Agriculture and Agri-Food Canada

Genome editing techniques, especially clustered regularly interspaced short palindromic repeats (CRISPR), brought researchers into a new era of molecular plant breeding because it enabled them to make targeted modifications in plant genomes and transcriptomes. However, the successful incorporation of large DNA segments into plant genomes, necessary for high genetic gains and desired traits, remains a critical challenge. As there is an increasing demand for technologies that support chromosomal integration of large DNA inserts suitable for application in synthetic biology and plant breeding, PrimeRoot editors have presented a revolutionary solution to this issue, as they integrate enhanced prime editing guide RNA (PegRNA) designs, improved plant prime editor systems and advanced recombinases, helping in the precise insertion of DNA fragments of up to 11.1kb into the plant genomes. Third-generation PrimeRoot editors further enhanced the precision and efficiency of transformation under different gene delivery systems. This technology holds enormous promise for accurately inserting long DNA sequences across different species of plants. This review highlights expected developments, opportunities, applications, advantages and challenges associated with PrimeRoot editors as well as the significance of expanding their applicability to more varieties of plants.

Dairy white wastewater (WW), a by-product of industrial cleaning processes, contains residual milk proteins that can be enzymatically converted into bioactive peptides. In this study, WW proteins were hydrolyzed using four enzymes, pepsin, trypsin, thermolysin, and pronase E, for up to 240min, and the resulting hydrolysates were evaluated for ACE inhibition, DPP-IV inhibition, and antioxidant capacity. Thermolysin hydrolysates exhibited the strongest ACE inhibition, with IC50 values as low as 21.0μg protein/mL, whereas pepsin and pronase E hydrolysates showed DPP-IV inhibitory activities with IC50 values of 2.4-3.1mg protein/mL. Pepsin hydrolysates presented the highest antioxidant capacity, reaching 3.5μM Trolox equivalents/mg protein. LC-MS/MS analysis combined with multivariate statistics identified 60 discriminant peptides, including 17 peptides previously reported to possess antihypertensive, antidiabetic, and/or antioxidant bioactivities. Based on a combination of PLS-DA loadings, QSAR scores, novelty relative to known bioactive peptides and physicochemical diversity, 20 peptides were synthesized and validated experimentally. Several peptides such as LRF, QW, GAWY, PPF, GPIVL, and SFNPTQL exhibited potent inhibitory effects, with micromolar IC50 values for ACE and/or DPP-IV. In comparison to chemically synthesized ACE inhibitors like captopril, the most potent peptide, LRF, is five times more active on a molar basis (11.34μM vs 63.06μM). These findings demonstrate that WW is a promising source of multifunctional peptides and that integrating peptidomics with machine learning accelerates peptide discovery and validation.

Transitioning from traditional to organic production is gaining popularity worldwide with significant challenges including weed management. We evaluated how legumes sown as cover crops in a synchronous intercropping (SI) system with organic oat (Avena sativa) as the main crop impacted weed communities. A split-plot design was set up on a farm in Poularies (Quebec, Canada) to compare Melilotus officinalis, Trifolium incarnatum, Trifolium repens and a control without legumes for two years (2019–2020). We determined the botanical composition, calculated diversity indices, and measured plant functional traits. Species richness was similar (S = 5.5 ± 0.4) across treatments in 2019, but higher in the control (S = 12.2 ± 2.6) and lower (S = 6.0 ± 1.2) under T. incarnatum in 2020. Shannon diversity was lower in 2019 (H′ = 1.49 ± 0.07) than in 2020 (H′ = 1.99 ± 0.04), and higher under the control (H′ = 1.87 ± 0.05) than under T. incarnatum (H′ = 1.46 ± 0.04). Weeds under T. incarnatum had a high specific leaf area and a resource-acquisition strategy, while those in the control had a higher leaf dry matter content and a resource-conservation strategy. Our study brings novel results on the use of legumes in SI systems to control weeds. Using T. incarnatum in a SI system with oat had the greatest capacity to cover the ground, control weeds and reduce their diversity, but this species and the acquisitive weeds in this treatment could compete with the main crop. Future research should evaluate the quantity and quality of yields to complete this ecological study and give appropriate agronomic recommendations. Our results could provide agronomists and farmers with indications on the level of competition weeds exert on the cropping system depending on the SI treatment.

