Originals

Fertilization is a common and effective restoration practice for some ecosystems. However, there are still knowledge gaps about the long-term effectiveness and impact of phosphorus fertilization during the restoration of degraded boreal Sphagnum peatlands using the Moss Layer Transfer Technique. Data gathered from 114 peatland sectors restored 1 to 25 years ago, encompassing around 2900 surveyed plots in Eastern Canada, were analyzed to investigate the influence of fertilization on plant re-establishment (cover, height, and aboveground biomass accumulation) and community composition. Fertilization with a low phosphorus dosage (1.64 g P m−2) of granular phosphate rock (P2O5; NPK 0–13-0) proved to accelerate peatland vegetation recovery by favoring a shift in plant community composition towards a Sphagnum dominance. This shift was encouraged by the fast colonization of Polytrichum strictum after fertilization, a nurse plant that stabilizes the peat substrate and facilitates the subsequent establishment of Sphagnum. Phosphorus fertilization increased by 42 % Sphagnum cover 25-year post-restoration and increased approximately by 15 % aboveground biomass accumulation 20-year post-restoration. Conversely, without fertilization, the success of restoration and long-term vegetation trajectories were uncertain. Phosphorus fertilization led to an increase in plant richness in the first 5 to 10 years after restoration and enhanced spatial heterogeneity in species composition throughout the later stages of restoration (20–25 years), suggesting that fertilization may foster dynamic, diverse plant communities. This study emphasizes fertilization's key role in restoring boreal Sphagnum peatland plant communities, especially in areas prone to episodes of freeze-thaw cycles, strongly advocating for the mandatory inclusion of phosphorus fertilization in the restoration process.

Amaryllidaceae alkaloids are a diverse group of alkaloids exclusively reported from the Amaryllidaceae plant family. In planta, their biosynthesis is still not fully characterized; however, a labeling study established 4ˈ-O-methylnorbelladine as the key intermediate compound of the pathway. Previous reports have characterized O-methyltransferases from several Amaryllidaceae species. Nevertheless, the formation of the different O-methylnorbelladine derivatives (3ˈ-O-methylnorbelladine, 4ˈ-O-methylnorbelladine, and 3ˈ4ˈ-O-dimethylnorbelladine), the role, and the preferred substrates of O-methyltransferases are not clearly understood. In this study, we performed the biochemical characterization of an O-methyltransferase candidate from Narcissus papyraceus (NpOMT) in vitro and in vivo, following biotransformation of norbelladine in Nicotiana benthamiana having transient expression of NpOMT. Docking analysis was further used to investigate substrate preferences, as well as key interacting residues of NpOMT. Our study shows that NpOMT methylates norbelladine preferentially at the 4ˈ-OH position in vitro and in planta. Interestingly, NpOMT also catalyzed the synthesis of 3ˈ,4ˈ-O-dimethylnorbelladine from norbelladine and 4ˈ-O-methylnorbelladine during in vitro enzymatic assay. Furthermore, we show that NpOMT methylates 3,4-dihydroxybenzylaldehyde and caffeic acid in a nonregiospecific manner to produce meta/para monomethylated products. This study reveals a novel catalytic potential of an Amaryllidaceae O-methyltransferase and its ability to regioselectively methylate norbelladine in the heterologous host N. benthamiana.

