Antheridiogen系统及其在树蕨中的保守性

Summary Sex expression of homosporous ferns is controlled by multiple factors, one being the antheridiogen system. Antheridiogens are pheromones released by sexually mature female fern gametophytes, turning nearby asexual gametophytes precociously male. Nevertheless, not all species respond. It is still unknown how many fern species use antheridiogens, how the antheridiogen system evolved, and whether it is affected by polyploidy and/or apomixis. We tested the response of 68 fern species to antheridiogens in cultivation. These results were combined with a comprehensive review of literature to form the largest dataset of antheridiogen interactions to date. Analyzed species also were coded as apomictic or sexual and diploid or polyploid. Our final dataset contains a total of 498 interactions involving 208 species (c. 2% of all ferns). About 65% of studied species respond to antheridiogen. Multiple antheridiogen types were delimited and their evolution is discussed. Antheridiogen responsiveness was not significantly affected by apomixis or polyploidy. Antheridiogens are widely used by ferns to direct sex expression. The antheridiogen system likely evolved multiple times and provides homosporous ferns with the benefits often associated with heterospory, such as increased rates of outcrossing. Despite expectations, antheridiogens may be beneficial to polyploids and apomicts.

… same family produce different antheridiogens shows that the structural diversity of fern antheridiogens may reach the genus level. The recent demonstration that the antheridiogens of A. …

… presence of antheridiogen in Pteridium aquilinum, it has been shown that developing prothallia of more than 10 species of ferns produce antheridiogens. Antheridiogens are classified …

Abstract Premise Antheridiogen systems are a set of pheromonal mechanisms that control sex expression in fern gametophytes. However, antheridiogen has rarely been studied outside of the laboratory, and little is known about its function in natural settings. Combining predictions based on field and laboratory study, we tested whether the sexual structure of gametophytic colonies of a tree fern were attributable to antheridiogen. Methods Gametophytic colonies of the antheridiogen‐producing tree fern Cyathea multiflora were collected at La Selva Biological Station in Costa Rica in January 2019. The sex of each gametophyte was determined, mapped, and spatial statistic approaches were used to examine the distribution of sex in each colony. Results In all gametophytic colonies, males were most common, representing 62–68% of individuals. No hermaphroditic gametophytes were identified in any colony. A quadrat‐based method showed female gametophytes were not clustered in each colony, while male gametophytes were clustered. In two of the colonies, the K(r) test statistic for males was greater than expected compared to random simulations of sex expression, indicating male sex expression was spatially associated with females. Conclusions This study provides the first documentation of spatial sex expression in natural settings of gametophytes of an antheridiogen‐producing tree fern species. The profound impact of antheridiogen on gametophytic sex expression in field settings suggests this system is intimately tied to mating system, fitness, and genetic diversity in Cyathea multiflora.

… leptosporangiates; hence, antheridiogen systems are thought … needed to clarify how antheridiogen systems evolved. Here, … existence of a putative antheridiogen system in …

… antheridiogens of many ferns have been characterized as gibberellins, orGAs (63,81,82,83,84,85). The antheridiogen … If the antheridiogen ofCeratopteris is a GA, it is likely to be a novel …

… -prized ornamental and economic tree fern and a significant … Since the suc cessful colonization of a fern in new habitats is de … may be due to antheridiogen activity. Due to the above …

… ferns, and they are all gibberellin (GA)-related compounds. The purpose of this article is to review chemical structures and biological activities of the antheridiogens and … of the tree fern, …

The fern life cycle includes a haploid gametophyte that is independent of the sporophyte and functions to produce the gametes. In homosporous ferns, the sex of the gametophyte is not fixed but can vary depending on its social environment. In many species, the sexual phenotype of the gametophyte is determined by the pheromone antheridiogen. Antheridiogen induces male development and is secreted by hermaphrodites once they become insensitive to its male-inducing effect. Recent genetic and biochemical studies of the antheridiogen response and sex-determination pathway in ferns, which are highlighted here, reveal many similarities and interesting differences to GA signaling and biosynthetic pathways in angiosperms.

