Ecological Adaptation Research Articles

Unveiling the Wing Shape Variation in Northern Altiplano Ecosystems: The Example of the Butterfly Phulia nymphula Using Geometric Morphometrics

The Andean Altiplano, characterized by its extreme climatic conditions and high levels of biodiversity, provides a unique environment for studying ecological and evolutionary adaptations in insect morphology. Butterflies, due their large wing surface compared to body surface, and wide distribution among a geographical area given the flight capabilities provided by their wings, constitute a good biological model to study morphological adaptations following extreme weathers. This study focuses on Phulia nymphula, a butterfly species widely distributed in the Andes, to evaluate wing shape variation across six localities in the Northern Chilean Altiplano. The geometric morphometrics analysis of 77 specimens from six locations from the Chilean Altiplano (Caquena, Sorapata Lake, Chungará, Casiri Macho Lake, Surire Salt Flat, and Visviri) revealed significant differences in wing shape among populations. According to the presented results, variations are likely influenced by local environmental conditions and selective pressures, suggesting specific adaptations to the microhabitats of the Altiplano. The first three principal components represented 60.92% of the total wing shape variation. The detected morphological differences indicate adaptive divergence among populations, reflecting evolutionary responses to the extreme and fragmented conditions of the Altiplano. This study gives insights into the understanding of how high-altitude species can diversify and adapt through morphological variation, providing evidence of ecological and evolutionary processes shaping biodiversity in extreme environments.

Diverse signatures of convergent evolution in cactus-associated yeasts.

Many distantly related organisms have convergently evolved traits and lifestyles that enable them to live in similar ecological environments. However, the extent of phenotypic convergence evolving through the same or distinct genetic trajectories remains an open question. Here, we leverage a comprehensive dataset of genomic and phenotypic data from 1,049 yeast species in the subphylum Saccharomycotina (Kingdom Fungi, Phylum Ascomycota) to explore signatures of convergent evolution in cactophilic yeasts, ecological specialists associated with cacti. We inferred that the ecological association of yeasts with cacti arose independently approximately 17 times. Using a machine learning-based approach, we further found that cactophily can be predicted with 76% accuracy from both functional genomic and phenotypic data. The most informative feature for predicting cactophily was thermotolerance, which we found to be likely associated with altered evolutionary rates of genes impacting the cell envelope in several cactophilic lineages. We also identified horizontal gene transfer and duplication events of plant cell wall-degrading enzymes in distantly related cactophilic clades, suggesting that putatively adaptive traits evolved independently through disparate molecular mechanisms. Notably, we found that multiple cactophilic species and their close relatives have been reported as emerging human opportunistic pathogens, suggesting that the cactophilic lifestyle-and perhaps more generally lifestyles favoring thermotolerance-might preadapt yeasts to cause human disease. This work underscores the potential of a multifaceted approach involving high-throughput genomic and phenotypic data to shed light onto ecological adaptation and highlights how convergent evolution to wild environments could facilitate the transition to human pathogenicity.

Evolution and Domestication of a Novel Biosynthetic Gene Cluster Contributing to the Flavonoid Metabolism and High-Altitude Adaptability of Plants in the Fagopyrum Genus.

The diversity of secondary metabolites is an important means for plants to cope with the complex and ever-changing terrestrial environment. Plant biosynthetic gene clusters (BGCs) are crucial for the biosynthesis of secondary metabolites. The domestication and evolution of BGCs and how they affect plant secondary metabolites biosynthesis and environmental adaptation are still not fully understood. Buckwheat exhibits strong resistance and abundant secondary metabolites, especially flavonoids, allowing it to thrive in harsh environments. A non-canonical BGC named UFGT3 cluster is identified, which comprises a phosphorylase kinase (PAK), two transcription factors (MADS1/2), and a glycosyltransferase (UFGT3), forming a complete molecular regulatory module involved in flavonoid biosynthesis. This cluster is selected during Tartary buckwheat domestication and is widely present in species of the Fagopyrum genus. In wild relatives of cultivated buckwheat, a gene encoding anthocyanin glycosyltransferase (AGT), which glycosylates pelargonidin into pelargonidin-3-O-glucoside, is found inserted into this cluster. The pelargonidin-3-O-glucoside can help plants resist UV stress, endowing wild relatives with stronger high-altitude adaptability. This study provides a new research paradigm for the evolutionary dynamics of plant BGCs, and offers new perspectives for exploring the mechanism of plant ecological adaptability driven by environmental stress through the synthesis of secondary metabolites.

