Angiosperm Families Research Articles

Gynoecial diversity in the Annonaceae and the evolution of functional traits that overcome the limitations of apocarpy

AbstractMost species in the early divergent angiosperm family Annonaceae are apocarpous, with very diverse gynoecial morphologies. Although several Annonaceae genera with apocarpous flowers are known to possess an extragynoecial compitum (EGC) that enables intercarpellary pollen‐tube growth to enhance fertilization success, the occurrence of EGC across the whole family remains obscure. Twenty Annonaceae species from all four subfamilies (Anaxagoreoideae, Ambavioideae, Annonoideae, and Malmeoideae) are examined here, with anatomical evidence revealing the occurrence of stigmatic exudate‐mediated suprastylar EGC in all four subfamilies. Histological and ontogenetic studies furthermore indicate that trichomes in Cananga and Drepananthus form a confluent zone that connects adjacent stigmas, providing a structural premise for suprastylar EGC. Infrastylar EGC are reported in the Annonaceae for the first time in several genera, including Artabotrys, Annona, and Miliusa, associated with the opening on the ovary ventral groove and/or basal placentation. In addition to the sister genera Isolona and Monodora that are clearly syncarpous, flowers of the distantly related genus Cyathocalyx with a unicarpellate gynoecium have also been hypothesized to be syncarpous. Evidence of carpel vasculature and primordium development does not support that the solitary Cyathocalyx carpel is originated from carpel fusion, however, although the increased number of ovules renders it functionally similar to syncarpy. Gynoecial features, including the extensive occurrence of EGC and the increased number of ovules per carpel (consonant with reduction to a solitary carpel) in Cyathocalyx, may have evolved to overcome limitations associated with apocarpy and possibly contribute to the reproductive success and diversification of the family.

A global assessment of plant–mite mutualism and its ecological drivers

Mutualisms are mediated by adaptive traits of interacting organisms and play a central role in the ecology and evolution of species. Thousands of plant species possess tiny structures called "domatia" that house mites which protect plants from pests, yet these traits remain woefully understudied. Here, we release a worldwide database of species with mite domatia and provide an evaluation of the phylogenetic and geographic distribution of this mutualistic trait. With >2,500 additions based on digital herbarium scans and published reports, we increased the number of known species with domatia by 27% and, importantly, documented their absence in >4,000 species. We show that mite domatia likely evolved hundreds of times among flowering plants, occurring in an estimated ~10% of woody species representing over a quarter of all angiosperm families. Contrary to classic hypotheses about the evolutionary drivers of mutualism, we find that mite domatia evolved more frequently in temperate regions and in deciduous lineages; this pattern is concordant with a large-scale geographic transition from predominantly ant-based plant defense mutualisms in the tropics to mite-based defense mutualisms in temperate climates. Our data also reveal a pattern of evolutionary convergence in domatia morphology, with tuft-form domatia more likely to evolve in dry temperate habitats and pit domatia more likely to evolve in wet tropical environments. We have shown climate-associated drivers of mite domatia evolution, demonstrating their utility and power as an evolutionarily replicated system for the study of plant defense mutualisms.

Orchid phylogenetics and evolution: history, current status and prospects.

Orchidaceae are one of the two largest families of angiosperms; they exhibit a host of changes -- morphological, ecological and molecular -- that make them excellent candidates for evolutionary study. Such studies are most effectively performed in a phylogenetic context, which provides direction to character change. Understanding of orchid relationships began in the pre-evolutionary classification systems of the 1800's that were based solely on morphology, and now is largely based on genomic analysis. The resulting patterns have been used to update family classification and to test many evolutionary hypotheses in the family. Recent analyses with dense sampling and large numbers of nuclear loci have yielded well-supported trees that have confirmed many longstanding hypotheses and overturned others. They are being used to understand evolutionary change and diversification in the family. These include dating the origination of the family, analysis of change in ecological habit (from terrestrial to epiphytic and back again in some cases), revealing significant plastid genome change in leafless holomycotrophs, studying biogeographic patterns in various parts of the world, and interpreting patterns of fungal associations with orchids. Understanding of orchid relationships has progressed significantly in recent decades, especially since DNA sequence data have been available. These data have contributed to an increasingly refined classification of orchids and the pattern has facilitated many studies on character evolution and diversification in the family. Whole genome studies of the family are just beginning and promise to reveal fine-level details underlying structure and function in these plants, and, when set in a phylogenetic context, provide a much richer understanding of how the family has been so successful in diversification.