Bacterial canker caused by Clavibacter michiganensis subsp. michiganensis (Cmm) is a worldwide bacterial disease affecting tomato plants. Very few control methods exist and their efficacy is limited. In recent years, plant extracts were studied for their potential as a safe and eco-friendly alternative to the use of chemical pesticides to control plant diseases. Recent work performed by our group revealed the antibacterial activity of an ethanolic sugar maple autumn-shed leaf (SMASL) extract against bacterial plant pathogens. To further investigate the antibacterial and prophylactic potential of SMASL against bacterial canker, assays were performed (a) to determine the polyphenol content and the in vitro antibacterial activity of sugar maple leaf extracts against Cmm, (b) to evaluate the potential of SMASL extracts as a seed treatment against Cmm and (c) as a foliar application to control bacterial canker development in greenhouse- and field-grown tomato plants. Variations in polyphenol content and antibacterial activity of sugar maple leaf extracts were studied monthly for a period of 2 years. Although polyphenol contents varied significantly, minimum inhibitory concentrations were constant between 1.56 and 3.13 mg/mL and minimum bactericidal concentrations between 12.5 and 25 mg/mL. SMASL extract at 25 mg/mL completely eliminated the pathogen from tomato seeds without negatively impacting on germination. SMASL extract foliar spray applications using concentrations of 6.25 and 12.5 mg/mL significantly repressed disease development under greenhouse and field conditions, showing better efficacy than copper octanoate. The antibacterial activity of SMASL extracts against Cmm shows great potential to control Cmm and bacterial canker in tomato.

After being harvested, strawberries experience a decline in nutrients and anthocyanins, which is further exacerbated by their vulnerability to plant pathogen-related decay. As postharvest losses encompass up to 50 % of total production, the development of a physical method complementary to refrigeration to reduce these losses is a goal pursued globally, given a global market of US$19 B per year. In this study, two non-thermal technologies, pulsed electric fields (PEF) and cold plasma (CP), were used to evaluate their effectiveness in maintaining phytochemical integrity in exposed strawberries. A PEF treatment of 1 pulse at 1 kV/cm field strength in 3 L of tap water could significantly alter the volatile and metabolomic composition of the fruit, while simultaneously reducing its firmness during cold storage. However, subjecting the fruit to a CP treatment at 15 % (210 watts) for 1 min did not impact the quality parameters. Furthermore, unlike the PEF treatment, the strawberries retained their firmness during storage and exhibited a consistent volatile and metabolomic profile. Based on these results, CP treatment enhances firmness and maintains the compounds found in strawberries, meanwhile, while PEF treatment might not be ideal for preserving the physicochemical parameters of fruit.

Cannabis sativa L., previously concealed by prohibition, is now a versatile and promising plant, thanks to recent legalization, opening doors for medical research and industry growth. However, years of prohibition have left the Cannabis research community lagging behind in understanding Cannabis genetics and trait inheritance compared to other major crops. To address this gap, we conducted a comprehensive genome-wide association study (GWAS) of nine key agronomic and morphological traits, using a panel of 176 drug-type Cannabis accessions from the Canadian legal market. Utilizing high-density genotyping-by-sequencing (HD-GBS), we successfully generated dense genotyping data in Cannabis, resulting in a catalog of 800 K genetic variants, of which 282 K common variants were retained for GWAS analysis. Through GWAS analysis, we identified 18 markers significantly associated with agronomic and morphological traits. Several identified markers exert a substantial phenotypic impact, guided us to putative candidate genes that reside in high linkage-disequilibrium (LD) with the markers. These findings lay a solid foundation for an innovative cannabis research, leveraging genetic markers to inform breeding programs aimed at meeting diverse needs in the industry.

Arctic ecosystems are undergoing rapid changes, including increasing disturbance by herbivore populations, which can affect plant species coexistence and community assemblages. Although the significance of mosses in Arctic wetlands is well recognized, the long-term influence of medium-sized herbivores on the composition of moss communities has received limited attention. We used data from a long-term (25 years) Greater Snow Goose (Anser caerulescens atlanticus) exclusion experiment in Arctic tundra wetlands to assess changes in the composition of moss communities at multiple spatial scales (cell, 4 cm2; quadrat, 100 cm2; exclosure, 16 m2). We investigated how snow goose grazing and grubbing can alter the composition of the moss community by measuring changes in alpha and beta diversity, as well as in the strength of plant interspecific interactions between moss species. Our results indicate that goose foraging significantly increased species diversity (richness, evenness, and inverse Simpson index) of moss communities at the cell and quadrat scales but not the exclosure scale. Goose foraging reduced the dissimilarity (beta diversity) of moss communities at all three scales, mainly due to decreased species turnover. Furthermore, goose foraging increased positive interaction between moss species pairs. These findings emphasize the critical role of geese in promoting moss species coexistence and increasing homogeneity in Arctic wetlands. This study illustrates how top-down regulation by herbivores can alter plant communities in Arctic wetlands and highlights the importance of considering herbivores when examining the response of Arctic plant biodiversity to future climate change.

