Canola Roots Research Articles

Quantitative Proteomic Analysis of Brassica Napus Reveals Intersections Between Nutrient Deficiency Responses.

Macronutrients such as nitrogen (N), phosphorus (P), potassium (K) and sulphur (S) are critical for plant growth and development. Field-grown canola (Brassica napus L.) is supplemented with fertilizers to maximize plant productivity, while deficiency in these nutrients can cause significant yield loss. A holistic understanding of the interplay between these nutrient deficiency responses in a single study and canola cultivar is thus far lacking, hindering efforts to increase the nutrient use efficiency of this important oil seed crop. To address this, we performed a comparative quantitative proteomic analysis of both shoot and root tissue harvested from soil-grown canola plants experiencing either nitrogen, phosphorus, potassium or sulphur deficiency. Our data provide critically needed insights into the shared and distinct molecular responses to macronutrient deficiencies in canola. Importantly, we find more conserved responses to the four different nutrient deficiencies in canola roots, with more distinct proteome changes in aboveground tissue. Our results establish a foundation for a more comprehensive understanding of the shared and distinct nutrient deficiency response mechanisms of canola plants and pave the way for future breeding efforts.

Diversification of crops and intensification of canola impact the diversity, community structure, and productivity in successive crop systems: A study on arbuscular mycorrhizal fungal communities in roots and rhizosphere

The widespread cultivation of canola, conventionally still considered a non-host plant for AM fungi, coupled with its increasing frequency in crop rotations, raises concerns about its impacts on soil microbial diversity and overall crop productivity. The main objective of this study is to assess the influence of different crop succession systems, incorporating canola, on AM fungal diversity and community structure in both the roots and in the rhizosphere, as well as on productivity of each crop present within the succession. Doubling the frequency of canola occurrence in a 4-year crop succession did not reduce the productivity of the other crops in the succession, nor did it result in a decrease in AM fungal biodiversity in the roots or rhizosphere of these crops. Interestingly, the diversity of AM fungi was higher in canola roots compared to wheat roots, indicating that canola might serve as a rudimentary host of AM fungi. The succession systems did, however, alter the AM fungal community structure in both roots and rhizosphere environments, exhibiting positive or negative correlations with crop productivity. This suggests that a simple modification of the cropping system could potentially be employed to manipulate root or rhizosphere microbiomes. Results of this study add to the growing body of evidences that plants that were thought to be non-AM fungi host, such as plants from the Brassicaceae family, could in fact interact with AM fungi.

Diversity and Pathogenicity of Fusarium Root Rot Fungi from Canola (Brassica napus) in Alberta, Canada.

Root rot disease poses a significant threat to canola (Brassica napus), underscoring the need for a comprehensive understanding of its causal agents for more effective disease mitigation. The composition and diversity of fungal pathogens associated with root rot of canola in Alberta, Canada, were evaluated from plant tissue samples collected in 2021 and 2022. The study revealed Fusarium spp. as the predominant pathogens found in almost all surveyed fields. Fusarium avenaceum, F. redolens, and F. solani were among the most frequently recovered species. Greenhouse trials confirmed their pathogenicity, with F. avenaceum and F. sporotrichioides found to be particularly aggressive. Additionally, F. sporotrichioides and F. commune were identified for the first time as canola root rot pathogens. Inoculation with isolates of most species resulted in significant reductions in seedling emergence, plant height, and shoot and root dry weights. Analysis of translation elongation factor 1-α (TEF-1α) and internal transcribed spacer (ITS) sequences confirmed the identity of the Fusarium spp., while concatenating the ITS and TEF-1α sequences enabled improved species differentiation. Geographic and year effects did not influence fungal diversity or aggressiveness, as determined by principal component analysis. This study emphasized the high diversity and impact of Fusarium spp. in causing canola root rot.

