Living Plant Tissues Research Articles

Antibacterial Properties in Fermentate Extracts of Endophytic Fungus Derived from Marine Algae Caulerpa lentillifera Against Gastrointestinal Pathogenic Bacteria

Endophytic fungi, residing symbiotically within living plant tissues, are a promising source of novel bioactive compounds. These fungi are known to produce secondary metabolites with a wide range of biological activities, including antibacterial properties. This study explored the antibacterial potential of fermented extracts from endophytic fungi isolated from the marine alga Caulerpa lentillifera, a food source consumed by coastal communities and traditionally used for medicinal purposes. Thin-layer chromatography (TLC) bioautography was employed to identify extracts with activity against common gastrointestinal pathogenic bacteria, such as Escherichia coli, Shigella dysenteriae, and Salmonella typhi. Two endophytic fungal isolates displayed promising antibacterial activity against these pathogens. TLC analysis tentatively identified the presence of flavonoids and alkaloids, potentially responsible for the observed effects. This research sheds light on the pharmacological potential of endophytic fungi and their applications in combating bacterial infections.

In vivo biosensing of subcellular pyruvate pools reveals photosynthesis-dependent metabolite dynamics in Nicotiana benthamiana

Abstract Pyruvate is central to metabolism across biology. It acts as a metabolic hub linking major pathways including glycolysis, the Krebs cycle, fermentation, and synthesis of amino acids, fatty acids, isoprenoids, and nucleotides. Even though the central role of pyruvate is well established biochemically, there is a remarkable gap in our understanding of how pyruvate levels behave within cells, where pyruvate is distributed across different compartments. Moreover, differential changes in pyruvate pools may occur rapidly upon changes in metabolic fluxes. Recently, this problem has been addressed by the development of a genetically encoded pyruvate biosensor to provide first insights into the pyruvate dynamics in animal cells. Here, we established in vivo biosensing of pyruvate in plants. We provided advanced characterization of the biosensor properties and demonstrated the functionality of the sensor in the cytosol, the mitochondria, and the chloroplasts of Nicotiana benthamiana epidermal cells. Finally, we harnessed the tool to investigate the impact of photosynthesis on pyruvate with unprecedented spatial and temporal resolution, revealing pronounced changes in subcellular pyruvate pools. While highlighting the current limitations of the biosensor, this study provides proof-of-concept for how the dynamics and regulation of central carbon metabolites can be revealed in living plant tissues.

Metabolic imaging in living plants: A promising field for chemical exchange saturation transfer (CEST) MRI.

Magnetic resonance imaging (MRI) is a versatile technique in the biomedical field, but its application to the study of plant metabolism in vivo remains challenging because of magnetic susceptibility problems. In this study, we report the establishment of chemical exchange saturation transfer (CEST) for plant MRI. This method enables noninvasive access to the metabolism of sugars and amino acids in complex sink organs (seeds, fruits, taproots, and tubers) of major crops (maize, barley, pea, potato, sugar beet, and sugarcane). Because of its high signal detection sensitivity and low susceptibility to magnetic field inhomogeneities, CEST analyzes heterogeneous botanical samples inaccessible to conventional magnetic resonance spectroscopy. The approach provides unprecedented insight into the dynamics and distribution of sugars and amino acids in intact, living plant tissue. The method is validated by chemical shift imaging, infrared microscopy, chromatography, and mass spectrometry. CEST is a versatile and promising tool for studying plant metabolism in vivo, with many applications in plant science and crop improvement.

Live cell imaging of cellular dynamics in poplar wood using computational cannula microscopy

This study presents significant advancements in computational cannula microscopy for live imaging of cellular dynamics in poplar wood tissues. Leveraging machine-learning models such as pix2pix for image reconstruction, we achieved high-resolution imaging with a field of view of 55µm using a 50µm-core diameter probe. Our method allows for real-time image reconstruction at 0.29 s per frame with a mean absolute error of 0.07. We successfully captured cellular-level dynamics in vivo, demonstrating morphological changes at resolutions as small as 3µm. We implemented two types of probabilistic neural network models to quantify confidence levels in the reconstructed images. This approach facilitates context-aware, human-in-the-loop analysis, which is crucial for in vivo imaging where ground-truth data is unavailable. Using this approach we demonstrated deep in vivo computational imaging of living plant tissue with high confidence (disagreement score ⪅0.2). This work addresses the challenges of imaging live plant tissues, offering a practical and minimally invasive tool for plant biologists.

