Competitive Interactions Research Articles

Coopetition in supply chain management: patterns, typology and propositions

Purpose This study aims to unravel the complex coopetitive interactions in supply chains. It delves into the paradoxical relationship between cooperative and competitive interactions among supply chain entities, offering a comprehensive exploration of coopetition’s manifestations and management across various supply chain types. Design/methodology/approach The study uses a three-phase methodology, beginning with a scoping review to establish a theoretical framework, followed by a systematic literature review yielding 130 papers and concluding with correspondence analysis using similarity indexes. This approach facilitates a deep dive into the diverse aspects of coopetition, including its drivers, practices, outcomes and associated risks. Findings The research identifies three distinct types of coopetition in supply chains: technology-based, socially based and channel-based. These models are underscored by specific drivers and outcomes, with technology-based coopetition focusing on market competitiveness and operational capacity, socially based on trust and power dynamics and channel based on product characteristics. The study introduces five propositions for further investigation and provides a comprehensive typology of coopetition within supply chains. Research limitations/implications The study’s findings are limited by the scope of the existing literature and the chosen academic databases. Future research should empirically validate the proposed coopetition configurations and propositions, exploring their applicability in other, less studied supply chains. Practical implications The study offers practitioners a valuable typology and framework to understand and manage coopetition in their respective supply chains. This typology serves as a decision-making tool for identifying suitable coopetition strategies and maximizing their benefits while mitigating associated risks. Originality/value This study stands out for its unique approach to categorizing coopetition in supply chains, offering a novel typology that goes beyond the manufacturer’s perspective. It fills a significant gap in the literature by providing a broad view of coopetition, considering various supply chain types and their respective coopetitive dynamics.

Prey or protection? Access to food alters individual responses to competition in black widow spiders

Abstract Animals influence the phenotype and reproductive success of their conspecifics through competitive interactions. Such effects of competition can alter the intensity of selection and ultimately change the rate of evolution. However, the magnitude of the effects of competition, and their evolutionary impact, should vary depending on environmental conditions and individual responses among competitors. We tested whether a key environmental variable, resource availability, affects the response to competition in black widow spiders by manipulating access to prey and the level of competition. We examined if focal spiders modify their web structure and aggressiveness towards prey stimuli when a competitor is present, and whether these responses depend on prior prey access. We also tested if any effects of competition vary with individual differences among competitors. Access to resources changed how individuals respond to competition. Spiders with limited access to prey were less likely to attack prey stimuli in the presence of a conspecific competitor than spiders with greater access to prey, suggesting that limiting resources hinders competitive responses. In contrast, all spiders built better-protected webs in the presence of competitors, regardless of prior access to prey. Crucially, these responses differed among focal spiders and depended on individual competitors. Our findings highlight the importance of environmental conditions and individual differences in mediating the impact of social interactions on phenotypes and eventually on their evolution.

The Development of Machine Learning-Assisted Software for Predicting the Interaction Behaviours of Lactic Acid Bacteria and Listeria monocytogenes

Biopreservation technology has emerged as a promising approach to enhance food safety and extend shelf life by leveraging the antimicrobial properties of beneficial microorganisms. This study aims to develop precise predictive models to characterize the growth and interaction dynamics of lactic acid bacteria (LAB) and Listeria monocytogenes, which serve as bioprotective agents in food systems. Using both traditional and machine learning modelling approaches, we analyzed data from previously published growth curves in broth (BHI) and milk under isothermal conditions (4, 10, and 30 °C). The models evaluated mono-culture conditions for L. monocytogenes and LAB, as well as their competitive interactions in co-culture scenarios. The modified Gompertz model demonstrated the best performance for mono-culture simulations, while a combination of the modified Gompertz and Lotka–Volterra models effectively described co-culture interactions, achieving high adjusted R-squared values (adjusted R2 = 0.978 and 0.962) and low root mean square errors (RMSE = 0.324 and 0.507) for BHI and milk, respectively. Machine learning approaches further validated these findings, with improved statistical indices (adjusted R2 = 0.988 and 0.966, RMSE = 0.242 and 0.475 for BHI and milk, respectively), suggesting their potential as robust alternatives to traditional methods. The integration of machine learning-assisted software developed in this work into predictive microbiology demonstrates significant advancements by bypassing the conventional primary and secondary modelling steps, enabling a streamlined, precise characterization of microbial interactions in food products.