Ladybird Beetle Diversity in Natural and Human-Modified Habitats in the San Cristóbal Island, Galapagos, Ecuador.

This study investigates the species richness and distribution of ladybird beetles (Coccinellidae) across various habitats on San Cristóbal Island in the Galápagos Archipelago, Ecuador. Through extensive field surveys, we catalogued nineteen species, including four previously known species (two endemics, Psyllobora bisigma and Scymnobius scalesius, and two natives, Cycloneda sanguinea and Tenuisvalvae bromelicola). We also identified nine possibly native species reported for the first time in the Galapagos islands in this study or correspond to the first voucher specimens for the island. We collected three previously reported non-native species: Cheilomenes sexmaculata, Novius cardinalis, and Paraneda guticollis. Three species belonging to the genera Stethorus, Calloeneis, and Delphastus remain undetermined, pending further taxonomic analyses. Our findings reveal a rich and complex community with notable differences in species abundance and habitat preference. Endemic species were found to be particularly scarce and restricted mainly to crops undergoing forest regeneration and deciduous forests, emphasising their vulnerability and specialised habitat requirements. The native Cycloneda sanguinea emerged as the most prevalent species, exhibiting broad ecological adaptability. Non-native species, like Cheilomenes sexmaculata, were predominantly found in disturbed habitats, with some showing early signs of spreading into more natural environments, raising concerns about their potential impact on local biodiversity. These findings contribute valuable knowledge to understanding Coccinellidae diversity on San Cristóbal Island and highlight the importance of continued monitoring, particularly in the face of ongoing environmental change and the introduction of non-native species. This study underscores the need for targeted conservation efforts to protect the unique and fragile ecosystems of the Galápagos Archipelago.

Quantitative eco-anatomical analysis reveals distinctive stem traits of six Cannabis sativa cultivars in Rif Mountains (Northern Morocco)

Cannabis sativa stands out as an important crop with significant socioeconomic importance in the Rif Mountains of North Morocco. Recently the number of new cultivars developed in this region has gradually increased for different purposes. In this current study, we delve into the eco-anatomical characteristics of stems across six of the most prevalent Cannabis sativa cultivars in Morocco: ‘Avocat’, ‘Beldiya’, ‘Critical Plus’, ‘Industriel’, ‘Khardala’, and ‘Mexicana’. The investigation encompasses the measurement and analysis of six key eco-anatomical traits: plant height, stem diameter, vessel size, vessel density, number of vessels joined in radial files, and coefficient of hydraulic conductivity. Our aim is to elucidate the variations among these cultivars and underscore their agricultural and ecological relevance. Through anatomical examinations of stem cross-sections, our findings reveal notable disparities and distinctive features among the cultivars. The ‘Khardala’ cultivar exhibits the highest values across most measured eco-anatomical traits, while ‘Beldiya’ and ‘Mexicana’ show similar trait values, particularly with low stem diameter and vessel density. In contrast, ‘Industriel’ stands out with the lowest vessel size and highest vessel density. ‘Critical Plus’ and ‘Avocat’ closely resemble ‘Khardala’ in vessel size and stem diameter. Regarding hydraulic conductivity, ‘Khardala’ ranks highest, followed by ‘Avocat’ and ‘Critical Plus’, while ‘Industriel’ registers the lowest. Our findings underscore increased water demand and uptake potential in ‘Khardala’, ‘Critical Plus’, and ‘Avocat’, contrasting with ‘Industriel’, ‘Beldiya’, and ‘Mexicana’. Anatomical diversity among Cannabis cultivars in our study likely stems from genetic lineage and ecological adaptation.

