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Premise: Density-dependent pollinator visitation can lead to density-dependent mating patterns and within-population genetic structure. In Gymnadenia conopsea, individuals in low-density patches receive more self pollen than individuals in high-density patches, suggesting higher relatedness at low density. Ongoing fragmentation is also expected to cause more local matings, potentially leading to biparental inbreeding depression. Methods: To evaluate whether relatedness decreases with local density, we analyzed 1315 SNP loci in 113 individuals within two large populations. We quantified within-population genetic structure in one of the populations, recorded potential habitat barriers, and visualized gene flow using estimated effective migration surfaces (EEMS). We further estimated the magnitude of biparental inbreeding depression that would result from matings restricted to within 5 m. Results: There was no significant relationship between local density and relatedness in any population. We detected significant fine-scale genetic structure consistent with isolation by distance, with positive kinship coefficients at distances below 10 m. Kinship coefficients were low, and predicted biparental inbreeding depression resulting from matings within the closest 5 m was a modest 1–3%. The EEMS suggested that rocks and bushes may act as barriers to gene flow within a population. Conclusions: The results suggest that increased self-pollen deposition in sparse patches does not necessarily cause higher selfing rates or that inbreeding depression results in low establishment success of inbred individuals. The modest relatedness suggests that biparental inbreeding depression is unlikely to be an immediate problem following fragmentation of large populations. The results further indicate that habitat structure may contribute to governing fine-scale genetic structure in G. conopsea.

The nomenclature and taxonomy of Acarospora molybdina is revised using morphological and molecular data. The new combination Myriospora molybdina is proposed and Acarospora hysgina is recognized as a distinct species while A. brunneola is reduced to synonymy with A. hysgina. In its new circumscription M. molybdina is an arctic species, in Scandinavia only occurring in northernmost Norway. Further localities are reported from Greenland, Russia, Svalbard and the USA (Alaska). Acarospora hysgina is the correct name for a species distributed along the west coast of Sweden and Norway, formerly thought to belong to A. molybdina. Localities are also reported from Canada (New Brunswick), Greenland and the USA (Maine). The following names are lectotypified: Acarospora brunneola, A. molybdina var. confusa, Lecanora ereutica beta microcyclos, Parmelia ereutica, P. hysgina and P. molybdina.

Subarctic regions are warming faster than other parts of the globe, and warming is expected to impact carbon (C) assimilation and its allocation into plant biomass and soluble sugars in plant tissues. We analyzed the concentration of soluble sugars (fructose, glucose, and sucrose) in fine roots and rhizomes for three dominant species: Anthoxanthum odoratum, Equisetum spp., and Ranunculus acris. We also examined the concentration and pool of soluble sugars at the plant community level with the aim to investigate the impact of soil warming duration [medium-term (11 years, MTW) vs. long-term (> 60 years, LTW)] and magnitude on soluble sugars in geothermally warmed subarctic grasslands. Among three species, R. acris exhibited the highest concentration of soluble sugars in both fine roots and rhizomes. Comparing total soluble sugar (TSS) between fine roots and rhizomes, rhizomes exhibited a higher concentration in A. odoratum and Equisetum. spp., whereas fine roots had a higher concentration in R. acris. Soil warming did not affect TSS in E. spp. and R. acris, while in A. odoratum, it increased TSS in fine roots and rhizomes in MTW and only in fine roots in LTW. At the plant community level in MTW, soil warming did not affect the soluble sugar concentration in fine roots. However, it increased the TSS and sucrose concentration in rhizomes, which positively correlated with the abundance of grasses. The TSS pool in fine roots decreased with soil warming in MTW, mainly due to a decline in fine root biomass that described 70 % of the decline in the TSS pool. Also, in LTW, soil warming decreased the TSS pool in fine roots, but 74 % of the decline was mainly driven by decreased soluble sugar concentration, specifically that of sucrose, and not by the change in fine root biomass. The decrease in sucrose concentration in fine roots in LTW was related to a decrease in the abundance of A. odoratum. We highlight the species-specific and organ-specific differences in soluble suga

Seasonal dynamics of root growth play an important role in large-scale ecosystem processes; they are largely governed by growth regulatory compounds and influenced by environmental conditions. Yet, our knowledge about physiological drivers of root growth is mostly limited to laboratory-based studies on model plant species. We sampled root tips of Eriophorum vaginatum and analyzed their auxin concentrations and meristem lengths biweekly over a growing season in situ in a subarctic peatland, both in surface soil and at the permafrost thawfront. Auxin concentrations were almost five times higher in surface than in thawfront soils and increased over the season, especially at the thawfront. Surprisingly, meristem length showed an opposite pattern and was almost double in thawfront compared with surface soils. Meristem length increased from peak to late season in the surface soils but decreased at the thawfront. Our study of in situ seasonal dynamics in root physiological parameters illustrates the potential for physiological methods to be applied in ecological studies and emphasizes the importance of in situ measurements. The strong effect of root location and the unexpected opposite patterns of meristem length and auxin concentrations likely show that auxin actively governs root growth to ensure a high potential for nutrient uptake at the thawfront.

Most animal pollination results from plant–insect interactions, but how we perceive these interactions may differ with the sampling method adopted. The two most common methods are observations of visits by pollinators to plants and observations of pollen loads carried by insects. Each method could favour the detection of different species and interactions, and pollen load observations typically reveal more interactions per individual insect than visit observations. Moreover, while observations concern plant and insect individuals, networks are frequently analysed at the level of species. Although networks constructed using visitation and pollen-load data have occasionally been compared in relatively specialised, bee-dominated systems, it is not known how sampling methodology will affect our perception of how species (and individuals within species) interact in a more generalist system. Here we use a Diptera-dominated high-Arctic plant–insect community to explore how sampling approach shapes several measures of species' interactions (focusing on specialisation), and what we can learn about how the interactions of individuals relate to those of species. We found that species degrees, interaction strengths, and species motif roles were significantly correlated across the two method-specific versions of the network. However, absolute differences in degrees and motif roles were greater than could be explained by the greater number of interactions per individual provided by the pollen-load data. Thus, despite the correlations between species roles in networks built using visitation and pollen-load data, we infer that these two perspectives yield fundamentally different summaries of the ways species fit into their communities. Further, individuals' roles generally predicted the species' overall role, but high variability among individuals means that species' roles cannot be used to predict those of particular individuals. These findings emphasize the importance of adopting

This study explores how material qualities of tools contribute to shape information practices of observing, documenting, identifying and reporting species in biodiversity citizen science. Through participant observation and trace ethnography, information practices enacted during a field excursion at a World Heritage Site in south-eastern Sweden are investigated in relation to reported data submitted to the species observation system Artportalen. The study, which adopts a theoretical lens comprising the analytical concepts of epistemic objects and inscriptions, finds that the participants’ situated questioning, discussion, documenting and comparison of species through tool use establishes the observations as projections of knowledge claims. These projections are subsequently constrained but also appended as they are reported as data via Artportalen. As material qualities are generally made invisible, the reported data are augmented by the observation system when merged with other reports to aggregated data. The study extends knowledge concerning how biodiversity citizen science field excursions are conducted by understanding information practices and their outcomes as entangled activities characterised by negotiations in relation to material tools rather than as streamlined processes. Consequently, the results expand knowledge of the messy practices carried out to produce biodiversity citizen science data.