Carnivore activity across landuse gradients in a Mexican biosphere reserve

Anthropogenic activities are increasingly encroaching into wildland areas, heightening interactions between human and carnivore communities. Area-based conservation measures, such as protected areas (PAs), employ different management strategies via land-use designations to mitigate anthropogenic pressures and reduce human-wildlife conflicts in shared landscapes. Here, we assessed carnivore diel activity and temporal activity overlap in and around El Triunfo Biosphere Reserve (REBITRI) in Chiapas, Mexico, along a land-use designation gradient. We deployed 33 camera traps along the gradient, leveraging the reserve’s core and buffer zones, and private lands surrounding the reserve. We calculated activity overlap between species to detect changes in interspecific competition and predator-prey interactions along the gradient. In total, we detected 14 carnivores in the core zones, 10 in the buffer zone, and 9 on private land across the 4777 trap-night survey. Significant shifts in single-species diel activity between the buffer zones and private land were detected for margay (Leopardus wiedii) and grey fox (Urocyon cinereoargenteus). Activity overlap was the highest in the buffer zone for all predator-prey pairs, and two competitor pairs, suggesting reduced diel niche partitioning in this land-use designation due to varied anthropogenic pressures. Our findings contribute to assessing PA efficacy and understanding carnivore activity in multiple-use landscapes where anthropogenic pressures are ubiquitous.

Changes in flowering phenology with altered rainfall and the potential community impacts in an annual grassland.

Shifts in the timing of life history events, or phenology, have been recorded across many taxa and biomes in response to global change. These phenological changes are often studied in a single species context, but considering the community context is essential for anticipating the cascading effects on biotic interactions that are likely to occur. Focusing on an annual grassland plant community, we examined how experimental changes in precipitation affect flowering phenology in a community context and explore the implications of these shifts for competitive interactions and species coexistence. We experimentally manipulated rainfall with rainout shelters and recorded detailed flowering phenology data for seven annual species including two grasses and five forbs. We assessed how their first and peak flowering days were affected by changes in rainfall and explored how flowering overlap between competing species changed. Changes in rainfall shifted flowering phenology of some species, but sensitivity differed among neighboring species. Four of the seven species studied started and/or peaked flowering earlier in response to reduced water availability. The idiosyncratic shifts in flowering phenology have the potential to alter existing temporal dynamics that may be maintaining coexistence, such as temporal separation of resource-use among neighbors. Our results show how species-specific phenological consequences of global change can impact community dynamics and competition between neighboring plants and warrant future research.

Fine roots of Scots pine and European beech respond differently to changes in nutrient availability in a mixed forest: results from a 4-year experiment

Abstract A nutrient availability experiment was carried out for four years in a mature mixed stand of Pinus sylvestris and Fagus sylvatica in the South-western Pyrenees mountains. Initial homogeneous pine regeneration (~58 years ago) was followed by uneven beech regeneration (~45 years ago), leading to the current successional stage in which areas resembling pine monospecific stands are at close distances and under comparable environmental conditions to mixed pine−beech areas. Soil and fine root samples were collected beside trees under three soil nutrient availability treatments: control, litter exclusion, and nitrogen-phosphorus-potassium (NPK) fertilization. Soil samples were collected twice a year (in May and October from 2017 to 2020), and fine root samples were collected twice (in May 2018 and May 2020). Soil fertilization had a bigger impact than litter exclusion on soil chemical parameters, leading to lower pH and NH4+ values. Also, increases in soil total nitrogen, soil available phosphorus, and microbial phosphorus were found after fertilization. Scots pine showed overall lower fine root biomass, specific root length, and root tissue density than beech, presenting also very little response to treatments. On the other hand, beech showed higher biomass and specific root length, but, when soil fertility was enhanced, lower root tissue density was recorded. A negative beech effect over pine fine root biomass was observed, as pine root presence decreased when growing near beech trees in mixed areas. Beech trees not only demonstrated an elevated capability to compete for soil resources but also showed greater root plasticity than pine, enhancing beech potential to take advantage of new soil resources. Our results do not support a complementary niche partitioning but rather a competitive interaction in which European beech has an edge on colonizing the soil volume in the detriment of Scots pine.