Unveiling Thrips (Thysanoptera) as Nature's Unsung Pollinators: A Survey From Obligatory Thripophily to Thrips as Supplementary Pollinators

ABSTRACTThrips are minute, paraneopteran insects with diverse ecological histories and plant associations, encompassing herbivory, fungivory, pollination and predation. They are typically not widely adored insects as many species are regarded to be destructive crop pests and vectors of crop diseases. Nevertheless, certain thrips play a significant role in pollination as they traverse from flower to flower with pollen attached to their bodies. However, most studies on relationships between flowering plants and pollinators have overlooked the prevalence and association of thrips with flowers, and the pollination services were often incorrectly attributed to wind, bees or other agents. This is primarily due to the minute size and cryptic behaviour of thrips, their limited range of movement and minimal structural modifications to carry and disperse pollen. In recent times, the involvement of thrips in pollination was investigated by many researchers and their role was established partly or fully in several angiosperm families. Their role in pollination through specialised thripophily, as minor or secondary pollinators, or via ambophily is well‐established now. The present paper reviews the evidence of pollen transfer by thrips, obligate and nonobligate pollination relationships between plants and pollinator thrips, evolutionary aspects of thripophily, morphological and physiological adaptations in thrips and floral syndromes associated with thripophily.

OGU: A Toolbox for Better Utilising Organelle Genomic Data.

Organelle genomes serve as crucial datasets for investigating the genetics and evolution of plants and animals, genome diversity, and species identification. To enhance the collection, analysis, and visualisation of such data, we have developed a novel open-source software tool named Organelle Genome Utilities (OGU). The software encompasses three modules designed to streamline the handling of organelle genome data. The data collection module is dedicated to retrieving, validating and organising sequence information. The evaluation module assesses sequence variance using a range of methods, including novel metrics termed stem and terminal phylogenetic diversity. The primer module designs universal primers for downstream applications. Finally, a visualisation pipeline has been developed to present comprehensive insights into organelle genomes across different lineages rather than focusing solely on individual species. The performance, compatibility and stability of OGU have been rigorously evaluated through benchmarking with four datasets, including one million mixed GenBank records, plastid genomic data from the Lamiaceae family, mitochondrial data from rodents, and 308 plastid genomes sourced from various angiosperm families. Based on software capabilities, we identified 30 plastid intergenic spacers. These spacers exhibit a moderate evolutionary rate and offer practical utility comparable to coding regions, highlighting the potential applications of intergenic spacers in organelle genomes. We anticipate that OGU will substantially enhance the efficient utilisation of organelle genomic data and broaden the prospects for related research endeavours.

Comparative analysis of complete chloroplast genomes of 14 Asteraceae species.

