Higher Plants Research Articles

Evaluation of the Ecological Environment of the Fuhe River Based on the Diversity of Fish

This article takes the Fuhe River, which has water flowing into Baiyangdian all year round, as the research object. Through actual investigation and measurement of planktonic flora and fauna, benthic organisms, fish, and large vascular plants in the river, and based on fish diversity, the comprehensive evaluation index method is used to scientifically evaluate the ecological environment quality of the Fuhe River. The results showed that a total of 28 species of phytoplankton, 30 species of zooplankton, 11 species of benthic animals, 8 species of submerged plants, and 11 species of fish were detected in the survey area; From a diversity perspective, the diversity of the upstream and downstream river sections is higher than that of the downstream. Overall, the ecological environment quality of the Fuhe River in Baoding City ranges from medium to good, with good water quality in the upstream section and moderate water quality in the middle and downstream sections. This study provides a case study for the scientific evaluation of the ecological environment quality of the upper reaches of Baiyangdian.

Impact of vegetation composition and seasonality on sensitivity of modelled CO2 exchange in temperate raised bogs

Encroachment of vascular plants (VP) in temperate raised bogs, as a consequence of altered hydrological conditions and nutrient input, is widely observed. Effects of such vegetation shift on water and carbon cycles are, however, largely unknown and identification of responsible plant physiological traits is challenging. Process-based modelling offers the opportunity of gaining insights into ecosystem functioning beyond observations, and to infer decisive trait shifts of plant functional groups. We adapted the Soil–Vegetation–Atmosphere Transfer model pyAPES to a temperate raised bog site by calibration against measured peat temperature, water table and surface CO2 fluxes. We identified the most important traits determining CO2 fluxes by conducting Morris sensitivity analysis (MSA) under changing conditions throughout the year and simulated VP encroachment. We further investigated transferability of results to other sites by extending MSA to parameter ranges derived from literature review. We found highly variable intra-annual plant traits importance determining ecosystem CO2 fluxes, but only a partial shift of importance of photosynthetic processes from moss to VP during encroachment. Ecosystem respiration was dominated by peat respiration. Overall, carboxylation rate, base respiration rate and temperature sensitivity (Q10) were most important for determining bog CO2 balance and parameter ranking was robust even under the extended MSA.

Nanocrystal cellulose from diverse biological sources: Application and innovations

Cellulose is the most abundant renewable polymer on Earth which is extensively distributed in diverse ecosystems. It is present in higher plants, marine organisms, and also produced through microbial processes in organisms like algae, fungi, and bacteria. From an industrial perspective, the semicrystalline nature of cellulose present in different plant and microbial sources enables the fabrication of various types of nanocellulose, such as nanofibre and nanocrystals, through mechanical disintegration and chemical methods, respectively. Nanocellulose distinguishes itself as a sustainable, nonharmful, and biodegradable polymer. It will enable sustainable development for responsible consumption and production. Possessing a range of excellent properties, it can be seamlessly integrated into various materials. Research on nanocellulose is gaining momentum in response to current issues related to fossil fuels, including concerns about CO2 emissions, plastic pollution, and the need for renewable energy sources. This review addresses nanocrystals production method from cellulose found in agricultural, microbial sources, and its applications in fields such as materials science, electronics, medicine, and environmental science.

Computer vision models enable mixed linear modeling to predict arbuscular mycorrhizal fungal colonization using fungal morphology

