Plants interfere with non-self recognition of a phytopathogenic fungus via proline accumulation to facilitate mycovirus transmission.

Non-self recognition is a fundamental aspect of life, serving as a crucial mechanism for mitigating proliferation of molecular parasites within fungal populations. However, studies investigating the potential interference of plants with fungal non-self recognition mechanisms are limited. Here, we demonstrate a pronounced increase in the efficiency of horizontal mycovirus transmission between vegetatively incompatible Sclerotinia sclerotiorum strains in planta as compared to in vitro. This increased efficiency is associated with elevated proline concentration in plants following S. sclerotiorum infection. This surge in proline levels attenuates the non-self recognition reaction among fungi by inhibition of cell death, thereby facilitating mycovirus transmission. Furthermore, our field experiments reveal that the combined deployment of hypovirulent S. sclerotiorum strains harboring hypovirulence-associated mycoviruses (HAVs) together with exogenous proline confers substantial protection to oilseed rape plants against virulent S. sclerotiorum. This unprecedented discovery illuminates a novel pathway by which plants can counteract S. sclerotiorum infection, leveraging the weakening of fungal non-self recognition and promotion of HAVs spread. These promising insights provide an avenue to explore for developing innovative biological control strategies aimed at mitigating fungal diseases in plants by enhancing the efficacy of horizontal HAV transmission.

Characteristics of duplicated gene expression and DNA methylation regulation in different tissues of allopolyploid Brassica napus.

Plant polyploidization increases the complexity of epigenomes and transcriptional regulation, resulting in genome evolution and enhanced adaptability. However, few studies have been conducted on the relationship between gene expression and epigenetic modification in different plant tissues after allopolyploidization. In this study, we studied gene expression and DNA methylation modification patterns in four tissues (stems, leaves, flowers and siliques) of Brassica napusand its diploid progenitors. On this basis, the alternative splicing patterns and cis-trans regulation patterns of four tissues in B. napus and its diploid progenitors were also analyzed. It can be seen that the number of alternative splicing occurs in the B. napus is higher than that in the diploid progenitors, and the IR type increases the most during allopolyploidy. In addition, we studied the fate changes of duplicated genes after allopolyploidization in B. napus. We found that the fate of most duplicated genes is conserved, but the number of neofunctionalization and specialization is also large. The genetic fate of B. napus was classified according to five replication types (WGD, PD, DSD, TD, TRD). This study also analyzed generational transmission analysis of expression and DNA methylation patterns. Our study provides a reference for the fate differentiation of duplicated genes during allopolyploidization.

Identification of transcriptional modules linked to the drought response of Brassica napus during seed development and their mitigation by early biotic stress.

In order to capture the drought impacts on seed quality acquisition in Brassica napus and its potential interaction with early biotic stress, seeds of the 'Express' genotype of oilseed rape were characterized from late embryogenesis to full maturity from plants submitted to reduced watering (WS) with or without pre-occurring inoculation by the telluric pathogen Plasmodiophora brassicae (Pb + WS or Pb, respectively), and compared to control conditions (C). Drought as a single constraint led to significantly lower accumulation of lipids, higher protein content and reduced longevity of the WS-treated seeds. In contrast, when water shortage was preceded by clubroot infection, these phenotypic differences were completely abolished despite the upregulation of the drought sensor RD20. A weighted gene co-expression network of seed development in oilseed rape was generated using 72 transcriptomes from developing seeds from the four treatments and identified 33 modules. Module 29 was highly enriched in heat shock proteins and chaperones that showed a stronger upregulation in Pb + WS compared to the WS condition, pointing to a possible priming effect by the early P. brassicae infection on seed quality acquisition. Module 13 was enriched with genes encoding 12S and 2S seed storage proteins, with the latter being strongly upregulated under WS conditions. Cis-element promotor enrichment identified PEI1/TZF6, FUS3 and bZIP68 as putative regulators significantly upregulated upon WS compared to Pb + WS. Our results provide a temporal co-expression atlas of seed development in oilseed rape and will serve as a resource to characterize the plant response towards combinations of biotic and abiotic stresses.

Genomic and phenomic predictions help capture low-effect alleles promoting seed germination in oilseed rape in addition to QTL analyses.