This perspective paper draws on insights from a 2024 symposium entitled ‘ Exploring methods for researching shifts in knowledge production for agroecology transition ’. The symposium critically examined emerging conceptual and methodological challenges arising from combining agroecology with living labs and research infrastructures as key instruments promoted within EU policy to strengthen Agricultural Knowledge and Innovation Systems (AKIS). Through presentations, group discussions, and iterative reflections, we identified four key tensions: structural constraints limiting farmers’ agency within living lab approaches, the problematic nature of AKIS as supposedly neutral frameworks, the oversimplification of transition frameworks as linear rather than overlapping categories, and risks of definitional dilution or cooptation. We then demonstrate that these tensions are not unique to agroecology, bridging the concepts and methods within agroecology research with those used in other fields of sustainable food system transition research, such as transdisciplinary research and sustainable transitions. This conceptual mapping of shared tensions reveals opportunities for mutual learning. Bridging these fields would help create clarity at the conceptual and methodological levels, ultimately strengthening the theoretical foundations and enabling more nuanced approaches to food system transition research.

Dietary trace mineral (TM) concentrations for lactating cows often exceed national recommendations under commercial feeding practices. Excess TM supplementation may exert selection pressure on the gut microbiota, promoting metal resistance and potentially co-selecting for important antimicrobial resistance genes (ARGs). This study used a cross-over design to investigate the impact of overfeeding a commericially representative TM premix on the gut microbiome and resistome of lactating dairy cattle. Cows were fed either recommended or surplus TM levels for 31 days followed by sample collection from rumen papillae, whole rumen content, and feces. Targeted amplicon, shotgun metagenomic sequencing, and droplet digital PCR (ddPCR) were used to assess microbial community compositions and the associated resistome. While a surplus TM did not significantly affect the overall microbial diversity, specific taxa differed between the matrices and to a lesser extent by diet. Spirochaetota were more abundant in papillae of cows fed the recommended TM diet, whereas Bacillota were more prevalent in the rumen and feces from cows fed the surplus TM. Phosphorus had the greatest impact on prokaryotic taxa in rumen content. Cows fed surplus levels of TM showed increased abundances of Ruminococcus in their rumen, but decreased Campylobacter, Desulfovibrio, and Treponema adhered to their rumen papillae, Methanosphaera in their rumen and feces, as well as Treponema in their feces. Despite these changes, no significant differences in the presence of key ARGs or metal resistance genes were detected by metagenomics, and ddPCR showed no significant impact of TM supplementation on blaCTX−M, pcoA and zntA gene levels. Overfeeding TM in a commercial premix resulted in modest matrix specific shifts I the microbial composition without detectable enrichment of selected ARGs or metal resistance genes. These findings suggest short-term resilience of the rumen ecosystem to surplus TM supplementation. Additionally this work provides foundational knowledge to further guide mechanistic and long-term investigations.

AAC Camrose, an awned hard red spring wheat (Triticum aestivum L.) cultivar, combines high grain yield and good agronomic characteristics with excellent resistance to leaf, stripe, and stem rust, Fusarium head blight (FHB) and common bunt. Based on 33 station-years of registration trial data from 2020 to 2022, the grain yield of AAC Camrose was 5% higher than AAC Foray and 11% over AAC Penhold. AAC Camrose was significantly shorter than AAC Foray, had straw strength similar to AAC Penhold and maturity was one day later than AAC Foray. AAC Camrose had similar test weight and protein concentration but lower thousand kernel weight as compared to AAC Foray. AAC Camrose had milling and baking quality suitable for grades of the Canada Prairie Spring Red wheat market class.

Human activities have increased atmospheric reactive nitrogen (N) deposition, with important consequences for ecosystem biogeochemical cycles. In forest ecosystems, tree canopies act as active filters that intercept, transform and redistribute atmospheric N before it reaches to the soil. These canopy-level processes determine the chemical forms of N that become available for biological uptake or are transferred to the soil. Despite their importance, the temporal variability of these processes remains poorly understood, particularly in Mediterranean ecosystems with pronounced seasonal contrasts.In this study, we investigated the seasonal dynamics of atmospheric N transformations within the canopy of a Mediterranean Holm oak forest (Quercus ilex / Q. rotundifolia) in Spain. We focused on canopy-scale nitrification processes and the abundance of N-fixing and nitrifying microorganisms associated with the phyllosphere and precipitation. Canopy N fluxes were quantified, nitrate sources were identified using Δ¹⁷O isotopic signatures, and microbial abundances were quantified by qPCR, to explore seasonal dynamics and their environmental drivers.Our results show that the canopy acted as a net sink for atmospheric N throughout the year, indicating that N inputs did not exceed ecosystem demand and suggesting potential N limitation. The nitrate measured in throughfall samples indicated a predominantly atmospheric origin during most of the year (76–92%). In contrast, during summer up to 76% of the nitrate was derived from in situ biological processes at canopy level. These enhanced biological transformations were correlated with weather conditions, particularly the higher temperatures and dry conditions typical of summer, which may favour nitrification and promote the accumulation of N compounds on leaf surfaces. Reduced plant activity and lower N uptake during summer further prolong N residence time within the canopy, increasing the likelihood of microbial transformations. Both archaeal and bacterial nitrifiers, as well as N-fixing microorganisms, were detected year-round in the phyllosphere and precipitation. Archaeal nitrifiers consistently outnumbered bacterial ones, and showed a marked increase during summer, driven by higher radiation, temperature and lower humidity. This pattern suggests that archaea may play a significant important role in nitrification, coinciding with the highest nitrification rates observed in summer. These findings highlight the crucial function of canopy processes in regulating N fluxes in Mediterranean forests, particularly during summer. The seasonal dynamics of biological transformations and microbial communities emphasise the influence of environmental conditions on N cycling.