The Asteraceae family, the largest and one of the most diverse families of angiosperms, presents significant challenges in taxonomic classification and systematic research due to its vast species diversity and morphological complexity. A comprehensive understanding of the chloroplast genomes within this family is essential for refining taxonomic classifications and advancing phylogenetic studies. In this study, we sequenced the complete chloroplast genomes of 14 Asteraceae species and conducted a thorough bioinformatic analysis of their characteristics. The chloroplast genomes, ranging from 150,907bp to 152,858bp, exhibit a typical quadripartite structure: a large single-copy (LSC) region (83,044bp to 84,625bp), a small single-copy (SSC) region (18,223bp to 18,673bp), and a pair of inverted repeats (IRs) (24,806bp to 25,201bp). These genomes encode 87 to 89 protein-coding genes (PCGs), 36 to 37 tRNA genes, and 8 rRNA genes, with high conservation in size, structure, gene content, and order. Comparative analysis with other Asteraceae species' chloroplast genomes revealed notable similarities and structural variations, particularly in the IR regions. Nucleotide polymorphism analysis identified four genes-trnY-GUA, trnE-UUC, ycf1, and rrn23-with higher Pi values, suggesting potential hotspots for evolutionary studies. Phylogenetic analysis using maximum likelihood (ML) and Bayesian inference (BI) approaches provided new insights, proposing the reclassification of Himalaiella auriculata and Jacobaea raphanifolia as independent genera, distinct from Saussurea and Senecio. This study presents a comprehensive analysis of the chloroplast genome structures and phylogenetic relationships of 14 Asteraceae species, offering critical data for future molecular identification, evolutionary biology, and population genetics research. The findings hold significant implications for the ongoing refinement of Asteraceae taxonomic classifications and enhance our understanding of the evolutionary dynamics within this complex family.

Cuticular morphology of Schinus L. and related genera

Abstract The Anacardiaceae are a characteristic angiosperm family of the Neotropics where they comprise ~32 genera and 200 species (~80 genera and 800 species globally). Among Neotropical Anacardiaceae genera, Schinus has the greatest species richness with 42 species distributed from tropical latitudes of Brazil and Peru south to the temperate steppe, matorral, and Valdivian temperate forest communities of Patagonia. Previous studies have found some anatomical and morphological leaf traits (e.g. simple vs. compound leaf organization) useful in characterizing lineages within Schinus, but also document traits that are homoplastic within the genus (e.g. stomatal distribution) and convergent among Schinus and its close relatives Lithrea and Mauria (e.g. mesophyll arrangement). Here, we present a survey of leaf cuticular traits in 53 species of Schinus and its closest relatives Lithrea, Mauria, and Euroschinus based on characters observed with scanning electron and optical light microscopy. We use ordinated Bray–Curtis distances based on 18 characters and 2D nonmetric multidimensional scaling to show that cuticular morphology resolves the three most diverse genera, Euroschinus, Mauria, and Schinus, but does not resolve intrageneric sections of Schinus. We propose that a distinctive acuminate gland type occurring only within Euroschinus may constitute a potential synapomorphy for this genus. Within Schinus, we find inconsistency in stomatal distribution among specimens of a single species, among species of a single section, and between sections of the genus, and suggest that current evidence is insufficient to implicate either phenotypic plasticity or homoplasy as the causative mechanism of this variation.

First Report on Taxonomic Significance of Foliar Microanatomy of Lamiaceae Taxa from Pakistan; A Correct Tool for Taxa Authentication

The foliar epidermal, stomatal and trichome properties are frequently used as plant microscopic attributes from a taxonomic or ecological perspective. Among the angiosperm families, the Lamiaceae is one of the most taxonomically difficult, economically significant, and medicinally important families. To better understand the foliar microanatomy of Lamiaceae taxa obtained from Northern Pakistan, this study attempts to determine the variational and diagnostic features of 27 species that were analyzed using light microscopy (LM) and scanning electron microscopy (SEM). UPGMA cluster analysis, principal component analysis (PCA) and semantic differential chart (SDC) were used to characterize, visualize, and compare the leaf micromorphology across all species. Three different types of epidermal cell types were examined on both foliar surfaces i.e., irregular, hexagonal, and polygonal. Anticlinal wall pattern also shows variation. Anomocytic stomata is dominant in 8 studied species followed by paractic in 5 species, anisocytic in 4 species and diacytic in 2 species. The trichomes could be broadly classified into two groups, glandular trichomes (GTs) and non-glandular trichomes (NGTs). Lamiaceae has two types of glandular trichomes, small capitate and large peltate, which differ in size, structure, and distribution. In present research five distinct forms of non-glandular trichomes are unicellular, multicellular, stellate, branched, and unbranched trichomes. The results that characterized, illustrated, and contrasted the leaf anatomical characteristics of the Lamiaceae taxa can be better understood with the aid of statistical analysis. Future research will depend on these findings to improve the systematics of Lamiaceae taxa. These characteristics have a large taxonomic potential when considered as a whole.