Development of a fluorescent scaffold by utilizing quercetin template for selective detection of Hg2+: Experimental and theoretical studies along with live cell imaging

Quercetin is an important antioxidant with high bioactivity and it has been used as SARS-CoV-2 inhibitor significantly. Quercetin, one of the most abundant flavonoids in nature, has been in the spot of numerous experimental and theoretical studies in the past decade due to its great biological and medicinal importance. But there have been limited instances of employing quercetin and its derivatives as a fluorescent framework for specific detection of various cations and anions in the chemosensing field. Therefore, we have developed a novel chemosensor based on quercetin coupled benzyl ethers (QBE) for selective detection of Hg2+ with “naked-eye” colorimetric and “turn-on” fluorometric response. Initially QBE itself exhibited very weak fluorescence with low quantum yield (Φ = 0.009) due to operating photoinduced electron transfer (PET) and inhibition of excited state intramolecular proton transfer (ESIPT) as well as intramolecular charge transfer (ICT) within the molecule. But in presence of Hg2+, QBE showed a sharp increase in fluorescence intensity by 18-fold at wavelength 444 nm with high quantum yield (Φ = 0.159) for the chelation-enhanced fluorescence (CHEF) with coordination of Hg2+, which hampers PET within the molecule. The strong binding affinity of QBE towards Hg2+ has been proved by lower detection limit at 8.47 µM and high binding constant value as 2 × 104 M−1. The binding mechanism has been verified by DFT study, Cyclic voltammograms and Jobs plot analysis. For the practical application, the binding selectivity of QBE with Hg2+ has been capitalized in physiological medium to detect intracellular Hg2+ levels in living plant tissue by using green gram seeds. Thus, employing QBE as a fluorescent chemosensor for the specific identification of Hg2+ will pave the way for a novel approach to simplifying the creation of various chemosensors based on quercetin backbone for the precise detection of various biologically significant analytes.

Real-time, depth-resolved, in vivo multiphoton fluorescence lifetime imaging microscopy of agricultural herbicide treatments in plants

The development of effective and safe agricultural treatments requires sub-cellular insight of the biochemical effects of treatments in living tissue in real-time. Industry-standard mass spectroscopic imaging lacks real-time in vivo capability. As an alternative, multiphoton fluorescence lifetime imaging microscopy (MPM-FLIM) allows for 3D sub-cellular quantitative metabolic imaging but is often limited to low frame rates. To resolve relatively fast effects (e.g., photosynthesis inhibiting treatments), high-frame-rate MPM-FLIM is needed. In this paper, we demonstrate and evaluate a high-speed MPM-FLIM system, “Instant FLIM”, as a time-resolved 3D sub-cellular molecular imaging system in highly scattering, living plant tissues. We demonstrate simultaneous imaging of cellular autofluorescence and crystalline agrochemical crystals within plant tissues. We further quantitatively investigate the herbicidal effects of two classes of agricultural herbicide treatments, photosystem II inhibiting herbicide (Basagran) and auxin-based herbicide (Arylex), and successfully demonstrate the capability of the MPM-FLIM system to measure biological changes over a short time with enhanced imaging speed. Results indicate that high-frame-rate 3D MPM-FLIM achieves the required fluorescence lifetime resolution, temporal resolution, and spatial resolution to be a useful tool in basic plant cellular biology research and agricultural treatment development.

A review on endophytic fungi: a potent reservoir of bioactive metabolites with special emphasis on blight disease management.