Competitive interactions for food resources between invasive Ponto-Caspian gobies and their native competitors in the context of global warming

Climate warming can modify the process of biological invasions by affecting the outcomes of competition between alien species and their native counterparts in invaded environments. Inland freshwaters are particularly vulnerable to the intensification of such phenomena due to the accumulation of invaders, including thermophilic species that may benefit from warming. We intended to check whether an elevated summer temperature (25 vs. 17 °C) affects the abilities of the Ponto-Caspian gobies to compete for food. These fish are considered temperature-tolerant, highly invasive freshwater fish in Europe. In laboratory experiments, we tested single- and two-species pairs of juvenile specimens of two goby species and their native counterparts from the same ecological guild (the racer goby Babka gymnotrachelus versus European bullhead Cottus gobio, and monkey goby Neogobius fluviatilis versus native gudgeon Gobio gobio). The fish competed for food (live chironomidae larvae provided at rates below satiation) for 1 hour at night. We analysed behaviours associated with direct interactions (aggression acts) and foraging activity (time to enter the feeder and the time spent in the feeder). We found that although the gobies did not show higher aggression than the natives, they more actively accessed food compared to the latter, irrespective of temperature. Our results suggest that, in the wild, the invasive fish have a competitive advantage over the native ones due to better resource allocation (gaining food without incurring the costs of aggression) and will maintain this advantage as water warming continues.

Co-Occurrence of Stromatinia cepivora and Fusarium proliferatum Fungi on Garlic: In Vitro Investigation of Pathogen–Pathogen Interactions and In Planta Screening for Resistance of Garlic Cultivars

Garlic (Allium sativum L.), a vital global crop, suffers significant losses from soil-borne fungal pathogens such as Fusarium proliferatum, responsible for Fusarium bulb rot, and Stromatinia cepivora, the causal agent of white rot. In May 2023, garlic fields near Makó City, Hungary, showed simultaneous yellowing and wilting symptoms of unknown fungal infestations, which appeared sporadically. The causal pathogens were later confirmed as F. proliferatum and S. cepivora through sampling of symptomatic garlic plants, incubation in humid chambers to stimulate fungal growth, and culturing on Potato Dextrose Agar (PDA) under sterile conditions. This was followed by hyphal tip isolation and purification. Molecular identification was performed using ITS1-2 sequencing, supported with morphological identification based on colony and microscopic features. This research aimed to elucidate pathogen interaction dynamics and assess the resistance of eleven garlic cultivars to both single and simultaneous inoculations by these pathogens, under in vitro and in planta tests. Dual culture assays of F. proliferatum and S. cepivora were studied at two time points: Day 8, marking the cessation of growth along the interacting fronts due to competitive coexistence, and Day 14, when single cultures reached full radial growth. On Day 8, inhibition percentages were 8.47% for F. proliferatum and 6.40% for S. cepivora, reflecting the initial effects of competitive interactions at the point of contact. By Day 14, inhibition rates increased to 25.39% and 28.61%, respectively, highlighting the cumulative effects of sustained competition and the growing difference between single and dual culture growth. Inoculation trials, involving placing fungal disks onto the basal areas of wounded garlic cloves, revealed considerable variability in disease incidence and severity. Cultivars such as ‘Aulxito’, ‘Sabadrome’, ‘Arno’, ‘Garcua’, and ‘Makói Tavaszi’ were highly susceptible to both pathogens, while ‘Flavor’ and ‘Sabagold’ exhibited only mild symptoms when inoculated with F. proliferatum and S. cepivora, respectively. Simultaneous inoculation resulted in more rapid and severe infections, exhibiting disease incidences above 96.00% across all cultivars. Remarkably, the cultivar ‘Elephant’ exhibited complete resistance to both pathogens, even under simultaneous inoculation, highlighting its potential for future garlic resistance breeding programs.