Recently, many literature reviews have focused on soil inorganic carbon (SIC) and concluded that SIC should be studied as much as soil organic carbon (SOC) to complete the soil C balance at global scale. However, as SIC has been rarely studied lately, analytical methods for measuring its carbon content and 13C in calcareous soils have not been refined. Similarly, the quantification of different SIC pools remained poorly assessed. This study aimed to illustrate the diversity of SOC and SIC pools in calcareous soils. A soil collection of 160 soil samples were selected from mostly agricultural lands in Canada, Hungary, France, Germany, Italy, and Tunisia to cover a large range of SOC and SIC contents. The carbonate composition was mainly in the form of calcite and, to a lesser extent, dolomite. The natural abundance in 13C of SOC and SIC showed a small range of values for SOC (-35 to -20 ‰, median: -27‰) signalling a predominance of C3-plants, and a large range of values for the SIC (-31 to +3 ‰; median -5 ‰), indicating a possible mixture of inorganic carbon from different sources (Hazera et al. 2025). Standard procedures to quantify SOC and SIC involving pretreatments to remove one of the C forms and/or calculations could lead to both analytical errors and substantial measurement errors (Jakab et al. submitted). Thermal analysis (i.e. Rock-Eval®, RE) has been adapted to estimate SOC and SIC contents on a non-pretreated soil sample without needing statistical post-hoc corrections (Hazera et al., 2023, in press). This RE method was applied to characterize more than 400 particle-size fractions of 65 calcareous soils i.e., particulate organic matters (POM, > 50 µm) and mineral associated organic matters (MaOM, 20-50, 0-20 and 0-2 µm). The variability of C distribution in the different fractions was more pronounced for SIC than SOC: the SOC was mainly contained in the

Aim: Analysis of species distributions often rests on the assumption of environmental equilibrium. That is, the distribution of a species (as documented by observation records) captures the full range of environmental conditions under which that species can maintain viable populations. Despite the centrality of this assumption to a variety of biogeographic questions, it is rarely empirically tested. This is particularly critical for recently introduced invasive species that are characterized by rapid expansion in their introduced range, often coupled with a niche shift relative to their native distribution. Defining equilibrium under these dynamic conditions is difficult. We developed the concept of environmental stasis as a more tractable proxy for equilibrium. In the context of species invasions, we define stasis as a prolonged period without an increase in the environmental conditions occupied by a species. Location: North America Time Period: 1614 to 2020. Major Taxa Studied: Invasive plants Methods: We applied the metric of climatic stasis to a suite of 258 invasive plant species in North America. We categorized their invasion trajectories into three classes (linear, two- and three-phase) based on theoretical expectations and then assessed how many had demonstrated environmental (climatic) stasis over a period of at least thirty years. Results: More than 80% of the species were best fit by two- or three-phase models, indicating a declining rate of expansion. Climatic stasis was only documented for 44% of the species. In contrast, 85% of the species were in climatic stasis in their native ranges. The time to reach stasis ranged from 30 to 145 years (mean 90), and species at stasis in their invaded range occupied 97% of the climatic space they occupied in their native range. Main Conclusions: This assessment provides valuable insight into the unrealized threat posed by the majority of invasive plants that have not yet reached stasis, as well as identifying which species can be most appropriately evaluated by methods that depend on the equilibrium assumption. Our work also demonstrates the useful perspective provided by the environmental stasis concept, which enables empirical quantification of one of the key aspects of equilibrium.