Biology subjects

Wood, T.

Publications and source records attributed to Wood, T..

At least 19 recordsLinked to original sources

bioRxiv2026

Developmental and physiological profiles define drought response diversity and genomic associations in common bean

Common bean (Phaseolus vulgaris L.) yields are strongly impacted by water deficit, yet there is substantial within-species diversity in how development, biomass accumulation, gas exchange, and photosynthetic performance are coordinated under stress. Based on this variation within a diversity panel, we characterise response profiles, define drought-response strategies, assess how these strategies relate to population structure and gene flow, and identify associated loci. A panel of 142 common bean accessions representing diverse genetic backgrounds was grown outdoors under controlled water-deficit conditions. Over five weeks, plants were monitored for phenology, biomass, pod production, and leaf traits related to stomatal and photosynthetic performance, including a brief recovery period. Genome-wide association analyses were then performed for developmental, physiological and recovery-related traits. Declining soil water availability revealed marked variation among accessions in developmental progression, biomass partitioning, stomatal behaviour and photosynthetic performance. We combined developmental and physiological traits to define above-ground response profiles and classify drought-response strategies in common bean, which were distributed across the diversity panel. GWAS identified multiple QTL and candidate loci associated with developmental, physiological and recovery-related traits. Common bean exhibits extensive diversity in overall above-ground responses to water deficit, likely reflecting local adaptation rather than population structure. Developmental data were essential for differentiating response strategies and, when combined with porometer and fluorometer measurements indicating the level of water stress experienced by the plants, for connecting traits and strategies to genomic variation. These results provide trait relationships, candidate loci and testable hypotheses for validation across environments and for future breeding-oriented studies.

plant biology↗

bioRxiv2026

Engineering Methyl-Coenzyme M Reductase for Enhanced Methane and Carbon Dioxide Capture through Biofilm Growth

Methane is a potent greenhouse gas, nearly half of which is consumed anaerobically by anaerobic methanotrophic archaea (ANME) through methyl-coenzyme M reductase (Mcr). However, ANME cannot be grown as pure cultures, and obtaining active ANME Mcr in vitro remains extremely challenging, preventing previous efforts to engineer this key enzyme. Here, we used directed evolution in the methanogen Methanosarcina acetivorans to enhance ANME-1 Mcr (McrANME-1) activity for methane and carbon dioxide capture by selecting McrANME-1 variants with improved growth during methane-dependent cultivation. As a result, we discovered two beneficial substitutions in the catalytic -subunit of McrANME-1, S60P and I154V, that increased biofilm growth as well as acetate production and methane capture. AlphaFold structural predictions suggest possible mechanistic explanations for these beneficial substitutions. These findings demonstrate that Mcr can be engineered to enhance methane and carbon dioxide capture, establishing a foundation for biological greenhouse gas mitigation and carbon utilization technologies.

Synthetic Biology↗

bioRxiv2026

Enhancer-based AAV approach for selective AADC delivery reduces motor symptoms and dyskinesia in Parkinson's mouse models

Degeneration of midbrain dopamine (DA) neurons and the resulting loss of striatal dopamine signaling are hallmarks of Parkinsons disease (PD). Although the dopamine precursor levodopa (L-DOPA) provides symptomatic relief, prolonged treatment often leads to abnormal involuntary movements (dyskinesia). Previous adeno-associated virus (AAV) approaches delivering aromatic L-amino acid decarboxylase (AADC) to the striatum under a ubiquitous promoter enhanced local dopamine synthesis and improved PD motor deficits, but this broad targeting strategy limited insight into the cellular populations underlying the behavioral improvements. Here, we engineered enhancer-driven AAVs to direct AADC expression to defined striatal and midbrain cell populations and paired these regulatory elements with a blood-brain barrier-penetrant capsid to enable both systemic and direct delivery. Targeted expression restored motor performance at reduced L-DOPA doses and decreased dyskinesia-like behaviors, producing improvements comparable to or greater than those achieved with ubiquitous expression. Distinct neuronal and non-neuronal populations each supported motor rescue but improved different behavioral domains to different extents, indicating complementary cell type-specific roles within PD-relevant circuits. Together, these findings establish enhancer-driven, cell type-specific AADC delivery as a better-tolerated strategy that enables rescue of motor deficits at lower L-DOPA doses in PD models.