Shifts in competition outcomes between two Daphnia species in response to algal phosphorus content

Competition is one of the key drivers of cladoceran community dynamics. Competitive abilities can be measured as the Threshold Food Concentration (TFC), i.e., concentration of food at which population growth rate equals zero. Species with lower TFC should be superior competitors. However, population TFC can vary with environmental conditions. We hypothesized that algal phosphorus (P) content influences TFC and can alter the outcome of competition between large and small-bodied cladocerans. We conducted competition and life table experiments with single clones of large Daphnia magna and small Daphnia longispina to assess how algal P content affected their TFC and competitive interactions. We also conducted computer simulations to further explore competition between the small and large species. Our experiments showed that TFC varied with the algal P content. P limitation increased the TFC of both species, but this increase was more pronounced for the smaller D. longispina. For this reason, D. magna was a superior competitor at low P content, while D.longispina was superior at high P content. We also found that enhanced food abundance gave an additional advantage to the large-bodied D. magna due to higher reproduction potential at high food concentrations.

Combining observational and experimental data to estimate environmental and species drivers of fungal metacommunity dynamics.

Understanding the distribution and dynamics of species is central to ecology and important for managing biodiversity. The distributions of species in metacommunities are determined by many factors, including environmental conditions and interactions between species. Yet, it is difficult to quantify the effect of species interactions on metacommunity dynamics from observational data. We present an approach to estimate the importance of species interactions that combines data from two observational presence-absence inventories (providing colonization-extinction data) with data from species interaction experiments (providing informative prior distributions in the Bayesian framework). We further illustrate the approach on wood-decay fungi that interact within a downed log through competition for resources and space, and facilitate the succession of other species by decomposing the wood. Specifically, we estimated the relative importance of species interactions by examining how the presence of a species influenced the colonization and extinction probability of other species. Temporal data on fruit body occurrence of 12 species inventoried twice were jointly analyzed with experimental data from two laboratory experiments that aimed to estimate competitive interactions. Both environmental variables and species interactions affected colonization and extinction dynamics. Late-successional fungi had more colonization interactions with predecessor species than early-successional species. We identified several species interactions, and the presence of certain species changed the probability that later-successional species colonized by -81% to 512%. The presence of certain species increased the probability that other species went extinct from a log by 14%-61%. Including the informative priors from experimental data added two colonization interactions and one extinction interaction for which the observational field data was inconclusive. However, most species had no detectable interactions, either because they did not interact or because of low species occupancy, meaning data limitation. We show how temporal presence-absence data can be combined with experimental data to identify which species influence the colonization-extinction dynamics of others. Accounting for species interactions in metacommunity models, in addition to environmental drivers, is important because interactions can have cascading effects on other species.

What Lies Behind Mycotoxin Presence in Animal Feed? A case study.

This study investigates seasonal trends and correlations among different mycotoxins in animal feed, employing time series analysis and Seasonal-Trend Decomposition using LOESS (STL) to uncover patterns and relationships. Data collected from Food Fortress, covering 2014 to 2024, includes feed for ruminants, pigs, and poultry. The analysis reveals that seasonality accounts for less than 15% of the variability in mycotoxin levels, suggesting a limited seasonal influence. High deoxynivalenol (DON) concentrations in ram feed were attributed to specific management practices, while persistent DON levels in pig and poultry feed highlight the need for enhanced interventions. A strong correlation between DON and zearalenone (ZEN) was identified in pig and poultry feed. Over the study period, aflatoxin levels exhibited a slight increase, potentially linked to evolving climatic conditions, whereas DON and ZEN levels showed a slight decline. Furthermore, an inverse correlation between aflatoxin and ochratoxin levels suggests competitive interactions among fungal species, such as Aspergillus and Penicillium. These findings provide valuable insights into the intricate interactions of seasonal factors, management practices, and fungal ecology shaping mycotoxin contamination in animal feed. The study emphasizes the need for advanced mitigation strategies, including predictive modeling and artificial intelligence, to monitor and manage mycotoxin risks effectively at regional level, ensuring feed safety and quality in the face of evolving environmental and management challenges.

