Plasmodiophora brassicae-Triggered Cell Enlargement and Loss of Cellular Integrity in Root Systems Are Mediated by Pectin Demethylation
| Autor: | Arkadiusz Kosmala, Robert Malinowski, Karolina Stefanowicz, Adam Augustyniak, Artur Zdunek, William Truman, Marcin Olszak, Piotr Walerowski, Monika Szymańska-Chargot |
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| Rok vydání: | 2021 |
| Předmět: |
0106 biological sciences
0301 basic medicine Arabidopsis thaliana clubroot disease Plant Science Biology 01 natural sciences SB1-1110 Clubroot Extracellular matrix Cell wall 03 medical and health sciences medicine Gall Pathogen Original Research Demethylation Cell growth Cell Enlargement fungi Plant culture food and beverages medicine.disease Cell biology 030104 developmental biology Plasmodiophora brassicae cell wall cell enlargement 010606 plant biology & botany |
| Zdroj: | Frontiers in Plant Science, Vol 12 (2021) Frontiers in Plant Science |
| ISSN: | 1664-462X |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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