Phytopathogenic microorganisms have caused blight diseases that present significant challenges to global agriculture. These diseases result in substantial crop losses and have a significant economic impact. Due to the limitations of conventional chemical treatments in effectively and sustainably managing these diseases, there is an increasing interest in exploring alternative and environmentally friendly approaches for disease control. Using endophytic fungi as biocontrol agents has become a promising strategy in recent years. Endophytic fungi live inside plant tissues, forming mutually beneficial relationships, and have been discovered to produce a wide range of bioactive metabolites. These metabolites demonstrate significant potential for fighting blight diseases and provide a plentiful source of new biopesticides. In this review, we delve into the potential of endophytic fungi as a means of biocontrol against blight diseases. We specifically highlight their significance as a source of biologically active compounds. The review explores different mechanisms used by endophytic fungi to suppress phytopathogens. These mechanisms include competing for nutrients, producing antifungal compounds, and triggering plant defense responses. Furthermore, this review discusses the challenges of using endophytic fungi as biocontrol agents in commercial applications. It emphasizes the importance of conducting thorough research to enhance their effectiveness and stability in real-world environments. Therefore, bioactive metabolites from endophytic fungi have considerable potential for sustainable and eco-friendly blight disease control. Additional research on endophytes and their metabolites will promote biotechnology solutions.

Evaluation of phytochemical responses and paclitaxel content of yew (Taxus baccata) seedlings subjected to the systemic fungicides

AbstractEndophytic fungi pass all or at least a part of their life cycle inside or between host cells in living plant tissues. These fungi are not capable of causing disease in the host plants, however, they are deemed to be associated with the production of some secondary metabolites in plants. Therefore, this study was laid out to shed light on how fungicides are involved in the formation of key metabolites of yew (Taxus baccata L.), especially taxol. Through the symbiotic fungal endophyte activities and population changes an experiment was conducted as a completely randomized block design using two foliar application treatments of Rovral‐TS and Fosetyl aluminium fungicides. Plants sprayed with distilled water were used as a control. The findings revealed that the diversity of endophytic fungi declined with the application of systemic fungicides, leading to a decrease in the production of certain secondary metabolites. Specifically, the levels of paclitaxel decreased by 35%, while the photosynthetic pigments chlorophyll‐a, chlorophyll‐b and total chlorophyll decreased by 26%, 20.6% and 19.6%, respectively. Additionally, the levels of carotenoids, total phenol and total flavonoids decreased by 18%, 15% and 21.8%, respectively. The highest amount of these compounds was observed in the control treatment. An increase in antioxidant activity, soluble sugars and proline content was observed soon after fungicides application. The variation in the content of soluble sugars, proline and antioxidant activity was fungicide‐dependent. Compared to Fosetyl aluminium fungicide, the numerical value of the above parameters in plants treated with Rovral‐TS was 14.4%, 11.7% and 25.4% higher, respectively. The fungicide‐mediated induction of Taxol production—key secondary metabolites in yew—was to a great extent associated with the change in endophytic fungi. This further establishes the role of fungal endophytes in the stimulation of secondary metabolite formation in yew plants.

A dual-functional rhodamine B and azo-salicylaldehyde derivative for the simultaneous detection of copper and hypochlorite: synthesis, biological applications and theoretical insights.