Optimizing the evaluation of root system architectural traits in Brassica napus

A semi-hydroponic system was developed to assess canola ( Brassica napus L.) root architectural traits. Four cultivars were grown under controlled conditions in germination paper rolls immersed in half-strength Hoagland’s solution. Eight parameters, including total root length, total root surface area, average root diameter, tip number, total primary root length, total lateral root length, total tertiary root length, and basal link length, were analyzed using the WinRHIZO software after 7, 14, and 21 days. The results suggested that 14 days in the semi-hydroponic system were optimal for accurate root trait assessment, as clear differences were observed while maintaining ease of handling and scanning.

Canola seeds coating with formulations based on sodium alginate, chitosan and Thichoderma harzianum

Seed coating technology combined with biopolymers offers an alternative method to reduce environmental contamination. However, when biological agents are incorporated, biopolymers would have diverse properties and effects. This underscores the necessity of exploring the optimal dosages and formulations of biopolymers to ensure the survival of beneficial microorganisms, seed quality, and proper storage. This study aimed to explore the effects of different sodium alginate and chitosan coating formulations on Trichoderma harzianum viability and canola seeds quality. The coating process involved mixing T. harzianum powder with sodium alginate, talc and chitosan in different doses, sequences and formulations. Trichoderma harzianum viability was assessed through colony-forming units per ml over time. Canola seed quality was evaluated by measuring radicle emergence, germination percentage, seedling growth, and field emergence. Sodium alginate, both alone and in combination with talc, improved T. harzianum viability immediately after treatment and during storage. These coatings did not impair seed germination and improved canola root growth. Among the different chitosan formulations, a 1 : 100 ratio in talc improved strain survival and root growth without affecting germination, radicle, and field emergence. Coating canola seeds is a practical alternative to the application of T. harzianum, sodium alginate and talc, as it preserves their viability over time and improves seedling performance. Chitosan formulations in acetic acid should be carefully developed to prevent negative effects on seeds or biological agents.

Potential allelopathic interactions from canola and pennycress postharvest roots and stubble

AbstractWinter oilseed Brassica plants have several documented allelochemicals; however, most literature revolves around the application of seed meal to fields, or the use of aerial parts of the plant. It is not clear if these chemicals interact with the surrounding environment to the same extent if the winter oilseeds are harvested as a cash crop in the spring. To determine this, we conducted a preliminary study bioassay using water extractable compounds from canola (Brassica napus L.) and pennycress (Thlaspi arvense L.) roots diluted to 25 and 50% (v/v). These four extracts, as well as deionized water for control, were used to irrigate plates with the seeds of soybean (Glycine max L.), Palmer amaranth [Amaranthus palmeri (S.) Watson], and mare's tail (Erigeron canadensis). We measured germination percent per plate and seedling radicle and hypocotyl lengths after 8 days of treatment. Mare's tail germination was lowered by 40% on day 4 by 50% pennycress extracts, and root length was stunted by both canola and pennycress extracts by 3–5 mm. Palmer amaranth root length was stunted by 10–15 mm by both species’ extracts, as well as shoots lengthened by 5–10 mm. Extract treatments did not affect soybean germination or growth. These interactions indicate potential for allelopathic interactions in the field following harvest of dual cropped winter oilseed and herbicide‐resistant weeds and warrant further study into the topic.

Canola inoculation with Pseudomonas baetica R27N3 under salt stress condition improved antioxidant defense and increased expression of salt resistance elements

Inoculation with growth promoting rhizobacteria (PGPR) can lessen salt salinity injury in plants by improving some physiological, biochemical, and molecular aspects. The current study aims to investigate Pseudomonas baetica R27N3 on photosynthetic capacity, and the antioxidant defense system of salt-affected canola plants (0, 100, 200,300 mM NaCl) under greenhouse conditions. Sodium concentration in inoculated canola plants was significantly decreased, whilst potassium increased through improved root architecture and relative expression of ion pump genes, such as SOS1 and KAT1. Moreover, inoculated canola plants showed higher antioxidant capacity which was evident in their higher antioxidant enzyme activity and those enzymes' higher relative gene expression. The study investigated additional physiological parameters related to enhanced antioxidant defense, including the electrolyte leakage index and malondialdehyde concentration as indicators of the stability of the plant cell plasma membrane. The plasma membrane of canola plants treated with PGPR was significantly more stable than those without the PGPR treatment. Furthermore, carotenoids and proline accumulation as non-enzymatic antioxidant solutes and total protein were increased in canola plants treated with R27N3. On the whole, these improvements coincided with increased antioxidant capacity, but all these positive effects of R27N3 were notable under 100 mM of NaCl concentration, whereas under 0 and 300 mM of NaCl concentration physiological and molecular changes between inoculated and non-inoculated canola plants were not statistically notable. Consequently, positive molecular and biochemical changes could be mediated by P.baetica R27N3 ability to clone on canola root and provide it with a decent level of macro-nutrients.

