Ion homeostasis and coordinated salt tolerance mechanisms in a barley (Hordeum vulgare L.)doubled haploid line

Salinization poses a significant challenge in agriculture. Identifying salt-tolerant plant germplasm resources and understanding their mechanisms of salt tolerance are crucial for breeding new salt-tolerant plant varieties. However, one of the primary obstacles to achieving this goal in crops is the physiological complexity of the salt-tolerance trait. In a previous study, we developed a salt-tolerant barley doubled haploid (DH) line, designated as DH20, through mutagenesis combined with microspore culture, establishing it as an idea model for elucidating the mechanisms of salt tolerance. In this study, ion homeostasis, key osmotic agents, antioxidant enzyme activities and gene expression were compared between Hua30 (the original material used as a control) and DH20. The results indicated that under salt treatment, DH20 exhibited significantly higher shoot fresh and dry weight, relative plant height, shoot K+/Na+ ratio, improved stomatal guard cell function, and better retention of chloroplast ultrastructure compared to Hua30. Notably, the K+ efflux in DH20 was significantly lower while the Na+ and H+ efflux was significantly higher than those in Hua30 under salt stress in mesophyll cells. Furthermore, the activities of ascorbate peroxidase, superoxide dismutase, and peroxidase, along with the levels of proline, betaine, malondialdehyde, and soluble protein, were correlated with ion efflux and played a vital role in the response of DH20 to salt stress. Compared to Hua30, the relative expression levels of the HvSOS1, HvSOS2, HvSOS3, HvHKT1;3, HvNHX1, HvNHX2, and HvNHX3 genes, which showed a strong correlation with Na+, K+, and H+ efflux, exhibited significant differences at 24 hours under salt stress in DH20. These findings suggest that ion homeostasis, key osmolytes, antioxidant enzyme activities, and associated gene expression are coordinated in the salt tolerance of DH20, with K+ retention and Na+ and H+ efflux serving as important mechanisms for coping with salt stress These findings present new opportunities for enhancing salinity tolerance, not only in barley but in other cereals as well, including wheat and rice, by integrating this trait with other traditional mechanisms. Furthermore, MIFE measurements of NaCl-induced ion fluxes from leaf mesophyll provide plant breeders with an efficient method to screen germplasm for salinity stress tolerance in barley and potentially other crop

Multi-year assessment of seed shedding for economically important grass weed species in Italy and the UK

approaches for future Integrated Weed Management (IWM) strategies. To be effective however, HWSC requires that target species have high seed retention at crop harvest. Here, a multi-year assessment of seed shedding was conducted across large geographical areas in the UK and Italy, for pernicious grass weed species that infest winter wheat and soybean crops. In the UK, an eight year assessment of Alopecurus myosuroides seed shedding was carried out in winter wheat crops. In Italy, seed shedding studies were conducted for three years, assessing A. myosuroides, Avena spp. and Lolium perenne ssp. multiflorum in winter wheat, and Sorghum halepense and Echinochloa crus-galli in soybean crops. Our results demonstrate low levels of seed retention (approximately 20 %) for A. myosuroides and Avena spp. at harvest, while higher mean seed retention (49 %) was found for L. perenne ssp. multiflorum. As such, Avena spp. and A. myosuroides are not good targets for HWSC across the studied locations, while HWSC could significantly contribute to L. perenne ssp. multiflorum management if combined with further control tactics. Seed retention at soybean harvest was on average 50 % for E. crus-galli, but higher at approximately 75 % for S. halepense. HWSC could therefore have a considerable impact on S. halepense populations in Italian soybean fields, but only an intermediate-low impact on E. crus-galli populations. Importantly however, we also find evidence for significant spatial and temporal variability in the extent of seed retention for all species. This study demonstrates that the potential for HWSC varies considerably between target weed species and highlights the importance of inter-annual variation in determining its expected performance

Oilseed-based metabolic engineering of astaxanthin and related ketocarotenoids using a plant-derived pathway: Lab-to-field-to-application