KEY MESSAGE: Phenomic prediction implemented on a large diversity set can efficiently predict seed germination, capture low-effect favorable alleles that are not revealed by GWAS and identify promising genetic resources. Oilseed rape faces many challenges, especially at the beginning of its developmental cycle. Achieving rapid and uniform seed germination could help to ensure a successful establishment and therefore enabling the crop to compete with weeds and tolerate stresses during the earliest developmental stages. The polygenic nature of seed germination was highlighted in several studies, and more knowledge is needed about low- to moderate-effect underlying loci in order to enhance seed germination effectively by improving the genetic background and incorporating favorable alleles. A total of 17 QTL were detected for seed germination-related traits, for which the favorable alleles often corresponded to the most frequent alleles in the panel. Genomic and phenomic predictions methods provided moderate-to-high predictive abilities, demonstrating the ability to capture small additive and non-additive effects for seed germination. This study also showed that phenomic prediction estimated phenotypic values closer to phenotypic values than GEBV. Finally, as the predictive ability of phenomic prediction was less influenced by the genetic structure of the panel, it is worth using this prediction method to characterize genetic resources, particularly with a view to design prebreeding populations.

Effect of methyl jasmonate and GA3 on canola (Brassica napus L.) growth, antioxidants activity, and nutrient concentration cultivated in salt-affected soils.

Salinity stress is a significant challenge in agricultural production. When soil contains high salts, it can adversely affect plant growth and productivity due to the high concentration of soluble salts in the soil water. To overcome this issue, foliar applications of methyl jasmonate (MJ) and gibberellic acid (GA3) can be productive amendments. Both can potentially improve the plant's growth attributes and flowering, which are imperative in improving growth and yield. However, limited literature is available on their combined use in canola to mitigate salinity stress. That's why the current study investigates the impact of different levels of MJ (at concentrations of 0.8, 1.6, and 3.2 mM MJ) and GA3 (0GA3 and 5 mg/L GA3) on canola cultivated in salt-affected soils. Applying all the treatments in four replicates. Results indicate that the application of 0.8 mM MJ with 5 mg/L GA3 significantly enhances shoot length (23.29%), shoot dry weight (24.77%), number of leaves per plant (24.93%), number of flowering branches (26.11%), chlorophyll a (31.44%), chlorophyll b (20.28%) and total chlorophyll (27.66%) and shoot total soluble carbohydrates (22.53%) over control. Treatment with 0.8 mM MJ and 5 mg/L GA3 resulted in a decrease in shoot proline (48.17%), MDA (81.41%), SOD (50.59%), POD (14.81%) while increase in N (10.38%), P (15.22%), and K (8.05%) compared to control in canola under salinity stress. In conclusion, 0.8 mM MJ + 5 mg/L GA3 can improve canola growth under salinity stress. More investigations are recommended at the field level to declare 0.8 mM MJ + 5 mg/L GA3 as the best amendment for alleviating salinity stress in different crops.

Genome-wide identification of GH28 family and insight into its contributions to pod shattering resistance in Brassica napus L.

Rapeseed (Brassica napus L.), accounts for nearly 16% of vegetable oil, is the world's second produced oilseed. However, pod shattering has caused significant yield loses in rapeseed production, particularly during mechanical harvesting. The GH28 genes can promote pod shattering by changing the structure of the pod cell wall in Arabidopsis. However, the role of the GH28 gene family in rapeseed was largely unknown. Therefore, a genome-wide comprehensive analysis was conducted to classify the role of GH28 gene family on rapeseed pod shattering. A total of 37 BnaGH28 genes in the rapeseed genome were identified. These BnaGH28s can be divided into five groups (Group A-E), based on phylogenetic and synteny analysis. Protein property, gene structure, conserved motif, cis-acting element, and gene expression profile of BnaGH28 genes in the same group were similar. Specially, the expression level of genes in group A-D was gradually decreased, but increased in group E with the development of silique. Among eleven higher expressed genes in group E, two BnaGH28 genes (BnaA07T0199500ZS and BnaC06T0206500ZS) were significantly regulated by IAA or GA treatment. And the significant effects of BnaA07T0199500ZS variation on pod shattering resistance were also demonstrated in present study. These results could open a new window for insight into the role of BnaGH28 genes on pod shattering resistance in rapeseed.

Genetic control of root morphology in response to nitrogen across rapeseed diversity.