… In many ferns, a chemical messenger, antheridiogen, controls the onset of antheridium … The induction of male gametophytes by antheridiogens correlated to a global increase in stress- …

… groups worldwide demonstrated that antheridiogen is a natural … Antheridiogens isolated in fern species from several different … Over the past a few decades, the fern Ceratopteris richardii …

… GAs in lycophyte and monilophyte gametophytes may prove to be insightful in the understanding of the evolution of fern antheridiogens and the hormonal role of GA in vascular plants. …

… an antheridiogen we see a predominance of unisexual gametophytes in colonies and a very sensitive and rather complicated system of reactions to the antheridiogen … for antheridiogen …

… thallus is activated by the gibberellin hormone antheridiogen [19]. It was revealed that each fern species is characterized by a specific chemical structure of antheridiogen. This …

… Neither antheridiogen biosynthesis … antheridiogen before they attain maturity, in contrast to what occurs in spore-derived gametophytes which are females and synthesize antheridiogen …

Premise of research. The gametophytes of ferns are nutritionally independent of the sporophytes and are potentially hermaphroditic. The sexual expression of fern gametophytes is based on environmental cues. To prevent excessive self-fertilization, fern gametophytes employ strategies to increase mating between gametophytes. One of these strategies relies on antheridiogens, pheromones released by older gametophytes and absorbed by younger gametophytes. There are multiple distinct antheridiogen types, some of which are poorly understood and in need of further examination. A still-unresolved antheridiogen type was described in Asplenium ruta-muraria. Methodology. We employed cultivation experiments using spores of 12 fern species to assess the extent and uniqueness of the antheridiogen released by A. ruta-muraria. We tested antheridiogen interactions between representatives of three well-established antheridiogen types and A. ruta-muraria to assess their uniqueness. Furthermore, the effect of potentially antheridiogen-releasing gametophytes of A. ruta-muraria on multiple Asplenium species was examined. Germination in darkness in response to antheridiogens was also tested. Pivotal results. The younger gametophytes of A. ruta-muraria did not respond to the presence of older conspecific gametophytes in a way that could be attributed to antheridiogens. No antheridiogen interactions between A. ruta-muraria and any other species were observed. Nevertheless, the exudates of older A. ruta-muraria gametophytes may affect the development of younger conspecific and interspecific gametophytes. Conclusions. On the basis of its interaction with representatives of known antheridiogen types and the lack of germination in darkness, we conclude that our sample of A. ruta-muraria does not use antheridiogens. This discrepancy between our experiment and the initial publication describing antheridiogens in A. ruta-muraria may have been caused by intraspecific genetic variability within the species. The studied individual of A. ruta-muraria may be able to affect the growth of other gametophytes by other means, possibly via allelopathy, although this aspect of gametophyte interaction is poorly understood.

… To answer the many questions raised by this study, similar experiments need to be conducted using isolated antheridiogen and other water-soluble substances released by fern …

The fern Ceratopteris richardii has been studied as a model organism for over 50 years because it is easy to grow and has a short life cycle. In particular, as the first homosporous vascular plant for which genomic resources were developed, C. richardii has been an important system for studying plant evolution. However, we know relatively little about the natural history of C. richardii. In this article, we summarize what is known about this aspect of C. richardii, and discuss how learning more about its natural history could greatly increase our understanding of the evolution of land plants.

Chi Kuang Wen, Rachel Smith, Jo Ann Banks, ANI1: A Sex Pheromone-Induced Gene in Ceratopteris Gametophytes and Its Possible Role in Sex Determination, The Plant Cell, Vol. 11, No. 7 (Jul., 1999), pp. 1307-1317

… Some ferns possess the ability to control their sex ratio to maintain genetic variation in their colony with the aid of antheridiogen pheromones, … We determined that ferns have evolved an …

… Haig & Westoby (1988) assumed that sperm dispersal is limited in fern gametophytes but the extent of dispersal in fern sperm remains, as far as we know, largely unexplored. Lloyd & …

… The sexuality of homosporous fern gametophytes is usually determined by antheridiogen, a pheromone that promotes maleness. In this work the effect of photomorphogenically active …

… The determinate of sex type is the pheromone antheridiogen (A CE ) which is secreted by the meristic hermaphrodite and promotes ameristic male development of sexually …

… Ferns possess a variety of mating systems and a labile sex determination mechanism which … , on the amount of heterozygosity in fern populations. Although genetic load aids in the …