Spatio-Temporal Variations of Volatile Metabolites as an Eco-Physiological Response of a Native Species in the Tropical Forest.

This study evaluates the essential oil (EO) composition of Piper rivinoides Kunth, a shrub native to the Brazilian tropical rainforest, across different plant parts and developmental phases. The aim was to explore the chemical diversity of EO and its reflection in the plant's ecological interactions and adaptations. Plant organs (roots, stems, branches, and leaves) at different developmental phases were subjected to hydrodistillation followed by chemical analysis using Gas Chromatography-Mass Spectrometry (GC-MS) and Gas Chromatography-Flame Ionization Detector (GC-FID). The results revealed a relevant variation in EO yield and composition among different plant parts and developmental phases. Leaves showed the highest yield and chemical diversity, with α-pinene and β-pinene as major constituents, while roots and stems were characterized by a predominance of arylpropanoids, particularly apiol. The chemical diversity in leaves increased with plant maturity, indicating a dynamic adaptation to environmental interactions. The study underscores the importance of considering the ontogeny of plant parts in understanding the ecological roles and potential applications of P. rivinoides in medicine and agriculture. The findings contribute to the overall knowledge of Piperaceae chemodiversity and ecological adaptations, offering insights into the plant's interaction with its environment and its potential uses based on chemical composition.

High-quality chromosome-level genomic insights into molecular adaptation to low-temperature stress in Madhuca longifolia in southern subtropical China

BackgroundMadhuca longifolia, the energy-producing and medicinal tropical tree originally from southern India, faces difficulties in adapting to the low temperatures of late autumn and early winter in subtropical southern China, impacting its usability. Therefore, understanding the molecular mechanisms controlling the ability of this species to adapt to environmental challenges is essential for optimising horticulture efforts. Accordingly, this study aimed to elucidate the molecular responses of M. longifolia to low-temperature stress through genomic and transcriptomic analyses to inform strategies for its effective cultivation and utilisation in colder climates.ResultsHerein, the high-quality reference genome and genomic assembly for M. longifolia are presented for the first time. Using Illumina sequencing, Hi-C technology, and PacBio HiFi sequencing, we assembled a chromosome-level genome approximately 737.92 Mb in size, investigated its genomic features, and conducted an evolutionary analysis of the genus Madhuca. Additionally, using transcriptome sequencing, we identified 17,941 differentially expressed genes related to low-temperature response. Through bioinformatics analysis of the WRKY gene family, 15 genes crucial for M. longifolia low-temperature resistance were identified.ConclusionsThis research not only lays the groundwork for the successful ecological adaptation and cultivation of M. longifolia in China’s southern subtropical regions but also offers valuable insights for the genetic enhancement of cold tolerance in tropical species, contributing to their sustainable horticulture and broader industrial, medicinal, and agricultural use.

Whole genome regulatory effect of MoISW2 and consequences for the evolution of the rice plant pathogenic fungus Magnaporthe oryzae.