Rapeseed (Brassica napus L.) is an oil-containing crop of great economic value but with considerable nitrogen requirement. Breeding root systems that efficiently absorb nitrogen from the soil could be a driver to ensure genetic gains for more sustainable rapeseed production. The aim of this study is to identify genomic regions that regulate root morphology in response to nitrate availability. The natural variability offered by 300 inbred lines was screened at two experimental locations. Seedlings grew hydroponically with low or elevated nitrate levels. Fifteen traits related to biomass production and root morphology were measured. On average across the panel, a low nitrate level increased the root-to-shoot biomass ratio and the lateral root length. A large phenotypic variation was observed, along with important heritability values and genotypic effects, but low genotype-by-nitrogen interactions. Genome-wide association study and bulk segregant analysis were used to identify loci regulating phenotypic traits. The first approach nominated 319 SNPs that were combined into 80 QTLs. Three QTLs identified on the A07 and C07 chromosomes were stable across nitrate levels and/or experimental locations. The second approach involved genotyping two groups of individuals from an experimental F2 population created by crossing two accessions with contrasting lateral root lengths. These individuals were found in the tails of the phenotypic distribution. Co-localized QTLs found in both mapping approaches covered a chromosomal region on the A06 chromosome. The QTL regions contained some genes putatively involved in root organogenesis and represent selection targets for redesigning the root morphology of rapeseed.

The fungus Acremonium alternatum enhances salt stress tolerance by regulating host redox homeostasis and phytohormone signaling.

While endophytic fungi offer promising avenues for bolstering plant resilience against abiotic stressors, the molecular mechanisms behind this biofortification remain largely unknown. This study employed a multifaceted approach, combining plant physiology, proteomic, metabolomic, and targeted hormonal analyses to illuminate the early response of Brassica napus to Acremonium alternatum during the nascent stages of their interaction. Notably, under optimal growth conditions, the initial reaction to fungus was relatively subtle, with no visible alterations in plant phenotype and only minor impacts on the proteome and metabolome. Interestingly, the identified proteins associated with the Acremonium response included TUDOR 1, Annexin D4, and a plastidic K+ efflux antiporter, hinting at potential processes that could counter abiotic stressors, particularly salt stress. Subsequent experiments validated this hypothesis, showcasing significantly enhanced growth in Acremonium-inoculated plants under salt stress. Molecular analyses revealed a profound impact on the plant's proteome, with over 50% of salt stress response proteins remaining unaffected in inoculated plants. Acremonium modulated ribosomal proteins, increased abundance of photosynthetic proteins, enhanced ROS metabolism, accumulation of V-ATPase, altered abundances of various metabolic enzymes, and possibly promoted abscisic acid signaling. Subsequent analyses validated the accumulation of this hormone and its enhanced signaling. Collectively, these findings indicate that Acremonium promotes salt tolerance by orchestrating abscisic acid signaling, priming the plant's antioxidant system, as evidenced by the accumulation of ROS-scavenging metabolites and alterations in ROS metabolism, leading to lowered ROS levels and enhanced photosynthesis. Additionally, it modulates ion sequestration through V-ATPase accumulation, potentially contributing to the observed decrease in chloride content.

Identification and expression analysis of the Xyloglucan transglycosylase/hydrolase (XTH) gene family under abiotic stress in oilseed (Brassica napus L.).

XTH genes are key genes that regulate the hydrolysis and recombination of XG components and plays role in the structure and composition of plant cell walls. Therefore, clarifying the changes that occur in XTHs during plant defense against abiotic stresses is informative for the study of the plant stress regulatory mechanism mediated by plant cell wall signals. XTH proteins in Arabidopsis thaliana was selected as the seed sequences in combination with its protein structural domains, 80 members of the BnXTH gene family were jointly identified from the whole genome of the Brassica napus ZS11, and analyzed for their encoded protein physicochemical properties, phylogenetic relationships, covariance relationships, and interoperating miRNAs. Based on the transcriptome data, the expression patterns of BnXTHs were analyzed in response to different abiotic stress treatments. The relative expression levels of some BnXTH genes under Al, alkali, salt, and drought treatments after 0, 6, 12 and 24 h were analyzed by using qRT-PCR to explore their roles in abiotic stress tolerance in B. napus. BnXTHs showed different expression patterns in response to different abiotic stress signals, indicating that the response mechanisms of oilseed rape against different abiotic stresses are also different. This paper provides a theoretical basis for clarifying the function and molecular genetic mechanism of the BnXTH gene family in abiotic stress tolerance in rapeseed.