Evolution from mixed to fixed handedness in mirror-image flowers: insights from adaptive dynamics.

Mirror-image flowers (enantiostyly) involve a form of sexual asymmetry in which a flower's style is deflected either to the left or right side, with a pollinating anther orientated in the opposite direction. This curious floral polymorphism, which was known but not studied by Charles Darwin, occurs in at least 11 unrelated angiosperm families and represents a striking example of adaptive convergence in form and function associated with cross-pollination by insects. In several lineages, dimorphic enantiostyly (one stylar orientation per plant, both forms occurring within populations) has evolved from monomorphic enantiostyly, in which all plants can produce both style orientations. We use a modelling approach to investigate the emergence of dimorphic enantiostyly from monomorphic enantiostyly under gradual evolution. We show using adaptive dynamics that depending on the balance between inbreeding depression following geitonogamy, pollination efficiency and plant density, dimorphism can evolve from an ancestral monomorphic population. In general, the newly emergent dimorphic population is stable against invasion of a monomorphic mutant. However, our model predicts that under certain ecological conditions, e.g., a decline of pollinators, dimorphic enantiostyly may revert to a monomorphic state. We demonstrate using population genetics simulations that the observed evolutionary transitions are possible assuming a plausible genetic architecture.

Flowers meet Newton: testing the role of gravitational pull in resupination of orchid flowers.

Resupination refers to the developmental orientation changes of flowers through ≈180º, leaving them effectively upside-down. It is a widespread trait present in 14 angiosperm families, including the Orchidaceae, where it is a gravitropic phenomenon actively controlled by auxins. Here, we demonstrate that the passive gravitational pull on flower parts can have an additional influence on resupination. We studied a lady's slipper orchid in which some flowers naturally fail to resupinate. We conducted a manipulative experiment removing floral parts and showed that both the probability of complete resupination and the degree of flower vertical movement (from 0º - 180º) are related to the mass of floral organs. During flower development, the tip of the ovary slightly curves actively (14.75º) due to gravitropism. This promotes a lever arm effect so that the gravitational pull acting on flower mass creates a torque that bends the ovary, orienting the flower into a resupinate position that is accessible to pollinators. The role of the mass of floral organs in resupination provides new insights into flower development and its role in pollination mechanisms.

Spatial Pattern Analysis and Conservation Assessment of Apiaceae in Mongolia.

The family Apiaceae, distributed throughout the Northern Hemisphere, is the largest family of angiosperms. However, little is known about the conservation status, diversity, and distribution of Apiaceae species in Mongolia. This study had two main aims: (1) to assess the national status of Apiaceae species under IUCN Red List Criterion B; (2) to evaluate the species diversity and richness of Apiaceae across Mongolia. We utilized ConR packages to assess the national Red List status of all known Mongolian Apiaceae species by analyzing their most comprehensive occurrence records. The results indicated that 27 species were classified as threatened, including 4 Critically Endangered (CR), 9 Endangered (EN), and 14 Vulnerable (VU) species. Meanwhile, 39 species were assessed as non-threatened, with 2 Near Threatened (NT) species and 37 species of Least Concern (LC). Furthermore, detailed distribution maps for 66 Apiaceae species in Mongolia were presented. We assessed the species diversity and Shannon and Simpson diversity indices of Apiaceae by analyzing all occurrence records using the iNext package. Overall, the Hill diversity estimates indicate that the sampling conducted in Mongolia adequately captured species occurrences. For species pattern analysis, we examined the species richness, weighted endemism, and the corrected weighted endemism index using Biodiverse v.4.1 software. Mongolia was portioned into 715 grid cells based on 0.5° × 0.5° grid sizes (equivalent to approximately 50 × 50 km2). There was a total of 3062 unique occurrences of all Apiaceae species across Mongolia. In the species richness analysis, we identified 10 grids that exhibited high species richness (18-29 species) and 36 grids with 11-17 species. For genus richness, we observed seven grids that exhibited a high genus richness of 16-22 genera. Furthermore, we analyzed species richness with a specific focus on threatened species, encompassing CR, EN, and VU species throughout Mongolia. A total of 92 grids contained at least one threatened species. There were six grids that had two to five threatened species, which were adequately covered by protected areas in western Mongolia. Overall, our results on species richness and conservation status will serve as important foundational research for future conservation and land management efforts in Mongolia.