Biosynthesis of Amaryllidaceae alkaloids (AA) starts with the condensation of tyramine with 3,4-dihydroxybenzaldehyde. The latter derives from the phenylpropanoid pathway that involves modifications of trans-cinnamic acid, p-coumaric acid, caffeic acid, and possibly 4-hydroxybenzaldehyde, all potentially catalyzed by hydroxylase enzymes. Leveraging bioinformatics, molecular biology techniques, and cell biology tools, this research identifies and characterizes key enzymes from the phenylpropanoid pathway in Leucojum aestivum. Notably, we focused our work on trans-cinnamate 4-hydroxylase (LaeC4H) and p-coumaroyl shikimate/quinate 3ʹ-hydroxylase (LaeC3′H), two key cytochrome P450 enzymes, and on the ascorbate peroxidase/4-coumarate 3-hydroxylase (LaeAPX/C3H). Although LaeAPX/C3H consumed p-coumaric acid, it did not result in the production of caffeic acid. Yeasts expressing LaeC4H converted trans-cinnamate to p-coumaric acid, whereas LaeC3′H catalyzed specifically the 3-hydroxylation of p-coumaroyl shikimate, rather than of free p-coumaric acid or 4-hydroxybenzaldehyde. In vivo assays conducted in planta in this study provided further evidence for the contribution of these enzymes to the phenylpropanoid pathway. Both enzymes demonstrated typical endoplasmic reticulum membrane localization in Nicotiana benthamiana adding spatial context to their functions. Tissue-specific gene expression analysis revealed roots as hotspots for phenylpropanoid-related transcripts and bulbs as hubs for AA biosynthetic genes, aligning with the highest AAs concentration. This investigation adds valuable insights into the phenylpropanoid pathway within Amaryllidaceae, laying the foundation for the development of sustainable production platforms for AAs and other bioactive compounds with diverse applications.

Climate change is reshaping agriculture and insect biodiversity worldwide. With rising temperatures, many insect species are expected to be pushed beyond their current thermal limits, and losses related to herbivory and diseases transmitted by them will be experienced in new regions. Here, we propose that climate change’s impact on agriculture can be forecast by studying migratory leafhoppers. From 2021 to 2022, we measured leafhopper numbers in eastern Canada's strawberry fields to test our hypothesis, observing that leafhopper species and phytoplasma disease-affected strawberry plants both doubled, trends influenced by temperature changes. A further post-insecticide application study reveals that insecticides used by strawberry growers could be ineffective in controlling leafhopper populations, possibly due to changes observed in their microbiome. Our research provides evidence that leafhoppers are sensitive to the effects of climate change, making them ideal markers to research the effect of climate change on agriculture.

The poplar-rust fungus Melampsora larici-populina is part of one of the most devastating group of fungi (Pucciniales) and causes important economic losses to the poplar industry. As an heteroecious obligate biotroph, M. larici-populina spread depends on its ability to carry out its reproductive cycle through larch and then poplar parasitism. Genomic approaches have identified over a thousand candidate secreted effector proteins (CSEPs) from the predicted secretome of M. laricipopulina which are potentially implicated in the infection process. In this study, we selected CSEP pairs (and one triplet) among CSEP gene families, which share high sequence homology but display specific gene expression profiles among the two distinct hosts. We determined their subcellular localization by confocal microscopy through expression in the heterologous plant system Nicotiana benthamiana. Five out of nine showed partial or complete chloroplastic localization. We also screened for potential protein interactors from larch and poplar by yeast two-hybrid. One pair of CSEPs and the triplet shared common interactors whereas the members of the two other pairs did not have common targets from either host. Finally, stromule induction quantification revealed that two pairs and the triplet of CSEPs induced stromules when transiently expressed in N. benthamiana. The use of N. benthamiana eds1 and nrg1 knock-out lines showed that CSEPs can induce stromules by an eds1-independent mechanism. However, CSEP homologs share the same impact on stromule induction and contributed to discovering a new stromule induction cascade that can be partially and/or fully independent of eds1.