neuroscience↗

bioRxiv2025

Systemic Metabolic Rewiring in a Mouse Model of Left Ventricular Hypertrophy

Left ventricular hypertrophy (LVH) refers to the pathological thickening of the myocardial wall, and is strongly associated with several adverse cardiac outcomes and sudden cardiac death. While the biomechanical drivers of LVH are well established, growing evidence points to a critical role for cardiac and systemic metabolism in modulating hypertrophic remodeling and disease pathogenesis. Despite the efficiency of fatty acid oxidation (FAO), LVH hearts preferentially increase glucose uptake and catabolism to drive glycolysis and oxidative phosphorylation (OXPHOS). Development of therapies to increase and enhance LFCA FAO are underway, with promising results. However, the mechanisms of systemic metabolic states and LCFA dynamics in the context of cardiac hypertrophy remain incompletely understood. Further, it is unknown to what extent cardiac metabolism is influenced by whole-body energy balance and lipid profiles, despite the common occurrence of lipotoxicity in LVH. In this study, we measured whole-body and cellular respiration along with analysis of lipid and glycogen stores in a mouse model of LVH. We found that loss of the cardiac-specific gene, Myosin binding protein-C3 (Mybpc3), resulted in depletion of adipose tissue, decreased mitochondrial function in skeletal muscle, increased lipid accumulation in both heart and liver, and loss of whole-body metabolic flux. We found that supplementation of exogenous LCFAs boosted LVH mitochondrial function and reversed cardiac lipid accumulation, but did not fully reverse the hypertrophied heart nor systemic metabolic phenotypes. This study indicates that the LVH phenotype caused systemic metabolic rewiring in Mybpc3-/- mice, and that exogenous LCFA supplementation boosted mitochondrial function in both cardiac and skeletal muscle.

physiology↗

bioRxiv2025

A microbiome-derived transfer RNA modification underlies behavioral optimums and predator avoidance in mosquito larvae

The gut microbiome is a rich source of nutrients that are critical to the development and biology of eukaryotes. Transfer RNAs (tRNAs) are essential components of protein synthesis, and some chemical modifications to tRNA rely on the availability of microbiome-derived nutrients. In eukaryotes, the micronutrient queuosine (Q) is salvaged from the microbiome or diet and then incorporated into eukaryotic tRNA to influence the speed and efficiency of protein synthesis. Here, we examine the role of microbiome-derived Q in mosquito larval development and behavior. When mosquito larvae are grown with a microbiome incapable of synthesizing Q, there is a significant impact on tyrosine levels and processes, which correlate with defects in behavior and cuticle formation. Due to defects in movement and behavioral responses, Q-deficient larvae demonstrate impaired predator evasion, leading to higher instances of capture by predaceous beetle larvae. The broad effects of Q-deficiency in mosquito larvae highlight the importance of microbiome-derived nutrients for eukaryotic physiology and behavior.

physiology↗

bioRxiv2025

Advancing RNAi-Based Strategies Against Downy Mildews: Insights Into dsRNA Uptake and Gene Silencing