Flavonoids and Devosia sp SL43 cell-free supernatant increase early plant growth under salt stress and optimal growth conditions.

Salt stress is a major threat to modern agriculture, significantly affecting plant growth and yield, and causing substantial economic losses. At this crucial time of increasing climate change conditions, soil salinity will continue to develop and become an even more serious challenge to crop agriculture. Hence, there is a pressing need for sustainable techniques in agricultural production that could meet the dual challenges of crop productivity and environmental instability. The use of biostimulants in agricultural production has greatly influenced plant health and global food production. In particular, the application of bioactive materials produced by beneficial microbes is becoming a common practice in agriculture and provides numerous benefits to plant growth and resistance to stressful conditions. In this research two biostimulants; a type of plant secondary metabolite (flavonoids) and a microbe-based material (CFS: Cell-Free Supernatant) containing active compounds secreted by a novel bacterial strain isolated from Amphecarpaea bracteata root nodules (Devosia sp - SL43), have been utilized to improve the growth and stress resistance of two major oil seed crops; canola and soybean, under optimal and salt stress conditions. Our findings suggested significant improvements in crop growth of canola and soybean following the application of both biostimulants. Under optimal growth conditions, soybean growth was significantly affected by foliar spray of flavonoids with increases in shoot fresh and dry weight, and leaf area, by 91, 99.5, and 73%, respectively. However, soybean growth was unaffected by flavonoids under salt stress. In contrast, CFS with a meaningful capacity to mitigate the negative effects of salinity stress improved soybean shoot fresh biomass, dry biomass, and leaf area by 128, 163 and 194%, respectively, under salt stress conditions. Canola was less responsive to both biostimulants, except for canola root variables which were substantially improved by flavonoid spray. Since this was the first assessment of these materials as foliar sprays, we strongly encourage further experimentation to confirm the findings reported here and to determine the full range of applicability of each of these potential technologies.

Plant growth promoting rhizobacteria increased canola yield and root system

Decreasing the use of synthetic chemicals including nitrogen fertilizers is a top priority worldwide for the establishment of sustainable agriculture and high productivity. Using plant growth promoting rhizobacteria (PGPR) can help in this regard. Identification of PGPRs associate with canola can be of great importance to produce sustainable and low-cost biodiesel also in less favored areas. The objective of this study was to evaluate the growth, and grain yield of canola grown with five different PGPRs. The treatments Azospirillum brasiliense, Methylobacterium komagatae, Rhizobium sp., Azomonas sp., mixture of microorganisms from 1 to 4, and control (no inoculation), in the canola (Brassica napus L) were evaluated. The experiment was performed in a clay soil with six replicates. Plants height and diameter were evaluated at 15, 50, 80, and 110 days after the sowing. At the end of the cycle, root area and grain yield were also calculated. The PGPRs significantly affect root development, shoot dry weight, and grain yield of canola. M. komagacae increased rooting area in 44%. M. komagacae and A. brasiliense resulted in 56 e 53% more grain yield compared to un-inoculated canola, respectively, indicating that PGPRs holds high potential to promote canola productivity.

In-Depth Characterization of Plant Growth Promotion Potentials of Selected Alkanes-Degrading Plant Growth-Promoting Bacterial Isolates.