A multifunctional rhodamine derivative containing azo-salicylaldehyde (BBS) was designed and synthesized as a colorimetric and fluorescence turn-on probe for the selective detection of copper cations (Cu2+) and hypochlorite anions (OCl-) in aqueous media. In the presence of Cu2+, the probe BBS exhibited turn-on absorption and fluorescence change at 554 nm and 585 nm, respectively. The binding mechanism of BBS with Cu2+ induces the opening of a spirolactam ring in the rhodamine moiety by the formation of a metal-ligand complex, achieving 10-fold enhancement in fluorescence and quantum yield, along with a binding constant of 1 × 104 M-1 and a detection limit of 2.61 μM. Addition of OCl- enhanced the absorbance and fluorescence intensities at 520 nm and 575 nm, respectively. The probe BBS underwent hypochlorite-mediated oxidation, followed by hydrolysis, resulting in the formation of rhodamine B itself, which is detectable by the naked eye via the color and fluorescence enhancement by 11-fold with a high quantum yield and a detection limit of 1.96 μM. For practical applications, sensor BBS can be used to detect Cu2+ in water samples and on cotton swabs. For biological applications, the interaction of the BBS-Cu(II) complex with transport proteins such as bovine serum albumin (BSA) and ct-DNA was investigated through UV-vis and fluorescence titration experiments. Additionally, the structural optimization of BBS and the BBS-Cu(II) complex was demonstrated using DFT, and the interactions of the BBS-Cu(II) complex with BSA and ct-DNA were analysed through theoretical docking studies. Bioimaging studies were conducted by capturing fluorescence images of BBS with Cu2+ and OCl- in a physiological medium containing living plant tissue using green gram seeds.

Turn-on fluorescence detection of carbon monoxide in plant tissues based on Cu2+ modulated polydihydroxyphenylalanine nanosensors.

As an important signaling molecule, carbon monoxide (CO) plays an important role in plant growth and development including affecting stomatal movement, stress response and root development. Thus, it is necessary to develop fluorescent probes that can be used to detect CO in live plant tissues and further enable a deep-understanding of its biological function, mechanism and metabolism. In this paper, a novel and sensitive fluorescent probe based on Cu2+ modulated polydihydroxyphenylalanine nanoparticles (PDOAs) has been developed for the detection of CO. The fluorescence of PDOAs can be effectively quenched by Cu2+ through the multi-coordination interaction. In the presence of CO, Cu2+ can be effectively reduced to Cu+, which resulted in the release of free PDOAs and the Cu2+-quenched bright green fluorescence was restored obviously. Through this ingenious strategy, the abiotic CO can be accurately detected and identified with high selectivity, rapid response time within 5 min and an ultralow detection limit of 72.4 nM. Due to the admirable biocompatibility, the nano-material based probe has been successfully applied for in vivo imaging CO in the root tip and leave tissues of lettuce. To the best of our knowledge, this is the first example of a fluorescent probe-based methodology for the sensitive tracking of CO in plant tissues.

A fungal RNA-dependent RNA polymerase is a novel player in plant infection and cross-kingdom RNA interference.

Small RNAs act as fungal pathogen effectors that silence host target genes to promote infection, a virulence mechanism termed cross-kingdom RNA interference (RNAi). The essential pathogen factors of cross-kingdom small RNA production are largely unknown. We here characterized the RNA-dependent RNA polymerase (RDR)1 in the fungal plant pathogen Botrytis cinerea that is required for pathogenicity and cross-kingdom RNAi. B. cinerea bcrdr1 knockout (ko) mutants exhibited reduced pathogenicity and loss of cross-kingdom small RNAs. We developed a "switch-on" GFP reporter to study cross-kingdom RNAi in real-time within the living plant tissue which highlighted that bcrdr1 ko mutants were compromised in cross-kingdom RNAi. Moreover, blocking seven pathogen cross-kingdom small RNAs by expressing a short-tandem target mimic RNA in transgenic Arabidopsis thaliana led to reduced infection levels of the fungal pathogen B. cinerea and the oomycete pathogen Hyaloperonospora arabidopsidis. These results demonstrate that cross-kingdom RNAi is significant to promote host infection and making pathogen small RNAs an effective target for crop protection.