Nitrogen can be taken up by trees in the form of nitrate, ammonium and amino acids, but the influence of the different forms on tree growth and development is poorly understood in angiosperm species like Populus. We studied the effects of both organic and inorganic forms of nitrogen on growth and wood formation of hybrid aspen trees in experimental conditions that allowed growth under four distinct steady-state nitrogen levels. Increased nitrogen availability had a positive influence on biomass accumulation and the radial dimensions of both xylem vessels and fibers, and a negative influence on wood density. An optimal level of nitrogen availability was identified where increases in biomass accumulation outweighed decreases in wood density. None of these responses depended on the source of nitrogen except for shoot biomass accumulation, which was stimulated more by treatments complemented with nitrate than by ammonium alone or the organic source arginine. The most striking difference between the nitrogen sources was the effect on lignin composition, whereby the abundance of H-type lignin increased only in the presence of nitrate. The differential effect of nitrate is possibly related to the well-known role of nitrate as a signaling compound. RNA-sequencing revealed that while the lignin-biosynthetic genes did not significantly (FDR <0.01) respond to added NO3- , the expression of several laccases, catalysing lignin polymerization, was dependent on N-availability. These results reveal a unique role of nitrate in wood formation and contribute to the knowledge basis for decision-making in utilizing hybrid aspen as a bioresource.

Plants tightly control growth of their lateral organs, which led to the concept of apical dominance. However, outgrowth of the dormant lateral primordia is sensitive to the plant's nutritional status, resulting in an immense plasticity in plant architecture. While the impact of hormonal regulation on apical dominance is well characterized, the prime importance of sugar signaling to unleash lateral organ formation has just recently emerged. Here, we aimed to identify transcriptional regulators, which control the trade-off between growth of apical versus lateral organs. Making use of locally inducible gain-of-function as well as single and higher-order loss-of-function approaches of the sugar-responsive S1-basic-leucine-zipper (S1-bZIP) transcription factors, we disclosed their largely redundant function in establishing apical growth dominance. Consistently, comprehensive phenotypical and analytical studies of S1-bZIP mutants show a clear shift of sugar and organic nitrogen (N) allocation from apical to lateral organs, coinciding with strong lateral organ outgrowth. Tissue-specific transcriptomics reveal specific clade III SWEET sugar transporters, crucial for long-distance sugar transport to apical sinks and the glutaminase GLUTAMINE AMIDO-TRANSFERASE 1_2.1, involved in N homeostasis, as direct S1-bZIP targets, linking the architectural and metabolic mutant phenotypes to downstream gene regulation. Based on these results, we propose that S1-bZIPs control carbohydrate (C) partitioning from source leaves to apical organs and tune systemic N supply to restrict lateral organ formation by C/N depletion. Knowledge of the underlying mechanisms controlling plant C/N partitioning is of pivotal importance for breeding strategies to generate plants with desired architectural and nutritional characteristics.

Quinoa is an agriculturally important crop species originally domesticated in the Andes of central South America. One of its most important phenotypic traits is seed colour. Seed colour variation is determined by contrasting abundance of betalains, a class of strong antioxidant and free radicals scavenging colour pigments only found in plants of the order Caryophyllales. However, the genetic basis for these pigments in seeds remains to be identified. Here we demonstrate the application of machine learning (extreme gradient boosting) to identify genetic variants predictive of seed colour. We show that extreme gradient boosting outperforms the classical genome-wide association approach. We provide re-sequencing and phenotypic data for 156 South American quinoa accessions and identify candidate genes potentially controlling betalain content in quinoa seeds. Genes identified include novel cytochrome P450 genes and known members of the betalain synthesis pathway, as well as genes annotated as being involved in seed development. Our work showcases the power of modern machine learning methods to extract biologically meaningful information from large sequencing data sets.

By-products of metal corrosion, when coming into contact with organic matter, have the capacity to preserve it from decay. A pilot study was conducted aiming to explore the potential and limitations of plant remains preserved in by-products of metal corrosion for archaeobotanical research. The organic remains considered come from the surface/immediate proximity of the metal funerary artefacts of two ancient cemeteries—Varna and Messambria, Eastern Bulgaria. Metal corrosion by-products were observed and sampled, under a low magnification stereo microscope. Subsequently, the plant macrofossils recognised were analysed under reflected light and a scanning electron microscope (SEM). Additionally, pollen was extracted from the metal corrosion by-products, using standard acetolysis. The analyses from the graves of both cemeteries allowed identification of textiles and plant fibres, as well as wood (Cornus sp., Pinus sp., Viburnum sp.). At Varna cemetery epidermis fragments of Juncus sp. were recognized, while at Messambria necropolis fruits of almond were found. The pollen analysis from Varna points to use of flowers in the ritual (Daphne tetrads were recorded) and shows a notably open landscape with 77% non-arboreal pollen (NAP). The palynological analysis from the Messambria necropolis revealed the use of flowers in the burial ritual indicated by clusters of Vitis, Cistus and Rosaceae pollen. The surrounding vegetation was dominated by open oak woodland and open habitats (43% NAP) with a strong presence of anthropogenic indicators. The outcome of the study proved to be promising for reconstructing details of the burial rituals including associated plant materials, as well as the surrounding plant habitats during the functioning of the cemeteries.

The nomenclature and taxonomy of Acarospora molybdina is revised using morphological and molecular data. The new combination Myriospora molybdina is proposed and Acarospora hysgina is recognized as a distinct species while A. brunneola is reduced to synonymy with A. hysgina. In its new circumscription M. molybdina is an arctic species, in Scandinavia only occurring in northernmost Norway. Further localities are reported from Greenland, Russia, Svalbard and the USA (Alaska). Acarospora hysgina is the correct name for a species distributed along the west coast of Sweden and Norway, formerly thought to belong to A. molybdina. Localities are also reported from Canada (New Brunswick), Greenland and the USA (Maine). The following names are lectotypified: Acarospora brunneola, A. molybdina var. confusa, Lecanora ereutica beta microcyclos, Parmelia ereutica, P. hysgina and P. molybdina.

As part of a taxonomic reassessment of species that were classified in Berkheya series Rigidae in the most recent monograph of Berkheya, the type material for Berkheya rigida and its putative heterotypic synonyms is reassessed. The original material for the basionym, Stobaea rigida, is heterospecific. Therefore, a second-step lectotype is designated consistent with predominant usage of the name Berkheya rigida. The name Apuleia rigida and its replacement name Stobaea gaertneri apply to a conspicuously radiate species and are excluded from the synonymy of Berkheya rigida. The morphological variability of Berkheya rigida is discussed.

MicroRNAs (miRNAs) are important and ubiquitous regulators of gene expression in both plants and animals. They are thought to have evolved convergently in these lineages and hypothesized to have played a role in the evolution of multicellularity. In line with this hypothesis, miRNAs have so far only been described in few unicellular eukaryotes. Here, we investigate the presence and evolution of miRNAs in Amoebozoa, focusing on species belonging to Acanthamoeba, Physarum and dictyostelid taxonomic groups, representing a range of unicellular and multicellular lifestyles. miRNAs that adhere to both the stringent plant and animal miRNA criteria were identified in all examined amoebae, expanding the total number of protists harbouring miRNAs from 7 to 15. We found conserved miRNAs between closely related species, but the majority of species feature only unique miRNAs. This shows rapid gain and/or loss of miRNAs in Amoebozoa, further illustrated by a detailed comparison between two evolutionary closely related dictyostelids. Additionally, loss of miRNAs in the Dictyostelium discoideum drnB mutant did not seem to affect multicellular development and, hence, demonstrates that the presence of miRNAs does not appear to be a strict requirement for the transition from uni- to multicellular life.