Functional and regulatory diversity of homeobox-leucine zipper transcription factors BnaHB6 under dehydration and salt stress in Brassica napus L.

The plant-specific homeodomain-leucine zipper I subfamily is involved in the regulation of various biological processes, particularly growth, development and stress response. In the present study, we characterized four BnaHB6 homologues from Brassica napus. All BnaHB6 proteins have transcriptional activation activity. Structural and functional data indicate the complex role of BnaHB6 genes in regulating biological processes, with some functions conserved and others diverged. Transcriptional analyzes revealed that they are induced in a similar manner in different tissues but show different expression patterns in response to stress and circadian rhythm. Only the BnaA09HB6 and BnaC08HB6 genes are expressed under dehydration and salt stress, and in darkness. The partial transcriptional overlap of BnaHB6s with the evolutionarily related genes BnaHB5 and BnaHB16 was also observed. Transgenic Arabidopsis thaliana plants expressing a single proBnaHB6::GUS partially confirmed the expression results. Bioinformatic analysis allowed the identification of TF-binding sites in the BnaHB6 promoters that may control their expression under stress and circadian rhythm. ChIP-qPCR analysis revealed that BnaA09HB6 and BnaC08HB6 bind directly to the promoters of the target genes BnaABF4 and BnaDREB2A. Comparison of their expression patterns in the WT plants and the bnac08hb6 mutant showed that BnaC08HB6 positively regulates the expression of the BnaABF4 and BnaDREB2A genes under dehydration and salt stress. We conclude that four BnaHB6 homologues have distinct functions in response to stress despite high sequence similarity, possibly indicating different binding preferences with BnaABF4 and BnaDREB2A. We hypothesize that BnaC08HB6 and BnaA09HB6 function in a complex regulatory network under stress.

RNA-Seq Bulked Segregant Analysis of an Exotic B. napus ssp. napobrassica (Rutabaga) F2 Population Reveals Novel QTLs for Breeding Clubroot-Resistant Canola.

In this study, a rutabaga (Brassica napus ssp. napobrassica) donor parent FGRA106, which exhibited broad-spectrum resistance to 17 isolates representing 16 pathotypes of Plasmodiophora brassicae, was used in genetic crosses with the susceptible spring-type canola (B. napus ssp. napus) accession FG769. The F2 plants derived from a clubroot-resistant F1 plant were screened against three P. brassicae isolates representing pathotypes 3A, 3D, and 3H. Chi-square (χ2) goodness-of-fit tests indicated that the F2 plants inherited two major clubroot resistance genes from the CR donor FGRA106. The total RNA from plants resistant (R) and susceptible (S) to each pathotype were pooled and subjected to bulked segregant RNA-sequencing (BSR-Seq). The analysis of gene expression profiles identified 431, 67, and 98 differentially expressed genes (DEGs) between the R and S bulks. The variant calling method indicated a total of 12 (7 major + 5 minor) QTLs across seven chromosomes. The seven major QTLs included: BnaA5P3A.CRX1.1, BnaC1P3H.CRX1.2, and BnaC7P3A.CRX1.1 on chromosomes A05, C01, and C07, respectively; and BnaA8P3D.CRX1.1, BnaA8P3D.RCr91.2/BnaA8P3H.RCr91.2, BnaA8P3H.Crr11.3/BnaA8P3D.Crr11.3, and BnaA8P3D.qBrCR381.4 on chromosome A08. A total of 16 of the DEGs were located in the major QTL regions, 13 of which were on chromosome C07. The molecular data suggested that clubroot resistance in FGRA106 may be controlled by major and minor genes on both the A and C genomes, which are deployed in different combinations to confer resistance to the different isolates. This study provides valuable germplasm for the breeding of clubroot-resistant B. napus cultivars in Western Canada.

Chemically tailored graphite oxide nanoparticles for improving material properties of canola protein-based films.

Canola protein obtained from canola meal, a byproduct of the canola industry, is an economical biopolymer with promising film-forming properties. It has significant potential for use as a food packaging material, though it possesses some functional limitations that need improvement. Incorporating nanomaterials is an option to enhance functional properties. This study aims to produce canola protein films by integrating GO exfoliated at several oxidation times and weight ratios to optimize mechanical, thermal, and barrier properties. Oxidation alters the C/O ratio and adds functional groups that bond with the amino/carboxyl groups of protein, enhancing the film properties. Significant improvement was obtained in GO at 60 and 120 min oxidation time and 3% addition level. Tensile strength and elastic modulus increased 200% and 481.72%, respectively, compared to control. Control films showed a 37.57 × 10-3 cm3m/m2/day/Pa oxygen permeability, and it was significantly reduced to 5.65 × 10-3 cm3m/m2/day/Pa representing a 665% reduction.