Downy mildew (DMs) dieases are caused by destructive obligate pathogens with limited control options, posing a significant threat to global agriculture. RNA interference (RNAi) has emerged as a promising, environmentally sustainable strategy for disease management. In this study, we evaluated the efficacy of dsRNA-mediated RNAi in suppressing key biological functions in DM pathogens of Arabidopsis thaliana, pea and lettuce DM pathogens, Hyaloperonospora arabidopsidis (Hpa), Peronospora viciae f. sp. pisi (Pvp) and Bremia lactucae (Bl), respectively. We specifically targeted the cellulose synthase 3 (CesA3) and the beta tubulin (BTUB) genes. Silencing CesA3 impaired spore germination and infection across multiple species, while BTUB silencing reinforced the potential of dsRNA-mediated inhibition. Reduction in gene expression levels correlated well with the sporulation assays confirming the effectiveness of dsRNA-mediated gene silencing. We used dsRNAs that were chemically synthesized, in vitro transcribed (IVT) or produced in E. coli. We found that the length and concentration of these dsRNAs significantly affected uptake efficiency, spore germination, and sporulation, with higher concentrations enhancing inhibitory effects. Confocal microscopy using Cy-5-labelled short-synthesized dsRNA (SS-dsRNA) provided direct evidence of spore uptake, confirming the potential of SS-dsRNA for pathogen control. However, species-specific sequence variations influenced dsRNA efficacy, underscoring the importance of target sequence design. Multiplexed RNAi impacted silencing synergisticly, further reducing germination and sporulation in Hpa. Additionally, we demonstrated that SS-dsRNA-mediated gene silencing is sustained over time, with a significant reduction in gene expression level at 4, 7, 10 and 11dpi. This indicates the durability and efficacy of this approach. Taken together, these findings demonstrate the potential of dsRNA-mediated gene silencing as a precision tool for managing DM pathogens.

plant biology↗

bioRxiv2025

Pea-Saving Partners: Bacillus and Pseudomonas combat downy mildew in pea crops

Downy mildew (DM) is a destructive disease that significantly reduces the yield and quality of important pulses (legumes) and horticultural crops, particularly during humid and cool seasons. This disease is caused by obligate and host-specific oomycete pathogens. Controlling the pathogen is challenging due to its long-term survival as spores and its rapid mutation. Use of chemical pesticides has been the most effective method to control DM pathogens, but their environmental hazards are a global concern. Current research is focused on exploring the potential of microbial biological control agents (MBCA), particularly rhizobacteria strains of the genera Bacillus and Pseudomonas, which have shown suppression of plant pathogens. However, to date, no MBCA has been reported to be effective against DM pathogens in pulses. We investigated the effectiveness of Bacillus and Pseudomonas strains as potential biopesticides against the pea downy mildew pathogen Peronospora viciae f. sp. pisi (Pvp). In our study, in vitro bioassays showed 100% inhibition of Pvp spore germination compared to the control. In planta antagonism assays further demonstrated significant suppression (>80%) of Pvp sporulation in pea plants sprayed with strains of Bacillus velezensis or P. fluorescens or their filtrates. The drench application also showed significant effects where either a Pseudomonas or cold-adapted Bacillus strain was used. We observed a synergistic effect for the dual foliar application of the microbes compared to individual application (27.6 to 46.7% suppression). Furthermore, the results from the molecular biomass analysis were consistent with the results of the sporulation assays. This demonstrates the strong interactive and promotive benefits of using Bacillus and Pseudomonas as biocontrol agents Based on these results, we conclude that these MBCAs could be effective in combatting Pvp infections in the field.

plant biology↗

bioRxiv2024

Modelling molecular differences in the innate immune system responses of chickens and ducks to highly pathogenic avian influenza virus