Isw2 proteins, ubiquitous across eukaryotes, exhibit a propensity for DNA binding and exert dynamic influences on local chromosome condensation in an ATP-dependent fashion, thereby modulating the accessibility of neighboring genes to transcriptional machinery. Here, we report the deletion of a putative MoISW2 gene, yielding substantial ramifications on plant pathogenicity. Subsequent gene complementation and chromatin immunoprecipitation sequencing (ChIP-seq) analyses were conducted to delineate binding sites. RNA sequencing (RNA-seq) assays revealed discernible impacts on global gene regulation along chromosomes in both mutant and wild-type strains, with comparative analyses against 55 external RNA-seq data sets corroborating these findings. Notably, MoIsw2-mediated binding and activities delineate genomic loci characterized by pronounced gene expression variability proximal to MoIsw2 binding sites, juxtaposed with comparatively stable expression in surrounding regions. The contingent genes influenced by MoIsw2 activity predominantly encompass niche-determinant genes, including those encoding secreted proteins, secondary metabolites, and stress-responsive elements, alongside avirulence genes. Furthermore, our investigations unveil a spatial correlation between MoIsw2 binding motifs and known transposable elements (TEs), suggesting a potential interplay wherein TE transposition at these loci could modulate the transcriptional landscape of Magnaporthe oryzae in a strain-specific manner. Collectively, these findings position MoIsw2 as a plausible master regulator orchestrating the delicate equilibrium between genes vital for biomass proliferation, akin to housekeeping genes, and niche-specific determinants crucial for ecological adaptability. Stress-induced TE transposition, in conjunction with MoIsw2 activity, emerges as a putative mechanism fostering enhanced mutagenesis and accelerated evolution of niche-determinant genes relative to housekeeping counterparts.IMPORTANCEIsw2 proteins are conserved in plants, fungi, animals, and other eukaryotes. We show that a fungal Isw2 protein in the rice pathogen Magnaporthe oryzae binds to retrotransposon (RT) DNA motifs and affects the epigenetic gene expression landscape of the fungal genome. Mainly ecological niche determinant genes close to the binding motifs are affected. RT elements occur frequently in DNA between genes in most organisms. They move place and multiply in the genome, especially under physiological stress. We further discuss the Isw2 and RT combined activities as a possible sought-after mechanism that can cause biased mutation rates and faster evolution of genes necessary for reacting to abiotic and biotic challenges. The most important biotic challenges for plant pathogens are the ones from the host plants' innate immunity. The overall result of these combined activities will be an adaptation-directed evolution of niche-determinant genes.

Exogenous methyl jasmonate induces CHS and promotes flavonoid accumulation in Zanthoxylum bungeanum

Methyl jasmonate (MeJA) is widely involved in the life processes of plants, especially playing an active role in regulating the synthesis and accumulation of metabolites. Prickly ash (Zanthoxylum bungeanum), as a species of spice tree, is rich in flavonoids throughout its entire plant, showing enormous potential for development into functional foods. Flavonoids play crucial roles in signal transduction and defense mechanisms between plants and their environment, influencing the ecological adaptability of plants. Analyzing the regulatory relationship between methyl jasmonate and flavonoid metabolites will help understand the self-protection mechanism of Zanthoxylum bungeanum under adverse stress. Research results show that the upstream promoter of CHSs (Chalcone synthase), a key gene for flavonoid synthesis, contains multiple methyl jasmonate response elements. Exogenous MeJA induction experiments proved that MeJA can significantly increase the expression levels of ZbCHS71, ZbCHS43 and ZbCHS26 in different tissues of Zanthoxylum bungeanum and directly promote the synthesis and accumulation of flavonoid metabolites. The research results help analyze the regulatory relationship between methyl jasmonate and flavonoids, and provide a reference for research on the accumulation of protective substances under stress conditions in Zanthoxylum bungeanum.

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.

Mesophyll airspace unsaturation drives C4 plant success under vapor pressure deficit stress

A fundamental assumption in plant science posits that leaf air spaces remain vapor saturated, leading to the predominant view that stomata alone control leaf water loss. This concept has been pivotal in photosynthesis and water-use efficiency research. However, recent evidence has refuted this longstanding assumption by providing evidence of unsaturation in the leaf air space of C3 plants under relatively mild vapor pressure deficit (VPD) stress. This phenomenon represents a nonstomatal mechanism restricting water loss from the mesophyll. The potential ubiquity and physiological implications of this phenomenon, its driving mechanisms in different plant species and habitats, and its interaction with other ecological adaptations have. In this context, C4 plants spark particular interest for their importance as crops, bundle sheath cells' unique anatomical characteristics and specialized functions, and notably higher water-use efficiency relative to C3 plants. Here, we confirm reduced relative humidities in the substomatal cavity of the C4 plants maize, sorghum, and proso millet down to 80% under mild VPD stress. We demonstrate the critical role of nonstomatal control in these plants, indicating that the role of the CO2 concentration mechanism in CO2 management at a high VPD may have been overestimated. Our findings offer a mechanistic reconciliation between discrepancies in CO2 and VPD responses reported in C4 species. They also reveal that nonstomatal control is integral to maintaining an advantageous microclimate of relatively higher CO2 concentrations in the mesophyll air space of C4 plants for carbon fixation, proving vital when these plants face VPD stress.