Separation of the synthesis and sensing of a signaling molecule controls sex in ferns [Also see Report by Tanaka et al.] Unlike animals, plants have two alternating generations: a diploid sporophyte and a haploid gametophyte. Through meiosis, the sporophyte produces haploid spores, which then give rise to gametophytes, a multicellular haploid structure that produces gametes for sexual reproduction. All seed plants and some non-seed plants are heterosporous, producing spores of different sizes: large female spores and small male spores. Most ferns, on the other hand, are homosporous; they produce a single type of spore. After germination, each fern spore has the potential to develop into a male, female, or hermaphrodite gametophyte. The developmental decision that determines the sex of a particular gametophyte depends on an interplant communication system mediated by chemical signals, termed antheridiogens (1, 2). On page 469 of this issue, Tanaka et al. (3) show that an antheridiogen in the Japanese climbing fern (Lygodium japonicum) functions as more than a simple chemical signal. Covalent modification of the antheridiogen is required to trigger the fern's response to form male gametophytes. Temporal and spatial separation of the biosynthetic pathway between the early- and late-maturing gametophytes ensures the production of the antheridiogen, and the active male-inducing chemically modified form, at just the right time and place.

… gametophyte and thus its sex is the pheromone A CE , which … sex determination in homosporous bryophytes and ferns, … chromosomal mechanism of sex determination and …

… This sexual distinction is regulated by a pheromone (calIed an antheridiogen) that is secreted by hermaphrodites and influences tbe developmenc of latcr-germinating gametophytes so …

… fern genus Cheilanthes and in their derived tetraploid, and if they are sensitive to antheridiogen (ie maleness-inducing pheromone)… sex determination (ESD), whereby sex is determined …

… have been much less studied than animal pheromones, they are involved in a wide variety … in sexual reproduction. In this review, the current knowledge concerning sex pheromones in …

… sex-determination theory. Our results suggest nutrient stoichiometry, not strictly concentration, influences sex determination … Although sex determination is not nutrient-dependent in the …

… a spore develops as a hermaphroditic gametophyte which produces and secrets the … male-inducing effects. When an antheridiogen is present, a spore develops as a male gametophyte […

… (transformer) mutants are phenotypically normal for hermaphrodite and male wild-type plants respectively, but they are both insensitive to the absence or presence of the male-inducing …

… gametophyte size. Antheridiogen was found to slow the growth of male and hermaphrodite gametophytes of the wild type and male gametophytes … insensitive to its maleinducing effect. …

… We used two controls to assess antheridiogen responsiveness and production. As the … is needed to evaluate the evolutionary significance of antheridiogens in homosporous ferns. …

Sex determination, involving the physiological and morphological separation of male and female gamete-producing structures, promotes outcrossing and helps maintain genetic diversity in land plants. In homosporous ferns, which lack sex chromosomes, sex determination is specified during the gametophyte stage and is regulated by intergametophytic signaling mediated by the pheromone antheridiogen. Ceratopteris richardii has long served as a model for dissecting the molecular and cellular mechanisms underlying fern sex determination and associated meristem development in fern gametophytes, and in recent years, important new progress has been achieved. In this review, we summarize recent findings that uncover key environmental and molecular factors influencing antheridiogen responses and highlight the cellular basis of sex-type specification and the initiation and maintenance of meristems in Ceratopteris gametophytes. We also discuss emerging directions in the field, emphasizing the importance of spatial expression dynamics and interacting regulatory networks in fern sexual differentiation. Future advances will likely be driven by integrating genetic tools, multi-omics platforms, and quantitative live-imaging approaches, offering a more comprehensive view of the regulatory logic underlying sex determination and meristem development in ferns.

… decades in flowering plants on reproduction, concretely, on … The importance of the antheridiogen induced signaling cascade is … in Arabidopsis 36, in signaling pathways. Possibly …

… The possibility of fern reproduction through … antheridiogen in the formation of fern gametophytes’ sexual dimorphism are discussed. Data on disturbances of the sexual process in …

… In many ferns antheridiogen, a pheromone secreted by bisexual gametophyte can control the sex expression in undifferentiated spores present in the in the surrounding. Though it is …

SynopsisEvolution of new forms of organisms must be accompanied by evolution of the informational processes which regulate the development of these new forms. During plant phylogeny, products of metabolism have become phytohormones through the evolution of receptor molecules. Although nothing is known about these receptor molecules, it is suggested that the schizaeaceous ferns are the most primitive group in which a gibberellin-like substance acts as a signal for morphogenesis, and that their antheridiogen pheromones, which stimulate antheridium formation and spore germination, are the ancestors of the gibberellin hormones which influence seed plant development. Chemical and biological evidence for this suggestion is discussed.