Effects of coastal embankments on seasonal variations in nitrogen storage in the plant-soil systems of Suaeda salsa salt marshes in Eastern China

The impacts of coastal embankments on nitrogen (N) dynamics are of great importance in salt marshes. However, effects of embankments on seasonal N dynamics in the plant-soil systems of Suaeda salsa salt marshes are still not well understood. Therefore, the edaphic moisture and salinity, biomass, N concentrations and storage in different plant tissues; the extent of organic and inorganic N subpools in soil subsystems; as well as N immobilization and mineralization by microorganisms in embanked and neighboring natural S. salsa salt marshes through all four seasons were investigated in Yancheng, Eastern China. Our results revealed that embankments increased the biomass and N storage of dead tissues (e.g., litter), while they decreased the biomass and N storage of live tissues (e.g., living aboveground tissues and roots) of S. salsa through decreased edaphic moisture and salinity. Furthermore, under the influence of embankments edaphic water-dissolvable N, e.g.,edaphic dissolved organic N (EDON) and nitrate and nitrite N (TNN), significantly increased with higher N inputs from S. salsa litter. This water-dissolvable N was an important source of N for plants, which translated to higher N concentrations in live plant tissues. However, this excess absorbed N appeared not to facilitate the growth of plants, which would ultimately return to the soil from plant residues. Our results suggested that the decreased edaphic soil moisture and salinity due to embankments had negative impacts on the biomass and N storage of S. salsa plant tissues, which were likely due to shifts in the edaphic osmotic potential. Subsequently, a cascading butterfly effect may be initiated due to the impaired growth of S. salsa, to which more attention should be paid. This study represents a step forward by providing valuable insights and an improved elucidation of the seasonal plant-soil N dynamics of S. salsa salt marshes.

The Effects of Arbuscular Mycorrhizal Fungi on the Growth of Apium graveolens

Arbuscular Mycorrhizal Fungi are obligate biotrophs, meaning they extract nutrients solely from living plant tissues and cannot grow apart from their hosts (Besemer, 2021). AMF also are symbionts; they are able to form a mutualistic relationship with plants (Tracey Besemer, 2021). To find the ideal amount of fungus that accelerated plant growth, research was conducted on Golden Self-Blanching Celery seeds, also known as ​​Apium graveolens. The hypothesis states that the celery plants with AMF would exhibit more growth than the control because AMF can aid in reducing fertilizer amounts that cause pollution and conserve water during droughts in the future. The experiment was conducted in bins with equal amounts of soil and differing quantities of AMF. The results showed that the control group without any AMF grew the best due to a multitude of reasons such as the altering amounts of water during the experiment and a lack of natural sunlight. One goal for future experiments is to control confounding factors that can inhibit or improve the growth of the Golden Self-Blanching Celery plant.

Arabidopsis cell suspension culture and RNA sequencing reveal regulatory networks underlying plant-programmed cell death.

Programmed cell death (PCD) facilitates selective, genetically controlled elimination of redundant, damaged, or infected cells. In plants, PCD is often an essential component of normal development and can mediate responses to abiotic and biotic stress stimuli. However, studying the transcriptional regulation of PCD is hindered by difficulties in sampling small groups of dying cells that are often buried within the bulk of living plant tissue. We addressed this challenge by using RNA sequencing and Arabidopsis thaliana suspension cells, a model system that allows precise monitoring of PCD rates. The use of three PCD-inducing treatments (salicylic acid, heat, and critical dilution), in combination with three cell death modulators (3-methyladenine, lanthanum chloride, and conditioned medium), enabled isolation of candidate core- and stimuli-specific PCD genes, inference of underlying regulatory networks and identification of putative transcriptional regulators of PCD in plants. This analysis underscored a disturbance of the cell cycle and mitochondrial retrograde signaling, and repression of pro-survival stress responses, as key elements of the PCD-associated transcriptional signature. Further, phenotyping of Arabidopsis T-DNA insertion mutants in selected candidate genes validated the potential of generated resources to identify novel genes involved in plant PCD pathways and/or stress tolerance.