CRF12 specifically regulates the flowering time of Arabidopsis thaliana under non-inductive conditions.

The flowering time of Arabidopsis thaliana, a model plant, is significantly accelerated when exposed to long-day (LD) conditions, as it is a typical LD plant. Consequently, the investigation of the flowering regulatory network in A. thaliana under LD conditions has garnered considerable attention in the study of flowering signals, resulting in a significant breakthrough. While many LD plants, including A. thaliana, exhibit delayed flowering under non-inductive short-day (SD) conditions, they are still capable of flowering. Nevertheless, research on the regulation of flowering induction in LD plants under non-inductive SD conditions has been limited. This study demonstrated the involvement of CYTOKININ RESPONSE FACTORS 12 (CRF12) in the regulation of flowering in A. thaliana under non-inductive conditions. Analysis of the expression patterns revealed that the activation of CRF12 expression and protein stability occurred exclusively in non-inductive environments. Molecular and genetic analyses revealed that under a non-inductive photoperiod of 12 h of light and 12 h of darkness, CRF12, CONSTANS (CO), and TARGET OF EAT 1/2 (TOE1/2) engage in competitive interactions to regulate flowering time, while in a SD photoperiod of 8 h of light and 16 h of darkness, CRF12 modulates flowering time by inhibiting the activity of TOE1/2.

Wolbachia Infection Alters the Microbiota of the Invasive Leaf-Miner Liriomyza huidobrensis (Diptera: Agromyzidae)

Microbe–microbe interactions within a host drive shifts in the host’s microbiota composition, profoundly influencing host physiology, ecology, and evolution. Among these microbes, the maternally inherited endosymbiont Wolbachia is widespread in the invasive pest Liriomyza huidorbrensis (Diptera: Agromyzidae). However, its influence on the host microbiota remains largely unexplored. In the study presented herein, we investigated the bacterial communities of Wolbachia wLhui-infected (wLhui+) and -uninfected lines (wLhui−) of L. huidorbrensis using 16S rRNA gene high-throughput sequencing. For both leaf-miner lines, Bacteroidota was the dominant phylum (relative abundance: 59.18%), followed by Pseudomonadota (36.63%), Actinomycetota (2.42%), and Bacillota (0.93%). We found no significant differences in alpha-diversity indices between the wLhui+ and wLhui− lines (p > 0.05). However, principal coordinates analysis revealed significant differences in microbiota composition between the wLhui+ and wLhui− lines (PERMANOVA: p < 0.001), explaining 76.70% of the variance in microbiota composition. Correlation network analysis identified robust negative and positive associations between Wolbachia and several genera, suggesting that Wolbachia shapes microbial composition through competitive or cooperative interactions with specific taxa. Overall, our study suggests that Wolbachia plays a key role in shaping the leaf-miner microbiome, potentially affecting host fitness.

Designing High-Damping, Optically Clear Ionogels through Competitive Binding for Flexible and Impact-Resistant Applications.

Developing damping materials that are both optically transparent and mechanically robust, while offering broad frequency damping capacity, is a significant challenge─particularly for devices that require protection without compromising visual clarity. Conventional methods often either fail to maintain transparency or involve complex designs that are difficult to implement. Here, we present an ionogel system that integrates a physically cross-linked elastic copolymer network with a viscous ionic liquid. The competitive interactions between the ionic liquid and the polymer network enable fine-tuning of the mechanical stability and damping capacity. The resulting ionogel is transparent and mechanically robust and exhibits excellent damping over a wide frequency range. Remarkably, a thin layer (0.15 mm) absorbs nearly 60% of the impact force and retains its performance after exposure to extreme conditions. This approach offers a straightforward method for designing advanced damping materials that meet both the aesthetic and functional demands of modern technologies.