Land plants alternate between generations of asexual sporophytes and sexual gametophytes. Unlike seed plants, ferns produce free-living gametophytes that grow independently from their sporophytes. Gametophytes of the model fern Ceratopteris exist in two sex types: hermaphrodites and males. Hermaphrodites maintain meristems and secrete the pheromone antheridiogen, inducing undecided gametophytes to become males. In the absence of antheridiogen, males exhibit developmental plasticity and dynamic cell fate specification by initiating de novo meristems to convert into hermaphrodites. Despite its essential role, the molecular signals governing this process remain unclear. Here, we show that local auxin biosynthesis, dynamically regulated during sex-type conversion, establishes new auxin maxima that are critical for specifying and promoting the proliferation of the meristem progenitor cell (MPC) lineage, ultimately enabling the de novo formation of a multicellular meristem from a single MPC. Time-lapse imaging revealed that upon antheridiogen removal, auxin signaling is specifically activated at the initial site of proliferation in Ceratopteris males, triggering new meristem formation. This auxin signaling subsequently becomes concentrated at the center of the proliferating meristem, aligning with localized auxin biosynthesis and the emergence of the meristem notch. Computationally reconstrued lineage maps further showed that chemical inhibition of CrTAA1 abolishes these dynamic auxin patterns, blocking MPC lineage initiation and its subsequent proliferation. Furthermore, genetic knockout of CrTAA1 via CRISPR-Cas9 phenocopies the effects of chemical inhibition, preventing new meristem formation and disrupting male-to-hermaphrodite conversion. Together, these findings uncover a molecular mechanism underlying sex-type conversion in land plants and highlight the pivotal role of de novo auxin biosynthesis in orchestrating cell fate and proliferation during meristem formation.

The spores of Lygodium japonicum, cultured in the dark, form a filamentous structure called protonema. Earlier studies have shown that gibberellin (GA) induces protonema elongation, along with antheridium formation, on the protonema. In this study, we have performed detailed morphological analyses to investigate the roles of multiple phytohormones in antheridium formation, protonema elongation, and prothallus formation in L. japonicum. GA4 methyl ester is a potent GA that stimulates both protonema elongation and antheridium formation. We found that these effects were inhibited by simultaneous application of abscisic acid (ABA). On the other hand, IAA (indole-3-acetic acid) promoted protonema elongation but reduced antheridium formation, while these effects were partially recovered by transferring to an IAA-free medium. An auxin biosynthesis inhibitor, PPBo (4-phenoxyphenylboronic acid), and a transport inhibitor, TIBA (2,3,5-triiodobenzoic acid), both inhibited protonema elongation and antheridium formation. L. japonicum prothalli are induced from germinating spores under continuous white light. Such development was negatively affected by PPBo, which induced smaller-sized prothalli, and TIBA, which induced aberrantly shaped prothalli. The evidence suggests that the crosstalk between these plant hormones might regulate protonema elongation and antheridium formation in L. japonicum. Furthermore, the possible involvement of auxin in the prothalli development of L. japonicum is suggested.

… aquilinum, which is antheridiogen sensitive and in which rhizome reproduction … the antheridiogen response in ferns reveal many similarities and interesting differences to GA signalling …

… fern species, we find that the same hormone signaling components are used in sex determination of ferns as are used for the control … for the hormonal control of sex determination. …

… sex organs which are … fern prothallium is discussed in terms of the growth hormone concept and Goebel's "attraction center " concept. The appearance of adventitious outgrowths on fern …

… growth and sexual organ development in the fern Blechnum … to sexual organ development, BAP inhibited the sexual organ … by an antheridium-inducing hormonal substance, known as …

… To understand how sexual fates can be … rous fern that is both dioecious and amenable to genetic analysis (Hickok et al. 1987; Chasan 1992). Sex determination in homosporous ferns oc…

… The sexual types of 200 gametophytes from each treatment and a control were scored. Gametophytes … of sexual type, 20 male and 20 female gametophytes from each treatment and a …

… The sexual reproduction of ferns is confined to the gametophytic generation. The potential to produce both sexes on the same individual requires mechanisms controlling breeding. In …