The presence of Arbuscular Mycorrhizal Fungi (AMF) in vascular land plant roots is one of the most ancient of symbioses supporting nitrogen and phosphorus exchange for photosynthetically derived carbon. Here we provide a multi-scale modeling approach to predict AMF colonization of a worldwide crop from a Recombinant Inbred Line (RIL) population derived from Sorghum bicolor and S. propinquum. The high-throughput phenotyping methods of fungal structures here rely on a Mask Region-based Convolutional Neural Network (Mask R-CNN) in computer vision for pixel-wise fungal structure segmentations and mixed linear models to explore the relations of AMF colonization, root niche, and fungal structure allocation. Models proposed capture over 95% of the variation in AMF colonization as a function of root niche and relative abundance of fungal structures in each plant. Arbuscule allocation is a significant predictor of AMF colonization among sibling plants. Arbuscules and extraradical hyphae implicated in nutrient exchange predict highest AMF colonization in the top root section. Our work demonstrates that deep learning can be used by the community for the high-throughput phenotyping of AMF in plant roots. Mixed linear modeling provides a framework for testing hypotheses about AMF colonization phenotypes as a function of root niche and fungal structure allocations.

Putative rhamnogalacturonan-II glycosyltransferase identified through callus gene editing bypasses embryo lethality.

Rhamnogalacturonan II (RG-II) is a structurally complex and conserved domain of the pectin present in the primary cell walls of vascular plants. Borate crosslinking of RG-II is required for plants to grow and develop normally. Mutations that alter RG-II structure also affect crosslinking and are lethal or severely impair growth. Thus, few genes involved in RG-II synthesis have been identified. Here we developed a method to generate viable loss-of-function Arabidopsis (Arabidopsis thaliana) mutants in callus tissue via CRISPR/Cas9-mediated gene editing. We combined this with a candidate gene approach to characterize the male gametophyte defective 2 (MPG2) gene that encodes a putative family GT29 glycosyltransferase. Plants homozygous for this mutation do not survive. We showed that in the callus mutant cell walls, RG-II does not crosslink normally because it lacks 3-deoxy-D-manno-octulosonic acid (Kdo) and thus cannot form the α-L-Rhap-(1→5)-α-D-kdop-(1→ sidechain. We suggest that MGP2 encodes an inverting RG-II CMP-β-Kdo transferase (RCKT1). Our discovery provides further insight into the role of sidechains in RG-II dimerization. Our method also provides a viable strategy for further identifying proteins involved in the biosynthesis of RG-II.

GLR-dependent calcium and electrical signals are not coupled to systemic, oxylipin-based wound-induced gene expression in Marchantia polymorpha.

In angiosperms, wound-derived signals travel through the vasculature to systemically activate defence responses throughout the plant. In Arabidopsis thaliana, activity of vasculature-specific Clade 3 glutamate receptor-like (GLR) channels is required for the transmission of electrical signals and cytosolic Ca2+ ([Ca2+]cyt) waves from wounded leaves to distal tissues, triggering activation of oxylipin-dependent defences. Whether nonvascular plants mount systemic responses upon wounding remains unknown. To explore the evolution of systemic defence responses, we investigated electrical and calcium signalling in the nonvascular plant Marchantia polymorpha. We found that electrical signals and [Ca2+]cyt waves are generated in response to mechanical wounding and propagated to nondamaged distal tissues in M. polymorpha. Functional analysis of MpGLR, the only GLR encoded in the genome of M. polymorpha, indicates that its activity is necessary for the systemic transmission of wound-induced electrical signals and [Ca2+]cyt waves, similar to vascular plants. However, spread of these signals is neither coupled to systemic accumulation of oxylipins nor to a transcriptional defence response in the distal tissues of wounded M. polymorpha plants. Our results suggest that lack of vasculature prevents translocation of additional signalling factors that, together with electrical signals and [Ca2+]cyt waves, contribute to systemic activation of defences in tracheophytes.

