scholarly journals Transcriptomic response in symptomless roots of clubroot infected kohlrabi (Brassica oleracea var. gongylodes) mirrors resistant plants

2018 ◽  
Author(s):  
Stefan Ciaghi ◽  
Arne Schwelm ◽  
Sigrid Neuhauser

AbstractBackgroundClubroot disease caused by Plasmodiophora brassicae (Phytomyxea, Rhizaria) is one of the economically most important diseases of Brassica crops. The formation of hypertrophied roots accompanied by altered metabolism and hormone homeostasis is typical for infected plants. Not all roots of infected plants show the same phenotypic changes. While some roots remain uninfected, others develop galls of diverse size. The aim of this study was to analyse and compare the intra-plant heterogeneity of P. brassicae root galls and symptomless roots of the same host plants (Brassica oleracea var. gongylodes) collected from a commercial field in Austria using transcriptome analyses.ResultsTranscriptomes were markedly different between symptomless roots and gall tissue. Symptomless roots showed transcriptomic traits previously described for resistant plants. Genes involved in host cell wall synthesis and reinforcement were up-regulated in symptomless roots indicating elevated tolerance against P. brassicae. By contrast, genes involved in cell wall degradation and modification processes like expansion were up-regulated in root galls. Hormone metabolism differed between symptomless roots and galls. Brassinosteroid-synthesis was down-regulated in root galls, whereas jasmonic acid synthesis was down-regulated in symptomless roots. Cytokinin metabolism and signalling were up-regulated in symptomless roots with the exception of one CKX6 homolog, which was strongly down-regulated. Salicylic acid (SA) mediated defence response was up-regulated in symptomless roots, compared with root gall tissue. This is probably caused by a secreted benzoic acid salicylic acid methyl transferase from the pathogen (PbBSMT), which was one of the highest expressed pathogen genes in gall tissue. The PbBSMT derived Methyl-SA potentially leads to increased pathogen tolerance in uninfected roots.ConclusionsInfected and uninfected roots of clubroot infected plants showed transcriptomic differences similar to those previously described between clubroot resistant and susceptible hosts. The here described intra-plant heterogeneity suggests, that for a better understanding of clubroot disease targeted, spatial analyses of clubroot infected plants will be vital in understanding this economically important disease.


Genome ◽  
2016 ◽  
Vol 59 (6) ◽  
pp. 379-391 ◽  
Author(s):  
Ranjith Kumar Manoharan ◽  
Ashokraj Shanmugam ◽  
Indeok Hwang ◽  
Jong-In Park ◽  
Ill-Sup Nou

Brassica oleracea var. capitata (cabbage) is an important vegetable crop in Asian countries such as Korea, China, and Japan. Cabbage production is severely affected by clubroot disease caused by the soil-borne plant pathogen Plasmodiophora brassicae. During clubroot development, methyl salicylate (MeSA) is biosynthesized from salicylic acid (SA) by methyltransferase. In addition, methyl salicylate esterase (MES) plays a major role in the conversion of MeSA back into free SA. The interrelationship between MES and methytransferases during clubroot development has not been fully explored. To begin to examine these relationships, we investigated the expression of MES genes in disease-susceptible and disease-resistant plants during clubroot development. We identified three MES-encoding genes potentially involved in the defense against pathogen attack. We found that SS1 was upregulated in both the leaves and roots of B. oleracea during P. brassicae infection. These results support the conclusion that SA biosynthesis is suppressed during pathogen infection in resistant plants. We also characterized the expression of a B. oleracea BSMT gene, which appears to be involved in glycosylation rather than MeSA biosynthesis. Our results provide insight into the functions and interactions of genes for MES and methyltransferase during infection. Taken together, our findings indicate that MES genes are important candidates for use to control clubroot diseases.



Genes ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 71 ◽  
Author(s):  
Wei Zhang ◽  
Shenyun Wang ◽  
Fangwei Yu ◽  
Jun Tang ◽  
Li Yu ◽  
...  