Highly pathogenic avian influenza virus (HPAIV) presents a global threat to chicken livestock; chickens infected by HPAIV tend to show severe symptoms and high mortality rates. In 2022, the largest recorded outbreak of HPAIV in Europe resulted in millions of chickens being culled in the UK alone to try to prevent further spread. Unlike chickens, mallard ducks show reduced symptom severity and lower mortality rates to HPAIV infection. Research into the immune system responses of these two species shows they differ in their molecular outputs: chickens produce a pro-inflammatory response; mallards produce an anti-viral response. These differences in immune responses are thought to be in part due to chickens missing pattern recognition receptor retinoic acid-inducible gene-I (RIG-I). This project aimed to model the innate immune systems of chickens and mallard ducks to an abstracted molecular level. A literature search was conducted, and the immune systems were modelled in NetLogo as an avian innate immune response agent-based model (AIIRABM). The AIIRABM enabled examination of the relative importance of molecular differences between the chicken and mallard duck innate immune systems and produced similar differences in chicken and mallard duck molecular outputs to those observed in vitro and in vivo. Simulation experiments with the AIIRABM supported the molecular difference RIG-I as key in causing the differences in the chicken and mallard duck innate immune responses to HPAIV. The AIIRABM will be used in further research on the chicken and mallard duck immune responses to HPAIV as the baseline in an iterative modelling cycle.

immunology↗

bioRxiv2023

Exploring Discrete Space-Time Models for Information Transfer: Analogies from Mycelial Networks to the Cosmic Web

Fungal mycelium networks are large scale biological networks along which nutrients, metabolites flow. Recently, we discovered a rich spectrum of electrical activity in mycelium networks, including action-potential spikes and trains of spikes. Reasoning by analogy with animals and plants, where travelling patterns of electrical activity perform integrative and communicative mechanisms, we speculated that waves of electrical activity transfer information in mycelium networks. Using a new discrete space-time model with emergent radial spanning-tree topology, hypothetically comparable mycelial morphology and physically comparable information transfer, we provide physical arguments for the use of such a model, and by considering growing mycelium network by analogy with growing network of matter in the cosmic web, we develop mathematical models and theoretical concepts to characterise the parameters of the information transfer.

bioinformatics↗

bioRxiv2023

Blunted glucocorticoid responsiveness to stress causes behavioral and biological alterations that lead to posttraumatic stress disorder vulnerability

BACKGROUNDUnderstanding why only a subset of trauma-exposed individuals develop posttraumatic stress disorder (PTSD) is critical for advancing clinical strategies. A few behavioral (deficits in fear extinction) and biological (blunted glucocorticoid levels, small hippocampal size, and rapid-eye movement sleep (REMS) disturbances) traits have been identified as potential vulnerability factors. However, whether and to what extent these traits are interrelated and whether one of them could causally engender the others are not known. METHODSIn a genetically selected rat model of reduced corticosterone responsiveness to stress, we explored PTSD-related biobehavioral traits using ex vivo magnetic resonance imaging, cued fear conditioning, and polysomnographic recordings combined with in vivo photometric measurements. RESULTSWe showed that genetic selection for blunted glucocorticoid responsiveness leads to a correlated multitrait response, including impaired fear extinction, small hippocampal volume, and REMS disturbances, supporting their interrelatedness. Fear extinction deficits and concomitant disruptions in REMS could be normalized through postextinction corticosterone administration, causally implicating glucocorticoid deficiency in two core PTSD-related risk factors and manifestations. Furthermore, reduced REMS was accompanied by higher norepinephrine levels in the hippocampal dentate gyrus that were also reverted by postextinction corticosterone treatment. CONCLUSIONSOur results indicate a predominant role for glucocorticoid deficiency over the contribution of reduced hippocampal volume in engendering both REMS alterations and associated deficits in fear extinction consolidation, and causally implicate blunted glucocorticoids in sustaining neurophysiological disturbances leading to fear extinction deficits.