Aim: The microclimate and light conditions on the forest floor are strongly modified by tree canopies. Therefore, we need to better consider the micro-environment when quantifying trait–environment relationships for forest understorey plants. Here, we quantify relationships between micro-environmental conditions and plant functional traits at the community level, including intraspecific trait variation, and their relationship with microclimate air temperature, light and soil properties. Location: Deciduous temperate forests across Europe. Time period: 2018. Major taxa studied: Herbaceous vegetation. Methods: We sampled 225 plots across 15 regions along four complementary gradients capturing both macro- and microclimatic conditions including latitude, elevation, forest management and distance to forest edges. We related the community-weighted mean of five plant functional traits (plant height, specific leaf area [SLA], plant carbon [C], plant nitrogen [N] and plant C:N ratio) across 150 vascular plant species to variation in local microclimate air temperature, light and soil properties. We tested the effect of accounting for intraspecific variation in trait–environment relationships and performed variation partitioning to identify major drivers of trait variation. Results: Microclimate temperature, light availability and soil properties were all important predictors of community-weighted mean functional traits. When light availability and variation in temperature were higher, the herb community often consisted of taller plants with a higher C:N ratio. In more productive environments (e.g. with high soil nitrogen availability), the community was dominated by individuals with resource-acquisitive traits: high SLA and N but low C:N. Including intraspecific trait variation increased the strength of the trait–micro-environment relationship, and increased the importance of light availability. Main conclusions: The trait–environment relationships were much stronger when the

High concentrations of sodium (Na+), chloride (Cl-), calcium (Ca2+), and sulphate (SO42-) are frequently found in saline soils. Crop plants cannot successfully develop and produce because salt stress impairs the uptake of Ca2+, potassium (K+), and water into plant cells. Different intracellular and extracellular ionic concentrations change with salinity, including those of Ca2+, K+, and protons. These cations serve as stress signaling molecules in addition to being essential for ionic homeostasis and nutrition. Maintaining an appropriate K+:Na+ ratio is one crucial plant mechanism for salt tolerance, which is a complicated trait. Another important mechanism is the ability for fast extrusion of Na+ from the cytosol. Ca2+ is established as a ubiquitous secondary messenger, which transmits various stress signals into metabolic alterations that cause adaptive responses. When plants are under stress, the cytosolic-free Ca2+ concentration can rise to 10 times or more from its resting level of 50-100 nanomolar. Reactive oxygen species (ROS) are linked to the Ca2+ alterations and are produced by stress. Depending on the type, frequency, and intensity of the stress, the cytosolic Ca2+ signals oscillate, are transient, or persist for a longer period and exhibit specific signatures. Both the influx and efflux of Ca2+ affect the length and amplitude of the signal. According to several reports, under stress Ca2+ alterations can occur not only in the cytoplasm of the cell but also in the cell walls, nucleus, and other cell organelles and the Ca2+ waves propagate through the whole plant. Here, we will focus on how wheat and other important crops absorb Na+, K+, and Cl- when plants are under salt stress, as well as how Ca2+, K+, and pH cause intracellular signaling and homeostasis. Similar mechanisms in the model plant Arabidopsis will also be considered. Knowledge of these processes is important for understanding how plants react to salinity stress and for the development of toler

Background and Aims Organelle genomes are usually maternally inherited in angiosperms. However, biparental inheritance has been observed, especially in hybrids resulting from crosses between divergent genetic lineages. When it concerns the plastid genome, this exceptional mode of inheritance might rescue inter-lineage hybrids suffering from plastid–nuclear incompatibilities. Genetically differentiated lineages of Silene nutans exhibit strong postzygotic isolation owing to plastid–nuclear incompatibilities, highlighted by inter-lineage hybrid chlorosis and mortality. Surviving hybrids can exhibit variegated leaves, which might indicate paternal leakage of the plastid genome. We tested whether the surviving hybrids inherited the paternal plastid genome and survived thanks to paternal leakage. Methods We characterized the leaf phenotype (fully green, variegated or white) of 504 surviving inter-lineage hybrids obtained from a reciprocal cross experiment among populations of four genetic lineages (W1, W2, W3 and E1) of S. nutans from Western Europe and genotyped 560 leaf samples (both green and white leaves for variegated hybrids) using six lineage-specific plastid single nucleotide polymorphisms. Key Results A high proportion of the surviving hybrids (≤98 %) inherited the paternal plastid genome, indicating paternal leakage. The level of paternal leakage depended on cross type and cross direction. The E1 and W2 lineages as maternal lineages led to the highest hybrid mortality and to the highest paternal leakage from W1 and W3 lineages in the few surviving hybrids. This was consistent with E1 and W2 lineages, which contained the most divergent plastid genomes. When W3 was the mother, more hybrids survived, and no paternal leakage was detected. Conclusions By providing a plastid genome potentially more compatible with the hybrid nuclear background, paternal leakage has the potential to rescue inter-lineage hybrids from plastid–nuclear incompatibilities. This phenomenon mi

This thesis has focused on the evolutionary history of Isoetes (Isoetales, Lycopsida), its phylogeny, megaspore morphology and evolutionary path through deep time. With a broadened sampling of species to include more of the worldwide diversity of the genus compared to previous work an unexpected sister to the rest of the genus was found. Isoetes wormaldii Sim is a critically endangered species from the southeastern Cape region in South Africa, which grows in ponds and slow-moving streams. There are only a few, small populations, and they are very sensitive to habitat changes. The rest of Isoetes is divided into five major clades, which show complex and not readily understandable biogeographic patterns, and by which processes the species came to live in their current locations in the world is often a conundrum. The age of the extant Isoetes is intriguing as it could potentially explain some of the baffling geographic distributions. Analyses based on whole chloroplast genomes and nuclear cistrons found that the choice of clock model and which genome dataset the dating analysis is based on matter greatly when trying to date the genus as the results were highly inconsistent. The solution to the dating analysis woes might be dependent on finding new bases, e.g., fossil evidence, for age calibrations which would require the morphology of Isoetes to be better understood. Our study of megaspore morphology found substantial differences among species of Isoetes in both ornamentation and surface texture/structure. While no major clade within the genus could be unambiguously defined by their spore morphology there are some characteristics of smaller clades and patterns of ornamentation and surface texture across the phylogeny. Our tentative hypothesis is that a pustulate megaspore ornamentation and a cobwebby texture are ancestral features in the megaspore of Isoetes.