Spatial pattern and ecological adaptation of heterostylous and homostylous species of Primula in China

Abstract Floral syndrome is one of the key components of plant pollination syndromes, affecting variety of evolutionary and ecological processes in angiosperms. The evolutionary transition from self-incompatible heterostyly to self-compatible homostyly occurred repeatedly in angiosperm families. Although the evolution of heterostyly and homostyly has been deeply studied, our understanding on their differences in ecological strategies is still lacking. In this work, using the floral syndrome and distributions of the Primula in China we compared the spatial pattern of floral syndrome frequency and its climatic determinants. Our results reveal that distylous and homostylous Primula have similar primary centers of species diversity in southwest China, while distylous species have larger range size than homostylous ones. Temperature seasonality is the dominant climate factor of these geographic patterns, but its effect is much stronger in distylous than in homostylous Primula. Distylous species have larger flower size and number, and fruit size than homostylous ones. Climate, especially temperature seasonality mainly influenced species range size via its effects on floral syndrome. Our study suggests that homostyly is likely derived from heterostylous ancestors in similar geographical context, and larger reproductive investment in floral phenotype may provide compensatory mechanisms for obligate out-breeding heterostyly. Future investigations regarding the evolutionary history and tolerance or resistance to environmental change between distyly and homostyly may greatly advance our understanding of their spatial pattern and adaptative differences.

Rapid Assessment of Riparian Vegetation at Calyawan River, Barangay Andap, Municipality of New Bataan, Davao de Oro Province, Philippines

Aims: The aim of this study was to examine the vegetation found along the riverbanks of the Calyawan River in Barangay Andap, Municipality of New Bataan, Province of Davao de Oro, Philippines using the transect walk method. The goals were to determine the variety and abundance of the flora along the riverbank, evaluate the conservation status of the discovered plant species, and suggest measures for safeguarding and preserving the riparian environment. Study Design: The study employed a transect walk method to carry out an initial survey of the riparian vegetation. A 1-kilometer transect was conducted along the riverbanks of the Calyawan River to gather qualitative and quantiatative measurements of plant diversity. The evaluation took place on December 20, 2022. This approach facilitated a quick and systematic examination of the vegetation along the riverbanks. Place and Duration: The study was carried out on the riverbanks of the Calyawan River in Barangay Andap, Municipality of New Bataan, Province of Davao de Oro. The fieldwork was conducted on December 20, 2022. The region can be reached by using the Compostela-Montevista-Mati Boundary Road. Methodology: The transect walk approach was employed to record the riparian flora during the survey. Plant species were identified and photographed, but no tangible plant specimens were collected. The obtained data encompassed the identification of fern and angiosperm taxa and families encountered along the transect. The conservation status assessments were conducted using the pre-existing classifications of the species. Results: A rapid assessment revealed the presence of 49 distinct genera of ferns and angiosperm plants belonging to 30 different families along the transect. Out of these, 74% of the riparian plant genera that were identified were found to be endemic to the region. The assessment of the riparian plants' conservation status indicated that 37% were classed as vulnerable, 30% as least concern, 22% as other threatened species, 10% as endangered, and 1% were not categorized. Although the sample time was short, these findings emphasize the abundance and importance of the riparian flora in terms of conservation. Conclusion: The initial study conducted along the riverbanks of Calyawan River indicated a notable variety of plants that grow along the river, with a large number of species that are unique to that area. Many identified plants have a conservation status that emphasizes the necessity for heightened sampling efforts and monitoring in order to gain a more comprehensive understanding of and safeguard this rich ecosystem. Considering the clear human-induced stresses on the forest fragments in the region, it is advisable to enhance and broaden conservation efforts in order to protect the riparian vegetation and guarantee its ongoing existence.