Sugar transporter protein (STP) genes are involved in multiple biological processes, such as plant responses to various stresses. However, systematic analysis and functional information of STP family genes in Brassica oleracea are very limited. A comprehensive analysis was carried out to identify BoSTP genes and dissect their phylogenetic relationships and to investigate the expression profiles in different organs and in response to the clubroot disease. A total of 22 BoSTP genes were identified in the B. oleracea genome and they were further classified into four clades based on the phylogenetic analysis. All the BoSTP proteins harbored the conserved sugar transporter (Sugar_tr, PF00083) domain, and the majority of them contained 12 transmembrane helices (TMHs). Rates of synonymous substitution in B. oleracea relative to Arabidopsis thaliana indicated that STP genes of B. oleracea diverged from those of A. thaliana approximately 16.3 million years ago. Expression profiles of the BoSTP genes in different organs derived from RNA-Seq data indicated that a large number of the BoSTP genes were expressed in specific organs. Additionally, the expression of BoSTP4b and BoSTP12 genes were induced in roots of the clubroot-susceptible cabbage (CS-JF1) at 28 days after inoculation with Plasmodiophora brassicae, compared with mock-inoculated plants. We speculated that the two BoSTPs might be involved in monosaccharide unloading and carbon partitioning associated with P. brassicae colonization in CS-JF1. Subcellular localization analysis indicated that the two BoSTP proteins were localized in the cell membrane. This study provides insights into the evolution and potential functions of BoSTPs.



2021 ◽  
Vol 12 ◽  
Author(s):  
Karolina Stefanowicz ◽  
Monika Szymanska-Chargot ◽  
William Truman ◽  
Piotr Walerowski ◽  
Marcin Olszak ◽  
...  

Gall formation on the belowground parts of plants infected with Plasmodiophora brassicae is the result of extensive host cellular reprogramming. The development of these structures is a consequence of increased cell proliferation followed by massive enlargement of cells colonized with the pathogen. Drastic changes in cellular growth patterns create local deformities in the roots and hypocotyl giving rise to mechanical tensions within the tissue of these organs. Host cell wall extensibility and recomposition accompany the growth of the gall and influence pathogen spread and also pathogen life cycle progression. Demethylation of pectin within the extracellular matrix may play an important role in P. brassicae-driven hypertrophy of host underground organs. Through proteomic analysis of the cell wall, we identified proteins accumulating in the galls developing on the underground parts of Arabidopsis thaliana plants infected with P. brassicae. One of the key proteins identified was the pectin methylesterase (PME18); we further characterized its expression and conducted functional and anatomic studies in the knockout mutant and used Raman spectroscopy to study the status of pectin in P. brassicae-infected galls. We found that late stages of gall formation are accompanied with increased levels of PME18. We have also shown that the massive enlargement of cells colonized with P. brassicae coincides with decreases in pectin methylation. In pme18-2 knockout mutants, P. brassicae could still induce demethylation; however, the galls in this line were smaller and cellular expansion was less pronounced. Alteration in pectin demethylation in the host resulted in changes in pathogen distribution and slowed down disease progression. To conclude, P. brassicae-driven host organ hypertrophy observed during clubroot disease is accompanied by pectin demethylation in the extracellular matrix. The pathogen hijacks endogenous host mechanisms involved in cell wall loosening to create an optimal cellular environment for completion of its life cycle and eventual release of resting spores facilitated by degradation of demethylated pectin polymers.



Genome ◽  
2020 ◽  
Vol 63 (2) ◽  
pp. 91-101 ◽  
Author(s):  
Mehdi Farid ◽  
Rong-Cai Yang ◽  
Berisso Kebede ◽  
Habibur Rahman

Clubroot disease caused by Plasmodiophora brassicae is a challenge to Brassica crop production. Breakdown of resistance controlled by major genes of the Brassica A genome has been reported. Therefore, identification of resistance in the Brassica C genome is needed to broaden the genetic base of resistance in Brassica napus canola. In this study, we evaluated 135 Brassica oleracea accessions, belonging to eight variants of this species to identify resistant accessions as well as to identify the genomic regions associated with resistance to two recently evolved P. brassicae pathotypes, F3-14 (3A) and F-359-13 (5X L-G2). Resistance to these pathotypes was observed more frequently in var. acephala (kale) followed by var. capitata (cabbage); few accessions also carried resistance to both pathotypes. Association mapping using single nucleotide polymorphism (SNP) markers developed through genotyping by sequencing technique identified 10 quantitative trait loci (QTL) from six C-genome chromosomes to be associated with resistance to these pathotypes; among these, two QTL associated with resistance to 3A and one QTL associated with resistance to 5X L-G2 carried ≥3 SNP markers. The 10 QTL identified in this study individually accounted for 8%–18% of the total phenotypic variance. Thus, the results from this study can be used in molecular breeding of Brassica crops for resistance to this disease.