Ketocarotenoids, including astaxanthin, are red lipophilic pigments derived from the oxygenation of b-carotene ionone rings. These carotenoids have exceptional antioxidant capacity and high commercial value as natural pigments, especially for aquaculture feedstocks to confer red flesh colour to salmon and shrimp. Ketocarotenoid biosynthetic pathways occur only in selected bacterial, algal, fungal and plant species, which provide genetic resources for biotechnological ketocarotenoid production. Toward pathway optimization, we developed a transient platform for ketocarotenoid production using Agrobacterium infiltration of Nicotiana benthamiana leaves with plant (Adonis aestivalis) genes, carotenoid b-ring 4-dehydrogenase 2 (CBFD2) and carotenoid 4-hydroxy-b-ring 4-dehydrogenase (HBFD1), or bacterial (Brevundimonas) genes,b-carotene ketolase (crtW) and b-carotene hydroxylase (crtZ). In this test system, heterologous expression of the plant-derived astaxanthin pathway conferred higher astaxanthin production with fewer ketocarotenoid intermediates than the bacterial pathway. We evaluated the plant-derived pathway for ketocarotenoid production using the oilseed camelina (Camelina sativa) as a production platform. Genes for CBFD2 and HBFD1 and maize phytoene synthase were introduced under the control of seed-specific promoters. In contrast to prior research with bacterial pathways, our strategy resulted in nearly complete conversion of b-carotene toketocarotenoids, including primarily astaxanthin. Tentative identities of other ketocarotenoids were established by chemical evaluation. Seeds from multi-season US and UK field sites maximally accumulated ~135 lg/g seed weight of ketocarotenoids, including astaxanthin(~47 lg/g seed weight). Although plants had no observable growth reduction, seed size and oil content were reduced in astaxanthin-producing lines. Oil extracted from ketocarotenoid-accumulating seeds showed significantly enhanced oxidative stability and was useful for food oleogel applications

State of nature 2023 terrestrial and freshwater animal dataset for the United Kingdom and its constituent countries

This article describes the terrestrial and freshwater animal trend data used in creating the 2023 State of Nature reports for the UK and its constituent countries. Trend data for long- (1970–2020/21) and short-term (2010–2020) periods have been calculated by fitting statistical models to measures of abundance (753 species) or occupancy (4979 species) across the UK. Trend data was also calculated for each constituent country: England, Northern Ireland, Scotland and Wales for reduced sets of species. Trends in abundance data were generally created from the analysis of repeat counts at specific sites. Trends in occupancy were created by analysing ad hoc species records of invertebrates provided by volunteers. Statistical methods partially controlled for the risk of bias and the noisy nature of such occupancy data. Trends were only calculated where the number of species records justified the creation of trend statistics. Species that make up three key groups of insects are identified in additional columns in the dataset, those responsible for key ecosystem functions: species providing freshwater nutrient cycling, pollinating insects and predators of crop pests. The data has one clear limitation in that it is only a partial representation of the fauna of the UK. Many cryptic, nocturnal or soil dwelling species are poorly recorded and even some easy to identify species such as amphibians and reptiles do not have a suitable recording scheme that captures abundance

Fusarium graminearum and zearalenone in wheat: A water activity–temperature model

Zearalenone (ZEN) is a nonsteroidal estrogenic mycotoxin produced primarily by Fusarium graminearum, posing significant threats to agricultural grain production. When ZEN levels exceed regulatory limits, grains face rejection, and its harmful effects on the female reproductive system raise health concerns. Despite its importance, there is a lack of information on the ecophysiological conditions that promote F. graminearum colonisation and ZEN production in wheat grains. This study aimed to develop and validate predictive models for the growth of F. graminearum and ZEN accumulation in wheat. For this purpose, two strains isolated from wheat were inoculated in agar wheat-based medium supplemented with glycerol to adjust the water activity (aw) to five different values of 0.88, 0.91, 0.94, 0.97 and 0.99. The cultures were incubated at 4, 6, 8.5, 15, 20, 25, 30 and 35 ◦C, the colony growth was measured daily, and ZEN accumulation assessed at day 10, 20 and 30. To analyse the growth kinetics of F. graminearum, the fungal growth rate (μ) and lag time (λ) were calculated, applying the Cardinal/Rosso, Davey, and Gibson models. These techniques, commonly used in secondary modelling, were enhanced through variable transformation, with the square root transformation yielding optimal results in the Cardinal models. The outcome showed probabilistic model accuracy for growth ranging 65–79 % and ZEN production ranging 45–77 % on internal and external data set. Optimum temperature for ZEN production was 25–30 ◦C in media and wheat. In wheat, a higher aW was required for both growing (0.92 aw) and ZEN production compared to media (0.90 aw). Probabilities of growth over 80 % were predicted in the range of 0.90–0.95 aw at 16–34 ◦C after 30 days. In conclusion, to avoid mycotoxin contamination in wheat an aw < 0.89 should be maintained, and temperatures in the range 18–31 ◦C should be avoided (P < 0.5). The integration of predictive models into decision support systems could assist farmers in identifying pre-harvest contamination risks and in optimising harvesting and drying practices to minimise post-harvest contamination. This study highlights the importance of understanding the ecophysiological profiles of mycotoxigenic species like F. graminearum to mitigate contamination risks and optimise storage conditions in wheat

Effect of High Temperatures on the Growth and Disease Development of Erysiphe quercicola on Rubber Trees