The influence of heat on phytolith morphology and implications for quantifying archaeological foxtail and common millets

Phytoliths are silica bodies formed in living plant tissues, and they can be reliable indicators of their parent plants when they demonstrate characteristic phytolith morphology. As shown by the growing case studies around the globe, phytolith morphology is of significant value for identifying and even quantifying domesticated plants. However, researchers also alert that phytoliths morphology can change, for example, in alkaline solutions or heat, causing the loss of characteristic phytoliths and eventually leading to the over- or under-identification of certain phytoliths. Focusing on the degree to which heat can cause changes to the phytolith morphology of millet, the present study carried out a series of controlled heating experiments on six varieties of modern common millet (Panicum miliaceum) growing in different regions of Northern China. Husked grains were heated following the dry ashing method. Specimens prepared from the dry ashing method were examined under an optical microscope to quantify articulated husk phytoliths, which are characteristic millet phytoliths, and to estimate the surface area of millet grains. We estimated that 30.8% to 59.5% of the common millet phytoliths underwent morphological damage in the heating experiments. Considering our previous heating experiments on foxtail millet, we conclude that compared to foxtail millet phytoliths, common millet phytoliths experience morphological damage more quickly when exposed to heat. This observation may explain (at least partially) the contradictory results between macro- and micro-botanical results. It reminds us that common millet can be underrepresented in the micro-botanical evidence (phytoliths). We conclude the paper by discussing the potential archaeological implications of our heating experiments.

Physiological responses of plants to in vivo X-ray damage from X-ray fluorescence measurements: insights from anatomical, elemental, histochemical, and ultrastructural analyses.

X-ray fluorescence spectroscopy (XRF) is a powerful technique for the in vivo assessment of plant tissues. However, the potential X-ray exposure damages might affect the structure and elemental composition of living plant tissues, leading to artefacts in the recorded data. Herein, we exposed in vivo soybean (Glycine max (L.) Merrill) leaves to several X-ray doses through a polychromatic benchtop microprobe X-ray fluorescence spectrometer, modulating the photon flux density by adjusting either the beam size, current, or exposure time. Changes in the irradiated plant tissues' structure, ultrastructure, and physiology were investigated through light and transmission electron microscopy (TEM). Depending on X-ray exposure dose, decreased K and X-ray scattering intensities and increased Ca, P, and Mn signals on soybean leaves were recorded. Anatomical analysis indicated the necrosis of epidermal and mesophyll cells on the irradiated spots, where TEM images revealed the collapse of cytoplasm and cell wall breaking. Furthermore, the histochemical analysis detected the production of reactive oxygen species and the inhibition of chlorophyll autofluorescence in these areas. Under certain X-ray exposure conditions, e.g. high photon flux density and long exposure time, XRF measurements may affect the soybean leaves structures, elemental composition, and cellular ultrastructure, inducing programmed cell death. Our characterization shed light on the plant's responses to the X-ray-induced radiation damage and might help to establish proper X-ray radiation limits and novel strategies for in vivo benchtop-XRF analysis of vegetal materials.

Interannuals variations in diversity of foliar mycoendophytes of Pistacia atlantica from dayate Aiat (Laghouat, Algeria)

Endophytic fungi live inside plant tissues and increase their resistance to abiotic and biotic factors. Our work is concerned with interannual variations of mycoendophyte diversity of leaves of Pistacia atlantica Desf. of dayate Aiat, in the region of Laghouat (Algeria) and this for the spring of 2013 and 2016. The morphological identification revealed the presence of 26 fungal genera. The difference in diversity is very significant between the two years of sampling, according to calculated Shannon Weaver indices. Based on principal component analysis, the distribution of these leaf microorganisms is influenced by the climatic conditions of the study area. Aspergillus and Epicoccum are dominant for 2013. In 2016, Aspergillus and Cladosporium dominate. The persistence of Aspergillus gives it an important role in the fight against the stress suffered by the leaf of Pistacia atlantica.