The unfolded protein response (UPR) allows cells to cope with endoplasmic reticulum (ER) stress induced by accumulation of misfolded proteins in the ER. Due to its sensitivity to Agrobacterium tumefaciens, the model plant Nicotiana benthamiana is widely employed for transient expression of recombinant proteins of biopharmaceutical interest, including antibodies and virus surface proteins used for vaccine production. As such, study of the plant UPR is of practical significance, since enforced expression of complex secreted proteins often results in ER stress. After 6 days of expression, we recently reported that influenza haemagglutinin H5 induces accumulation of UPR proteins. Since up-regulation of corresponding UPR genes was not detected at this time, accumulation of UPR proteins was hypothesized to be independent of transcriptional induction, or associated with early but transient UPR gene up-regulation. Using time course sampling, we here show that H5 expression does result in early and transient activation of the UPR, as inferred from unconventional splicing of NbbZIP60 transcripts and induction of UPR genes with varied functions. Transient nature of H5-induced UPR suggests that this response was sufficient to cope with ER stress provoked by expression of the secreted protein, as opposed to an antibody that triggered stronger and more sustained UPR activation. As up-regulation of defence genes responding to H5 expression was detected after the peak of UPR activation and correlated with high increase in H5 protein accumulation, we hypothesize that these immune responses, rather than the UPR, were responsible for onset of the necrotic symptoms on H5-expressing leaves.

Background

Cannabis is historically, culturally, and economically significant crop in human societies, owing to its versatile applications in both industry and medicine. Over many years, native cannabis populations have acclimated to the various environments found throughout Iran, resulting in rich genetic and phenotypic diversity. Examining phenotypic diversity within and between indigenous populations is crucial for effective plant breeding programs. This study aimed to classify indigenous cannabis populations in Iran to meet the needs of breeders and breeding programs in developing new cultivars.

Results

Here, we assessed phenotypic diversity in 25 indigenous populations based on 12 phenological and 14 morphological traits in male and female plants. The extent of heritability for each parameter was estimated in both genders, and relationships between quantitative and time-based traits were explored. Principal component analysis (PCA) identified traits influencing population distinctions. Overall, populations were broadly classified into early, medium, and late flowering groups. The highest extent of heritability of phenological traits were found in Start Flower Formation Time in Individuals (SFFI) for females (0.91) Flowering Time 50% in Individuals (50% of bracts formed) (FT50I) for males (0.98). Populations IR7385 and IR2845 exhibited the highest commercial index (60%). Among male plants, the highest extent of Relative Growth Rate (RGR) was observed in the IR2845 population (122 mg.g-1.day-1 ). Finally, populations were clustered into seven groups according to the morphological traits in female and male plants.

Conclusions

Overall, significant phenotypic diversity was observed among indigenous populations, emphasizing the potential for various applications. Early-flowering populations, with their high RGR and Harvest Index (HI), were found as promising options for inclusion in breeding programs. The findings provide valuable insights into harnessing the genetic diversity of indigenous cannabis for diverse purposes.

Effectors encoded by avirulence genes (Avr) interact with the Phytophthora sojae resistance gene (Rps) products to generate incompatible interactions. The virulence profile of P. sojae is rapidly evolving as a result of the large-scale deployment of Rps genes in soybean. For a successful exploitation of Rps genes, it is recommended that soybean growers use cultivars containing the Rps genes corresponding to Avr genes present in P. sojae populations present in their fields. Determination of the virulence profile of P. sojae isolates is critical for the selection of soybean cultivars. High-resolution melting curve (HRM) analysis is a powerful tool, first applied in medicine, for detecting mutations with potential applications in different biological fields. Here, we report the development of an HRM protocol, as an original approach to discriminate effectors, to differentiate P. sojae haplotypes for six Avr genes. An HRM assay was performed on 24 P. sojae isolates with different haplotypes collected from soybean fields across Canada. The results clearly confirmed that the HRM assay discriminated different virulence genotypes. Moreover, the HRM assay was able to differentiate multiple haplotypes representing small allelic variations. HRM-based prediction was validated by phenotyping assays. This HRM assay provides a unique, cost-effective and efficient tool to predict virulence pathotypes associated with six different Avr (1b, 1c, 1d, 1k, 3a and 6) genes from P. sojae, which can be applied in the deployment of appropriate Rps genes in soybean fields.