Powdery mildew is a serious disease of rubber tree (Hevea brasiliensis) worldwide. Tem-perature is the main climatic factor that influences the development of this disease. In this study, the effects of five high temperatures (30, 32, 34, 36, and 38°C) at each of six exposure durations (0.5, 1, 3, 6, 12, and 24 h) were measured for the pathogen at 0, 3, 12, and 48 hr post-inoculation (hpi), which represented four life stages of the fungus (conidia, conidial germination, infection, and hyphal growth). The results indicated that the germination, infection and disease severity was reduced with the increasing temperature and exposure duration. Temperature and exposure duration also significantly interacted to affect all life stages (P< 0.001). The relationships of inhibition rate of conidial germination, infection and disease severity with duration of exposure time (et) and high temperature (T) were described by logistic equations with the percentage variance accounted for above 68%. Ungerminated conidia were found to be the most resistant stage to high-temperature for E. quercicola from rubber tree out of the four stages tested in this study. Only con-trolled-environmental experiments were conducted and field studies are needed to en-hance disease forecasting of rubber tree powdery mildew

Understanding insect predator–prey interactions using camera trapping: A review of current research and perspectives

Cameras are increasingly used by ecologists to study species distribution and interactions. They are mainly used to study large animals such as mammals but can also be used to record small invertebrates, including insects. Camera traps, capturing images within a specified field of view, can be used for biomonitoring and investigating insect-related interactions, such as predation. Understanding predation on insect prey has direct implications for agriculture and conservation biology, enabling predator species identification and quantification of biological control. This review examines 28 studies published between 1988 and March 2024 focusing on the use of cameras to monitor insect predator–prey interactions, predominantly targeting agricultural pests. Studies varied in recording equipment used and tended to be spatially and temporally limited, making results difficult to generalise at larger scale. We provide an overview of equipment options, camera settings, the merits of video versus picture recording, night-time imaging strategies, trigger mechanisms, equipment costs, and strategies for managing theft and vandalism. Additionally, we discuss avenues for improving image processing efficiency, including enhancing predator identification through artificial intelligence methods. Challenges related to limitations in the taxonomic levels of predator identification are also addressed. Finally, we offer guidelines for researchers interested in using camera technology and propose future perspectives on their use in insect conservation and biocontrol efforts

Livestock farmer-reported knowledge and attitudes regarding agroforestry planning and management

This study aimed to explore the knowledge and attitudes of livestock farmers from the United Kingdom regarding agroforestry planning and management issues. The farmers (n = 48) answered an online survey with demographic, open, closed and Likert scale questions. Almost half of the participants said they need more information to successfully plan and manage an agroforestry system, and self-reported low knowledge on management practices related to trees. Participants stated they did not expect to receive technical support from governmental agencies to maintain the agroforestry area. However, they would like to improve their knowledge through field days, courses, and Internet sources. Benefits to the environment, animals and farm profitability were considered central to successful agroforestry systems. In conclusion, participants cannot successfully plan and manage agroforestry, but they are willing to improve their knowledge and skills

Emerging opportunities and research questions for green ammonia adoption in agriculture and beyond

Comment Green ammonia production could contribute to the decarbonization of multiple sectors and decentralize fertilizer production, but it brings critical challenges, including a lack of infrastructure, economic disruption and environmental and health risks. These challenges need to be addressed and monitored in real-time to avoid or mitigate unintended consequences

Microfluidics for the biological analysis of atmospheric ice-nucleating particles: Perspectives and challenges

Atmospheric ice-nucleating particles (INPs) make up a vanishingly small proportion of atmospheric aerosol, but are key to triggering the freezing of supercooled liquid water droplets, altering the lifetime and radiative properties of clouds and having a substantial impact on weather and climate. However, INPs are notoriously difficult to model due to a lack of information on their global sources, sinks, concentrations, and activity, necessitating the development of new instrumentation for quantifying and characterising INPs in a rapid and automated manner. Microfluidic technology has been increasingly adopted by ice nucleation research groups in recent years as a means of performing droplet freezing analysis of INPs, enabling the measurement of hundreds or thousands of droplets per experiment at temperatures down to the homogeneous freezing of water. The potential for microfluidics extends far beyond this, with an entire toolbox of bioanalytical separation and detection techniques developed over 30 years for medical applications that could easily be adapted to biological and biogenic INP analysis to revolutionise the field, for example in the identification and quantification of ice-nucleating bacteria and fungi. Combined with miniaturised sampling techniques, we can envisage the development and deployment of microfluidic sample-to-answer platforms for automated, user-friendly sampling and analysis of biological INPs in the field that would enable a greater understanding of their global and seasonal activity. Here, we review the various components that such a platform would incorporate to highlight the feasibility, and the challenges, of such an endeavour, from sampling and droplet freezing assays to separations and bioanalysis