2020 ◽  
Author(s):  
Julia Badstöber ◽  
Stefan Ciaghi ◽  
Sigrid Neuhauser

AbstractBiotic interactions of plants and microbial pathogens can cause drastic changes in cell wall composition in response to developmental reprogramming caused as consequence of an infection. Clubroot disease, caused by the biotrophic plant pathogen Plasmodiophora brassicae (Phytomyxea, Rhizaria), is the economically most important disease of Brassica crops worldwide. The disease is best known by the characteristic hypertrophied roots (root galls, clubroots). Amongst a series of physiological changes of the host tissue, the formation of the characteristic root galls leads to cell wall modification and reorganization. Cell wall chemistry and the hosts genetic repertoire are discussed to play a role in the resilience of plants against clubroot disease. Plant cells infected with P. brassicae are markedly enlarged, and look very differently from uninfected, healthy cells. Here we systematically review cell wall related processes that lead to the typical clubroot phenotype and provide novel insights how P. brassicae uses these modifications to benefit its own development. An infection with P. brassicae impacts on nearly all cell wall related processes, but all alterations are meaningful for successful growth and development of P. brassicae. Processes related to cell wall stability and rigidity (e.g. cellulose, pectin or lignin synthesis) are down-regulated, while cell wall degrading enzymes or processes that increase the flexibility of the host cell wall (e.g. expansin) are up-regulated. The here presented findings indicate that P. brassicae weakens the structural stability of its host cell while it increases its elasticity, which in consequence allows P. brassicae to grow bigger and ultimately to develop more resting spores. Consequently, the understanding of the modification of the host cell wall is important for the formation of the characteristic root galls but also to better understand clubroot disease.



Horticulturae ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 9
Author(s):  
Regina Mencia ◽  
Elina Welchen ◽  
Susann Auer ◽  
Jutta Ludwig-Müller

The clubroot disease (Plasmodiophora brassicae) is one of the most damaging diseases worldwide among brassica crops. Its control often relies on resistant cultivars, since the manipulation of the disease hormones, such as salicylic acid (SA) alters plant growth negatively. Alternatively, the SA pathway can be increased by the addition of beneficial microorganisms for biocontrol. However, this potential has not been exhaustively used. In this study, a recently characterized protein Oxidation Resistant 2 (OXR2) from Arabidopsis thaliana is shown to increase the constitutive pathway of SA defense without decreasing plant growth. Plants overexpressing AtOXR2 (OXR2-OE) show strongly reduced clubroot symptoms with improved plant growth performance, in comparison to wild type plants during the course of infection. Consequently, oxr2 mutants are more susceptible to clubroot disease. P. brassicae itself was reduced in these galls as determined by quantitative real-time PCR. Furthermore, we provide evidence for the transcriptional downregulation of the gene encoding a SA-methyltransferase from the pathogen in OXR2-OE plants that could contribute to the phenotype.



2012 ◽  
Vol 48 (No. 4) ◽  
pp. 156-161 ◽  
Author(s):  
P. Kopecký ◽  
I. Doležalová ◽  
M. Duchoslav ◽  
K. Dušek

Fifty genotypes of cauliflovwer (Brassica oleracea var. botrytis) were evaluated for resistance to clubroot disease (Plasmodiophora brassicae Wor.) under controlled conditions in a plant growth chamber. The cultivars with the highest resistance were Brilant, Agora, and Bora, while the most susceptible were the cultivars White Top, White Fox, and Octavian. The variation in disease index is probably due to different pathogenicity rates of clubroot pathotypes and genetic heterogeneity of European cauliflower cultivars. The obtained results will be tested in an infested and non-infested field.  