Comprehensive identification, characterization, and expression analysis of the MORF gene family in Brassica napus.

BACKGROUND: RNA editing in chloroplast and mitochondrion transcripts of plants is an important type of post-transcriptional RNA modification in which members of the multiple organellar RNA editing factor gene family (MORF) play a crucial role. However, a systematic identification and characterization of MORF members in Brassica napus is still lacking. RESULTS: In this study, a total of 43 MORF genes were identified from the genome of the Brassica napus cultivar "Zhongshuang 11". The Brassica napus MORF (BnMORF) family members were divided into three groups through phylogenetic analysis. BnMORF genes distributed on 14 chromosomes and expanded due to segmental duplication and whole genome duplication repetitions. The majority of BnMORF proteins were predicted to be localized to mitochondria and chloroplasts. The promoter cis-regulatory element analysis, spatial-temporal expression profiling, and co-expression network of BnMORF genes indicated the involvement of BnMORF genes in stress and phytohormone responses, as well as growth and development. CONCLUSION: This study provides a comprehensive analysis of BnMORF genes and lays a foundation for further exploring their physiological functions in Brassica napus.

Mechanisms of low nighttime temperature promote oil accumulation in Brassica napus L. based on in-depth transcriptome analysis.

Rape (Brassica napus L.; AACC) is an important oil-bearing crop worldwide. Temperature significantly affects the production of oil crops; however, the mechanisms underlying temperature-promoted oil biosynthesis remain largely unknown. In this study, we found that a temperature-sensitive cultivar (O) could accumulate higher seed oil content under low nighttime temperatures (LNT,13°C) compared with a temperature-insensitive cultivar (S). We performed an in-depth transcriptome analysis of seeds from both cultivars grown under different nighttime temperatures. We found that low nighttime temperatures induced significant changes in the transcription patterns in the seeds of both cultivars. In contrast, the expression of genes associated with fatty acid and lipid pathways was higher in the O cultivar than in the S cultivar under low nighttime temperatures. Among these genes, we identified 14 genes associated with oil production, especially BnLPP and ACAA1, which were remarkably upregulated in the O cultivar in response to low nighttime temperatures compared to S. Further, a WGCNA analysis and qRT-PCR verification revealed that these genes were mainly regulated by five transcription factors, WRKY20, MYB86, bHLH144, bHLH95, and NAC12, whose expression was also increased in O compared to S under LNT. These results allowed the elucidation of the probable molecular mechanism of oil accumulation under LNT conditions in the O cultivar. Subsequent biochemical assays verified that BnMYB86 transcriptionally activated BnLPP expression, contributing to oil accumulation. Meanwhile, at LNT, the expression levels of these genes in the O plants were higher than at high nighttime temperatures, DEGs (SUT, PGK, PK, GPDH, ACCase, SAD, KAS II, LACS, FAD2, FAD3, KCS, KAR, ECR, GPAT, LPAAT, PAP, DGAT, STERO) related to lipid biosynthesis were also upregulated, most of which are used in oil accumulation.

Treatment of marble industry wastewater by Brassica napus (L.) under oxalic acid amendment: efficacy as fodder and carcinogenic risk assessment.

In the present study, Brassica napus, a food plant, was grown for phytoextraction of selected heavy metals (HMs) from marble industry wastewater (WW) under oxalic acid (OA) amendment. The hydroponic experiment was performed under different combination of WW with OA in complete randomized design. Photosynthetic pigments and growth reduction were observed in plants treated with WW alone amendments. The combination of OA in combination with WW significantly enhanced the growth of plants along with antioxidant enzyme activities compared with WW-treated-only plants. HM stress alone enhanced the hydrogen peroxide, electrolyte leakage, and malondialdehyde contents in plants. OA-treated plants were observed with enhanced accumulation of cadmium (Cd), copper (Cu), and lead (Pb) concentrations in the roots and shoots of B. napus. The maximum concentration and accumulation of Cd in root, stem, and leaves was increased by 25%, 30%, and 30%; Cu by 42%, 24%, and 17%; and Pb by 45%, 24%, and 43%, respectively, under OA amendment. Average daily intake and hazard quotient (HQ) were calculated for males, females, and children in two phases of treatments in phytoremediation of metals before and after accumulation into B. napus leaves and stems. HQ of metals in the leaves and stem was < 1 before metal accumulation, whereas > 1 was observed after HM accumulation for all males, females, and children. Similarly, the hazard index of the three study types was found > 1. It was observed that the estimated excess lifetime cancer risk was of grade VII (very high risk), not within the accepted range of 1 × 10-4 to 1 × 10-6. Based on the present study, the increased levels of HMs up to carcinogenicity was observed in the B. napus which is not safe to be consumed later as food.