Climate is assumed to strongly influence species distribution and abundance. Although the performance of many organisms is influenced by the climate in their immediate proximity, the climate data used to model their distributions often have a coarse spatial resolution. This is problematic because the local climate experienced by individuals might deviate substantially from the regional average. This problem is likely to be particularly important for sessile organisms like plants and in environments where small-scale variation in climate is large. To quantify the effect of local temperature on vital rates and population growth rates, we used temperature values measured at the local scale (in situ logger measures) and integral projection models with demographic data from 37 populations of the forest herb Lathyrus vernus across a wide latitudinal gradient in Sweden. To assess how the spatial resolution of temperature data influences assessments of climate effects, we compared effects from models using local data with models using regionally aggregated temperature data at several spatial resolutions (≥1 km). Using local temperature data, we found that spring frost reduced the asymptotic population growth rate in the first of two annual transitions and influenced survival in both transitions. Only one of the four regional estimates showed a similar negative effect of spring frost on population growth rate. Our results for a perennial forest herb show that analyses using regionally aggregated data often fail to identify the effects of climate on population dynamics. This emphasizes the importance of using organism-relevant estimates of climate when examining effects on individual performance and population dynamics, as well as when modeling species distributions. For sessile organisms that experience the environment over small spatial scales, this will require climate data at high spatial resolutions.

Most animal pollination results from plant–insect interactions, but how we perceive these interactions may differ with the sampling method adopted. The two most common methods are observations of visits by pollinators to plants and observations of pollen loads carried by insects. Each method could favour the detection of different species and interactions, and pollen load observations typically reveal more interactions per individual insect than visit observations. Moreover, while observations concern plant and insect individuals, networks are frequently analysed at the level of species. Although networks constructed using visitation and pollen-load data have occasionally been compared in relatively specialised, bee-dominated systems, it is not known how sampling methodology will affect our perception of how species (and individuals within species) interact in a more generalist system. Here we use a Diptera-dominated high-Arctic plant–insect community to explore how sampling approach shapes several measures of species' interactions (focusing on specialisation), and what we can learn about how the interactions of individuals relate to those of species. We found that species degrees, interaction strengths, and species motif roles were significantly correlated across the two method-specific versions of the network. However, absolute differences in degrees and motif roles were greater than could be explained by the greater number of interactions per individual provided by the pollen-load data. Thus, despite the correlations between species roles in networks built using visitation and pollen-load data, we infer that these two perspectives yield fundamentally different summaries of the ways species fit into their communities. Further, individuals' roles generally predicted the species' overall role, but high variability among individuals means that species' roles cannot be used to predict those of particular individuals. These findings emphasize the importance of adopting

Subarctic regions are warming faster than other parts of the globe, and warming is expected to impact carbon (C) assimilation and its allocation into plant biomass and soluble sugars in plant tissues. We analyzed the concentration of soluble sugars (fructose, glucose, and sucrose) in fine roots and rhizomes for three dominant species: Anthoxanthum odoratum, Equisetum spp., and Ranunculus acris. We also examined the concentration and pool of soluble sugars at the plant community level with the aim to investigate the impact of soil warming duration [medium-term (11 years, MTW) vs. long-term (> 60 years, LTW)] and magnitude on soluble sugars in geothermally warmed subarctic grasslands. Among three species, R. acris exhibited the highest concentration of soluble sugars in both fine roots and rhizomes. Comparing total soluble sugar (TSS) between fine roots and rhizomes, rhizomes exhibited a higher concentration in A. odoratum and Equisetum. spp., whereas fine roots had a higher concentration in R. acris. Soil warming did not affect TSS in E. spp. and R. acris, while in A. odoratum, it increased TSS in fine roots and rhizomes in MTW and only in fine roots in LTW. At the plant community level in MTW, soil warming did not affect the soluble sugar concentration in fine roots. However, it increased the TSS and sucrose concentration in rhizomes, which positively correlated with the abundance of grasses. The TSS pool in fine roots decreased with soil warming in MTW, mainly due to a decline in fine root biomass that described 70 % of the decline in the TSS pool. Also, in LTW, soil warming decreased the TSS pool in fine roots, but 74 % of the decline was mainly driven by decreased soluble sugar concentration, specifically that of sucrose, and not by the change in fine root biomass. The decrease in sucrose concentration in fine roots in LTW was related to a decrease in the abundance of A. odoratum. We highlight the species-specific and organ-specific differences in soluble suga

The nomenclature and taxonomy of Acarospora molybdina is revised using morphological and molecular data. The new combination Myriospora molybdina is proposed and Acarospora hysgina is recognized as a distinct species while A. brunneola is reduced to synonymy with A. hysgina. In its new circumscription M. molybdina is an arctic species, in Scandinavia only occurring in northernmost Norway. Further localities are reported from Greenland, Russia, Svalbard and the USA (Alaska). Acarospora hysgina is the correct name for a species distributed along the west coast of Sweden and Norway, formerly thought to belong to A. molybdina. Localities are also reported from Canada (New Brunswick), Greenland and the USA (Maine). The following names are lectotypified: Acarospora brunneola, A. molybdina var. confusa, Lecanora ereutica beta microcyclos, Parmelia ereutica, P. hysgina and P. molybdina.

Seasonal dynamics of root growth play an important role in large-scale ecosystem processes; they are largely governed by growth regulatory compounds and influenced by environmental conditions. Yet, our knowledge about physiological drivers of root growth is mostly limited to laboratory-based studies on model plant species. We sampled root tips of Eriophorum vaginatum and analyzed their auxin concentrations and meristem lengths biweekly over a growing season in situ in a subarctic peatland, both in surface soil and at the permafrost thawfront. Auxin concentrations were almost five times higher in surface than in thawfront soils and increased over the season, especially at the thawfront. Surprisingly, meristem length showed an opposite pattern and was almost double in thawfront compared with surface soils. Meristem length increased from peak to late season in the surface soils but decreased at the thawfront. Our study of in situ seasonal dynamics in root physiological parameters illustrates the potential for physiological methods to be applied in ecological studies and emphasizes the importance of in situ measurements. The strong effect of root location and the unexpected opposite patterns of meristem length and auxin concentrations likely show that auxin actively governs root growth to ensure a high potential for nutrient uptake at the thawfront.

This study explores how material qualities of tools contribute to shape information practices of observing, documenting, identifying and reporting species in biodiversity citizen science. Through participant observation and trace ethnography, information practices enacted during a field excursion at a World Heritage Site in south-eastern Sweden are investigated in relation to reported data submitted to the species observation system Artportalen. The study, which adopts a theoretical lens comprising the analytical concepts of epistemic objects and inscriptions, finds that the participants’ situated questioning, discussion, documenting and comparison of species through tool use establishes the observations as projections of knowledge claims. These projections are subsequently constrained but also appended as they are reported as data via Artportalen. As material qualities are generally made invisible, the reported data are augmented by the observation system when merged with other reports to aggregated data. The study extends knowledge concerning how biodiversity citizen science field excursions are conducted by understanding information practices and their outcomes as entangled activities characterised by negotiations in relation to material tools rather than as streamlined processes. Consequently, the results expand knowledge of the messy practices carried out to produce biodiversity citizen science data.