Dry grasslands and thorn-cushion communities of Armenia: a first syntaxonomic classification

Aim: To provide the first syntaxonomic, plot-based classification of the dry grasslands and thorn-cushion communities in Armenia. Study area: Armenia. Methods: We sampled 111 vegetation plots (10 m2) and recorded environmental and structural parameters. We collected additional 487 relevés from surrounding countries for a broad-scale comparison. We used modified TWINSPAN to derive a syntaxonomic classification system, whose units were then compared among each other regarding species composition, structure, site conditions and distribution. Results: The classification of Armenian vegetation plots resulted in a 12-cluster solution. Unsupervised classification of the broad-scale dataset yielded five main groups, which were used for the high-level syntaxonomic assignments of the Armenian data. We assigned about half of the plots of the Armenian dataset to the Festuco-Brometea, while the remaining represented a potential new class, preliminarily called “Ziziphora tenuior-Stipa arabica grasslands”. Most of the syntaxa below class level are new to science, therefore we provide formal descriptions of three orders (Plantagini atratae-Bromopsietalia variegatae, Onobrychido transcaucasicae-Stipetalia pulcherrimae, Cousinio brachypterae-Stipetalia arabicae), four alliances (Acantholimono caryophyllacei-Stipion holosericeae, Artemision fragrantis, Onobrychido michauxii-Stipion capillatae, Onobrychido transcaucasicae-Stipion pulcherrimae) and six associations. We found significant differences in the topographic, climatic and soil characteristics, and structural parameters, species life forms and distribution range types between the grassland types at different syntaxonomic levels. The mean species richness was 47.3 (vascular plants: 46.8, bryophytes: 0.4, lichens: 0.1). Conclusions: We found remarkable differences of the Armenian dry grasslands from the previously known units and described most of the higher syntaxa and all the associations as new to science. Our study provides arguments for a potential new class of Ziziphora tenuior-Stipa arabica grasslands separate both from the Euro-Siberian Festuco-Brometea and the Anatolian Astragalo-Brometea. Finally, we found plot scale richness of vascular plants clearly above the Palaearctic average of dry grasslands and that of non-vascular plants clearly below, which calls for further biodiversity analyses. Taxonomic reference: Euro+Med (2023) for vascular plants, Hodgetts et al. (2020) for bryophytes, Nimis et al. (2018) for lichens except for Xanthoparmelia camtschadalis (Ach.) Hale. Abbreviations: EDGG = Eurasian Dry Grassland Group; DCA = detrended correspondence analysis; ICPN = International Code of Phytosociological Nomenclature (Theurillat et al. 2021); TWINSPAN = two-way indicator species analysis.

Overexpression of Calcineurin B-like Interacting Protein Kinase 31 Promotes Lodging and Sheath Blight Resistance in Rice

A breakthrough “Green Revolution” in rice enhanced lodging resistance by using gibberellin-deficient semi-dwarf varieties. However, the gibberellic acid (GA) signaling regulation on rice disease resistance remains unclear. The resistance test showed that a positive GA signaling regulator DWARF1 mutant d1 was more susceptible while a negative GA signaling regulator Slender rice 1 (SLR1) mutant was less susceptible to sheath blight (ShB), one of the major rice diseases, suggesting that GA signaling positively regulates ShB resistance. To isolate the regulator, which simultaneously regulates rice lodging and ShB resistance, SLR1 interactors were isolated. Yeast two-hybrid (Y2H), bimolecular fluorescence complementation (BiFC), and Co-IP assay results indicate that SLR1 interacts with Calcineurin B-like-interacting protein kinase 31 (CIPK31). cipk31 mutants exhibited normal plant height, but CIPK31 OXs showed semi-dwarfism. In addition, the SLR1 level was much higher in CIPK31 OXs than in the wild-type, suggesting that CIPK31 OX might accumulate SLR1 to inhibit GA signaling and thus regulate its semi-dwarfism. Recently, we demonstrated that CIPK31 interacts and inhibits Catalase C (CatC) to accumulate ROS, which promotes rice disease resistance. Interestingly, CIPK31 interacts with Vascular Plant One Zinc Finger 2 (VOZ2) in the nucleus, and expression of CIPK31 accumulated VOZ2. Inoculation of Rhizoctonia solani AG1-IA revealed that the voz2 mutant was more susceptible to ShB. Thus, these data prove that CIPK31 promotes lodging and ShB resistance by regulating GA signaling and VOZ2 in rice. This study provides a valuable reference for rice ShB-resistant breeding.