The gametophyte of ferns reproduces either by sexual or asexual means. In the latter, apogamy represents a peculiar case of apomixis, in which an embryo is formed from somatic cells. A proteomic and physiological approach was applied to the apogamous fern Dryopteris affinis ssp. affinis and its sexual relative D. oreades. The proteomic analysis compared apogamous vs. female gametophytes, whereas the phytohormone study included, in addition to females, three apogamous stages (filamentous, spatulate, and cordate). The proteomic profiles revealed a total of 879 proteins and, after annotation, different regulation was found in 206 proteins of D. affinis and 166 of its sexual counterpart. The proteins upregulated in D. affinis are mostly associated to protein metabolism (including folding, transport, and proteolysis), ribosome biogenesis, gene expression and translation, while in the sexual counterpart, they account largely for starch and sucrose metabolism, generation of energy and photosynthesis. Likewise, ultra-performance liquid chromatography-tandem spectrometry (UHPLC-MS/MS) was used to assess the levels of indol-3-acetic acid (IAA); the cytokinins: 6-benzylaminopurine (BA), trans-Zeatine (Z), trans-Zeatin riboside (ZR), dyhidrozeatine (DHZ), dyhidrozeatin riboside (DHZR), isopentenyl adenine (iP), isopentenyl adenosine (iPR), abscisic acid (ABA), the gibberellins GA3 and GA4, salicylic acid (SA), and the brassinosteroids: brassinolide (BL) and castasterone (CS). IAA, the cytokinins Z, ZR, iPR, the gibberellin GA4, the brassinosteoids castasterone, and ABA accumulated more in the sexual gametophyte than in the apogamous one. When comparing the three apogamous stages, BA and SA peaked in filamentous, GA3 and BL in spatulate and DHRZ in cordate gametophytes. The results point to the existence of large metabolic differences between apogamous and sexual gametophytes, and invite to consider the fern gametophyte as a good experimental system to deepen our understanding of plant reproduction.

Abstract Pteridophytes include the Psilotales, (Psilotum and Tmesipteris), Sphenophyllales (Equisetum), Lycopodiales (Lycopodium, Selaginella, and Isoetes), and the fern orders Ophioglossales (Botrychium and Ophioglossum), Marattiales, Filicales, Salviniales, and Marsileales. The cardinal points of the pteridophyte life cycle are the meiotic production of spores by the sporophyte and the mitotic production of gametes by the gametophyte. Meiosis initiates the gametophyte generation and the fusion of mitotically formed gametes initiates the sporophyte.

… the model fern species C. richardii, when treated with the pheromone antheridiogen. Several … They employed tree fern fibers, coconut husk fibers, soil, and farm yard manure (1:1:1:1) as …

The tree fern Culcita macrocarpa, a threatened Iberian–Macaronesian endemism, represents the sole European species of the order Cyatheales. Considered a Tertiary relict of European Palaeotropical flora, its evolutionary history and genetic diversity, potentially influenced by presumed high clonal propagation, remain largely unknown. This study elucidates the phylogeographic history of C. macrocarpa, assessing the impact of vegetative reproduction on population dynamics and genetic variability. We provide genetic data from eight newly identified nuclear microsatellite loci and one plastid DNA region for 17 populations spanning the species’ range, together with species distribution modeling data. Microsatellites reveal pervasive clonality in C. macrocarpa, which has varied among populations. We assess the impact of clonality on genetic diversity and evaluate how estimates of intra-population genetic diversity indices and genetic structuring are affected by the chosen definition of “individual” (focusing exclusively on genetically distinct individuals, genets, as opposed to considering all independent clonal replicates, ramets). We identify two main population groups, one in the northern Iberian Peninsula and the other in the Macaronesian archipelagos and southern Iberian Peninsula. Within each group, we found relict populations (in the Azores and the Cantabrian Cornice) as well as recent originated populations. This population structure suggests colonization dynamics in which recent populations originated from one or a few genets of relict populations and became established through intra-gametophytic self-fertilization and vegetative expansion. DAPC analysis facilitated the identification of alleles that most significantly contributed to the observed population structure. The current Andalusian populations appear to have originated from colonization events from the Azores and the Cantabrian Cornice. Our findings suggest that C. macrocarpa persisted through the Last Glacial Maximum in two refugia: the Azores and the Cantabrian Cornice. Colonization into new areas occurred presumably from these refuges, generating two large population groups with structured genetic diversity. This study underscores the significance of clonality in establishing new populations and shaping genetic structure.