neuroscience↗

bioRxiv2021

Seeing the future: predictive control in neural models of ocular accommodation

Ocular accommodation is the process of adjusting the eyes crystalline lens so as to bring the retinal image into sharp focus. The major stimulus to accommodation is therefore retinal defocus, and in essence, the job of accommodative control is to send a signal to the ciliary muscle which will minimize the magnitude of defocus. In this paper, we first provide a tutorial introduction to control theory to aid vision scientists without this background. We then present a unified model of accommodative control that explains properties of the accommodative response for a wide range of accommodative stimuli. Following previous work, we conclude that most aspects of accommodation are well explained by dual integral control, with a "fast" or "phasic" integrator enabling response to rapid changes in demand, which hands over control to a "slow" or "tonic" integrator which maintains the response to steady demand. Control is complicated by the sensorimotor latencies within the system, which delay both information about defocus and the accommodation changes made in response, and by the sluggish response of the motor plant. These can be overcome by incorporating a Smith predictor, whereby the system predicts the delayed sensory consequences of its own motor actions. For the first time, we show that critically-damped dual integral control with a Smith predictor accounts for adaptation effects as well as for the gain and phase for sinusoidal oscillations in demand. In addition, we propose a novel proportional-control signal to account for the power spectrum of accommodative microfluctuations during steady fixation, which may be important in hunting for optimal focus, and for the nonlinear resonance observed for low-amplitude, high-frequency input. Complete Matlab/Simulink code implementing the model is provided at https://doi.org/10.25405/data.ncl.14945550.

neuroscience↗

bioRxiv2018

High-throughput characterisation of bull semen motility using differential dynamic microscopy

We report a high-throughput technique for characterising the motility of spermatozoa using differential dynamic microscopy. A large field of view movie (~ 10mm2) records thousands of cells (e.g. {approx} 5000 cells even at a low cell density of 20 x 106 cells/ml) at once and yields averaged measurements of the mean ({upsilon}) and standard deviation ({sigma}) of the swimming speed, a head oscillation amplitude (A0) and frequency (f0), and the fraction of motile spermatozoa (). Interestingly, the measurement of relies on the swimming spermatozoa enhancing the motion of the non-swimming population. We demonstrate the ease and rapidity of our method by performing on-farm characterisation of bull spermatozoa motility, and validate the technique by comparing laboratory measurements with tracking. Our results confirm the long-standing theoretical prediction that [Formula] for swimming spermatozoa.

biophysics↗

bioRxiv2018

Corticospinal neuroplasticity and sensorimotor recovery in rats treated by infusion of neurotrophin-3 into disabled forelimb muscles started 24 h after stroke

Stroke often leads to arm disability and reduced responsiveness to stimuli on the other side of the body. Neurotrophin-3 (NT3) is made by skeletal muscle during infancy but levels drop postnatally and into adulthood. It is essential for the survival and wiring-up of sensory afferents from muscle. We have previously shown that gene therapy delivery of human NT3 into the affected triceps brachii forelimb muscle improves sensorimotor recovery after ischemic stroke in adult and elderly rats. Here, to move this therapy one step nearer to the clinic, we set out to test the hypothesis that intramuscular infusion of NT3 protein could improve sensorimotor recovery after ischemic cortical stroke in adult rats. To simulate a clinically-feasible time-to-treat, twenty-four hours later rats were randomized to receive NT3 or vehicle by infusion into triceps brachii for four weeks using implanted minipumps. NT3 increased the accuracy of forelimb placement during walking on a horizontal ladder and increased use of the affected arm for lateral support during rearing. NT3 also reversed sensory deficits on the affected forearm. There was no evidence of forepaw sensitivity to cold stimuli after stroke or NT3 treatment. MRI confirmed that treatment did not induce neuroprotection. Functional MRI during low threshold electrical stimulation of the affected forearm showed an increase in peri-infarct BOLD signal with time in both stroke groups and indicated that neurotrophin-3 did not further increase peri-infarct BOLD signal. Rather, NT3 induced spinal neuroplasticity including sprouting of the spared corticospinal and serotonergic pathways. Neurophysiology showed that NT3 treatment increased functional connectivity between the corticospinal tracts and spinal circuits controlling muscles on the treated side. After intravenous injection, radiolabelled NT3 crossed from bloodstream into the brain and spinal cord in adult mice with or without strokes. Our results show that delayed, peripheral infusion of neurotrophin-3 can improve sensorimotor function after ischemic stroke. Phase I and II clinical trials of NT3 (for constipation and neuropathy) have shown that peripheral, high doses are safe and well tolerated, which paves the way for NT3 as a therapy for stroke.