Genome ◽  
1992 ◽  
Vol 35 (3) ◽  
pp. 409-420 ◽  
Author(s):  
Benoit S. Landry ◽  
Nathalie Hubert ◽  
René Crete ◽  
Morgan S. Chang ◽  
Steven E. Lincoln ◽  
...  

F2 segregation analyses of DNA restriction fragment length polymorphisms (RFLPs) detected between a cabbage line (No. 86-16-5) resistant to race 2 of Plasmodiophora brassicae (Woronin), the fungus responsible for clubroot disease, and a rapid cycling line (CrGC No. 85) was used to construct a detailed genetic map of Brassica oleracea. RFLP markers were random and seedling-specific cDNA clones. The 201 loci so far mapped in B. oleracea covered 1112 cM. They are assembled into nine major linkage groups and four small linkage groups. Twelve loci were found unlinked to any other markers. Twenty-one loci were detected with the 18 seedling-specific cDNAs. Two dominant QTLs for resistance to race 2 of the clubroot disease causal agent were also identified. Leaf morphology and biennial flowering appeared to segregate as single Mendelian traits, but only leaf morphology could be linked to other markers. This RFLP study in B. oleracea is providing additional information on genome organization and complements current RFLP mapping effort in B. napus.Key words: genetic mapping, Brassica oleracea, Plasmodiophora brassicae, breeding, clubroot resistance, DNA markers, RFLP.



Author(s):  
Ni Nengah Darmiati ◽  
I Made Sudarma

DIVERSITY OF SUPRESSIVE LAND MICROFLORA IN CONTROL OF PALLDER DISEASE IN CUBES PLANT (BRASSICA OLERACEA L.)Cabbage (Brassica oleracea L.) was a vegetable crops cultivated in the highlands to meet the needs of the community vegetable. The main obstacle was the cultivation of cabbage root disease outbreak mace (clubroot), which until now have not found an effective control techniques. Clubroot disease caused by organisms that resemble fungi: Plasmodiophora brassicae Wor. which was the soil inhibitant and soil borne pathogen. Therefore, there must be a way to control environmentally friendly by using suppressive soil, find microbes antagonists related to the cabbage plant habitat in the soil. The results showed that the index of diversity both on suppressive and conducive soil of 1.2304 and 1.2811 respectively, and the index of dominance on the suppressive and conducive soil were 0.6677 and 0.6838.  Prevalence micoflora of the suppressive soil amounted to 44.22 % and 43.06 % conducive soil all dominated by Fusarium spp. Microbial antagonist as a potential control of P. brassicae was Trichoderma sp. Based on the analysis in the suppressive soil as much as 171 x 103 cfu /g soil, higher than on the conducive soil to 90 x 103 cfu /g soil.



2013 ◽  
Vol 41 (2) ◽  
pp. 237-243 ◽  
Author(s):  
R. L. Gabrielson ◽  
Józef Robak

Several methods were evaluated in an attempt to develop a greenhouse screening procedure that would predict field resistance of brassica breeding lines to clubroot disease caused by <i>Plasmodiophora brassicae</i>. Several <i>Brassica oleracea</i> cultivars and breeding lines bred for resistance to <i>Plasmodiophora brassicae</i> and a susceptible Chinese cabbage cultivar were exposed to high levels of inoculum of both pathotypes PB 6, PB 7 at 12, 15, 20, 25 and 30°C. No infection occurred on any host at 12°C. Chinese cabbage was heavily diseased from 15-30°C. Bagder Shipper cabbage, a cauliflower deriving resistance from this variety, and Oregon CR-1 broccoli were resistant to pathotype PB 6 at 15 and 20°C and partially resistant at 25 and 30°C. They were resistant to pathotype PB 7 and 15°C and almost totally susceptible at 20, 25° and 30°C. Oregon cabbage line OR 123 was resistant to pathotype PB 6 at 15°C at almost completely susceptible at 20, 25 and 30°C. It was resistant to pathotype PB 7 at all temperatures. Temperature sensitivity of resistance can partially explain why breeding lines are resistant in field trials and susceptible in greenhouse tests.



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