The use of plant growth-promoting rhizobacteria (PGPR) as a bioremediation enhancer in plant-assisted phytoremediation requires several steps, consisting of the screening, selection, and characterization of isolates. A subset of 50 bacterial isolates representing a wide phylogenetic range were selected from 438 morphologically different bacteria that were originally isolated from a petroleum hydrocarbon (PHC)-polluted site of a former petrochemical plant. Selected candidate bacteria were screened using six conventional plant growth-promoting (PGP) traits, complemented with the genetic characterization of genes involved in alkane degradation, as well as other pertinent functions. Finally, the bacterial isolates were subjected to plant growth promotion tests using a gnotobiotic approach under normal and stressed conditions. Our results indicated that 35 bacterial isolates (70%) possessed at least four PGP traits. Twenty-nine isolates (58%) were able to utilize n-hexadecane as a sole carbon source, whereas 43 isolates (86%) were able to utilize diesel as the sole carbon source. The presence of catabolic genes related to hydrocarbon degradation was assessed using endpoint PCR, with the alkane monooxygenase (alkB) gene found in 34 isolates, the cytochrome P450 hydroxylase (CYP153) gene found in 24 isolates, and the naphthalene dioxygenase (nah1) gene found to be present in 33 isolates. Thirty-six strains (72%) promoted canola root elongation in the growth pouch assay. After several rounds of screening, seven bacterial candidates (individually or combined in a consortium) were tested for canola root and shoot growth promotion in substrates amended by different concentrations of n-hexadecane (0%, 1%, 2%, and 3%) under gnotobiotic conditions. Our results showed that Nocardia sp. (WB46), Pseudomonas plecoglossicida (ET27), Stenotrophomonas pavanii (EB31), and Gordonia amicalis (WT12) significantly increased the root length of canola grown in 3% n-hexadecane compared with the control treatment, whereas Nocardia sp. (WB46) and Bacillus megaterium (WT10) significantly increased shoot length compared to control treatment at the same concentration of n-hexadecane. The consortium had a significant enhancement effect on root length compared to all isolates inoculated individually or to the control. This study demonstrates that the combination of PGPR traits and the PHC degradation potential of bacteria can result in an enhanced beneficial effect in phytoremediation management, which could lead to the development of innovative bacterial inoculants for plants to remediate PHC-contaminated soils.

Salt\u2011responsive transcriptome analysis of canola roots reveals candidate genes involved in the key metabolic pathway in response to salt stress

Salinity is a major constraint on crop growth and productivity, limiting sustainable agriculture in arid regions. Understanding the molecular mechanisms of salt-stress adaptation in canola is important to improve salt tolerance and promote its cultivation in saline lands. In this study, roots of control (no salt) and 200 mM NaCl-stressed canola seedlings were collected for RNA-Seq analysis and qRT-PCR validation. A total of 5385, 4268, and 7105 DEGs at the three time points of salt treatment compared to the control were identified, respectively. Several DEGs enriched in plant signal transduction pathways were highly expressed under salt stress, and these genes play an important role in signaling and scavenging of ROS in response to salt stress. Transcript expression in canola roots differed at different stages of salt stress, with the early-stages (2 h) of salt stress mainly related to oxidative stress response and sugar metabolism, while the late-stages (72 h) of salt stress mainly related to transmembrane movement, amino acid metabolism, glycerol metabolism and structural components of the cell wall. Several families of TFs that may be associated with salt tolerance were identified, including ERF, MYB, NAC, WRKY, and bHLH. These results provide a basis for further studies on the regulatory mechanisms of salt stress adaptation in canola.