neuroscience↗

bioRxiv2018

Homogenization of sub-genome secretome gene expression patterns in the allodiploid fungus Verticillium longisporum

Hybridization is an important evolutionary mechanism that can enable organisms to adapt to environmental challenges. It has previously been shown that the fungal allodiploid species Verticillium longisporum, causal agent of Verticillium stem striping in rape seed, has originated from at least three independent hybridization events between two haploid Verticillium species. To reveal the impact of genome duplication as a consequence of the hybridization, we studied the genome and transcriptome dynamics upon two independent V. longisporum hybridization events, represented by the hybrid lineages "A1/D1" and "A1/D3". We show that the V. longisporum genomes are characterized by extensive chromosomal rearrangements, including between parental chromosomal sets. V. longisporum hybrids display signs of evolutionary dynamics that are typically associated with the aftermath of allodiploidization, such as haploidization and a more relaxed gene evolution. Expression patterns of the two sub-genomes within the two hybrid lineages are more similar than those of the shared A1 parent between the two lineages, showing that expression patterns of the parental genomes homogenized within a lineage. However, as genes that display differential parental expression in planta do not typically display the same pattern in vitro, we conclude that sub-genome-specific responses occur in both lineages. Overall, our study uncovers the genomic and transcriptomic plasticity during evolution of the filamentous fungal hybrid V. longisporum and illustrate its adaptive potential. ImportanceVerticillium is a genus of plant-associated fungi that include a handful of plant pathogens that collectively affect a wide range of hosts. On several occasions, haploid Verticillium species hybridized into the stable allodiploid species Verticillium longisporum, which is, in contrast to haploid Verticillium species, a Brassicaceae specialist. Here, we studied the evolutionary genome and transcriptome dynamics of V. longisporum and the impact of the hybridization. V. longisporum genomes display a mosaic structure due do genomic rearrangements between the parental chromosome sets. Similar to other allopolyploid hybrids, V. longisporum displays an ongoing loss of heterozygosity and a more relaxed gene evolution. Also, differential parental gene expression is observed, with an enrichment for genes that encode secreted proteins. Intriguingly, the majority of these genes displays sub-genome-specific responses under differential growth conditions. In conclusion, hybridization has incited the genomic and transcriptomic plasticity that enables adaptation to environmental changes in a parental allele-specific fashion.

microbiology↗

bioRxiv2018

Dynamic virulence-related regions of the fungal plant pathogen Verticillium dahliae display remarkably enhanced sequence conservation

Selection pressure impacts genomes unevenly, as different genes adapt with differential speed to establish an organisms optimal fitness. Plant pathogens co-evolve with their hosts, which implies continuously adaption to evade host immunity. Effectors are secreted proteins that mediate immunity evasion, but may also typically become recognized by host immune receptors. To facilitate effector repertoire alterations, in many pathogens, effector genes reside in dynamic genomic regions that are thought to display accelerated evolution, a phenomenon that is captured by the two-speed genome hypothesis. The genome of the vascular wilt pathogen Verticillium dahliae has been proposed to obey to a similar two-speed regime with dynamic, lineage-specific regions that are characterized by genomic rearrangements, increased transposable element activity and enrichment in in planta-induced effector genes. However, little is known of the origin of, and sequence diversification within, these lineage-specific regions. Based on comparative genomics among Verticillium spp. we now show differential sequence divergence between core and lineage-specific genomic regions of V. dahliae. Surprisingly, we observed that lineage-specific regions display markedly increased sequence conservation. Since single nucleotide diversity is reduced in these regions, host adaptation seems to be merely achieved through presence/absence polymorphisms. Increased sequence conservation of genomic regions important for pathogenicity is an unprecedented finding for filamentous plant pathogens and signifies the diversity of genomic dynamics in host-pathogen co-evolution.

