scholarly journals Comparative Transcriptome Analysis of Rutabaga (Brassica napus) Cultivars Indicates Activation of Salicylic Acid and Ethylene-Mediated Defenses in Response to Plasmodiophora brassicae

2020 ◽  
Vol 21 (21) ◽  
pp. 8381
Author(s):  
Qinqin Zhou ◽  
Leonardo Galindo-González ◽  
Victor Manolii ◽  
Sheau-Fang Hwang ◽  
Stephen E. Strelkov
Keyword(s):  
Salicylic Acid ◽  
Brassica Napus ◽  
Defense Mechanisms ◽  
Plasmodiophora Brassicae ◽  
Leucine Zippers ◽  
Brassica Napus L ◽  
Soilborne Disease ◽  
Essential Components ◽  
Genes Encoding ◽  
Respiratory Burst Oxidase

Clubroot, caused by Plasmodiophora brassicae Woronin, is an important soilborne disease of Brassica napus L. and other crucifers. To improve understanding of the mechanisms of resistance and pathogenesis in the clubroot pathosystem, the rutabaga (B. napus subsp. rapifera Metzg) cultivars ‘Wilhelmsburger’ (resistant) and ‘Laurentian’ (susceptible) were inoculated with P. brassicae pathotype 3A and their transcriptomes were analyzed at 7, 14, and 21 days after inoculation (dai) by RNA sequencing (RNA-seq). Thousands of transcripts with significant changes in expression were identified in each host at each time-point in inoculated vs. non-inoculated plants. Molecular responses at 7 and 14 dai supported clear differences in the clubroot response mechanisms of the two genotypes. Both the resistant and the susceptible cultivars activated receptor-like protein (RLP) genes, resistance (R) genes, and genes involved in salicylic acid (SA) signaling as clubroot defense mechanisms. In addition, genes related to calcium signaling and genes encoding leucine-rich repeat (LRR) receptor kinases, the respiratory burst oxidase homolog (RBOH) protein, and transcription factors such as WRKYs, ethylene responsive factors, and basic leucine zippers (bZIPs), appeared to be upregulated in ‘Wilhelmsburger’ to restrict P. brassicae development. Some of these genes are essential components of molecular defenses, including ethylene (ET) signaling and the oxidative burst. Our study highlights the importance of activation of genes associated with SA- and ET-mediated responses in the resistant cultivar. A set of candidate genes showing contrasting patterns of expression between the resistant and susceptible cultivars was identified and includes potential targets for further study and validation through approaches such as gene editing.

Genetic structure of Plasmodiophora brassicae populations virulent on clubroot resistant canola (Brassica napus)

Plant Disease ◽  
2021 ◽  
Author(s):  
Homa Askarian ◽  
Alireza Akhavan ◽  
Leonardo Galindo González ◽  
Sheau-Fang Hwang ◽  
Stephen Ernest Strelkov
Keyword(s):  
Brassica Napus ◽  
Genetic Structure ◽  
Plasmodiophora Brassicae ◽  
Single Spore ◽  
Specific Primers ◽  
Brassica Napus L ◽  
Before And After ◽  
Differential Hosts ◽  
And Migration ◽  
Simple Sequence

Clubroot, caused by Plasmodiophora brassicae Woronin, is a significant threat to the canola (Brassica napus L.) industry in Canada. Clubroot resistance has been overcome in more than 200 fields since 2013, representing one of the biggest challenges to sustainable canola production. The genetic structure of 36 single-spore isolates derived from 12 field isolates of P. brassicae collected before and after the introduction of clubroot resistant (CR) canola cultivars (2005-2014) was evaluated by simple sequence repeat (SSR) marker analysis. Polymorphisms were detected in 32 loci with the identification of 93 distinct alleles. A low level of genetic diversity was found among the single-spore isolates. Haploid linkage disequilibrium and number of migrants suggested that recombination and migration were rare or almost absent in the tested P. brassicae population. A relatively clear relationship was found between the genetic structure and virulence phenotypes of the pathogen as defined on the differential hosts of Somé et al., Williams and the Canadian Clubroot Differential (CCD) set. Although genetic variability within each pathotype group, as classified on each differential system, was low, significant genetic differentiation was observed among the pathotypes. The highest correlation between genetic structure and virulence was found among matrices produced with genetic data and the hosts of the CCD set, with a threshold index of disease of 50% to distinguish susceptible from resistant reactions. Genetically homogeneous single-spore isolates provided a more complete and clearer picture of the population genetic structure of P. brassicae, and the results suggest some promise for the development of pathotype-specific primers.

scholarly journals Impact of Foliar Application with Salicylic Acid on Biochemical Characters of Canola Plants under Cold Stress Condition