Feasibility, Acceptability, and Outcomes of Project Rally: Pilot Study of a YMCA-Based Pickleball Program for Cancer Survivors

Background: Physical activity helps cancer survivors ameliorate physiological and psychosocial effects of disease and treatments. However, few cancer survivors meet physical activity recommendations, with many facing barriers such as limited interest, enjoyment, and social support. It is critical to develop enjoyable and supportive physical activity programs to improve well-being among the growing population of cancer survivors. Pickleball is increasingly popular due to its unique combination of physical activity, friendly competition, and social interaction, making it a promising strategy to increase and sustain physical activity in cancer survivorship. Objective: We examined feasibility, acceptability, and preliminary outcomes in a single-arm pilot study of Project Rally, a YMCA-based pickleball program for adult cancer survivors. Results: Twenty-one cancer survivors and seven family or friend partners enrolled in Project Rally with a targeted program duration of 3–7 months. All programming and study assessments occurred at a single YMCA with coaching and supervision from a YMCA exercise trainer and certified pickleball coach. Feasibility and acceptability were strong and met a priori targets for recruitment, retention, intervention adherence, and ratings of program aspects. Participants demonstrated significant increases in physical activity and improvements in aspects of fitness, physical functioning, and social support. Conclusion: These results will inform further development of the Project Rally program to increase physical activity and improve cancer survivorship outcomes, including efforts to expand the program’s scale and reach more survivors via community-based delivery.

Assessing the speed of individual bacteria dispersing on mycelial networks

Abstract The movement of bacteria on the hyphae of fungi and other mycelial-forming organisms is an important process that determines their ability to actively disperse in water-unsaturated habitats. However, direct observation and characterization of bacterial cell movement on mycelial networks have been difficult to achieve. In this study, we developed a new method that uses high-speed video recording to track the dispersal of individual fluorescently tagged cells of two closely related strains of Pseudomonas putida (UWC1 and KT2440) over the mycelial network of the oomycete Pythium ultimum. We found high intra-population heterogeneity and between-population differences in dispersal speeds for the two bacterial strains. The fitting of the speed distribution functions led to the separation of speeds into two ranges (fast/slow) at an intersection of the fitted curves. In the lower speed range, the UWC1 strain dispersed faster, while the KT2440 strain moved faster in the higher speed range. This finding helps explain conflicting competition outcomes revealed in previous studies and suggests that population mean speed alone does not capture key aspects of bacterial dispersal in mycelial networks. Our new method opens the possibility of studying bacterial dispersal, competition, and other social interactions in spatially heterogeneous environments, such as soils.

Design of Highly Selective and Sensitive Optical Sensor for Arsenic(III) Based on the Orientational Coupling Between L‐Cysteine and Liquid Crystals

AbstractWater pollution by toxic arsenic compounds, As(III), has emerged as a global problem, because prolonged exposure causes serious health issues. Accordingly, it is critical to monitor As(III) in drinking water and food, but conventional techniques still require complex and costly instruments that are not affordable in third‐world countries where As(III) contamination is significant. To resolve this social issue, simple and generalizable principles for the design of As(III) sensors are proposed by integrating the selective binding of L‐cysteine (L‐cys) with As(III) into the unique ability of liquid crystals (LCs) to transduce stimuli into macroscopic optical signals. We revealed significant orientational coupling of L‐cys with LCs that can be modulated by the selective binding of L‐cys with As(III) at the LC‐aqueous interface. When decorated with both L‐cys and surfactants, the LC‐aqueous interface is subjected to competition between the L‐cys‐imposed tangential (bright state) and surfactant‐imposed homeotropic (dark state) anchoring of LCs. Consequently, the competitive intermolecular interactions offers the basis for a highly stable and versatile LC material that can selectively detect As(III) in water and also quantify its concentration from trace to high levels (1 ppb – 4 ppm) via distinct optical outputs within 2 min.