The moss layer transfer technique has been developed to restore the carbon sequestration function and typical vegetation of Sphagnum-dominated peatlands after peat extraction in North America. However, the technique does not lead to successful bryophyte establishment when applied to peatlands with a richer residual fen peat. Therefore, we evaluated an alternative method of active rewetting and passive vegetation establishment using vegetation surveys and carbon dioxide and methane (CH4) flux measurements at a post-extracted fen in southern Manitoba, Canada. After one growing season post-rewetting, wetland vegetation established and the site was a net carbon sink over the growing season. However, high abundance of Carex lasiocarpa 10 years post-treatment led to higher CH4 emissions than the reference ecosystem. Successful establishment of wetland vegetation is attributed to the area being surrounded by undisturbed fens that can provide a local source of plant propagules. Bryophyte expansion was less successful than vascular plants, likely due to episodic flooding and shading from the sedge communities. Therefore, careful management of water levels to just below the peat surface is needed if reference vegetation community recovery is the goal of restoration. Water level management will also play a key role in controlling CH4 emissions to maximize carbon sequestration potential.

Plant molecular farming is currently operating a transition from soil-based cultures toward hydroponic systems. In this study, we designed a whole-plant NFT (nutrient film technique) platform for the transient expression of influenza virus-like particles harboring hemagglutinin H1 proteins in Nicotiana benthamiana. In particular, we examined the effects of plant density during the post-infiltration expression phase on plant growth and H1 yield in relation to the daily light integral (DLI) received by the crop and the exogenous application of 6-BAP cytokinin (CK). We expected from previous work that high DLI and CK treatments would stimulate the development of highly productive leaves on axillary (secondary) stems and thereby improve the H1 yield at the whole-plant scale. Increasing plant density from 35.7 to 61 plants m–2 during the post-infiltration phase significantly decreased the proportion of axillary leaf biomass by 30% and H1 yield per plant by 39%, resulting in no additional yield gain on a whole-crop area basis. Adding CK to the recirculated nutrient solution decreased the harvested leaf biomass by 31% and did not enhance the relative proportion of S leaves of the plants as previously reported with foliar CK application. There was a 36% increase in H1 yield when doubling the DLI from 14 to 28 mol m–2 s–1, and up to 71% yield gain when combining such an increase in DLI with the hydroponic CK treatment. Contrary to our expectations, leaves located on the main stem, particularly those from the upper half of the plant (i.e., eighth leaf and above), contributed about 80% of total H1 yield. Our study highlights the significantly different phenotype (~30% less secondary leaf biomass) and divergent responses to light and CK treatments of NFT-grown N. benthamiana plants compared to previous studies conducted on potted plants.

Plasmodiophora brassicae (Woronin, 1877), a biotrophic, obligate parasite, is the causal agent of clubroot disease in brassicas. The clubroot pathogen has been reported in more than 80 countries worldwide, causing economic losses of hundreds of millions every year. Despite its widespread impact, very little is known about the molecular strategies it employs to induce the characteristic clubs in the roots of susceptible hosts during infection, nor about the mechanisms it uses to overcome genetic resistance. Here, we provide the first telomere-to-telomere complete genome of P. brassicae. We generated ∼27 Gb of Illumina, Oxford Nanopore, and PacBio HiFi data from resting spores of strain Pb3A and produced a 25.3 Mb assembly comprising 20 chromosomes, with an N50 of 1.37 Mb. The BUSCO score, the highest reported for any member of the group Rhizaria (Eukaryota: 88.2%), highlights the limitations within the Eukaryota database for members of this lineage. Using available transcriptomic data and protein evidence, we annotated the Pb3A genome, identifying 10,521 protein-coding gene models. This high-quality, complete genome of P. brassicae will serve as a crucial resource for the plant pathology community to advance the much-needed understanding of the evolution of the clubroot pathogen.