2016 ◽  
Vol 8 (1) ◽  
pp. 98-105 ◽  
Author(s):  
Hamed KESHAVARZ ◽  
Seyed Ali Mohammad MODARRES SANAVY ◽  
Ramin SADEGH GHOL MOGHADAM
Keyword(s):  
Salicylic Acid ◽  
Brassica Napus ◽  
Acid Treatment ◽  
Stress Condition ◽  
Foliar Application ◽  
Total Chlorophyll ◽  
Salicylic Acid Treatment ◽  
Biochemical Traits ◽  
Brassica Napus L ◽  
Salicylic Acid Concentration

In this study the effect of foliar application of salicylic acid on the chlorophyll content, antioxidant enzymes activity, and the content of solute protein and proline were investigated in two canola varieties (Brassica napus L., cv ‘RGS’ and ‘Licord’) leaves during 0, 24, and 48 hours after salicylic acid treatment. The results showed that the content of total chlorophyll was decreased in ‘RGS’ cultivar during the experiment and this process was related with increasing of salicylic acid concentration. The activity of superoxide dismutase, peroxidase, and also lipid peroxidation were increased significantly after 48 hours compared with the first day. The results of catalase activity showed that, this trait was decreased 24 hours after salicylic acid treatment and this decrease was related with salicylic concentration. The content of protein in both cultivars slightly changed and plants treated with salicylic acid had more protein content, by contrast proline was greatly affected by salicylic acid treatment and its content was the highest 24 hours after treatment. According to the present findings the application of salicylic acid has useful effects on the biochemical traits of Brassica napus cultivars. Therefore it may be effective for the improvement of plant growth in cold regions.

scholarly journals Virulence Spectrum of Single-Spore and Field Isolates of Plasmodiophora brassicae Able to Overcome Resistance in Canola (Brassica napus)

Plant Disease ◽  
2021 ◽  
Vol 105 (1) ◽  
pp. 43-52 ◽  
Author(s):  
Homa Askarian ◽  
Alireza Akhavan ◽  
Victor P. Manolii ◽  
Tiesen Cao ◽  
Sheau-Fang Hwang ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Confidence Interval ◽  
Plasmodiophora Brassicae ◽  
Large Collection ◽  
Single Spore ◽  
Brassica Napus L ◽  
Clubroot Resistance ◽  
Field Isolates ◽  
Virulence Spectrum ◽  
Important Disease

Clubroot, caused by Plasmodiophora brassicae Woronin, is an important disease of canola (Brassica napus L.) that is managed mainly by planting clubroot-resistant (CR) cultivars. Field isolates of P. brassicae can be heterogeneous mixtures of various pathotypes, making assessments of the genetics of host–pathogen interactions challenging. Thirty-four single-spore isolates were obtained from nine field isolates of the pathogen collected from CR canola cultivars. The virulence patterns of the single-spore and field isolates were assessed on the 13 host genotypes of the Canadian Clubroot Differential (CCD) set, which includes the differentials of Williams and Somé et al. Indices of disease (IDs) severity of 25, 33, and 50% (±95% confidence interval) were compared as potential thresholds to distinguish between resistant and susceptible reactions, with an ID of 50% giving the most consistent responses for pathotype classification purposes. With this threshold, 13 pathotypes could be distinguished based on the CCD system, 7 on the differentials of Williams, and 3 on the hosts of Somé et al. The highest correlations were observed among virulence matrices generated using the three threshold IDs on the CCD set. Genetically homogeneous single-spore isolates gave a clearer profile of the P. brassicae pathotype structure. Novel pathotypes, not reported in Canada previously, were identified among the isolates. This large collection of single-spore isolates can serve as a reference in screening and breeding for clubroot resistance.

Variation for virulence on Brassica napus L. amongst Plasmodiophora brassicae collections from France and derived single‐spore isolates

1996 ◽  
Vol 45 (3) ◽  
pp. 432-439 ◽  
Author(s):  
A. SOME ◽  
M. J. MANZANARES ◽  
F. LAURENS ◽  
F. BARON ◽  
G. THOMAS ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Plasmodiophora Brassicae ◽  
Single Spore ◽  
Brassica Napus L

scholarly journals Role of salicylic acid in heat stress tolerance in tri-genomic Brassica napus L.