Do Stands Self-Thin Through a Common Point? An Additional Concept for the Self-Thinning Rule

Once the steady and ongoing mortality of individuals in a plant population has started, the widely accepted ‘self-thinning rule’ holds; this maintains that the set of progressive average sizes of the plants and their residual stocking densities bear a constant relationship to each other. This work aimed to quantify the self-thinning processes of monospecific Eucalyptus obliqua L’Hér. forest using data from each of a set of plots in Tasmania, Australia. Unexpectedly, it was found that, with or without extrapolation, the self-thinning lines of all the plots tended to intersect near a common plant average size and stocking density. This finding was extended using previously published data for monospecific forests of seven other tree species spread widely across the world, five hardwood and two softwood. All five showed the same phenomenon. Whilst this adds a new concept to the existing self-thinning rule, no immediate explanation could be offered as to why it occurs. It was concluded that it will require studying the various mechanisms that determine tree growth behavior, the competitive interactions between individuals for the resources each requires from the site (light, water, and mineral nutrients), and how these lead to the mortality of smaller, less competitively successful individuals.

Unexpected scarcity of ANME archaea in hydrocarbon seeps within Monterey Bay

Abstract. Marine hydrocarbon seeps typically harbor a relatively predictable microbiome, including anaerobic methanotrophic (ANME) archaea. Here, we sampled two cold seeps in Monterey Bay, CA – Clam Field and Extrovert Cliff – which have been known for decades but never characterized microbiologically. Many aspects of these seeps were typical of seeps worldwide, including elevated methane and sulfide concentrations, 13C-depleted dissolved inorganic carbon, and the presence of characteristic macrofauna. However, we observed atypical microbial communities: extremely few ANME sequences were detected in either 16S rRNA or mcrA gene surveys at Clam Field (< 0.1 % of total community reads), even after 6 months of incubation with methane in the laboratory, and only slightly more ANME sequences were recovered from Extrovert Cliff (< 0.3 % of total community reads). At Clam Field, a lack of ANME mcrA transcription, a lack of methane-dependent sulfate reduction, and a linear porewater methane profile were consistent with low or absent methanotrophy. Although the reason for the scarcity of ANME archaea is still unclear, we postulate that non-methane hydrocarbon release excludes anaerobic methanotrophs directly or indirectly (e.g., through competitive interactions with hydrocarbon-degrading bacteria). Our findings highlight the potential for hydrocarbon seeps without this critical biofilter and therefore greater methane emissions from sediments.

The wheat NLR pair RXL/Pm5e confers resistance to powdery mildew.

Powdery mildew poses a significant threat to global wheat production and most cloned and deployed resistance genesfor wheat breeding encode nucleotide-binding and leucine-rich repeat (NLR) immune receptors. Although two genetically linked NLRs function together as an NLR pair have been reported in other species, this phenomenon has been relatively less studied in wheat. Here, we demonstrate that two tightly linked NLR genes, RXL and Pm5e, arranged in a head-to-head orientation, function together as an NLR pair to mediate powdery mildew resistance in wheat. The resistance function of the RXL/Pm5e pair is validated by mutagenesis, gene silencing, and gene-editing assays. Interestingly, both RXL and Pm5e encode atypical NLRs, with RXL possessing a truncated NB-ARC (nucleotide binding adaptor shared by APAF-1, plant R proteins and CED-4) domain and Pm5e featuring an atypical coiled-coil (CC) domain. Notably, RXL and Pm5e lack an integrated domain associated with effector recognition found in all previously reported NLR pairs. Additionally, RXL and Pm5e exhibit a preference for forming hetero-complexes rather than homo-complexes, highlighting their cooperative role in disease resistance. We further show that the CC domain of Pm5e specifically suppresses the hypersensitive response induced by the CC domain of RXL through competitive interaction, revealing regulatory mechanisms within this NLR pair. Our study sheds light on the molecular mechanism underlying RXL/Pm5e-mediated powdery mildew resistance and provides a new example of an NLR pair in wheat disease resistance.