The use of fungicides, many of which are of chemical origin and are governed by stringent laws, such as maximum residual limits (MRLs), has proven to be the most successful method to date, especially when used prior to harvest. In light of regulatory compliance and public health considerations, there is interest in exploring fungicides of natural origin as alternatives to chemical fungicides. The objective of this study is to validate the antifungal potential of reuterin at the postharvest stage and to compare it over a commercial fungicide, fludioxonil, by in vivo testing on common strawberry pathogens, including Botrytis cinerea, Colletotrichum acutatum, Rhizopus stolonifer, and Penicillium expansum. Analysis of strawberries stored at 4 °C/95 % RH for 12 d revealed that 2000 mM squalene and 100 mM reuterin did not adversely affect fruit quality parameters such as color, total soluble solids, titratable acidity, weight loss, and visual quality. Reuterin at 50 mM resulted in a sizable decrease in spore count of 3 log CFU mL−1 (p = 0.003). These results suggest that reuterin may be promising as a potential new biofungicide suitable for pre- and post-harvest application.

Clubroot caused by the obligate parasite Plasmodiophora brassicae is a devastating disease affecting the canola industry worldwide. The socio-economic impact of clubroot can be significant, particularly in regions where Brassica crops are a major agricultural commodity. The disease can cause significant crop losses, leading to reduced yield and income for farmers. Extensive studies have been conducted to understand the biology and genetics of the pathogens and develop more effective management strategies. However, the basic procedures used for pathogen storage and virulence analysis have not been assembled or discussed in detail. As a result, there are discrepancies among the different protocols used today. The aim of this article is to provide a comprehensive and easily accessible resource for researchers who are interested in replicating or building upon the methods used in the study of the clubroot pathogen. Here, we discuss in detail the methods used for P. brassicae spore isolation, inoculation, quantification, propagation, and molecular techniques such as DNA extraction and PCR. © 2024 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Extraction of Plasmodiophora brassicae resting spores and propagation Support Protocol 1: Evans blue staining to identify resting spore viability Support Protocol 2: Storage of Plasmodiophora brassicae Basic Protocol 2: Generation of single spore isolates from P. brassicae field isolates Basic Protocol 3: Phenotyping of Plasmodiophora brassicae isolates Basic Protocol 4: Genomic DNA extraction from Plasmodiophora brassicae resting spores Basic Protocol 5: Molecular detection of Plasmodiophora brassicae.

Fusarium spp. are commonly associated with the root rot complex of soybean (Glycine max). Previous surveys identified six common Fusarium species from Manitoba, including F. oxysporum, F. redolens, F. graminearum, F. solani, F. avenaceum, and F. acuminatum. This study aimed to determine their pathogenicity, assess host resistance, and evaluate the genetic diversity of Fusarium spp. isolated from Canada. The pathogenicity of these species was tested on two soybean cultivars, ‘Akras’ (moderately resistant) and ‘B150Y1′ (susceptible), under greenhouse conditions. The aggressiveness of the fungal isolates varied, with root rot severities ranging from 1.5 to 3.3 on a 0–4 scale. Subsequently, the six species were used to screen a panel of 20 Canadian soybean cultivars for resistance in a greenhouse. Cluster and principal component analyses were conducted based on the same traits used in the pathogenicity study. Two cultivars, ‘P15T46R2′ and ‘B150Y1′, were consistently found to be tolerant to F. oxysporum, F. redolens, F. graminearum, and F. solani. To investigate the incidence and prevalence of Fusarium spp. in Canada, fungi were isolated from 106 soybean fields surveyed across Manitoba, Saskatchewan, Ontario, and Quebec. Eighty-three Fusarium isolates were evaluated based on morphology and with multiple PCR primers, and phylogenetic analyses indicated their diversity across the major soybean production regions of Canada. Overall, this study contributes valuable insights into host resistance and the pathogenicity and genetic diversity of Fusarium spp. in Canadian soybean fields.

