Biology subjects

Gurr, G. M.

Publications and source records attributed to Gurr, G. M..

4 recordsLinked to original sources

bioRxiv2026

Arginine activates a conserved sphingolipid defense axis against infection

Metabolism is generally viewed as supporting immune responses rather than acting as a direct mediator of host defense. Here, we show that arginine directly activates the sphingolipid metabolic pathway in Plutella xylostella, promoting ceramide accumulation and consequently exerting antibacterial effects. Furthermore, we find that arginine synthesized by the host gut bacteria can activate this pathway, revealing an independent metabolic defense mechanism driven by gut bacterial arginine, which operates independently of classical immune cascades. Cross species validation shows that the ceramide biosynthesis pathway is highly conserved across eukaryotes, and its antipathogen effects display potential universality across insect species. This study opens new directions in gut innate immunity research, provides novel targets for the development of antimicrobial agents against insect pests, offers important reference value for eukaryotic pathology studies, and provides new insights into the development of novel therapeutic strategies against drug resistant bacterial infections.

immunology↗

bioRxiv2026

Adaptive evolution to thermal stress underpins climate resilience in a cosmopolitan arthropod

Adaptive evolution enables species to survive and thrive under changing environmental conditions. In the face of accelerating global climate change, thermal stress represents a major challenge to the persistence of terrestrial arthropods. Understanding the genetic mechanisms underlying thermal adaptation is therefore critical for predicting species evolutionary potential and future success. Here, we combine experimental evolution, phenotypic assays, and multi-omics analyses to investigate the adaptive responses of the diamondback moth (Plutella xylostella), a globally destructive pest of cruciferous crops, to contrasting thermal environments. Populations evolved under hot (32{degrees}C/27{degrees}C) and cold (15{degrees}C/10{degrees}C) regimes exhibited distinct life history and fitness traits relative to those maintained under favorable conditions (26{degrees}C). The hot strain showed accelerated development, higher fecundity, and increased survival under extreme heat, while the cold strain exhibited lower supercooling and freezing points, indicating enhanced cold hardiness. Integrated transcriptomic and metabolomic analyses revealed extensive transcriptional reprogramming and convergent metabolic adjustments, notably a reduction in lipid metabolism to conserve energy under thermal stress. Crucially, non-synonymous mutations in PxSODC enhance superoxide scavenging efficiency, enabling effective oxidative stress management at lower gene expression levels. Furthermore, we identified epigenetic regulation via DNA methylation as a key mediator of this thermal tolerance. Together, these coordinated mutational, epigenetic, and metabolic insights highlight this arthropods capacity for global dispersal and likely persistence under climate change, establishing a framework for understanding equivalent effects in other species.

evolutionary biology↗

bioRxiv2022

Gut microbiota assemblages of generalist predators are driven by local- and landscape-scale factors

The gut microbiomes of arthropods are reported to have significant impact on key physiological functions such as nutrition, reproduction, behavior, and health. Spiders are diverse and numerically dominant predators in crop fields where they are potentially important regulators of pests. The taxonomic structure of spider gut microbiomes, and environmental drivers of composition are unknown. Harnessing spiders to support agricultural productivity is likely to be supported by an understanding of the gut microbiomes of these predators. This study aimed to deciphering the gut microbiome assembly of predators as well as elucidating the potential implications of key environmental constraints in this process. Here, we used high-throughput sequencing to examine for the first time how the assemblages of bacteria in the gut of spiders are shaped by diverse environmental variables. A total of 27 bacterial phyla were detected with Proteobacteria and Firmicutes dominant. The core bacterial communities included the families Enterobacteriaceae, Chloroplast, Lactobacillaceae, Pseudomonadaceae, Lachnospiraceae, Leuconostocaceae and Ruminococcaceae. Local drivers of microbiome composition were the globally-relevant input use system (organic production versus conventional practice), and crop identity (Chinese cabbage versus cauliflower). Landscape-scale factors, proportion of forest and grassland, compositional diversity, and habitat edge density, also strongly affected gut microbiota. Specific bacterial taxa were enriched in the gut of spiders sampled from different settings and seasons. These findings provide a comprehensive insight into the composition and plasticity of spider gut microbiota. Understanding the temporal responses of specific microbiota could lead to innovative strategies development for boosting biological control services of predators.

ecology↗

bioRxiv2022

DNA metabarcoding of gut contents reveals key habitat and seasonal drivers of trophic networks involving generalist predators in agricultural landscapes

BACKGROUNDUnderstanding the networks of trophic interactions into which generalist predators are embedded is key to assessing their ecological role of in trophic networks and the biological control services they provide. The advent of affordable DNA metabarcoding approaches greatly facilitates quantitative understanding of trophic networks and their response to environmental drivers. Here, we examine how key environmental gradients interact to shape predation by Lycosidae in highly dynamic vegetable growing systems in China. RESULTSFor the sampled Lycosidae, crop identity, pesticide use, and seasons shape the abundance of preydetected in spider guts. For the taxonomic richness of prey, local- and landscape-scale factors gradients were more influential. Multivariate ordinations confirm that these crop-abundant spiders dynamically adjust their diet to reflect environmental constraints and seasonal availability to prey. CONCLUSIONThe plasticity in the diet composition is likely to account for the persistence of spiders in relatively ephemeral brassica crops. Our findings provide further insights into the optimization of habitat management for predator-based biological control practices.

ecology↗