Nitrogen can be taken up by trees in the form of nitrate, ammonium and amino acids, but the influence of the different forms on tree growth and development is poorly understood in angiosperm species like Populus. We studied the effects of both organic and inorganic forms of nitrogen on growth and wood formation of hybrid aspen trees in experimental conditions that allowed growth under four distinct steady-state nitrogen levels. Increased nitrogen availability had a positive influence on biomass accumulation and the radial dimensions of both xylem vessels and fibers, and a negative influence on wood density. An optimal level of nitrogen availability was identified where increases in biomass accumulation outweighed decreases in wood density. None of these responses depended on the source of nitrogen except for shoot biomass accumulation, which was stimulated more by treatments complemented with nitrate than by ammonium alone or the organic source arginine. The most striking difference between the nitrogen sources was the effect on lignin composition, whereby the abundance of H-type lignin increased only in the presence of nitrate. The differential effect of nitrate is possibly related to the well-known role of nitrate as a signaling compound. RNA-sequencing revealed that while the lignin-biosynthetic genes did not significantly (FDR <0.01) respond to added NO3- , the expression of several laccases, catalysing lignin polymerization, was dependent on N-availability. These results reveal a unique role of nitrate in wood formation and contribute to the knowledge basis for decision-making in utilizing hybrid aspen as a bioresource.

Plants tightly control growth of their lateral organs, which led to the concept of apical dominance. However, outgrowth of the dormant lateral primordia is sensitive to the plant's nutritional status, resulting in an immense plasticity in plant architecture. While the impact of hormonal regulation on apical dominance is well characterized, the prime importance of sugar signaling to unleash lateral organ formation has just recently emerged. Here, we aimed to identify transcriptional regulators, which control the trade-off between growth of apical versus lateral organs. Making use of locally inducible gain-of-function as well as single and higher-order loss-of-function approaches of the sugar-responsive S1-basic-leucine-zipper (S1-bZIP) transcription factors, we disclosed their largely redundant function in establishing apical growth dominance. Consistently, comprehensive phenotypical and analytical studies of S1-bZIP mutants show a clear shift of sugar and organic nitrogen (N) allocation from apical to lateral organs, coinciding with strong lateral organ outgrowth. Tissue-specific transcriptomics reveal specific clade III SWEET sugar transporters, crucial for long-distance sugar transport to apical sinks and the glutaminase GLUTAMINE AMIDO-TRANSFERASE 1_2.1, involved in N homeostasis, as direct S1-bZIP targets, linking the architectural and metabolic mutant phenotypes to downstream gene regulation. Based on these results, we propose that S1-bZIPs control carbohydrate (C) partitioning from source leaves to apical organs and tune systemic N supply to restrict lateral organ formation by C/N depletion. Knowledge of the underlying mechanisms controlling plant C/N partitioning is of pivotal importance for breeding strategies to generate plants with desired architectural and nutritional characteristics.

Quinoa is an agriculturally important crop species originally domesticated in the Andes of central South America. One of its most important phenotypic traits is seed colour. Seed colour variation is determined by contrasting abundance of betalains, a class of strong antioxidant and free radicals scavenging colour pigments only found in plants of the order Caryophyllales. However, the genetic basis for these pigments in seeds remains to be identified. Here we demonstrate the application of machine learning (extreme gradient boosting) to identify genetic variants predictive of seed colour. We show that extreme gradient boosting outperforms the classical genome-wide association approach. We provide re-sequencing and phenotypic data for 156 South American quinoa accessions and identify candidate genes potentially controlling betalain content in quinoa seeds. Genes identified include novel cytochrome P450 genes and known members of the betalain synthesis pathway, as well as genes annotated as being involved in seed development. Our work showcases the power of modern machine learning methods to extract biologically meaningful information from large sequencing data sets.

By-products of metal corrosion, when coming into contact with organic matter, have the capacity to preserve it from decay. A pilot study was conducted aiming to explore the potential and limitations of plant remains preserved in by-products of metal corrosion for archaeobotanical research. The organic remains considered come from the surface/immediate proximity of the metal funerary artefacts of two ancient cemeteries—Varna and Messambria, Eastern Bulgaria. Metal corrosion by-products were observed and sampled, under a low magnification stereo microscope. Subsequently, the plant macrofossils recognised were analysed under reflected light and a scanning electron microscope (SEM). Additionally, pollen was extracted from the metal corrosion by-products, using standard acetolysis. The analyses from the graves of both cemeteries allowed identification of textiles and plant fibres, as well as wood (Cornus sp., Pinus sp., Viburnum sp.). At Varna cemetery epidermis fragments of Juncus sp. were recognized, while at Messambria necropolis fruits of almond were found. The pollen analysis from Varna points to use of flowers in the ritual (Daphne tetrads were recorded) and shows a notably open landscape with 77% non-arboreal pollen (NAP). The palynological analysis from the Messambria necropolis revealed the use of flowers in the burial ritual indicated by clusters of Vitis, Cistus and Rosaceae pollen. The surrounding vegetation was dominated by open oak woodland and open habitats (43% NAP) with a strong presence of anthropogenic indicators. The outcome of the study proved to be promising for reconstructing details of the burial rituals including associated plant materials, as well as the surrounding plant habitats during the functioning of the cemeteries.

The nomenclature and taxonomy of Acarospora molybdina is revised using morphological and molecular data. The new combination Myriospora molybdina is proposed and Acarospora hysgina is recognized as a distinct species while A. brunneola is reduced to synonymy with A. hysgina. In its new circumscription M. molybdina is an arctic species, in Scandinavia only occurring in northernmost Norway. Further localities are reported from Greenland, Russia, Svalbard and the USA (Alaska). Acarospora hysgina is the correct name for a species distributed along the west coast of Sweden and Norway, formerly thought to belong to A. molybdina. Localities are also reported from Canada (New Brunswick), Greenland and the USA (Maine). The following names are lectotypified: Acarospora brunneola, A. molybdina var. confusa, Lecanora ereutica beta microcyclos, Parmelia ereutica, P. hysgina and P. molybdina.

Ethnopharmacological relevance: Witches in Western Europe are associated with the use of medicinal, abortifacient, hallucinogenic, and toxic plants. Curiously, these associations are not backed up by first-hand evidence and historians are unconvinced that people convicted as witches were herbalists. Local plant names provide an untapped source for analysing witchcraft–plant relationships. Aim of the study: We analysed vernacular plant names indicating an association with witches and devils to find out why these species and witchcraft were linked. Materials and methods: We constructed a database with vernacular names containing the terms witch and devil in related north-west European languages. The devil was added because of its association with witchcraft. The plant species’ characteristics (e.g., medicinal use, toxicity) were assessed to determine if there were non-random associations between these traits and their names. Results: We encountered 1263 unique vernacular name–taxa combinations (425 plant taxa; 97 families). Most species named after witches and/or devils were found within the Asteraceae, Ranunculaceae, and Rosaceae. For Dutch, German and English we confirmed associations between witchcraft names and toxicity. Hallucinogenic plants do not appear to be associated with witch-names. For Dutch, we found significant associations between plant names and medicinal and apotropaic uses, although we did not find any association with abortifacient qualities. Conclusions: This study demonstrates that there is a wide variety of plants associated with witches and the devil in north-western Europe. Plant names with the terms witch and devil were likely used in a pejorative manner to name toxic and weedy plants, and functioned as a warning for their harmful properties. Our study provides novel insights for research into the history of witchcraft and its associated plant species.