Species habitat suitability increased during COVID-19 lockdowns

COVID-19 lockdowns had strong positive and negative effects on the environment and biodiversity. The most evident effects were the occurrence of wildlife in the middle of urban settlements, the reduction of noise, and the improvement in air quality. However, other effects on species are less well known. Our main question is: did species habitat suitability increase during lockdowns? Here, we analysed trends in species habitat suitability over time by modelling the species distributions with a time series of environmental variables obtained from satellite remote sensing. We modelled the habitat suitability of 381 species of vascular plants, amphibians, reptiles, birds, and mammals, before, during, and after the lockdowns in the Iberian Peninsula (Portugal and Spain), from July 2017 to August 2022 with the Maxent presence-background algorithm and five MODIS variables (Albedo, Evapotranspiration, LST, NDVI, and Surface reflectance) with a periodicity of 8 days, and analysed their trends with the Mann-Kendall test. We compared our results with air quality data (PM10, CO, and NO2) from ground stations and Sentinel 5 P and with mobility data from Google mobility reports. Habitat suitability increased during both lockdowns when considering all species together. The peak in species' habitat suitability trends during the first lockdown was coincident with air quality and mobility trends: air pollution decreased when people stayed at home. Reduction in human mobility during COVID-19 lockdowns revealed positive effects on species’ habitat quality, highlighting the importance of reducing human activities as the only solution for nature conservation.

Factors affecting the foliar endophyte community in the invasive weed, Impatiens glandulifera

All vascular plants contain communities of endophyte fungi within their foliar tissues. These fungi can act as plant bodyguards and disrupt the efficacy of weed biological control agents, yet studies of invasive plant biology hardly ever consider the background endophyte communities. Here, we investigated the factors that affect the structure of cultivable endophyte communities in the highly invasive weed Impatiens glandulifera. We found that community composition varies according to location, but that seasonal accumulation patterns of endophytes are similar between sites. Biotic factors influencing endophytes include arbuscular mycorrhizal fungi, insect herbivores and plant pathogens. Endophyte species richness per plant was consistently low compared with other herbaceous plants and communities appear to be a random sub-set of the available species pool, with the plant acting as a strong filter of species. This information should enable community structure to be modelled and manipulated, making biological control of this weed more effective.

ACRE, a class of AP2/ERF transcription factors, activates the expression of sweet potato ß-amylase and sporamin genes through the sugar-responsible element CMSRE-1

Sugars, synthesized by photosynthesis in source organs, are loaded and utilized as an energy source and carbon skeleton in sink organs, and also known to be important signal molecules regulating gene expression in higher plants. The expression of genes coding for sporamin and β-amylase, the two most abundant proteins in storage roots of sweet potato, is coordinately induced by sugars. We previously reported on the identification of the carbohydrate metabolic signal-responsible element-1 (CMSRE-1) essential for the sugar-responsible expression of two genes. However, transcription factors that bind to this sequence have not been identified. In this study, we performed yeast one-hybrid screening using the sugar-responsible minimal promoter region of the ß-amylase gene as bait and a library composed only transcription factor cDNAs of Arabidopsis. Two clones, named Activator protein binding to CMSRE-1 (ACRE), encoding AP2/ERF transcription factors were isolated. ACRE showed transactivation activity of the sugar-responsible minimal promoter in a CMSRE-1-dependent manner in Arabidopsis protoplasts. Electric mobility shift assay (EMSA) using recombinant proteins and transient co-expression assay in Arabidopsis protoplasts revealed that ACRE could actually act to the CMSRE-1. Among the DEHYDRATION -RESPONSIVE ELEMENT BINDING FACTOR (DREB) subfamily, almost all homologs including ACRE, could act on the DRE, while only three ACREs could act to the CMSRE-1. Moreover, ACRE-homologs of Japanese morning glory also have the same property of DNA-binding preference and transactivation activity through the CMSRE-1. These findings suggested that ACRE plays an important role in the mechanism regulating the sugar-responsible gene expression through the CMSRE-1 conserved across plant species.