Morphological and Anatomical Characteristics of the Species Paliurus spina-christi

In plants and all living beings, the fundamental influence comes from ecological factors that operate simultaneously and in a complex manner. The influence of these factors is expressed in the morphological and anatomical features of the vegetative organs of plants, especially the leaves, which are among the most delicate organs where a series of adaptations occur. Although biological science today recognizes approximately 500,000 plant species, they differ from each other morphologically, anatomically, and genetically because they live in different life conditions and circumstances. Understanding the morphological‒anatomical characteristics of plants is highly important for determining their taxonomic and ecological adaptability. This connection between the morphological-anatomical structure of vegetative organs, especially leaves, and external factors has been addressed by many authors: Lakusiç (1962), Greb (1957), Pavlov (1965), Hoxha (1995), Mustafa (1995), and others. To obtain a clearer picture of the impact of ecological factors on the morphological and anatomical characteristics of vegetative organs of plants, we conducted research on the anatomical structure of leaves from different insertions: upper (E) and middle (M) of the plant species Pailurus spina Christi.

From Skin to Gut: Understanding Microbial Diversity in Rana amurensis and R. dybowskii.

Amphibians face the threat of decline and extinction, and their health is crucially affected by the microbiota. Their health and ecological adaptability essentially depend on the diverse microbial communities that are shaped by unique host traits and environmental factors. However, there is still limited research on this topic. In this study, cutaneous (C) and gut (G) microbiota in Rana amurensis (A) and R. dybowskii (D) was analyzed through 16S amplicon sequencing. Groups AC and DC significantly differed in alpha diversity, while the gut groups (AG and DG) showed no such differences. Analyses of Bray-Curtis dissimilarity matrix and unweighted UniFrac distances showed significant differences in cutaneous microbiota between groups AC and DC, but not between groups AG and DG. Stochastic processes significantly influenced the assembly of cutaneous and gut microbiota in amphibians, with a notably higher species dispersal rate in the gut. The predominant phyla in the skin of R. amurensis and R. dybowskii were Bacteroidetes and Proteobacteria, respectively, with significant variations in Bacteroidota. Contrarily, the gut microbiota of both species was dominated by Firmicutes, Proteobacteria, and Bacteroidetes, without significant phylum-level differences. Linear discriminant analysis effect size (LEfSe) analysis identified distinct microbial enrichment in each group. Predictive analysis using phylogenetic investigation of communities by reconstruction of unobserved states 2 (PICRUSt2) revealed the significant functional pathways associated with the microbiota, which indicates their potential roles in immune system function, development, regeneration, and response to infectious diseases. This research underscores the critical impact of both host and environmental factors in shaping amphibian microbial ecosystems and emphasizes the need for further studies to explore these complex interactions for conservation efforts.

Exploring Extremotolerant and Extremophilic Microalgae: New Frontiers in Sustainable Biotechnological Applications.

Exploring extremotolerant and extremophilic microalgae opens new frontiers in sustainable biotechnological applications. These microorganisms thrive in extreme environments and exhibit specialized metabolic pathways, making them valuable for various industries. The study focuses on the ecological adaptation and biotechnological potential of these microalgae, highlighting their ability to produce bioactive compounds under stress conditions. The literature reveals that extremophilic microalgae can significantly enhance biomass production, reduce contamination risks in large-scale systems, and produce valuable biomolecules such as carotenoids, lipids, and proteins. These insights suggest that extremophilic microalgae have promising applications in food, pharmaceutical, cosmetic, and biofuel industries, offering sustainable and efficient alternatives to traditional resources. The review concludes that further exploration and utilization of these unique microorganisms can lead to innovative and environmentally friendly solutions in biotechnology.