Urbanization coupled with climate change results in significant stormwater management challenges. In this context, the use of green infrastructures such as bioswales and bioretention systems to intercept, slow down and filter runoff has been increasing in North America in recent years. However, little data is available on the selection of optimal plant species adapted to cold climates, their optimal positioning in the swale and intra and inter-seasonal variation in plant growth. A field experiment was conducted during three growing seasons from July 2020 to August 2022 in a proximal suburb of Qu´ebec City, Canada, to monitor the survival rate. Growth (height and plant area), and floridity (number of flower buds and flower stems) of 22 plant species in 48 cold climate bioretention cells located along streets. The study aimed to understand the influence of planting position (margin: upper position, usually dryer; slope; middle position, fluctuating water conditions; bottom: lower position, usually moister) on species development, in order to identify the species most and least adapted to the different moisture conditions. Results showed that survival was generally high (> 86%) and was not affected by position within the bioretention cells. However, for most species, plant area increased, and height decreased at the margin compared to the slope position, while floridity only increased at the margin for four species (Heliopsis helianthoides (L.) Sweet, Coreopsis verticillata L., Hemerocallis ‘Stella Supreme” L., Verbena hastata L.). Seven species (Campanula carpatica Jacq “Alba”, Hesperis matronalis L., Osmundastrum cinnamomeum (L.) C. Presl, Rudbeckia hirta L., Verbena hastata L., Cerastium tomentosum L., Athyrium filix-femina (L.) Roth ex Mertens) exhibited lower survival and growth rates over time than the others. Overall, 15 out of 22 species performed well in the bioretention cells with minimum maintenance over the course of the experiment. Results also showed that plant area at the end of the growing season was much more influenced by position in the bioretention cells than were height or floridity, while survival was not influenced by this factor. A better knowledge of plant interactions in varying spatial distribution over time can contribute to improving and potentially maximizing bioretention performance.

Over the last few years, phytocannabinoids have been studied for their bioactive properties as potential drug candidates to treat or alleviate symptoms of several diseases. The isolation of single and pure cannabinoid (CB) from their natural source, i.e., Cannabis plants results in a low yield, diluted among hundreds of other plant metabolites. The use of biotechnological platforms to produce single CBs is appealing to the pharmaceutical industry. Therefore, our aim was to develop a sustainable system using the model diatom Phaeodactylum tricornutum to produce cannabigerolic acid (CBGA), the precursor to several CBs such as well-known cannabidiol (CBD) and delta-9-tetrahydrocannabinol (THC). We engineered P. tricornutum to express a mutant version of the Streptomyces sp. strain CL190’s naptherpin biosynthetic cluster gene B NphB (Y288A/G286S, nphB), a nonCannabis aromatic prenyltransferase enzyme, either by random integrated chromosomal expression (RICE) or extrachromosomal expression (EE), to maximize the success of protein production. The gene of nphB was linked to the reporter cyan fluorescent protein (CFP) and introduced in P. tricornutum. Clones were characterized by CFP fluorescence intensity, protein synthesis, enzymatic activity, and production of CBGA. We present, for the first time in diatoms, the successful production of a CB, CBGA up to 4.1 (± 0.2) mg/kg of microalgal fresh biomass weight. This work shows the potential of P. tricornutum as a sustainable controlled heterologous platform for CBs production, plant bioactive compounds, and relevant pharmaceuticals.