Genome-wide characterization of LEA gene family reveals a positive role of BnaA.LEA6.a in freezing tolerance in rapeseed (Brassica napus L.).

BACKGROUND: Freezing stress is one of the major abiotic stresses that causes extensive damage to plants. LEA (Late embryogenesis abundant) proteins play a crucial role in plant growth, development, and abiotic stress. However, there is limited research on the function of LEA genes in low-temperature stress in Brassica napus (rapeseed). RESULTS: Total 306 potential LEA genes were identified in B. rapa (79), B. oleracea (79) and B. napus (148) and divided into eight subgroups. LEA genes of the same subgroup had similar gene structures and predicted subcellular locations. Cis-regulatory elements analysis showed that the promoters of BnaLEA genes rich in cis-regulatory elements related to various abiotic stresses. Additionally, RNA-seq and real-time PCR results indicated that the majority of BnaLEA family members were highly expressed in senescent tissues of rapeseed, especially during late stages of seed maturation, and most BnaLEA genes can be induced by salt and osmotic stress. Interestingly, the BnaA.LEA6.a and BnaC.LEA6.a genes were highly expressed across different vegetative and reproductive organs during different development stages, and showed strong responses to salt, osmotic, and cold stress, particularly freezing stress. Further analysis showed that overexpression of BnaA.LEA6.a increased the freezing tolerance in rapeseed, as evidenced by lower relative electrical leakage and higher survival rates compared to the wild-type (WT) under freezing treatment. CONCLUSION: This study is of great significance for understanding the functions of BnaLEA genes in freezing tolerance in rapeseed and offers an ideal candidate gene (BnaA.LEA6.a) for molecular breeding of freezing-tolerant rapeseed cultivars.

Persistence of genetically engineered canola populations in the U.S. and the adventitious presence of transgenes in the environment.

Feralization of genetically engineered (GE) crops increases the risk that transgenes will become integrated into natural and naturalizing plant populations. A key assumption of the management of GE crops is that populations of escaped plants are short-lived and therefore the risks they pose are limited. However, few populations of escaped crop plants have been tracked over the long term so our understanding of their persistence in ruderal or natural landscapes is limited. We repeated a large-scale road survey of feral GE canola populations in North Dakota, USA, initially conducted in 2010. Our objectives in 2021 were to determine the current distribution of feral canola populations, and to establish the relative frequency of GE and non-GE phenotypes in populations of canola throughout North Dakota. Our results indicate that, although the incidence of feral canola was less in 2021 than 2010, escaped canola populations remain common throughout the state. The prevalence of alternate forms of GE herbicide resistance changed between surveys, and we found an overabundance of non-GE plants compared to the frequency of non-transgenic forms in cultivation. Indirect evidence of persistence includes sampling plants with multiple transgenic traits, and finding populations far from transportation routes. We conclude that feral canola populations expressing transgenic herbicide resistance are established outside of cultivation, that they may be under selection for loss of the transgene, but that they nonetheless pose long-term risks by harboring transgenes in the unmanaged landscape.

Genome-Wide Identification and Characterization of the CCT Gene Family in Rapeseed (Brassica napus L.).