… A subset of the ancestral character state reconstruction including taxa from the Equisetales to the Cyatheales can be found in the electronic supplementary material, figure S7. (Online …

Abstract Pteridophytes (vascular cryptogams or ferns and fern allies) comprise about 12 000 species of primitive vascular plants; they do not produce flowers or seeds and reproduce instead via spores. They occur in most terrestrial habitats and also in some aquatic communities. Some species are very beneficial to humans, but the group also contains important species of weeds.

Hybridization is common in many ferns and has been a significant factor in fern evolution and speciation. However, hybrids are rare between the approximately 30 species of Dicksonia tree ferns world-wide, and none are well documented. In this study we examine the relationship of a newly-discovered Dicksonia tree fern from Whirinaki, New Zealand, which does not fit the current taxonomy of the three species currently recognized in New Zealand. Our microsatellite genotyping and ddRAD-seq data indicate these plants are F1 hybrids that have formed multiple times between D. fibrosa and D. lanata subsp. lanata. The Whirinaki plants have intermediate morphology between D. fibrosa and D. lanata subsp. lanata and their malformed spores are consistent with a hybrid origin. The Whirinaki plants–Dicksonia fibrosa × D. lanata subsp. lanata–are an example of hybridization between distantly related fern lineages, with the two parent species estimated to have diverged 55–25 mya. Our chloroplast sequencing indicates asymmetric chloroplast inheritance in the Whirinaki morphology with D. lanata subsp. lanata always contributing the chloroplast genome.

Ferns represent the second-largest group of vascular plants, yet their genomic resources lag far behind. Here, we present a chromosome-scale genome assembly of Cibotium barometz (L.) J. Sm., a medicinally important fern species. The 3.49 Gb genome, assembled into 66 chromosomes with 99.41% sequence anchorage, revealed an exceptionally high proportion (83.93%) of repetitive elements, dominated by recently expanded LTR retrotransposons. We identified 30,616 protein-coding genes, providing insights into fern-specific gene families. Genomic analyses uncover the evolutionary dynamics of 513 key biosynthetic genes, particularly those involved in terpenoid and flavonoid production. Expression profiling across tissues revealed tissue-specific regulation of these pathways, with notable upregulation of chalcone synthase genes in roots. Our structural analysis of 1-deoxy-d-xylulose-5-phosphate synthase, a key enzyme in terpenoid biosynthesis, demonstrated high conservation across land plants while highlighting fern-specific adaptations. The identification of multiple isoforms for key enzymes points to potential gene-duplication events or the evolution of fern-specific variants. This genome provides a foundation for understanding fern biology, evolution, and the molecular basis of their medicinal properties. It also offers valuable resources for conservation efforts and pharmacological research, paving the way for sustainable utilization of this valuable medicinal plant and advancing our understanding of plant diversity and natural product biosynthesis.

Pteridophytes (lycophytes and ferns) are the second most diverse lineage of vascular plants on the earth. These plants share several morphological and physiological traits with other …

Female Cannabis sativa plants have important therapeutic properties. The sex ratio of the dioecious cannabis is approximately 1:1. Cultivating homozygous female plants by inducing female plants to produce male flowers is of great practical significance. However, the mechanism underlying cannabis male development remains unclear. In this study, single-molecule real-time (SMRT) sequencing was performed using a mixed sample of female and induced male flowers from the ZYZM1 cannabis variety. A total of 15,241 consensus reads were identified, and 13,657 transcripts were annotated across seven public databases. A total of 48 lncRNAs with an average length of 986.54 bp were identified. In total, 8202 transcripts were annotated as transcription factors, the most common of which were bHLH transcription factors. Moreover, tissue-specific expression pattern analysis showed that 13 MADS transcription factors were highly expressed in male flowers. Furthermore, 232 reads of novel genes were predicted and enriched in lipid metabolism, and qRT-PCR results showed that CER1 may be involved in the development of cannabis male flowers. In addition, 1170 AS events were detected, and two AS events were further validated. Taken together, these results may improve our understanding of the complexity of full-length cannabis transcripts and provide a basis for understanding the molecular mechanism of cannabis male development.