Genomic evidence for the widespread presence of GH45 cellulases among soil invertebrates.

Lignocellulose is a major component of vascular plant biomass. Its decomposition is crucial for the terrestrial carbon cycle. Microorganisms are considered primary decomposers, but evidence increases that some invertebrates may also decompose lignocellulose. We investigated the taxonomic distribution and evolutionary origins of GH45 hydrolases, important enzymes for the decomposition of cellulose and hemicellulose, in a collection of soil invertebrate genomes. We found that these genes are common in springtails and oribatid mites. Phylogenetic analysis revealed that cellulase genes were acquired early in the evolutionary history of these groups. Domain architectures and predicted 3D enzyme structures indicate that these cellulases are functional. Patterns of presence and absence of these genes across different lineages prompt further investigation into their evolutionary and ecological benefits. The ubiquity of cellulase genes suggests that soil invertebrates may play a role in lignocellulose decomposition, independently or in synergy with microorganisms. Understanding the ecological and evolutionary implications might be crucial for understanding soil food webs and the carbon cycle.

Performance of Construction and Demolition Waste Coupled with Selected Vascular Plants to Treat Gray Water in Nature-Based Solutions

Performance of Construction and Demolition Waste Coupled with Selected Vascular Plants to Treat Gray Water in Nature-Based Solutions

Grasslands are more vulnerable to plant invasions than forests in south-central Nepal

Understanding the patterns of plant invasions across vegetation types and identifying the underlying drivers for such patterns is essential to prioritize sites for the effective management of invasive species. We sampled three forest types (Shorea robusta, Dalbergia sissoo, and Tropical deciduous riverine forest) and two grasslands in south-central Nepal to evaluate the richness of naturalized and invasive alien plant species (IAPS). Species richness of naturalized species and the IAPS among vegetation types within each physiographic region was compared using analysis of variance and t-test, and the ordination was used to analyze species-environment relations. Of the total 327 species of vascular plants recorded, 14% were naturalized, and over a third of the naturalized species were invasive. Grasslands had the highest richness of naturalized species and the IAPS. In contrast, S. robusta forest had the lowest naturalized and IAPS richness. Naturalized species richness increased with native species richness. Ordination revealed that a high number of IAPS were associated with areas exposed to frequent fire and livestock grazing and close to human settlements. The results suggest that the grasslands closer to the human settlements and exposed to frequent disturbance are vulnerable to the establishment of IAPS. Early detection and control of IAPS in such frequently disturbed grasslands could prevent their spread into the surrounding landscapes.

Spectral Library of Plant Species from Montesinho Natural Park in Portugal

In this work, we present and describe a spectral library (SL) with 15 vascular plant species from Montesinho Natural Park (MNP), a protected area in Northeast Portugal. We selected species from the vascular plants that are characteristic of the habitats in the MNP, based on their prevalence, and also included one invasive species: Alnus glutinosa (L.) Gaertn, Castanea sativa Mill., Cistus ladanifer L., Crataegus monogyna Jacq., Frangula alnus Mill., Fraxinus angustifolia Vahl, Quercus pyrenaica Willd., Quercus rotundifolia Lam., Trifolium repens L., Arbutus unedo L., Dactylis glomerata L., Genista falcata Brot., Cytisus multiflorus (L’Hér.) Sweet, Erica arborea L., and Acacia dealbata Link. We collected spectra (300–2500 nm) from five records per leaf and leaf side, which resulted in 538 spectra compiled in the SL. Additionally, we computed five vegetation indices from spectral data and analysed them to highlight specific characteristics and differences among the sampled species. We detail the data repository information and its organisation for a better understanding of the data and to facilitate its use. The SL structure can add valuable information about the selected plant species in MNP, contributing to conservation purposes. This plant species SL is publicly available in Zenodo platform.