A new species of Pachyrhabda Meyrick (Lepidoptera: Stathmopodidae) from the Korean Peninsula

The Stathmopodidae, belonging to the Gelechioidea, was first reported by Edward Meyrick in 1913. Since then, species with various morphological characters and various ecological adaptations such as feeding on crops, mosses, and aphids have been reported. In this study, we report the genus Pachyrhabda Meyrick, 1897, for the first time in the Korean Peninsula. This genus of moths is known for consuming spores of ferns. In the present article, we report the discovery of a new species, Pachyrhabda benearena sp. nov. It is diagnosed from the congeneric species by irregular brown spots on the forewings. The new species' description and geographic distribution information are provided. Additionally, a world checklist of the genus is provided.

Pollen morphology reveals genetic diversity between some superior sour cherry (Prunus cerasus L.) genotypes; an opportunity for expanding breeding possibilities

AbstractPreservation of the genetic diversity of sour cherry in Iran is imperative for the development of improved cultivars tailored to specific ecological conditions. Addressing gaps in research concerning ecological adaptation, resource management and international collaboration related to sour cherry genetic resources in Iran is essential. Bridging these research lacunae can facilitate the implementation of sustainable cultivation practices, optimize production systems and enhance the global utilization of sour cherry genetic diversity. A comprehensive analysis of the morphology and ultrastructure of pollen grains from ten native sour cherry genotypes in Iran was conducted over a two-year period using scanning electron microscopy (SEM). The examination revealed that all pollen grains were unipolar, radially symmetrical and tricolpate. The length and width of pollen grains varied among genotypes, with lengths ranging from 42.17 to 57.57 μm and widths from 20.28 to 28.13 μm. Furthermore, all genotypes exhibited prolate pollen grains, with differing colpus lengths. Examination of pollen exine revealed striate shapes with varying numbers of ridges, ranging from 18.5 to 8.5 furrows per 50 m2. The horizontal area of pollen grains varied from 333.28 to 1491.69 μm. Polar perspective analysis showed considerable variation in the distance between mesocolpium endpoints. Sour cherry displays significant genetic diversity in Iran, and the application of SEM has proven instrumental in characterizing this diversity. This understanding will aid in further breeding research aimed at enhancing sour cherry varieties and their adaptation to specific ecological conditions.

Geographic patterns and ecological adaptations of Manila clam (Ruditapes philippinarum) along the Chinese coast: Insights from migration dynamics and gene flow

The Manila Clam (Ruditapes Philippinarum) is one of the most economically significant marine bivalves along the China coast. In recent years, due to the escalating scale of aquaculture, the artificial activities of "cross-regional introduction" have to some extent exerted an influence on the genetic diversity and structure of clam larvae, leading to an ongoing occurrence of genetically mixed clam larvae populations and ambiguous genetic foundation of germplasm resources in China. Therefore, there is an imperative need to gain profound insights into the lineage, genetic structure, and assess the adaptability potential of clams originating from both northern and southern regions. We use Specific Locus Amplified Framents technology to simplify genome sequencing of wild clams along the coast of China. Through genetic diversity, genetic structure, gene flow, and selection elimination analysis, the results show that clams can be divided into distinct north-south lineages, with Wafangdian in Liaoning (RPLW), Zhangzi Island in Liaoning (RPLZ), and Laizhou in Shandong (RPSL) comprise the northern lineage, while Lianjiang in Fujian (RPFL) constitutes the southern lineage. The artificial relocation of clams in China has resulted in a blended population structure among local clams. The genetic functional differences between clams from the north and south are primarily manifest in energy metabolism, and the adaptive evolution of clams is mainly associated with temperature. This integrative research not only furnishes valuable insights into the genetic structure of clam populations, thereby contributing to the advancement of natural conservation and genetic breeding efforts for clams but also establishes the groundwork for a comprehensive exploration of clam adaptive evolution.

Repeatome evolution across space and time: Unravelling repeats dynamics in the plant genus Erythrostemon Klotzsch (Leguminosae Juss).