Genome-wide identification of the phenylalanine ammonia-lyase gene from Epimedium Pubescens Maxim. (Berberidaceae): novel insight into the evolution of the PAL gene family

BackgroundPhenylalanine ammonia-lyase (PAL) serves as a key gateway enzyme, bridging primary metabolism and the phenylpropanoid pathway, and thus playing an indispensable role in flavonoid, anthocyanin and lignin biosynthesis. PAL gene families have been extensively studied across species using public genomes. However, a comprehensive exploration of PAL genes in Epimedium species, especially those involved in prenylated flavonol glycoside, anthocyanin, or lignin biosynthesis, is still lacking. Moreover, an in-depth investigation into PAL gene family evolution is warranted.ResultsSeven PAL genes (EpPAL1-EpPAL7) were identified. EpPAL2 and EpPAL3 exhibit low sequence identity to other EpPALs (ranging from 61.09 to 64.38%) and contain two unique introns, indicating distinct evolutionary origins. They evolve at a rate ~ 10 to ~ 54 times slower compared to EpPAL1 and EpPAL4-7, suggesting strong purifying selection. EpPAL1 evolved independently and is another ancestral gene. EpPAL1 formed EpPAL4 through segmental duplication, which lead to EpPAL5 and EpPAL6 through tandem duplications, and EpPAL7 through transposed duplication, shaping modern EpPALs. Correlation analysis suggests EpPAL1, EpPAL2 and EpPAL3 play important roles in prenylated flavonol glycosides biosynthesis, with EpPAL2 and EpPAL3 strongly correlated with both Epimedin C and total prenylated flavonol glycosides. EpPAL1, EpPAL2 and EpPAL3 may play a role in anthocyanin biosynthesis in leaves. EpPAL2, EpPAL3, EpPAL6, and EpPAL7 might be engaged in anthocyanin production in petals, and EpPAL2 and EpPAL3 might also contribute to anthocyanin synthesis in sepals. Further experiments are needed to confirm these hypotheses. Novel insights into the evolution of PAL gene family suggest that it might have evolved from a monophyletic group in bryophytes to large-scale sequence differentiation in gymnosperms, basal angiosperms, and Magnoliidae. Ancestral gene duplications and vertical inheritance from gymnosperms to angiosperms likely occurred during PAL evolution. Most early-diverging eudicotyledons and monocotyledons have distinct histories, while modern angiosperm PAL gene families share similar patterns and lack distant gene types.ConclusionsEpPAL2 and EpPAL3 may play crucial roles in biosynthesis of prenylated flavonol glycosides and anthocyanins in leaves and flowers. This study provides novel insights into PAL gene family evolution. The findings on PAL genes in E. pubescens will aid in synthetic biology research on prenylated flavonol glycosides production.

Novel Perspectives on Chloroplast tRNA Genomic and Structural Variations Imply the Evolution of Papilionoideae (Fabaceae)

Papilionoideae is the most species-rich subfamily of the third largest angiosperm family Fabaceae. One constituent large group, the inverted-repeat-lacking clade (IRLC), is well-known for the broad loss of one IR copy. Accumulating observations of massive plastomic disparities have made IRLC a well-suited model for exploring plastome evolution. However, there is still a large amount left to explore. The present study focused on the plastid tRNA (pttRNA) evolution within Papilionoideae, employing the currently densest sampling strategies for both the IRLC (156) and non-IRLC (109) lineages. Strikingly, our results revealed abundant inter-lineage variabilities in both tRNA sequences and structures, including a 3 nt difference in the average size of trnS-UGA, the consensus sequence disparities across 29 tRNAs, the distinct 3 nt indels in trnA-UGC, and an impressive 248 nt intron loss of IRLC trnI-GAU (potential markers). Additionally, there was unequal stability of the atypical secondary structures in trnS-GGA and trnS-UGA, as well as significantly diverse compositions of substitution events in all compared tRNAs (p < 0.05). Ultimately, these findings not only demonstrate the significant differences and unique markers of IRLC pttRNAs compared to other non-IRLC Papilionoideae, but also draw an important conclusion that the large losses of one IR potentially promote highly diverse evolutionary patterns of IRLC, which could partly compensate for the potential IR-lacking impacts.