Metabolic profile of canola (Brassica napus L.) seedlings under hydric, osmotic and temperature stresses

Canola is an important oilseed crop and its oil is used in human diet and biodiesel production. Abiotic stressors severely constrain canola growing causing economic losses. Under adverse conditions, plant cells coordinate their metabolic pathways to produce anti-stress agents. The understanding of the metabolic profile can be used to improve target traits since there is a direct relationship with the phenotype. Here we take advantage of the non-targeted metabolite profiling analysis GC–MS technique to assess the differences in metabolite accumulation in canola seedling tissues subjected to heat, waterlogging, drought and salt stresses. Phenotypically, abiotic stresses affected canola root development, mainly in waterlogging, salt and drought conditions, in which root length was increased. We assayed the metabolic profile in each tissue and abiotic stress and organic acids, free amino acid and sugars were detected. Accumulation of these metabolites were variable between shoots and roots under abiotic stresses. Heat stress affected mainly shoots increasing some essential and non-essential amino acids and sucrose while decreasing glucose and fructose contents. Waterlogging also affected mainly shoots decreasing malic and citric acids, some essential and non-essential amino acids and xylose content. Salt stress leads to a reduction of most of the metabolic compounds from organic acids, free amino acid and sugar groups in shoots and roots. Controversially, drought stress resulted in an increasing in most of the metabolite groups in shoots and roots. Shoots presented greater variation in metabolite content in response to abiotic stress. Our data is useful as basic knowledge to improve canola specific traits.

Evaluation of the Effect of Different Sowing Dates and Cultivars against Canola Root Rot Diseases

Evaluation of the Effect of Different Sowing Dates and Cultivars against Canola Root Rot Diseases

Inter-Kingdom Networks of Canola Microbiome Reveal Bradyrhizobium as Keystone Species and Underline the Importance of Bulk Soil in Microbial Studies to Enhance Canola Production.

The subterranean microbiota of plants is of great importance for plant growth and health, as root-associated microbes can perform crucial ecological functions. As the microbial environment of roots is extremely diverse, identifying keystone microorganisms in plant roots, rhizosphere, and bulk soil is a necessary step towards understanding the network of influence within the microbial community associated with roots and enhancing its beneficial elements. To target these hot spots of microbial interaction, we used inter-kingdom network analysis on the canola growth phase of a long-term cropping system diversification experiment conducted at four locations in the Canadian Prairies. Our aims were to verify whether bacterial and fungal communities of canola roots, rhizosphere, and bulk soil are related and influenced by diversification of the crop rotation system; to determine whether there are common or specific core fungi and bacteria in the roots, rhizosphere, and bulk soil under canola grown in different environments and with different levels of cropping system diversification; and to identify hub taxa at the inter-kingdom level that could play an important ecological role in the microbiota of canola. Our results showed that fungi were influenced by crop diversification, which was not the case on bacteria. We found no core microbiota in canola roots but identified three core fungi in the rhizosphere, one core mycobiota in the bulk soil, and one core bacterium shared by the rhizosphere and bulk soil. We identified two bacterial and one fungal hub taxa in the inter-kingdom networks of the canola rhizosphere, and one bacterial and two fungal hub taxa in the bulk soil. Among these inter-kingdom hub taxa, Bradyrhizobium sp. and Mortierella sp. are particularly influential on the microbial community and the plant. To our knowledge, this is the first inter-kingdom network analysis utilized to identify hot spots of interaction in canola microbial communities.

Early season root growth, soil aggregation and stratification of nutrients and soil properties after six annual treatments of fertilizer rates and seeding systems

Fertilizer application and tillage practices have been found to influence root growth and soil properties. The objectives of the current study were to assess the response of early season root growth of canola (Brassica napus L.) and barley (Hordeum vulgare L.), aggregates stability in the 0–7.5 cm of soil, and nutrient concentrations and soil properties in the 0–7.5, 7.5–15.0, 15.0–22.5 and 22.5–30.0 cm soil, to 6 years of different soil test-based fertilizer rates and seeding systems. Before these assessments, soil test-based fertilizer rates (0, 60, 100 and 140%) and seeding systems (direct seeding, DS; and minimum tillage, MT) had been used for six years (2010–2015) to grow crops on a clay loam soil in the southeast Peace Region (legal: NW7-77-20W5; GPS: 55°39′38.43″N, 117°6′10.64″W) of Alberta, Canada. The length, surface area, volume and number of tips for canola and barley roots in the early growing season (from May 11 to June 17) of 2015 were greater with the 100% than the 0% fertilizer rate. They also tended to be greater under the DS than MT system. The length, surface area and volume of roots were greater for barley than canola, while the number of tips for both crops were in a similar range. The stability of soil aggregate (after the 2015 growing season) showed positive effects of fertilizer application and reduced tillage intensity. Soil samples collected in the spring 2016 indicated increased stratification of some nutrients and soil properties from higher fertilizer rates. These trends were more evident under the DS than the MT seeding system. Organic matter content and P concentration declined with depth, while pH, Ca and Mg increased with depth, and the change with depth tended to be greater at the 100% than 0% fertilizer rate. No change in stratification of NO3-N and SO4-S was noticed as a result of fertilizer rates. Overall, 6 years of different fertilizer rates and tillage systems influenced the early season growth of canola and barley roots, the soil aggregates stability and the stratification of some nutrients and soil properties.