2020 ◽  
Vol 33 (1) ◽  
pp. 13-20
Author(s):  
Muhammad Awais Ghani ◽  
Muhammad Mehran Abbas ◽  
Basharat Ali ◽  
Khurram Ziaf ◽  
Muhammad Azam ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Heat Stress ◽  
High Temperature ◽  
Brassica Napus ◽  
Biochemical Analysis ◽  
Foliar Application ◽  
Brassica Napus L ◽  
Elevated Activity ◽  
Heat Stress Tolerance

Tri-genomic Brassica napus L.wasdeveloped by the cross between Brassica napusand Brassica nigra. The crop is animportant source of vegetable seed oil in Pakistan,after cotton. The low oilseed rape yield is attributed to high temperature in the production zones. Interspecific hybridization using these two speciescan be helpful to produce heat resistant hybrids. On the other hand, it has been found that foliar application of different plant growth regulators can be used to reduce the heat stress in Brassica. The objectiveof this studywas to test the response of three different tri-genomic hybrids to high temperature stressat seedling stage. Seedlings were foliar sprayed with 0.13 mM salicylic acid (SA) prior to exposure tohigh temperatureat two true leaf stage. The plants were harvested after 30 days of sowing for growth and biochemical analysis. Plants ofV38 showed the highest values for all morphological traits and biochemical activities among the threehybrids. In general, plants exposed to the temperature stress exhibited a significant decline in growth, chlorophyll content and enzyme activity.Foliar application of SA significantly improved leaf and root biomass under heat stress.Further, antioxidativeenzyme activities significantly increased in response to SA either compared to control or to plants exposed to temperature stress.It is concluded thatapplication of salicylic acid elevated activity of antioxidative enzymes and was helpful in mitigating the detrimental effects of high temperature inoil seed rape.

scholarly journals Salicylic Acid Phytohormone Decreased the Toxicity Damage of Exogenous Lead Absorption in Seedlings of an Oilseed Plant, Brassica napus L. Grown in Hydroponic Conditions

2019 ◽  
pp. 1-15
Author(s):  
Mahdi Khozaei ◽  
Shiva Boroumand Jazi
Keyword(s):  
Salicylic Acid ◽  
Brassica Napus ◽  
Soluble Sugars ◽  
Lead Toxicity ◽  
Chlorophyll Synthesis ◽  
Dry Mass ◽  
Inhibitory Effects ◽  
Brassica Napus L ◽  
Carbohydrate Levels

Oilseed plant, Brassica napus L. seedlings grown in hydroponic condition with different concentrations of Pb were treated with salicylic acid (SA) to investigate the role of exogenous salicylic acid in alleviating lead toxicity on biochemical and physiological activities of the plant. The results showed that application of different concentrations of Pb increased soluble sugars and reduced carbohydrate levels significantly in roots and shoots of the plants. The stress induced by application of Pb triggered significant inhibitory effects on growth and chlorophyll synthesis induced on the production of protein and proline and enhanced the levels of antioxidant activity. Salicylic acid (SA) treated plants showed alleviation increasing total dry mass, leaf area, shoot and root length as well as leaf total chlorophyll content in responses to Pb stress. Results revealed the importance of salicylic acid (SA) activity in enabling plants to reduce the soluble sugars and increase of insoluble sugar in heavy -metal-stressed plants. The content of proline and proteins were also reduced in plants were treated with salicylic acid. Our data provide evidence that salicylic acid treatment decreased the activity of antioxidant enzymes in plants were exposed to different levels of Pb.

scholarly journals CRb and PbBa8.1 Synergically Increases Resistant Genes Expression upon Infection of Plasmodiophora brassicae in Brassica napus

Genes ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 202 ◽  
Author(s):  
Nadil Shah ◽  
Qian Li ◽  
Qiang Xu ◽  
Ju Liu ◽  
Fan Huang ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Defense Mechanisms ◽  
Plasmodiophora Brassicae ◽  
Dominant Role ◽  
Expression Patterns ◽  
Transcriptomic Response ◽  
Resistant Genes ◽  
Genetic Mechanisms ◽  
Parental Lines ◽  
Plant Hormone Signaling

PbBa8.1 and CRb are two clubroot-resistant genes that are important for canola breeding in China. Previously, we combined these resistant genes and developed a pyramid-based, homozygous recurrent inbred line (618R), the results of which showed strong resistance to Plasmodiophora brassicae field isolates; however, the genetic mechanisms of resistance were unclear. In the present work, we conducted comparative RNA sequencing (RNA-Seq) analysis between 618R and its parental lines (305R and 409R) in order to uncover the transcriptomic response of the superior defense mechanisms of 618R and to determine how these two different resistant genes coordinate with each other. Here, we elucidated that the number and expression of differentially expressed genes (DEGs) in 618R are significantly higher than in the parental lines, and PbBa8.1 shares more DEGs and plays a dominant role in the pyramided line. The common DEGs among the lines largely exhibit non-additive expression patterns and enrichment in resistance pathways. Among the enriched pathways, plant–pathogen interaction, plant hormone signaling transduction, and secondary metabolites are the key observation. However, the expressions of the salicylic acid (SA) signaling pathway and reactive oxygen species (ROS) appear to be crucial regulatory components in defense response. Our findings provide comprehensive transcriptomic insight into understanding the interactions of resistance gene pyramids in single lines and can facilitate the breeding of improved resistance in Brassica napus.

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