum and P. macahense possess curved walls. Psidium corynanthum and P. macahense are the only species with sinuous anticlinal walls on both sides of the epidermis, with all other species having straight or curved walls. Open bicollateral vascular bundles are present in all the studied species except P. guineense. With the exception of P. cauliflorum, all the studied species possess druses. The absence of collenchyma in the adaxial face is exclusive to P. ovale. The leaf anatomy of P. macahense, P. corynanthum, P. oligospermum and P. ovale are described for the first time here. [ABSTRACT FROM AUTHOR]

Aim: Biodiversity hotspots are regions with the highest species richness, and the most threatened species. Previous studies have shown that the extinction risk may be more related to evolutionary history than to species' traits. However, there is a knowledge gap on the relationship between evolutionary history and species extinction risk in biodiversity hotspots. Here, we link evolutionary history to species extinction risk for flowering plants (angiosperms) in global biodiversity hotspots. Location: Global biodiversity hotspots. Methods: We calculated historical evolutionary measures (family species richness, family age, family diversification rate and the ratio of crown age to stem age) of angiosperms from 36 global biodiversity hotspots, which were grouped into 27 regions. Bayesian binomial‐logit univariate and multivariable regression models in conjunction with phylogenetic control and null models were used to identify the evolutionary history predictors of extinction risk for the 27 regions as a whole and for each of the regions. Results: Family species richness, family age and family diversification rate are all good indicators for predicting extinction risk. Specifically, when all the 27 regions were considered as a whole, families with higher species richness, older age and/or faster diversification rates have a higher risk of species extinction. However, high extinction risk in some regions, especially in temperate regions, tends to occur in families with low species richness and low diversification rates. Main conclusions: Geographic origin and evolutionary history of species should be jointly taken into account in conservation planning. In general, protection priority should be given to families with high species richness, ancient origins and fast diversification rate because these families seem to be prone to higher extinction risk. Additionally, different strategies should be applied to protect biodiversity in temperate versus tropical regions given that factors affecting extinction risk are different between these regions. [ABSTRACT FROM AUTHOR]