Identification of Canola Roots Endophytic Bacteria and Analysis of Their Potential as Biofertilizers for Canola Crops with Special Emphasis on Sporulating Bacteria

Canola (Brassica napus L. var. oleracea) is the third most common oil-producing crop worldwide after palm and soybean. Canola cultivation requires the use of chemical fertilizers, but the amount required can be reduced by applying plant growth-promoting bacteria (PGPB). Among PGPB, endophytic bacteria have certain advantages as biofertilizers, but canola endophytic bacteria have rarely been studied. In this work, we identified a collection of bacterial endophytes isolated from canola roots using MALDI-TOF MS, a technique that is still rarely used for the identification of such bacteria, and rrs gene sequencing, a methodology that is commonly used to identify canola endophytes. The results demonstrated that some bacterial isolates from canola roots belonged to the genera Bacillus, Neobacillus, Peribacillus (Pe.), and Terribacillus, but most isolates belonged to the genera Paenibacillus (P.) and Pseudomonas (Ps.). Inoculation of these isolates indicated that several of them could efficiently promote canola seedling growth in hydroponic conditions. These results were then confirmed in a microcosm experiment using agricultural soil, which demonstrated that several isolates of Pseudomonas thivervalensis, Paenibacillus amylolyticus, Paenibacillus polymyxa, Paenibacillus sp. (Paenibacillus glucanolyticus/Paenibacillus lautus group), and Peribacillus simplex (previously Bacillus simplex) could efficiently promote canola shoot growth under greenhouse conditions. Among them, the isolates of Paenibacillus and Peribacillus were the most promising biofertilizers for canola crops as they are sporulated rods, which is an advantageous trait when formulating biofertilizers.

Integrated transcriptomics and metabolomics analysis to characterize alkali stress responses in canola (Brassica napus L.)

BackgroundSoil salinization is a major constraint limiting agricultural development and affecting crop growth and productivity, especially in arid and semi-arid regions. Understanding the molecular mechanism of the adaptability of canola to salt stress is very important to improve the salt tolerance of canola and promote its cultivation in saline alkali soil. ResultsTo identify the metabolomic and transcriptomic mechanisms of canola under alkaline salt stress, we collected roots of control (no salt treatment) and 72 h Na2CO3-stressed canola seedlings (hydroponics) for metabolic profiling of metabolites, supplemented with RNA-Seq analysis and real-time quantitative PCR validation. Metabolomic analysis showed that the metabolites of amino acids and fatty acids were higher accumulated under alkaline salt stress, including L-proline, L-glutamate, L-histidine, L-phenylalanine, L-citrulline, L-tyrosine, L-saccharopine, L-tryptophan, linoleic acid, dihomo gamma linolenic acid, alpha linolenic acid, Eric acid, oleic acid and neuronic acid, while the metabolism of carbohydrate (sucrase, alpha, alpha trehalose), polyol (ribitol), UDP-D-galactose, D-mannose, D-fructose and D-glucose 6-phosphate decreased. Transcriptomic and metabolomic pathway analysis indicated that carbohydrate metabolism may not play an important role in the resistance of canola to alkaline salt stress. Organic acid metabolism (fatty acid accumulation) and amino acid metabolism are important metabolic pathways in the root of canola under alkaline salt stress. ConclusionsThese results suggest that the genes and metabolites involved in fatty acid metabolism and amino acids metabolism in roots of canola may regulate salt tolerance of canola seedlings under alkaline salt stress, which improves our understanding of the molecular mechanisms of salt tolerance in canola.