Shoot development in land plants is a remarkably complex process that gives rise to an extreme diversity of forms. Our current understanding of shoot developmental mechanisms comes almost entirely from studies of angiosperms (flowering plants), the most recently diverged plant lineage. Shoot development in angiosperms is based around a layered multicellular apical meristem that produces lateral organs and/or secondary meristems from populations of founder cells at its periphery. In contrast, non-seed plant shoots develop from either single apical initials or from a small population of morphologically distinct apical cells. Although developmental and molecular information is becoming available for non-flowering plants, such as the model moss Physcomitrella patens, making valid comparisons between highly divergent lineages is extremely challenging. As sister group to the seed plants, the monilophytes (ferns and relatives) represent an excellent phylogenetic midpoint of comparison for unlocking the evolution of shoot developmental mechanisms, and recent technical advances have finally made transgenic analysis possible in the emerging model fern Ceratopteris richardii. This review compares and contrasts our current understanding of shoot development in different land plant lineages with the aim of highlighting the potential role that the fern C. richardii could play in shedding light on the evolution of underlying genetic regulatory mechanisms.

… Equally critical to our understanding of fern ecology and evolutionary experimentation in land plants is expansion of studies on pteridophyte stomatal behavior and links to hydraulics …

Cyatheaceae, assigned to the fern order Eufilicales, is one of the most ancient extant lineages of arborescent tree-ferns and is widely distributed across tropical, subtropical, and parts of the temperate Southern Hemisphere. This group is ecologically, scientifically, and medicinally valuable. It serves as a critical bioindicator of forest ecosystem stability, provides an ideal model system for investigating adaptive evolution and stress response mechanisms in plants, and produces secondary metabolites with promising pharmaceutical applications. Recent advances in modern molecular biology have markedly promoted omics-based research on the family. Here, we systematically review multi-omics achievements—genomics, transcriptomics, and related fields—with emphasis on how sequencing technologies and functional genes have elucidated genetic diversity, cryptic lineage divergence, and adaptive evolutionary mechanisms in response to biotic and abiotic stressors, including climate change, habitat fragmentation, and interspecific competition. We summarize current conservation applications, highlight core problems such as taxonomic and geographical sampling bias and insufficient multi-omics integration, and propose future research directions so as to provide a scientific basis for the systematic conservation, sustainable utilization, and in-depth study of the genetic resources of Cyatheaceae under increasing environmental pressures.

… on sexually mature gametophytes. This value represents the ratio of the variable to maximum fluorescence and gives a quantitative evaluation of photosynthetic efficiency. This value is …

… insights into: (1) if certain of these gametophyte populations sexually reproduced in the past; (2) when long-distance gene flow ceased; and (3) their most likely geographical origin. …

Ferns are the second most diverse vascular plant lineage after angiosperms and have been a key ecological component of Earth's biodiversity for more than 380 million years. Importantly, ferns are sister to seed plants, providing a critical outgroup for understanding the evolution of seed plant features. Ferns are remarkably resilient to abiotic and biotic stresses due to a long evolutionary history with adaptations to diverse habitats, stresses, and herbivores. As a result, ferns produce a multitude of secondary metabolites with unique bioactivities; these chemicals are potentially linked to the adaptation of ferns to herbivory, various abiotic and biotic stresses, and changing environments. Assembled reference genomes and the identification of key metabolic compounds of multiple ferns have already made significant contributions to human health and well-being. Here, we review the recent scientific advances in fern research, including evolution, stress resistance, metabolites and medicinal utilization, and comparative multi-omics applications. We propose that integrated investigations involving ecological, physiological, and molecular techniques will facilitate the future research translation of fern resources in diverse areas including soil remediation, biopesticides, and medicine. Advances in our understanding of fern molecular biology will provide new insights into the evolution of land plants and promote the utilization of ferns for heightened environmental restoration, crop protection and human health.