microbiology↗

bioRxiv2018

Nuclear and mitochondrial genomes of the hybrid fungal plant pathogen Verticillium longisporum display a mosaic structure

Allopolyploidization, genome duplication through interspecific hybridization, is an important evolutionary mechanism that can enable organisms to adapt to environmental changes or stresses. This increased adaptive potential of allopolyploids can be particularly relevant for plant pathogens in their quest for host immune response evasion. Allodiploidization likely caused the shift in host range of the fungal pathogen plant Verticillium longisporum, as V. longisporum mainly infects Brassicaceae plants in contrast to haploid Verticillium spp. In this study, we investigated the allodiploid genome structure of V. longisporum and its evolution in the hybridization aftermath. The nuclear genome of V. longisporum displays a mosaic structure, as numerous contigs consists of sections of both parental origins. V. longisporum encountered extensive genome rearrangements, whereas the contribution of gene conversion is negligible. Thus, the mosaic genome structure mainly resulted from genomic rearrangements between parental chromosome sets. Furthermore, a mosaic structure was also found in the mitochondrial genome, demonstrating its bi-parental inheritance. In conclusion, the nuclear and mitochondrial genomes of V. longisporum parents interacted dynamically in the hybridization aftermath. Conceivably, novel combinations of DNA sequence of different parental origin facilitated genome stability after hybridization and consecutive niche adaptation of V. longisporum.

genomics↗

bioRxiv2017

Variable impact of Verticillium longisporum on oilseed rape yield in field trials in the United Kingdom

The Verticillium genus comprises economically important plant pathogens that collectively affect a broad range of annual and perennial crops. Verticillium longisporum mainly infects brassicaceous hosts, including oilseed rape. The most conspicuous symptom of V. longisporum infection on oilseed rape is black stem striping that appears towards the end of the cropping season. Thus far, the impact of V. longisporum infection on oilseed yield remains unclear. Verticillium stem striping recently emerged as a new disease in UK and currently displays a widespread occurrence in England. In this study, we assessed the impact of Verticillium stem striping on British oilseed rape production. To this end, four cultivars (Incentive, Vision, Harper and Quartz) were grown in field plots with different levels of V. longisporum disease pressure at different locations over two consecutive years. Whereas Incentive and Vision developed relatively few stem striping symptoms, Harper and especially Quartz showed severe symptoms during these field experiments. Furthermore, higher inoculum levels induced more severe symptoms in these cultivars. Intriguingly, significant yield reductions upon V. longisporum infection only occurred in a single field trial on all tested oilseed rape cultivars. Thus we conclude that Verticillium stem striping does not consistently impact oilseed rape yield, despite the occurrence of abundant disease symptoms.

plant biology↗

bioRxiv2017

The emerging British Verticillium longisporum population consists of aggressive Brassica pathogens

The impact of diseases depends on the dynamic interplay between host, pathogen and the environment. Newly emerging diseases may be the consequence of novel pathogen introductions that are typically associated with unpredictable outcomes, as their interaction with the host in a novel environment is unprecedented. Alternatively, new diseases may emerge from latent, previously established, pathogen populations that are triggered by changes in environmental factors like weather, agricultural practices and ecosystem management. Verticillium stem striping recently emerged in British oilseed rape (Brassica napus) production from a latent Verticillium longisporum population. V. longisporum is a hybrid fungal pathogen consisting of three lineages, each representing a separate hybridization event. Despite its prevalence, little is known of the pathogenicity of the British V. longisporum population. In this study, the pathogenicity of British isolates was tested on four different cultivars of three different Brassica crop species as well as on the model plant Arabidopsis thaliana and compared with previously characterized V. longisporum strains from other regions of the world, including representatives of all three hybrid lineages. Intriguingly, the British isolates appeared to be amongst the most pathogenic strains on Brassica crops. In conclusion, Verticillium stem striping poses a genuine threat to oilseed rape production as the British V. longisporum population consists of aggressive pathogens that have the potential to significantly impact Brassica crops.

plant biology↗