A Comprehensive Targeted Metabolomics Assay for Crop Plant Sample Analysis.

Metabolomics plays an important role in various fields from health to agriculture. However, the comprehensive quantitative metabolomic analysis of plants and plant metabolites has not been widely performed. Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS)-based plant metabolomics offers the sensitivity and breadth of coverage for both phenotyping and disease diagnosis of plants. Here, we report a high-coverage and quantitative MS-based assay for plant metabolite analysis. The assay detects and quantifies 206 primary and secondary plant metabolites, including many key plant hormones. In total, it measures 28 amino acids and derivatives, 27 organic acids, 20 biogenic amines and derivatives, 40 acylcarnitines, 90 phospholipids and C-6 sugars. All the analysis methods in this assay are based on LC-MS/MS techniques using both positive and negative-mode multiple reaction monitoring (MRM). The recovery rates of spiked plant samples at three different concentration levels (low, medium and high) ranged from 80% to 120%, with satisfactory precision values of less than 20%. This targeted plant metabolomic assay has been successfully applied to the analysis of large numbers of pine and spruce needle samples, canola root samples, as well as cannabis samples. Moreover, the assay was specifically developed in a 96-well plate format, which enables automated, high-throughput sample analysis. This assay has already been used to analyze over 1500 crop plant samples in less than two months.

Antifungal potential against Sclerotinia sclerotiorum (Lib.) de Bary and plant growth promoting abilities of Bacillus isolates from canola (Brassica napus L.) roots

Endophytic bacteria show important abilities in promoting plant growth and suppressing phytopathogens, being largely explored in agriculture as biofertilizers or biocontrol agents. Bacteria from canola roots were isolated and screened for different plant growth promotion (PGP) traits and biocontrol of Sclerotinia sclerotiorum. Thirty isolates belonging to Bacillus, Paenibacillus, Lysinibacillus, and Microbacterium genera were obtained. Several isolates produced auxin, siderophores, hydrolytic enzymes, fixed nitrogen and solubilized phosphate. Five isolates presented antifungal activity against S. sclerotiorum by the dual culture assay and four of them also inhibited fungal growth by volatile organic compounds production. All antagonistic isolates belonged to the Bacillus genus, and had their genomes sequenced for the search of biosynthetic gene clusters (BGC) related to antimicrobial metabolites. These isolates were identified as Bacillus safensis (3), Bacillus pumilus (1), and Bacillus megaterium (1), using the genomic metrics ANI and dDDH. Most strains showed several common BGCs, including bacteriocin, polyketide synthase (PKS), and non-ribosomal peptide synthetase (NRPS), related to pumilacidin, bacillibactin, bacilysin, and other antimicrobial compounds. Pumilacidin-related mass peaks were detected in acid precipitation extracts through MALDI-TOF analysis. The genomic features demonstrated the potential of these isolates in the suppression of plant pathogens; however, some aspects of plant-bacterial interactions remain to be elucidated.

Seed treatment of canola (Brassica napus) with the endomycorrhizal fungus Piriformospora indica does not reduce clubroot

A Basidiomycota endomycorrhizal fungus, Piriformospora indica Verma, colonizes and promotes the growth of canola (Brassica napus L.) and other Brassica crops and can reduce diseases of other crops. Clubroot is an important disease of Brassica crops caused by the obligate, soil-borne pathogen Plasmodiophora brassicae Woronin. The effect of P. indica on clubroot severity in canola was assessed in replicated growth room studies. Seed was treated with P. indica using a proprietary process. Microscopic observation confirmed that canola roots grown from treated seed were colonized by P. indica; however, P. indica did not consistently reduce clubroot severity and did not promote the growth of canola.