Project description:Structure of manure resistome and associated mobilome in the context of the risk assessment of drug resistance transmission to crops
Project description:Green manure is widely advocated as a sustainable alternative to chemical fertilizers in crop systems, yet the mechanisms underlying its yield benefits remain unclear. Moreover, vigorous vegetative growth under green manure can elevate lodging risk, undermining yield and harvest efficiency. Here, we describe mechanisms by which hairy vetch–based green manure enhances yield and evaluate the practical value of deploying functionally weak alleles of gibberellin 20-oxidase (GA20ox) in this management context. We conducted field comparisons of green manure and conventional chemical fertilization to evaluate effects on rice productivity, grain appearance quality, and canopy physiology. Green manure significantly increased grain yield and grain appearance quality in the leading Japanese cultivar ‘Koshihikari’, accompanied by higher lodging. By contrast, high-yielding cultivars homozygous for a single-copy GA20ox1 allele and/or a non-functional GA20ox2 allele maintained superior lodging resistance under green manure treatment while improving yield and grain appearance quality, indicating an effective combination of its treatment and genotypes. Physiologically, green manure increased chlorophyll index during vegetative growth and at the reproductive stage, and nitrogen (N) concentration on the whole plant. Furthermore, green manure increased flag-leaf width and tiller number; these canopy changes were associated with reduced panicle temperature at the ripening stage. Green manure treatment induced upregulation of OsNADH-GOGAT2, a known gene associated with increased N loading to grains, and more grain storage proteins, providing a positive link to improved grain appearance quality. Collectively, this study demonstrates that integrating hairy vetch with functionally weak GA20ox alleles can enhance productivity and grain appearance quality while mitigating lodging risk. This sheds light on the importance of aligning green-manure treatment with targeted allelic selection to stabilize performance across intensive-farming systems and reduce chemical fertilizer dependency.
Project description:Reproductive-stage heat stress reduces rice yield and grain appearance quality, even in modern heat-resilient cultivars. Although our previous work showed that green manure can lessen ripening heat damage in the widely grown but heat-susceptible Japanese cultivar Koshihikari, it remains unclear whether similar benefits occur in heat-resilient cultivars and how green manure influences source–sink molecular responses during ripening. Here, using the heat-resilient cultivar Nijinokirameki, we tested whether green manure alleviates ripening heat stress by modifying panicle thermal status, nitrogen assimilation, and early endosperm stress responses. Green manure increased flag-leaf size and tiller (panicle) number and enhanced ripening-stage heat resilience by lowering panicle temperature without a meaningful phenological shift. Consistent with reduced heat load at the target organ, endosperm RNA-seq at 5 days after flowering (DAF) revealed weaker induction of heat-responsive programs under green manure, accompanied by increased grain protein content and reduced chalkiness classes (e.g., white milky, and white belly and back kernels). In parallel, shoot nitrogen contents at panicle formation stage were increased and flag-leaf RNA-seq at 5 DAF showed upregulation of ASN1 and NADH-GOGAT2, suggesting contribution to nitrogen assimilation in source organs and nitrogen allocation to grains. Together, these results link a sustainable fertility practice to tissue-scale heat stress mitigation and coordinated source–sink transcriptional responses at ripening that reflects enhanced grain protein accumulation and appearance quality under green manure treatment.
Project description:Long time considered as « junk DNA », the evolutive force of transposable elements (TEs) is now well established and TEs contribute strongly to eukaryote genome plasticity. However, it is difficult to fully characterize the mobile part of a genome, or active mobilome, and tracking TE activity remains challenging. He we have applied the detection of extrachromosomal circular DNA (mobilome-seq) as a diagnostic for plant TE activity on Poplar mersitems from WT and ddm1 RNAi plants grown in normal or hydric stress conditions.
Project description:Meta-proteomics analysis approach in the application of biogas production from anaerobic digestion has many advantages that has not been fully uncovered yet. This study aims to investigate biogas production from a stable 2-stage chicken manure fermentation system in chemical and biological perspective. The diversity and functional protein changes from the 1st stage to 2nd stage is a good indication to expose the differential metabolic processes in anaerobic digestion. The highlight of identified functional proteins explain the causation of accumulated ammonia and carbon sources for methane production. Due to the ammonia stress and nutrient limitation, the hydrogenotrophic methanogenic pathway is adopted as indicative of meta-proteomics data involving the key methanogenic substrates (formate and acetate). Unlike traditional meta-genomic analysis, this study could provide both species names of microorganism and enzymes to directly point the generation pathway of methane and carbon dioxide in investigating biogas production of chicken manure.
Project description:Study generating and describing the faecal metagenomes of 194 persons occupationally exposed to antimicrobial resistance in livestock (including 46 control subjects).
Highlights:
- DNA of faecal samples of 194 persons occupationally exposed to antimicrobial resistance (AMR) in livestock, i.e. persons living or working on pig and poultry farms and pig slaughterhouse workers and control subjects, was sequenced and metagenomically analysed.
- The faecal resistomes and microbiomes of farmers and slaughterhouse workers were described and compared between occupationally exposed groups and controls.
- We found an increased ARG carriage in persons working in the Dutch pork production chain as compared to poultry farmers and controls.
- Significant differences were found in the resistome and bacteriome composition of pig and pork exposed workers compared to a control group, as well as within-population (farms, slaughterhouse) compositional differences.
- On-farm working hours and working or living on a pig farm (versus poultry farm) are determinants for the human faecal resistome.
- Direct or indirect contact with AMR in livestock may be a determinant for human ARG carriage.