Human wildlife interactions (HWI) pose a complex challenge for wildlife managers. Human encroachment into wildlife habitat and the growing number of outdoor recreationists are increasing the frequency of contact and conflict, especially in regions such as the Front Range of Colorado. Geographic information systems (GIS), which use a combination of remote sensing and environmental survey data, allow for predictive spatial analyses of where human wildlife interactions are likely to occur. I used publicly reported observations of moose to create spatial predictive maps in a species distribution model framework. Slope and elevation were shown to be the strongest predictors of HWI, and additional environmental variables added modest predictive power to the SDM. Additionally, a parsimonious model is presented here for a streamlined and practical framework for future monitoring and analysis. Investigation of suitable habitats based on recent observations provides land managers information to identify the likely locations of human-moose encounters. This study identifies the spatial distribution of moose in the wildland urban interface, the potential for increasing populations in nearby suitable habitats, and subsequent implications for wildlife managers.

The current study was designed in a factorial randomized block with 16 treatment combinations, including four concentrations of GA3 (G0-control or water spray, G1 at 200 ppm, G2 at 300 ppm, and G3 at 400 ppm) and four levels of pinching (no pinching, pinching at 25 days after transplanting, pinching at 40 days after transplanting, and double pinching at 25 and 40 days after transplanting), and replicated three times. The results showed that the G2P2 treatment had greater effects on the number of primary branches (46.3), the number of leaves (135.8), the number of flowers (107.5), the Flower diameter (6.93 cm), the Weight of flowers per plant (287.1 g) and the Flower yield per ha. (15.7 t). Pinching and plant growth regulators can either induce or decrease plant height and spread, ultimately affecting yield.

Bryophytes, which include liverworts, mosses, and hornworts, have a long history of traditional medicinal use and are now gaining attention for their biotechnological applications. The evolution of bryophytes and their transition from traditional medicine to biotechnological applications can be explored through various studies. With more than 25,000 species, they constitute a significant part of the terrestrial flora. Bryophytes produce a variety of secondary metabolites, including terpenoids, phenols, glycosides, fatty acids, and amino acids. Bryophytes exhibit cytotoxic and antimicrobial activities, making them promising resources for pharmaceutical, cosmetic, and food industry applications. The traditional uses of bryophytes in medicine are reported in various cultures, including traditional Chinese, Indian, and Native American medicine. Recent advancements in technology and research methodologies have revealed the intricate chemical composition and pharmacological potential of bryophytes, leading to the identification of bioactive compounds with promising therapeutic properties. However details about the potential of bryophytes are currently scattered and not thoroughly documented. The present review focuses on gathering and organizing information about bryophytes and highlighting the challenges, opportunities, and future prospects in harnessing their therapeutic potential for the benefit of global healthcare. &nbsp

Habitat degradation and conversion have become a ubiquitous problem globally and are expected to increase with climate change. In areas where degradation and conversion have already occurred, ecological restoration – defined by the Society for Ecological Restoration as the process of assisting the recovery of an ecosystem that has been degraded, damaged, or destroyed – provides a promising avenue to conserve biodiversity and ecosystem function. However, while projects have achieved restoration success, that is not a consistent outcome, even in the most well-studied ecosystems. The burgeoning field of plant functional trait ecology posits, however, that there are fundamental relationships between plant functional traits and how species respond to their environment. Therefore, classifying species by their plant traits, instead of taxonomic identity, offers a promising way to expand the findings of restoration ecology research to new settings and species.Here, we investigate how to conduct successful ecological restoration in the mediterranean shrublands of southern California, an ecosystem with very little ecological restoration research. Specifically, the research presented herein took place in the Los Padres National Forest, just outside Piru, California. This area has experienced extensive shrubland conversion to non-native grasses over the last few decades and has been identified as a specific area of restoration interest by the United States Forest Service. We first conduct a regional spatial analysis to identify where and why shrublands are being lost to inform how we might conduct restoration. Second, we conducted a large-scale landscape restoration project with a physiologically diverse set of ten species, measured a variety of plant traits (i.e. wood density, integrated water use efficiency, and parts of the leaf economics spectrum) and measured daily microsite temperature (n = 115), humidity (n = 39) and soil moisture (n = 30). This then allowed us to map mi

Juglans californica and J. hindsii are sister taxa endemic to California with significant economic, ecological, and cultural relevance to the state. Each taxon is a foundation species for a rare and threatened plant community, the walnut woodland, in their respective regions. Both species are distributed throughout much of California, but their species identities still need clarification due to some authorities' treatment of both taxa as subspecies of Juglans californica. The future of either taxon will need to confront climate change within a highly urbanized and fragmented landscape, where the usual options for long-living tree species are to adapt, disperse, or die, but landscape genomic-based predictions cannot occur without a clear understanding of how each taxon is genetically and ecologically distinct. Using herbarium specimens and whole-genome sequences for 104 field-identified Juglans californica sampled throughout California, we describe spatially explicit patterns of leaf morphology, genetic structure, and genetic diversity in both taxa and leverage genetic-environment associations to describe distinct patterns of local adaptation that corroborate that these taxa are should be treated as different species. Genetic structure analyses suggest that J. californica is restricted to the Los Angeles Metropolitan area and the Transverse Ranges. J. hindsii occurs throughout much of Northern California and extends into the southmost portion of the species range in San Diego County. Hybridization with a third cluster occurs throughout both of the species. Leaf trait values, including abaxial vein axil hair area, leaflet number, and petiole length, significantly differ between species and corroborate genetic structure results. J. hindsii has higher genetic diversity than J. californica (nucleotide diversity, biallelic richness, and observed heterozygosity) and local adaptation patterns strongly influenced by winter bioclimatic variables based on GEA analyses. J. cali

Microbial communities indigenous to crop fields- particularly root-nodulating rhizobia – enhance growth and yield of legume crops, but the magnitude of microbial effects and their drivers are poorly understood. We sampled cultivated soils across a 1000km transect in California focusing on ten sites with recent cowpea cultivation. Grower practices and crop histories were analyzed, and soils were characterized for resident microbial communities and physiochemical features. Live soil inocula were created from each of the field soils to test the capacity to induce root nodulation and growth effects to six legume cultivars, including cowpea, soybean, and lima- selected because they associate with root-nodulating Bradyrhizobium. Soil inoculations influenced host growth response, which was largely positive to cowpeas on average, but varied depending on soil source and cowpea genotype. Soybean and lima showed little compatibility with root-nodulating rhizobia resident to cowpea fields. Soil source, plant genotype, and soil-plant interactions all impacted variation in plant growth, nodule counts and nodule mass. Crop history and plant genotype were primary factors influencing plant-soil interactions, suggesting a primacy of host plants in reshaping resident soil microbial communities. Links between soil physiochemical features, resident microbial communities, and plant performance offer novel routes to manipulate soils towards improved crop yields.

The Akrotiri Peninsula hosts one of the largest and most ecologically complex ecosystems in Cyprus, supporting rare, vulnerable and endangered flora and fauna. The present study concerns 5 plants included in the Red Data Book of the flora of Cyprus, namely Convolvulus lineatus, Linum maritimum, Lotus cytisoides, Mentha aquatica and Taraxacum aphrogenes and contains information on their geographical distribution at the Akrotiri Peninsula, together with population estimates and observations of their insect flower visitors. The main threats for each of the plants are presented. Current conservation efforts are highlighted and conservation measures are proposed.