… evaluated gametophyte desiccation tolerance using saturated salt solutions and gametophyte … In species of ferns that reproduce sexually, the gametophyte produces the sporophyte and …

… Ferns and lycophytes produce spores to initiate the gametophyte stage for sexual reproduction. Approximately 10% of these seedless vascular plants are apomictic, and produce …

Background DNA barcoding will revolutionize our understanding of fern ecology, most especially because the accurate identification of the independent but cryptic gametophyte phase of the fern's life history—an endeavor previously impossible—will finally be feasible. In this study, we assess the discriminatory power of the core plant DNA barcode (rbcL and matK), as well as alternatively proposed fern barcodes (trnH-psbA and trnL-F), across all major fern lineages. We also present plastid barcode data for two genera in the hyperdiverse polypod clade—Deparia (Woodsiaceae) and the Cheilanthes marginata group (currently being segregated as a new genus of Pteridaceae)—to further evaluate the resolving power of these loci. Principal Findings Our results clearly demonstrate the value of matK data, previously unavailable in ferns because of difficulties in amplification due to a major rearrangement of the plastid genome. With its high sequence variation, matK complements rbcL to provide a two-locus barcode with strong resolving power. With sequence variation comparable to matK, trnL-F appears to be a suitable alternative barcode region in ferns, and perhaps should be added to the core barcode region if universal primer development for matK fails. In contrast, trnH-psbA shows dramatically reduced sequence variation for the majority of ferns. This is likely due to the translocation of this segment of the plastid genome into the inverted repeat regions, which are known to have a highly constrained substitution rate. Conclusions Our study provides the first endorsement of the two-locus barcode (rbcL+matK) in ferns, and favors trnL-F over trnH-psbA as a potential back-up locus. Future work should focus on gathering more fern matK sequence data to facilitate universal primer development.

… is a lack of sexual reproduction and the gametophyte and … In summary, the gametophyte shares some cell types with the … of the gametophyte, rhizoids, and hairs but the gametophyte …

… photosynthetic gametophyte, and from seed plants. In the latter, male and female gametophytes … It is therefore possible to merge all families of Cyatheales in a single family, which has …

… a common sexual life cycle that alternates between a diploid sporophyte and a haploid gametophyte; only in ferns and lycophytes are the sporophytic and gametophytic phases both free…

… ) evolution of the peculiar hornwort plastid, 4) symbiotic relationships with fungal and cyanobacterial endophytes, and 5) new insights on hornwort stomata and clefts in the gametophyte …

The life cycle of land plants is characterized by alternating generations of sexual gametophytes and asexual sporophytes. Unlike seed plants, seed-free vascular plants, including ferns, initiate and maintain pluripotent meristems during their gametophyte phase to sustain body expansion and drive the formation of sexual organs for reproduction. This review summarizes meristem development among various fern species during the gametophyte phase, focusing on the cellular basis of meristem initiation, proliferation, and termination. We review the different types of gametophytic meristems in ferns, including apical cell (AC)-based meristems, multicellular apical meristems, and multicellular marginal meristems. We highlight both conserved and lineage-specific patterns of cell division, which are closely associated with these meristem identities and play crucial roles in shaping gametophytic morphology. Additionally, we highlight recent progress in understanding the dynamics of cell division and growth that drive meristem development, through studies that integrate confocal live imaging and computational quantitative analysis. Furthermore, we discuss the influence of environmental and genetic factors on cell division activity in fern gametophytes, including conserved transcriptional regulators that sustain meristem indeterminacy and proliferation in the model fern Ceratopteris richardii.

… However, the leaf cleavage in Fern-NL was not pronounced, and the fern mutant exhibited … both Fern and Fern-NL, using AC as a control, indicated that the upper epidermal cells of Fern …

Water ferns of the Salviniaceae family are successfully used for bioremediation and bioindication of contaminated waters. Due to intensive propagation they are able to produce a great volume of biomass enriched with natural plant growth regulators. Simultaneously, water ferns have become an impediment to the use of water resources through the fast spread. Their growth and development is under control of phytohormones, which are main chemical messengers regulating the responses to environmental changes. Today hormonal system of water ferns of the Salviniaceae family remains understudied. In this review, we analyzed and summarized the literature data and the results of our own research about the role of auxins, cytokinins, gibberellic, abscisic, salicylic and jasmonic acids in regulation of growth and development of water ferns from Salvinia and Azolla genera emphasizing the specific hallmarks of these phytohormones in ferns. We have submitted brief information about methodological approaches for endogenous phytohormones determination in water ferns of the Salviniaceae family. The effects of exogenous regulators on growth, development and tolerance of water macrophytes from Salvinia and Azolla genera were discussed, as well as the possibility of using water ferns to create ecological biofertilizers.