The CCT gene family is present in plants and is involved in biological processes such as flowering, circadian rhythm regulation, plant growth and development, and stress resistance. We identified 87, 62, 46, and 40 CCTs at the whole-genome level in B. napus, B. rapa, B. oleracea, and A. thaliana, respectively. The CCTs can be classified into five groups based on evolutionary relationships, and each of these groups can be further subdivided into three subfamilies (COL, CMF, and PRR) based on function. Our analysis of chromosome localization, gene structure, collinearity, cis-acting elements, and expression patterns in B. napus revealed that the distribution of the 87 BnaCCTs on the chromosomes of B. napus was uneven. Analysis of gene structure and conserved motifs revealed that, with the exception of a few genes that may have lost structural domains, the majority of genes within the same group exhibited similar structures and conserved domains. The gene collinearity analysis identified 72 orthologous genes, indicating gene duplication and expansion during the evolution of BnaCCTs. Analysis of cis-acting elements identified several elements related to abiotic and biotic stress, plant hormone response, and plant growth and development in the promoter regions of BnaCCTs. Expression pattern and protein interaction network analysis showed that BnaCCTs are differentially expressed in various tissues and under stress conditions. The PRR subfamily genes have the highest number of interacting proteins, indicating their significant role in the growth, development, and response to abiotic stress of B. napus.

Thiourea improves yield and quality traits of Brassica napus L. by upregulating the antioxidant defense system under high temperature stress.

High temperature stress influences plant growth, seed yield, and fatty acid contents by causing oxidative damage. This study investigated the potential of thiourea (TU) to mitigate oxidative stress and restoring seed oil content and quality in canola. The study thoroughly examined three main factors: (i) growth conditions-control and high temperature stress (35 °C); (ii) TU supplementation (1000 mg/L)-including variations like having no TU, water application at the seedling stage, TU application at seedling stage (BBCH Scale-39), water spray at anthesis stage, and TU application at anthesis stage (BBCH Scale-60); (iii) and two canola genotypes, 45S42 and Hiola-401, were studied separately. High temperature stress reduced growth and tissue water content, as plant height and relative water contents were decreased by 26 and 36% in 45S42 and 27 and 42% Hiola-401, respectively, resulting in a substantial decrease in seed yield per plant by 36 and 38% in 45S42 and Hiola-401. Seed oil content and quality parameters were also negatively affected by high temperature stress as seed oil content was reduced by 32 and 35% in 45S42 and Hiola-401. High-temperature stress increased the plant stress indicators like malondialdehyde, H2O2 content, and electrolyte leakage; these indicators were increased in both canola genotypes as compared to control. Interestingly, TU supplementation restored plant performance, enhancing height, relative water content, foliar chlorophyll (SPAD value), and seed yield per plant by 21, 15, 30, and 28% in 45S42; 19, 13, 26, and 21% in Hiola-401, respectively, under high temperature stress as compared to control. In addition, seed quality, seed oil content, linoleic acid, and linolenic acid were improved by 16, 14, and 22% in 45S42, and 16, 11, and 23% in Hiola-401, as compared to control. The most significant improvements in canola seed yield per plant were observed when TU was applied at the anthesis stage. Additionally, the research highlighted that canola genotype 45S42 responded better to TU applications and exhibited greater resilience against high temperature stress compared to genotype Hiola-401. This interesting study revealed that TU supplementation, particularly at the anthesis stage, improved high temperature stress tolerance, seed oil content, and fatty acid profile in two canola genotypes.

Genome-wide characterization of Remorin gene family and their responsive expression to abiotic stresses and plant hormone in Brassica napus.

KEY MESSAGE: Remorin proteins could be positively related to salt and osmotic stress resistance in rapeseed. Remorins (REMs) play a crucial role in adaptations to adverse environments. However, their roles in abiotic stress and phytohormone responses in oil crops are still largely unknown. In this study, we identified 47 BnaREM genes in the B.napus genome. Phylogenetic relationship and synteny analysis revealed that they were categorized into 5 distinct groups and have gone through 55 segmental duplication events under purifying selection. Gene structure and conserved domains analysis demonstrated that they were highly conserved and all BnaREMs contained a conserved Remorin_C domain, with a variable N-terminal region. Promoter sequence analysis showed that BnaREM gene promoters contained various hormones and stress-related cis-acting elements. Transcriptome data from BrassicaEDB database exhibited that all BnaREMs were ubiquitously expressed in buds, stamens, inflorescences, young leaves, mature leaves, roots, stems, seeds, silique pericarps, embryos and seed coats. The qRT-PCR analysis indicated that most of them were responsive to ABA, salt and osmotic treatments. Further mutant complementary experiments revealed that the expression of BnaREM1.3-4C-1 in the Arabidopsis rem1.3 mutant restored the retarded growth phenotype and the ability to resistance to salt and osmotic stresses. Our findings provide fundamental information on the structure and evolutionary relationship of the BnaREM family genes in rapeseed, and reveal the potential function of BnaREM1.3-4C-1 in stress and hormone response.