The genetic control underlying natural variation in lignin content and composition in trees is not fully understood. We performed a systems genetic analysis to uncover the genetic regulation of lignin biosynthesis in a natural ‘SwAsp’ population of aspen (Populus tremula) trees. We analyzed gene expression by RNA sequencing (RNA-seq) in differentiating xylem tissues, and lignin content and composition using Pyrolysis-GC-MS in mature wood of 268 trees from 99 genotypes. Abundant variation was observed for lignin content and composition, and genome-wide association study identified proteins in the pentose phosphate pathway and arabinogalactan protein glycosylation among the top-ranked genes that are associated with these traits. Variation in gene expression and the associated genetic polymorphism was revealed through the identification of 312 705 local and 292 003 distant expression quantitative trait loci (eQTL). A co-expression network analysis suggested modularization of lignin biosynthesis and novel functions for the lignin-biosynthetic CINNAMYL ALCOHOL DEHYDROGENASE 2 and CAFFEOYL-CoA O-METHYLTRANSFERASE 3. PHENYLALANINE AMMONIA LYASE 3 was co-expressed with HOMEOBOX PROTEIN 5 (HB5), and the role of HB5 in stimulating lignification was demonstrated in transgenic trees. The systems genetic approach allowed linking natural variation in lignin biosynthesis to trees´ responses to external cues such as mechanical stimulus and nutrient availability.

The plant endoplasmic reticulum (ER) contacts heterotypic membranes at membrane contact sites (MCSs) through largely undefined mechanisms. For instance, despite the well-established and essential role of the plant ER-chloroplast interactions for lipid biosynthesis, and the reported existence of physical contacts between these organelles, almost nothing is known about the ER-chloroplast MCS identity. Here we show that the Arabidopsis ER membrane-associated VAP27 proteins and the lipid-binding protein ORP2A define a functional complex at the ER-chloroplast MCSs. Specifically, through in vivo and in vitro association assays, we found that VAP27 proteins interact with the outer envelope membrane (OEM) of chloroplasts, where they bind to ORP2A. Through lipidomic analyses, we established that VAP27 proteins and ORP2A directly interact with the chloroplast OEM monogalactosyldiacylglycerol (MGDG), and we demonstrated that the loss of the VAP27-ORP2A complex is accompanied by subtle changes in the acyl composition of MGDG and PG. We also found that ORP2A interacts with phytosterols and established that the loss of the VAP27-ORP2A complex alters sterol levels in chloroplasts. We propose that, by interacting directly with OEM lipids, the VAP27-ORP2A complex defines plant-unique MCSs that bridge ER and chloroplasts and are involved in chloroplast lipid homeostasis.

The present study evaluated the repercussions of magnetopriming on the root system architecture of soybean plants subjected to arsenic toxicity using synchrotron radiation source based micro-computed tomography (SR-µCT). This will be used evey where as abbreviation for the technique for three-dimensional imaging. Seeds of soybean were exposed to the static magnetic field (SMF) of strength (200 mT) for 1h prior to sowing. Magnetoprimed and non-primed seeds were grown for 1 month in a soil-sand mixture containing four different levels of sodium arsenate (0, 5, 10, and 50 mg As kg−1 soil). The results showed that arsenic adversely affects the root growth in non-primed plants by reducing their root length, root biomass, root hair, size and number of root nodules, where the damaging effect of As was observed maximum at higher concentrations (10 and 50 mg As kg−1 soil). However, a significant improvement in root morphology was detected in magnetoprimed plants where SMF pretreatment enhanced the root length, root biomass, pore diameter of cortical cells, root hair formation, lateral roots branching, and size of root nodules and girth of primary roots. Qualitative analysis of x-ray micro-CT images showed that arsenic toxicity damaged the epidermal and cortical layers of the root as well as reduced the pore diameter of the cortical cells. However, the diameter of cortical cells pores in magnetoprimed plants was observed higher as compared to plants emerged from non-primed seeds at all level of As toxicity. Thus, the study suggested that magnetopriming has the potential to attenuate the toxic effect of As and could be employed as a pre-sowing treatment to reduce the phytotoxic effects of metal ions in plants by improving root architecture and root tolerance index. This study is the very first exploration of the potential benefits of magnetopriming in mitigating the toxicity of metals (As) in plant roots utilizing the micro-CT technique.

Chlorophyll is essential in photosynthesis, converting sunlight into chemical energy in plants, algae, and certain bacteria. Its structure, featuring a porphyrin ring enclosing a central magnesium ion, varies in forms like chlorophyll a, b, c, d, and f, allowing light absorption at a broader spectrum. With a 20-carbon phytyl tail (except for chlorophyll c), chlorophyll is anchored to proteins. Previous findings suggested the presence of chlorophyll with a modified farnesyl tail in thermophilic cyanobacteria Thermosynechoccocus vestitus. In our Arabidopsis thaliana PSII cryo-EM map, specific chlorophylls showed incomplete phytyl tails, suggesting potential farnesyl modifications. However, further high-resolution mass spectrometry (HRMS) analysis in A. thaliana and T. vestitus did not confirm the presence of any farnesyl tails. Instead, we propose the truncated tails in PSII models may result from binding pocket flexibility rather than actual modifications.

Marine heatwaves (MHWs) caused by anthropogenic climate change are becoming a key driver of change at the ecosystem level. Thermal conditions experienced by marine organisms across their distribution, particularly towards the equator, are likely to approach their physiological limits, resulting in extensive mortality and subsequent changes at the population level. Populations at the margins of their species’ distribution are thought to be more sensitive to climate-induced environmental pressures than central populations, but our understanding of variability in fitness-related physiological traits in trailing versus leading-edge populations is limited. In a laboratory simulation study, we tested whether two leading (Iceland) and two trailing (Spain) peripheral populations of the intertidal macroalga Corallina officinalis display different levels of maximum potential quantum efficiency (Fv/Fm) resilience to current and future winter MHWs scenarios. Our study revealed that ongoing and future local winter MHWs will not negatively affect leading-edge populations of C. officinalis, which exhibited stable photosynthetic efficiency throughout the study. Trailing edge populations showed apositive though non-significant trend in photosynthetic efficiency throughout winter MHWs exposure. Poleward and equatorward populations did not produce significantly different results, with winter MHWs having no negative affect on Fv/Fm of either population. Additionally, we found no long-term regional or population-level influence of a winter MHWs on this species’ photosynthetic efficiency. Thus, we found no statistically significant difference in thermal stress responses between leading and trailing populations. Nonetheless, C. officinalis showed a trend towards higher stress responses in southern than northern populations. Because responses rest on a variety of local population traits, they are difficult to predict based solely on thermal pressures.

BBXs are B-Box zinc finger proteins that can act as transcription factors and regulators of protein complexes. Several BBX proteins play important roles in plant development. Two Arabidopsis thaliana microProteins belonging to the BBX family, named miP1a and miP1b, homotypically interact with and modulate the activity of other BBX proteins, including CONSTANS, which transcriptionally activates the florigen, FLOWERING LOCUS T. Arabidopsis plants overexpressing miP1a and miP1b showed delayed flowering. In tomato, the closest homologs of miP1a and miP1b are the microProteins SlBBX16 and SlBBX17. This study was aimed at investigating whether the constitutive expression of SlBBX16/17 in Arabidopsis and tomato impacted reproductive development. The heterologous expression of the two tomato microProteins in Arabidopsis caused a delay in the flowering transition; however, the effect was weaker than that observed when the native miP1a/b were overexpressed. In tomato, overexpression of SlBBX17 prolonged the flowering period; this effect was accompanied by downregulation of the flowering inhibitors Self Pruning (SP) and SP5G. SlBBX16 and SlBBX17 can hetero-oligomerize with TCMP-2, a cystine-knot peptide involved in flowering pattern regulation and early fruit development in tomato. The increased expression of both microProteins also caused alterations in tomato fruit development: we observed in the case of SlBBX17 a decrease in the number and size of ripe fruits as compared to WT plants, while for SlBBX16, a delay in fruit production up to the breaker stage. These effects were associated with changes in the expression of GA-responsive genes.