The production of influenza vaccines in plants is achieved through transient expression of viral hemagglutinins (HAs), a process mediated by the bacterial vector Agrobacterium tumefaciens. HA proteins are then produced and matured through the secretory pathway of plant cells, before being trafficked to the plasma membrane where they induce formation of virus-like particles (VLPs). Production of VLPs unavoidably impacts plant cells, as do viral suppressors of RNA silencing (VSRs) that are co-expressed to increase recombinant protein yields. However, little information is available on host molecular responses to foreign protein expression. This work provides a comprehensive overview of molecular changes occurring in Nicotiana benthamiana leaf cells transiently expressing the VSR P19, or co-expressing P19 and an influenza HA. Our data identifies general responses to Agrobacterium-mediated expression of foreign proteins, including shutdown of chloroplast gene expression, activation of oxidative stress responses and reinforcement of the plant cell wall through lignification. Our results also indicate that P19 expression promotes salicylic acid (SA) signalling, a process dampened by co-expression of the HA protein. While reducing P19 level, HA expression also induces specific signatures, with effects on lipid metabolism, lipid distribution within membranes and oxylipin-related signalling. When producing VLPs, dampening of P19 responses thus likely results from lower expression of the VSR, crosstalk between SA and oxylipin pathways, or a combination of both outcomes. Consistent with the upregulation of oxidative stress responses, we finally show that reduction of oxidative stress damage through exogenous application of ascorbic acid improves plant biomass quality during production of VLPs.

Nucleopore Complexes are intricate protein assemblies composed of diverse nucleoporins, which serve as crucial mediators for the bidirectional movement of molecules between the nucleus and cytosol. These nucleoporins share both structural and functional characteristics across yeast, mammals, and plants. This review highlights these shared architectural elements and further examines specific nucleoporins. A particular emphasis is placed on the putative homologs yeast NUP1, human NUP153, and plant NUP136, and their shared involvement in critical processes such as developmental coordination, gene regulation, and immune responses. Despite variations in their amino acid sequences, these proteins exhibit a notable degree of structural conservation, supporting a convergent evolution that would underlie their similar functionalities.

Despite bryophytes being well adapted to various ecological settings, they are rarely considered in reclamation projects. In this study, propagation regenerative capabilities of bryophytes on different substrates (sand, amphibolite, and pegmatite) and conditions (with or without peat amendment, shade and shredding) were tested in greenhouse and field experiments. In the greenhouse trial, after 6 months of reintroduction, Racomitrium species (Racomitrium canescens (Hedw.) Brid. and Racomitrium elongatum Frisvoll.) had higher regeneration compared to Polytrichum species (Polytrichum juniperinum Hedw. mixed with Polytrichum piliferum Hedw.; a combination of shade (65% shading) and peat amendment (0.5 cm depth) was found to be particularly effective, resulting in up to 100% of Racomitrium species regeneration; shredding the stems of Polytrichum species into small pieces of 0.5–1.0 cm inhibited its regeneration. In the field trial, peat amendment had no effect on moss regeneration. The addition of fluvioglacial sand or till on waste rocks promoted bryophytes regeneration in both the greenhouse and field. These results provide science-based practical knowledge to support the inclusion of native bryophytes in waste rock restoration plans for mines located in northern boreal forests.

Fusarium spp. are commonly associated with the root rot complex of soybean (Glycine max). Previous surveys identified six common Fusarium species from Manitoba, including F. oxysporum, F. redolens, F. graminearum, F. solani, F. avenaceum and F. acuminatum. This study aimed to determine their pathogenicity, assess host resistance and evaluate the genetic diversity of Fusarium spp. isolated from Canada. Pathogenicity was tested on two cultivars, ‘Akras’ (moderate resistance) and ‘B150Y1’ (susceptible), under greenhouse conditions. The virulence of the fungal isolates varied, with root rot severities ranging from 1.5 to 3.3 on a 0-4 scale. The six species were used to screen a panel of 20 Canadian soybean cultivars for resistance in a greenhouse. Cluster and principal component analyses were conducted based on the same traits as for the pathogenicity study. Two of the cultivars, ‘P15T46R2’ and ‘B150Y1’, were consistently found to be tolerant to F. oxysporum, F. redolens, F. graminearum and F. solani. To investigate the incidence and prevalence of Fusarium spp. in Canada, fungi were isolated from 106 soybean fields surveyed across Manitoba, Saskatchewan, Ontario and Quebec. Two-hundred twenty-one Fusarium isolates were identified, with phylogenetic analyses indicating diversity of the isolates in the major soybean production regions of Canada.