A REVIEW ON THE β-CAROTENE: PRODUCTION, EXTRACTION, SYNTHESIS AND BIOLOGICAL PROPERTIES

The presence of double bonds gives β-carotene its distinctive hue, making it an oxygen-deficient isoprene-containing molecule. There are cyclic rings at both ends of the molecule. The present review was based on the production, extraction, synthesis and biological properties of β-carotene. Mammals can't produce carotenoids from scratch; therefore, they must get them from somewhere else. Algae, higher plants (in fruits and flowers as esters), fungi, and animals all have these yellow, red, and orange pigments in their natural forms. Carotenoids are found in human breast milk and can be modified through the mother's diet. Hexane, tetrahydrofuran, and acetone are examples of aprotic organic solvents that can be used for solvent-based extraction of -carotene from algae after and before they have been treated. The -carotene in algae, fungi, and plants can be extracted with the help of these solvents. The extraction process for -carotene is sped up and improved by the use of supercritical fluids. Increasing beta-carotene production can be accomplished by tailoring a number of environmental factors, including the type of organism used in the cultivation process, the amount of light available, the amount of salt present, the pH level, and the type and availability of carbon sources. Microalgae, plants, and fungus have all been optimised to increase their beta-carotene synthesis. It concluded that when administered in different doses, it has been shown to have effects like antioxidant and anti-inflammatory. it is also effective against cancer, cardiovascular diseases, Covid-19 and various other diseases.

Bryophytes of Two Peoples Bay Nature Reserve, Western Australia

Context Although the vascular flora of Western Australia is renowned for high species diversity and endemism, very little is known about the state’s moss and liverwort flora. Aims In 1984 we conducted surveys of bryophytes in Two Peoples Bay Nature Reserve. Methods We searched comprehensively for bryophytes at seven major habitats on the Reserve, collecting voucher specimens subsequently identified with modern literature and with the help of Australian bryophyte experts. We updated the text to reflect modern taxonomy and considering modern literature on phytogeography and hypotheses associated with OCBIL (Old, Climatically Buffered, Infertile Landscapes) theory. Key results A total of 38 species of mosses representing 25 genera from 13 families were identified along with 10 species of liverworts representing nine genera and six families. Two moss species (Distichium inclinatum and Tortella dakinii) were previously unknown from Western Australia. Another represented a new species (Pleurophascum occidentale) in a heretofore monotypic genus, family, and order. The Pottiaceae, with 11 species, was the most diverse family of mosses. The Lepidoziaceae, with three species, was the most diverse family of liverworts. Conclusions Lower levels of endemism in bryophytes versus vascular plants may reflect the bryophytes’ capacity for wide and long-distance dispersal of spores and fragments. Bryophyte diversity and endemism may be less than on extensive OCBILs because much of the Reserve emerged from the ocean as recently as the mid-Pleistocene. Implications This, the first listing published of bryophytes on a Reserve in WA, indicates the potential rewards for further survey of mosses and liverworts.

Estrogen-Related Receptor α: A Key Transcription Factor in the Regulation of Energy Metabolism at an Organismic Level and a Target of the ABA/LANCL Hormone Receptor System.

The orphan nuclear receptor ERRα is the most extensively researched member of the estrogen-related receptor family and holds a pivotal role in various functions associated with energy metabolism, especially in tissues characterized by high energy requirements, such as the heart, skeletal muscle, adipose tissue, kidney, and brain. Abscisic acid (ABA), traditionally acknowledged as a plant stress hormone, is detected and actively functions in organisms beyond the land plant kingdom, encompassing cyanobacteria, fungi, algae, protozoan parasites, lower Metazoa, and mammals. Its ancient, cross-kingdom role enables ABA and its signaling pathway to regulate cell responses to environmental stimuli in various organisms, such as marine sponges, higher plants, and humans. Recent advancements in understanding the physiological function of ABA and its mammalian receptors in governing energy metabolism and mitochondrial function in myocytes, adipocytes, and neuronal cells suggest potential therapeutic applications for ABA in pre-diabetes, diabetes, and cardio-/neuroprotection. The ABA/LANCL1-2 hormone/receptor system emerges as a novel regulator of ERRα expression levels and transcriptional activity, mediated through the AMPK/SIRT1/PGC-1α axis. There exists a reciprocal feed-forward transcriptional relationship between the LANCL proteins and transcriptional coactivators ERRα/PGC-1α, which may be leveraged using natural or synthetic LANCL agonists to enhance mitochondrial function across various clinical contexts.