A phylogenetic approach for identifying new sources of economically important fatty acids in plants and algae

Societal Impact StatementNew sources of essential and other nutritionally and/or pharmacologically important fatty acids for human use can be discovered through bioprospecting. Demonstrating how fatty acids in plants and algae are distributed across a phylogeny is a critical first step in this process. Here, new sources of essential omega‐3 fatty acids that are critically important to human health were identified, such as green and Chromista algae, bryophytes and some angiosperm families. The identification of certain taxa that are high in critical fatty acids is important for developing new sources of these healthful compounds.Summary Essential fatty acids (EFA) including long‐chain omega‐3 and omega‐6 EFA are key nutrients that broadly support the health of individuals and the ecosystems they inhabit. Production of these EFA is critical to global nutritional security, and therefore, it is imperative to assess the distribution patterns of FA in plants to bioprospect new resources that do not threaten biodiversity. We used a meta‐analytic approach (phylogenetic signal analysis), which incorporated a wide variety of taxa to map FA profiles including both presence and abundance of specific FA and EFA onto a plant phylogeny including algae, bryophytes, pteridophytes, gymnosperms and angiosperms. Our phylogenetic signal analysis revealed that presence/absence of most FA of interest were randomly or ubiquitously distributed, while FA content was significantly clustered in specific clades for most key FA (including eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and nervonic acid). Both green and Chromista algae displayed relatively high proportions of EPA and DHA, while green algae contained higher proportional amounts of stearidonic acid (SDA). Further, signal analysis revealed high proportional content of gamma‐linoleic acid (GLA) in bryophytes and some angiosperm families, suggesting potential sources for bioprospecting GLA. This analysis provides a crucial foundation for understanding the influence of phylogenetic relationships in the relative proportions of key FA in plants and algae across a diverse phylogeny. Furthermore, in demonstrating how fatty acids in plants and algae are distributed across a phylogeny, we provide a critical first step in bioprospecting for new sources of essential and other nutritionally‐ and/or pharmacologically important fatty acids for human use.

Reproductive Morphology and Success in Annual versus Perennial Legumes: Evidence from Astragalus and the Fabeae (Papilionoideae).

The third largest angiosperm family, Leguminosae, displays a broad range of reproductive strategies and has an exceptional practical value. Whereas annual legume species are mostly planted as crops, there is a significant interest in breeding and cultivating perennials. It is therefore of importance to compare reproductive traits, their interactions and the resulting productivity between related annual and perennial species. Two highly variable taxa were chosen for this purpose, the Fabeae tribe, including numerous temperate crops, and the largest angiosperm 'megagenus' Astragalus. A dataset of quantitative reproductive traits was composed of both originally obtained and previously published data. As a result of statistical analysis, we found that perennials in both groups tend to produce more flowers per axillary racemose inflorescence as well as more ovules per carpel. Perennial Astragalus also have larger flowers. Only a part of the developing flowers and ovules gives rise to mature pods and seeds. This difference is especially pronounced in small populations of rare and threatened perennials. Numerous reasons underlie the gap between potential and real productivity, which may be potentially bridged in optimal growing conditions.