Molecular phylogeny and identification of agromyzid leafminers in China, with a focus on the worldwide genus Liriomyza (Diptera: Agromyzidae)

Leaf-mining flies (Diptera: Agromyzidae) are a diverse family of small-bodied insects that feed on living plant tissues as larvae. Various species in this family are considered globally invasive and have caused great agricultural economic losses. In China, economically important vegetable crops have been seriously damaged by these pest insects, especially by species of the genus Liriomyza. However, these species are difficult to differentiate because of their morphological similarities, and the Chinese fauna remains poorly known. To explore the relevant pest species in China and their phylogeny, agromyzid leafminers were collected from 2016 to 2019, and identified based on morphological characteristics and DNA barcodes. In total, 27 species from five genera of Agromyzidae were sampled and identified, including 16 species of Liriomyza. Both mitochondrial and nuclear genes were used to reconstruct their phylogenetic relationships and estimate the divergence time. Highly congruent and well-supported phylogenetic trees were obtained using the Bayesian inference and maximum-likelihood methods. This analysis revealed two main clades in Liriomyza, and clade 2 was inferred to have diverged from clade 1 approximately 27.40 million years ago (95% highest posterior density: 23.03–31.52 million years ago) in the Oligocene. Differences were observed in the distribution patterns and host associations between the Liriomyza clades. Clade 2 species are distributed in cool, high-latitude environments, suggesting that they may have evolved into a cool-adapted lineage.

Measuring the photostability of agrochemicals on leaves: understanding the balance between loss processes and foliar uptake.

Photostability is an important property in agrochemicals, impacting their biological efficacy, environmental fate and registrability. As such, it is a property that is routinely measured during the development of new active ingredients and their formulations. To make these measurements, compounds are typically exposed to simulated sunlight after application to a glass substrate. While useful, these measurements neglect key factors that influence photostability under true field conditions. Most importantly, they neglect the fact that compounds are applied to living plant tissue, and that uptake and movement within this tissue provides a mechanism to protect compounds from photodegradation. In this work, we introduce a new photostability assay incorporating leaf tissue as a substrate, designed to run at medium throughput under standardized laboratory conditions. Using three test cases, we demonstrate that our leaf-disc-based assays provides quantitatively different photochemical loss profiles to an assay employing a glass substrate. And we also demonstrate that these different loss profiles are intimately linked to the physical properties of the compounds, the effect that those properties have on foliar uptake and, thereby, the availability of the active ingredient on the leaf surface. The method presented provides a quick and simple measure of the interplay between abiotic loss processes and foliar uptake, supplying additional information to facilitate the interpretation of biological efficacy data. The comparison of loss between glass slides and leaves also provides a better understanding of when intrinsic photodegradation is likely to be a good model for a compound's behaviour under field conditions. © 2023 Society of Chemical Industry.

Unraveling the Secrets of a Double-Life Fungus by Genomics: Ophiocordyceps australis CCMB661 Displays Molecular Machinery for Both Parasitic and Endophytic Lifestyles.

Ophiocordyceps australis (Ascomycota, Hypocreales, Ophiocordycipitaceae) is a classic entomopathogenic fungus that parasitizes ants (Hymenoptera, Ponerinae, Ponerini). Nonetheless, according to our results, this fungal species also exhibits a complete set of genes coding for plant cell wall degrading Carbohydrate-Active enZymes (CAZymes), enabling a full endophytic stage and, consequently, its dual ability to both parasitize insects and live inside plant tissue. The main objective of our study was the sequencing and full characterization of the genome of the fungal strain of O. australis (CCMB661) and its predicted secretome. The assembled genome had a total length of 30.31 Mb, N50 of 92.624 bp, GC content of 46.36%, and 8,043 protein-coding genes, 175 of which encoded CAZymes. In addition, the primary genes encoding proteins and critical enzymes during the infection process and those responsible for the host-pathogen interaction have been identified, including proteases (Pr1, Pr4), aminopeptidases, chitinases (Cht2), adhesins, lectins, lipases, and behavioral manipulators, such as enterotoxins, Protein Tyrosine Phosphatases (PTPs), and Glycoside Hydrolases (GHs). Our findings indicate that the presence of genes coding for Mad2 and GHs in O. australis may facilitate the infection process in plants, suggesting interkingdom colonization. Furthermore, our study elucidated the pathogenicity mechanisms for this Ophiocordyceps species, which still is scarcely studied.