[Brassica juncea BjuWRKY71-1 accelerates flowering by regulating the expression of SOC1].

Brassica juncea (mustard) is a vegetable crop of Brassica, which is widely planted in China. The yield and quality of stem mustard are greatly influenced by the transition from vegetative growth to reproductive growth, i.e., flowering. The WRKY transcription factor family is ubiquitous in higher plants, and its members are involved in the regulation of many growth and development processes, including biological/abiotic stress responses and flowering regulation. WRKY71 is an important member of the WRKY family. However, its function and mechanism in mustard have not been reported. In this study, the BjuWRKY71-1 gene was cloned from B. juncea. Bioinformatics analysis and phylogenetic tree analysis showed that the protein encoded by BjuWRKY71-1 has a conserved WRKY domain, belonging to class Ⅱ WRKY protein, which is closely related to BraWRKY71-1 in Brassica rapa. The expression abundance of BjuWRKY71-1 in leaves and flowers was significantly higher than that in roots and stems, and the expression level increased gradually along with plant development. The result of subcellular localization showed that BjuWRKY71-1 protein was located in nucleus. The flowering time of overexpressing BjuWRKY71-1 Arabidopsis plants was significantly earlier than that of the wild type. Yeast two-hybrid assay and dual-luciferase reporter assay showed that BjuWRKY71-1 interacted with the promoter of the flowering integrator BjuSOC1 and promoted the expression of its downstream genes. In conclusion, BjuWRKY71-1 protein can directly target BjuSOC1 to promote plant flowering. This discovery may facilitate further clarifying the molecular mechanism of BjuWRKY71-1 in flowering time control, and creating new germplasm with bolting and flowering tolerance in mustard.

Spatial organisation of fungi in soil biocrusts of the Kalahari is related to bacterial community structure and may indicate ecological functions of fungi in drylands.

Biological soil crusts, or biocrusts, are microbial communities found in soil surfaces in drylands and in other locations where vascular plant cover is incomplete. They are functionally significant for numerous ecosystem services, most notably in the C fixation and storage due to the ubiquity of photosynthetic microbes. Whereas carbon fixation and storage have been well studied in biocrusts, the composition, function and characteristics of other organisms in the biocrust such as heterotrophic bacteria and especially fungi are considerably less studied and this limits our ability to gain a holistic understanding of biocrust ecology and function. In this research we characterised the fungal community in biocrusts developed on Kalahari Sand soils from a site in southwest Botswana, and combined these data with previously published bacterial community data from the same site. By identifying organisational patterns in the community structure of fungi and bacteria, we found fungi that were either significantly associated with biocrust or the soil beneath biocrusts, leading to the conclusion that they likely perform functions related to the spatial organisation observed. Furthermore, we showed that within biocrusts bacterial and fungal community structures are correlated with each other i.e., a change in the bacterial community is reflected by a corresponding change in the fungal community. Importantly, this correlation but that this correlation does not occur in nearby soils. We propose that different fungi engage in short-range and long-range interactions with dryland soil surface bacteria. We have identified fungi which are candidates for further studies into their potential roles in biocrust ecology at short ranges (e.g., processing of complex compounds for waste management and resource provisioning) and longer ranges (e.g., translocation of resources such as water and the fungal loop model). This research shows that fungi are likely to have a greater contribution to biocrust function and dryland ecology than has generally been recognised.