Hypodermis or multiple epidermis: Leaf ontogenesis in nine species of subfamily Myrtoideae (Myrtaceae)

The ninth largest family of angiosperms is Myrtaceae, which comprises 127 genera and over 6000 species. The leaf anatomy of Myrtaceae has been widely studied and can be used in phylogenetic analyses and species delimitations in complexes within the family. A multiple epidermis and hypodermis have been described for the leaves of representatives of the family but have not been confirmed using ontogenetic studies, which could lead to incorrect interpretations about these tissues. Thus, we studied the leaf ontogenesis of the following 9 species in subfamily Myrtoideae: tribe Syzigieae - Syzigium cumini; tribe Myrteae - Myrceugenia alpigena and M. euosma (subtribe Luminae), Psidium sartorianum, P. guajava, Campomanesia adamantium and Pimenta pseudocaryophyllus (subtribe Pimentinae), Myrcianthes pungens and M. gigantea (subtribe Eugeniinae). Shoot apices and leaves up to the fourth node were transversally and longitudinally sectioned following techniques used for plant anatomy. Leaf development in all species is from apical, intercalary, dorsal, marginal and plate meristematic activity. Protodermal periclinal divisions only occur to give rise to secretory cavities. The results show that in all the species the subepidermal layer is a hypodermis, which originates from periclinal divisions of the ground meristem. The occurrence of this layer could have phylogenetic implications according to reports in the literature, reinforcing the relationships among the subtribes in current topologies of Myrteae. However, the occurrence of a hypodermis in representatives of other subtribes of Myrteae and Syzigieae need to be better studied and discussed in relation to the phylogeny of Myrtaceae.

Expowo: An R package for mining global plant diversity and distribution data.

Data on plant distribution and diversity from natural history collections and taxonomic databases are increasingly becoming available online as exemplified by the Royal Botanic Gardens, Kew's Plants of the World Online (POWO) database. This growing accumulation of biodiversity information requires an advance in bioinformatic tools for accessing and processing the massive data for use in downstream science. We present herein expowo, an open-source package that facilitates extracting and using botanical data from POWO. The expowo package is implemented in R and designed to handle the entire vascular plant tree of life. It includes functions to readily distill taxonomic and distributional information about all families, genera, or species of vascular plants. It outputs a complete list of species in each genus of any plant family, with the associated original publication, synonyms, and distribution, and plots global maps of species richness at the country and botanical country levels, as well as graphs displaying species-discovery accumulation curves and nomenclatural changes over time. To demonstrate expowo's strengths in producing easy-to-handle outputs, we also show empirical examples from a set of biodiverse countries and representative species-rich and ecologically important angiosperm families. By harnessing bioinformatic tools that accommodate varying levels of R programming proficiency, expowo functions assist users who have limited R programming expertise in efficiently distilling specific botanical information from online sources and producing maps and graphics for the further interpretation of biogeographic and taxonomic patterns.

Genomic and Transcriptomic Insights into the Evolution of C4 Photosynthesis in Grasses.

C4 photosynthesis has independently evolved over 62 times within 19 angiosperm families. The recurrent evolution of C4 photosynthesis appears to contradict the complex anatomical and biochemical modifications required for the transition from C3 to C4 photosynthesis. In this study, we conducted an integrated analysis of genomics and transcriptomics to elucidate the molecular underpinnings of convergent C4 evolution in the grass family. Our genome-wide exploration of C4-related gene families suggests that the expansion of these gene families may have played an important role in facilitating C4 evolution in the grass family. A phylogenomic synteny network analysis uncovered the emergence of C4 genes in various C4 grass lineages from a common ancestral gene pool. Moreover, through a comparison between non-C4 and C4 PEPCs, we pinpointed 14 amino acid sites exhibiting parallel adaptations. These adaptations, occurring post the BEP-PACMAD divergence, shed light on why all C4 origins in grasses are confined to the PACMAD clade. Furthermore, our study revealed that the ancestor of Chloridoideae grasses possessed a more favorable molecular preadaptation for C4 functions compared to the ancestor of Panicoideae grasses. This molecular preadaptation potentially explains why C4 photosynthesis evolved earlier in Chloridoideae than in Panicoideae and why the C3-to-C4 transition occurred once in Chloridoideae but multiple times in Panicoideae. Additionally, we found that C4 genes share similar cis-elements across independent C4 lineages. Notably, NAD-ME subtype grasses may have retained the ancestral regulatory machinery of the C4 NADP-ME gene, while NADP-ME subtype grasses might have undergone unique cis-element modifications.