Metacaspases are cysteine proteases present in plants, fungi and protists. While the association of metacaspases with cell death is studied in a range of organisms, their native substrates are largely unknown. Here, we explored the in vivo proteolytic landscape of the two metacaspases, CrMCA-I and CrMCA-II, present in the green freshwater alga Chlamydomonas reinhardtii, using mass spectrometry-based degradomics approach, during control conditions and salt stress. Comparison between the cleavage events of CrMCA-I and CrMCA-II in metacaspase mutants revealed unique cleavage preferences and substrate specificity. Degradome analysis demonstrated the relevance of the predicted metacaspase substrates to the physiology of C. reinhardtii cells and its adaptation during salt stress. Functional enrichment analysis indicated an involvement of CrMCA-I in the catabolism of carboxylic acids, while CrMCA-II plays an important role in photosynthesis and translation. Altogether, our findings suggest distinct cellular functions of the two metacaspases in C. reinhardtii during salt stress response.

Long non-coding RNAs (lncRNAs) play essential roles in various biological processes, such as chromatin remodeling, post-transcriptional regulation, and epigenetic modifications. Despite their critical functions in regulating plant growth, root development, and seed dormancy, the identification of plant lncRNAs remains a challenge due to the scarcity of specific and extensively tested identification methods. Most mainstream machine learning-based methods used for plant lncRNA identification were initially developed using human or other animal datasets, and their accuracy and effectiveness in predicting plant lncRNAs have not been fully evaluated or exploited. To overcome this limitation, we retrained several models, including CPAT, PLEK, and LncFinder, using plant datasets and compared their performance with mainstream lncRNA prediction tools such as CPC2, CNCI, RNAplonc, and LncADeep. Retraining these models significantly improved their performance, and two of the retrained models, LncFinder-plant and CPAT-plant, alongside their ensemble, emerged as the most suitable tools for plant lncRNA identification. This underscores the importance of model retraining in tackling the challenges associated with plant lncRNA identification. Finally, we developed a pipeline (Plant-LncPipe) that incorporates an ensemble of the two best-performing models and covers the entire data analysis process, including reads mapping, transcript assembly, lncRNA identification, classification, and origin, for the efficient identification of lncRNAs in plants. The pipeline, Plant-LncPipe, is available at: https://github.com/xuechantian/Plant-LncRNA-pipline.

Due to their sessile nature, plants must precisely time and coordinate their physiological processes with daily and seasonal changes in the environment. In this PhD thesis, I explored the interaction between an internal timekeeper, or circadian clock, and hormonal regulation, and how it may control plant growth and adaptation in the model species Arabidopsis thaliana (Arabidopsis) and hybrid aspen (Populus tremula x P. tremuloides). Our research showed how the circadian clock component ZEITLUPE (ZTL) regulates abscisic acid (ABA)-mediated stomatal closure, indicating its central role in environmental adaptation. We investigated the effects of manipulating gibberellin (GA) metabolism in hybrid aspen by the strategic expression of the Arabidopsis GIBBERELLIN20-OXIDASE1 gene, using a clock-controlled promoter. This approach struck a delicate balance between enhanced growth and seasonal adaptation and showed potential for increased tree performance through biotechnological means. Our studies on the circadian clock components LATE ELONGATED HYPOCOTYL (LHY) and EARLY BIRD (EBI) in hybrid aspen suggested their involvement in regulating GA metabolism and overall plant growth. Taken together, these findings improve our understanding of how plants regulate growth and respond to environmental stresses and help to provide solutions for enhancing plant resilience and productivity.

Forestry in Sweden largely relies on planting genetically improved seedlings after clear-cutting, and high survival and early growth of planted seedlings is vital for stand establishment, economic viability, and carbon sequestration. Norway spruce (Picea abies) and Scots pine (Pinus sylvestris) are the two most important tree species in Swedish forest stands and both are associated with a variety of ectomycorrhizal fungi. While seedlings are generally not fertilized at outplanting, previous results have shown that fertilization with arginine phosphate can increase root growth and seedling survival. However, it is not clear how this affects fungal community composition on the roots of growing seedlings. In a planting experiment sampled after one and two growing seasons, we found that planting position had the largest effects both on seedling performance and on fungal community composition and provide insight into the early stages of fungal community succession on planted Norway spruce and Scots pine seedlings. Fungal taxa present on seedlings before planting persisted on seedling roots, while some degree of novel colonization by site indigenous taxa was observed. Fertilization modified the relative abundance of some fungal taxa but did not lead to significant changes in overall community composition. In terms of seedling performance, ammonium nitrate led to increased mortality while arginine phosphate improved root growth.

Enter the fascinating world of fungi Fungi are responsible for life on land as we know it and integral to sustained living on earth. They are a perpetual inspiration for artists. Through music, literature, fashion, design, scent and visual art, Fungi Forms will take you on a spectacular journey, exploring fungi in science, culture and innovation. Group exhibition 'Stinkhorn' video 2020, with Siôn Parkinson, included.

Enter the fascinating world of fungi Fungi are responsible for life on land as we know it and integral to sustained living on earth. They are a perpetual inspiration for artists. Through music, literature, fashion, design, scent and visual art, Fungi Forms will take you on a spectacular journey, exploring fungi in science, culture and innovation. Group exhibition 'Stinkhorn' video 2020, with Siôn Parkinson, included.

Arbuscular mycorrhizal fungi (AMF) are beneficial soil organisms that can form symbiotic associations with the host plant roots. Mycorrhizal symbiosis between plant root and fungi can influence plant diversity and ecosystem productivity. However, the impacts of AMF frequently documented in the loamy to sandy soil, whereas it has no precise mechanism of influencing plant productivity, macronutrient uptake, and aggregation in a clay soil. A pot experiment was carried out to investigate the impact of AMF on plant growth, nutrient uptake and soil aggregation in a clay soil of Bangladesh. Okra (Abelmoschus esculentus L.) was cultivated over 105 days with AMF and without AMF (NAMF) with 5 replications. Plant productivity, nutrient uptake, soil organic carbon (SOC), microbial biomass carbon (MBC), aggregate stability (MWD), and glomalin-related soil protein (GRSP) were measured after 105 days. Results showed that the plant productivity and nutrient availability in soil and their subsequent uptake in AMF were significantly higher compared to the NAMF treatment (p < 0.01). We observed 17% increase in aggregate stability (measured as mean weight diameter) and 28% increase in organic carbon in AMF inoculated soil compared to NAMF. The microbial biomass carbon and GRSP were significantly higher in the AMF than NAMF treatment (p < 0.01). The findings highlight that AMF introduction can be a promising tool for improving plant production and soil condition in the clay soil instead of conventional farming system.