Salicylic acid suppression of clubroot in broccoli (Brassicae oleracea var. italica) caused by the obligate biotroph Plasmodiophora brassicae

Lovelock, David A.; Donald, Caroline; Conlan, Xavier A.; Cahill, David M.

doi:10.1007/s13313-012-0167-x

Cited by 55 publications

(42 citation statements)

References 55 publications

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“…The accumulation of PRs via SA pathways has been reported in canola [27], and an exogenous application of SA to broccoli resulted in upregulation of PR-1 and PR-2 genes and a moderate reduction in clubroot severity [68]. The strong expression of BnPR2 ( β -1,3-glucanase) in this study, coupled with the evidence above, suggests possible involvement of PR-2 in Hc-mediated plant defence against clubroot, despite assertions that PRs are not essential for ISR [66].…”

Section: Discussionmentioning

confidence: 84%

Heteroconium chaetospira Induces Resistance to Clubroot via Upregulation of Host Genes Involved in Jasmonic Acid, Ethylene, and Auxin Biosynthesis

et al. 2014

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An endophytic fungus, Heteroconium chaetospira isolate BC2HB1 (Hc), suppressed clubroot (Plasmodiophora brassicae -Pb) on canola in growth-cabinet trials. Confocal microscopy demonstrated that Hc penetrated canola roots and colonized cortical tissues. Based on qPCR analysis, the amount of Hc DNA found in canola roots at 14 days after treatment was negatively correlated (r = 0.92, P<0.001) with the severity of clubroot at 5 weeks after treatment at a low (2×105 spores pot−1) but not high (2×105 spores pot−1) dose of pathogen inoculum. Transcript levels of nine B. napus (Bn) genes in roots treated with Hc plus Pb, Pb alone and a nontreated control were analyzed using qPCR supplemented with biochemical analysis for the activity of phenylalanine ammonia lyases (PAL). These genes encode enzymes involved in several biosynthetic pathways related potentially to plant defence. Hc plus Pb increased the activity of PAL but not that of the other two genes (BnCCR and BnOPCL) involved also in phenylpropanoid biosynthesis, relative to Pb inoculation alone. In contrast, expression of several genes involved in the jasmonic acid (BnOPR2), ethylene (BnACO), auxin (BnAAO1), and PR-2 protein (BnPR-2) biosynthesis were upregulated by 63, 48, 3, and 3 fold, respectively, by Hc plus Pb over Pb alone. This indicates that these genes may be involved in inducing resistance in canola by Hc against clubroot. The upregulation of BnAAO1 appears to be related to both pathogenesis of clubroot and induced defence mechanisms in canola roots. This is the first report on regulation of specific host genes involved in induced plant resistance by a non-mycorrhizal endophyte.

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Section: Discussionmentioning

confidence: 84%

Heteroconium chaetospira Induces Resistance to Clubroot via Upregulation of Host Genes Involved in Jasmonic Acid, Ethylene, and Auxin Biosynthesis

et al. 2014

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“…; Lovelock et al . ) led to a decrease in clubroot disease severity, but only if the treatment was prior to, or at very early time points after, inoculation. Later treatments did not result in a reduction of clubroot symptoms (Lovelock et al .…”

Section: Discussionmentioning

confidence: 99%

“…; Lovelock et al . ). This pattern coincides with the expression of PbBSMT , a gene encoding a SABATH‐type methyltransferase from P. brassicae that was detected as early as 4 days after inoculation (Ludwig‐Müller et al .…”

Section: Introductionmentioning

confidence: 97%

Arabidopsis thaliana expressing PbBSMT, a gene encoding a SABATH‐type methyltransferase from the plant pathogenic protist Plasmodiophora brassicae, show leaf chlorosis and altered host susceptibility

et al. 2018

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The plant pathogenic protist Plasmodiophora brassicae causes clubroot disease of Brassicaceae. This biotrophic organism can down-regulate plant defence responses. The previously characterised P. brassicae PbBSMT methyltransferase has substrate specificity for salicylic, benzoic and anthranilic acids. We therefore propose a role for the methylation of SA in attenuating plant defence response in infected roots as a novel strategy for intracellular parasitism. We overexpressed PbBSMT under the control of an inducible promoter in Arabidopsis thaliana and performed physiological, molecular and phytopathological analyses with the transgenic plants under control and induced conditions in comparison to the wild type. Upon induction, transcription of PbBSMT was associated with: (1) strong leaf phenotypes from anthocyanin accumulation and chlorosis followed by browning; (2) increased plant susceptibility after infection with P. brassicae that was manifested as more yellow leaves and reduced growth of upper plant parts; and (3) induced transgenic plants were not able to support large galls and had a brownish appearance of some clubs. Microarray data indicated that chlorophyll loss was accompanied by reduced transcription of genes involved in photosynthesis, while genes encoding glucose metabolism, mitochondrial functions and cell wall synthesis were up-regulated. Our results indicate a role for PbBSMT in attenuation of host defence responses in the roots by metabolising a plant defence signal.

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“…Exogenous application of SA to roots generally results in cross-compartment SAR. For instance, root SA application to broccoli results in systemic upregulation of the pathogenesisrelated genes PR-1 and PR-2 in leaves in a SAR-like response as early as 24-h post-treatment (101). Likewise, root SA application results in increased leaf levels of SA and PR proteins in tomato and a strong reduction in leaf lesions caused by the pathogen Alternaria solani (149).…”

Section: Cross-compartment Effects Of Exogenous Hormone Applicationmentioning

confidence: 99%

Plant-Mediated Systemic Interactions Between Pathogens, Parasitic Nematodes, and Herbivores Above- and Belowground

Biere

Goverse

2016

Annu. Rev. Phytopathol.

105

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Plants are important mediators of interactions between aboveground (AG) and belowground (BG) pathogens, arthropod herbivores, and nematodes (phytophages). We highlight recent progress in our understanding of within- and cross-compartment plant responses to these groups of phytophages in terms of altered resource dynamics and defense signaling and activation. We review studies documenting the outcome of cross-compartment interactions between these phytophage groups and show patterns of cross-compartment facilitation as well as cross-compartment induced resistance. Studies involving soilborne pathogens and foliar nematodes are scant. We further highlight the important role of defense signaling loops between shoots and roots to activate a full resistance complement. Moreover, manipulation of such loops by phytophages affects systemic interactions with other plant feeders. Finally, cross-compartment-induced changes in root defenses and root exudates extend systemic defense loops into the rhizosphere, enhancing or reducing recruitment of microbes that induce systemic resistance but also affecting interactions with root-feeding phytophages.

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Salicylic acid suppression of clubroot in broccoli (Brassicae oleracea var. italica) caused by the obligate biotroph Plasmodiophora brassicae

Cited by 55 publications

References 55 publications

Heteroconium chaetospira Induces Resistance to Clubroot via Upregulation of Host Genes Involved in Jasmonic Acid, Ethylene, and Auxin Biosynthesis

Heteroconium chaetospira Induces Resistance to Clubroot via Upregulation of Host Genes Involved in Jasmonic Acid, Ethylene, and Auxin Biosynthesis

Arabidopsis thaliana expressing PbBSMT, a gene encoding a SABATH‐type methyltransferase from the plant pathogenic protist Plasmodiophora brassicae, show leaf chlorosis and altered host susceptibility

Plant-Mediated Systemic Interactions Between Pathogens, Parasitic Nematodes, and Herbivores Above- and Belowground

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