Fluctuations in genomic repetitive fractions (repeatome) are known to impact several facets of evolution, such as ecological adaptation and speciation processes. Therefore, investigating the divergence of repetitive elements can provide insights into an important evolutionary force. However, it is not clear how the different repetitive element clades are impacted by the different factors such as ecological changes and/or phylogeny. To discuss this, we used the Neotropical legume genus Erythrostemon (Caesalpinioideae) as a model, given its ancient origin (~33 Mya), lineage-specific niche conservatism, macroecological heterogeneity, and disjunct distribution in Meso- and South American (MA and SA respectively) lineages. We performed a comparative repeatomic analysis of 18 Erythrostemon species to test the impact of environmental variables over repeats diversification. Overall, repeatome composition was diverse, with high abundances of satDNAs and Ty3/gypsy-Tekay transposable elements, predominantly in the MA and SA lineages respectively. However, unexpected repeatome profiles unrelated to the phylogeny/biogeography were found in a few MA (E. coccineus, E. pannosus and E. placidus) and SA (E. calycinus) species, related to reticulate evolution and incongruence between nuclear and plastid topology, suggesting ancient hybridizations. The plesiomorphic Tekay and satDNA pattern was altered in the MA-sensu stricto subclade with a striking genomic differentiation (expansion of satDNA and retraction of Tekay) associated with the colonization of a new environment in Central America around 20 Mya. Our data revealthat the current species-specific Tekay pool was the result of two bursts of amplification probably in the Miocene, with distinct patterns for the MA and SA repeatomes. This suggests a strong role of the Tekay elements as modulators of the genome-environment interaction in Erythrostemon, providing macroevolutionary insights about mechanisms of repeatome differentiation and plant diversification across space and time.

Geographic location shapes fungal communities associated with Epidendrum roots

Fungal biodiversity significantly influences ecosystem dynamics through various interactions with plants, ranging from pathogenic to mutually beneficial associations. This study explores the fungal diversity associated with an ornamental orchid genus Epidendrum that is widely propagated globally but native to northern South America. Root samples were collected from Epidendrum in diverse geographic locations: Brazil, Colombia, Germany, Spain and six South African provinces. Fungal biodiversity was catalogued from the genomic DNA extracted from these roots using fungal-specific primers and Illumina MiSeq sequencing. Bioinformatic and statistical analyses revealed significant fungal diversity in the roots, with distinct dominant orders in each geographic region. Among the South African samples, significant differences were found in alpha diversity indices and species richness. Even though samples originating from different provinces overlapped in the PCoA plot, PERMANOVA indicated a significant difference in the fungal biodiversity, which was further supported by PERMDISP. In the global dataset, alpha diversity indices were insignificant, but species richness was. In the PCoA plot, data points clustered by sampling sites, indicating substantial differences in fungal biodiversity between the samples. This was validated by PERMANOVA and PERMDISP analyses. Outcomes from the core fungal analyses showed Epidendrum retained a conserved set of fungal orders from its native habitat when it transitioned to exotic regions, while it also formed new associations with local fungal communities in these introduced regions. These findings highlight the role of both core and region-specific fungal communities in the ecological adaptability and success of this widely planted orchid genus.

Chamaeleo calyptratus (veiled chameleon) chromosome-scale genome assembly and annotation provides insights into the evolution of reptiles and developmental mechanisms.

The family Chamaeleonidae comprises 228 species, boasting an extensive geographic spread and an array of evolutionary novelties and adaptations, but a paucity of genetic and molecular analyses. Veiled chameleon (Chamaeleo calyptratus) has emerged as a tractable research organism for the study of squamate early development and evolution. Here we report a chromosomal-level assembly and annotation of the veiled chameleon genome. We note a remarkable chromosomal conservation across squamates, but comparisons to more distant genomes reveal GC peaks correlating with ancestral chromosome fusion events. We subsequently identified the XX/XY region on chromosome 5, confirming environmental-independent sex determination in veiled chameleons. Furthermore, our analysis of the Hox gene family indicates that veiled chameleons possess the most complete set of 41 Hox genes, retained from an amniote ancestor. Lastly, the veiled chameleon genome has retained both ancestral paralogs of the Nodal gene, but is missing Dand5 and several other genes, recently associated with the loss of motile cilia during the establishment of left-right patterning. Thus, a complete veiled chameleon genome provides opportunities for novel insights into the evolution of reptilian genomes and the molecular mechanisms driving phenotypic variation and ecological adaptation.