| dc.contributor.advisor | Ischebeck, Till Dr. | |
| dc.contributor.author | Guzha, Athanas | |
| dc.date.accessioned | 2020-04-02T10:18:26Z | |
| dc.date.available | 2020-04-02T10:18:26Z | |
| dc.date.issued | 2020-04-02 | |
| dc.identifier.uri | http://hdl.handle.net/21.11130/00-1735-0000-0005-1375-2 | |
| dc.identifier.uri | http://dx.doi.org/10.53846/goediss-7939 | |
| dc.language.iso | eng | de |
| dc.rights.uri | http://creativecommons.org/licenses/by-nc-nd/4.0/ | |
| dc.subject.ddc | 572 | de |
| dc.title | Targeted secretion and remodelling of pectin in response to pathogen infection | de |
| dc.type | doctoralThesis | de |
| dc.contributor.referee | Haughn, George Prof. Dr. | |
| dc.date.examination | 2019-08-15 | |
| dc.description.abstracteng | Plant cell walls are a complex mix of three major classes of polysaccharides; cellulose, hemicellulose and pectin together with a minor amount of proteins, and they surround every plant cell. Besides serving as a structural component helping to maintain the shape and integrity of the plant cell. Cell walls are an interaction interface between plant cells as well as the plant and its environment and they undergo various modifications in response to developmental and environmental changes. The attack of plants by plant pathogens results in the remodelling of the pectin component in response to the pathogens. The remodelling of pectin and its implications on plant-pathogen interactions are largely unknown. Here we firstly developed a robust GC-MS based method to analyse the monosaccharide profile of pectin extracted from leaves, mucilage and commercial pectin. The method is quick and easy, and both neutral sugars and galacturonic acid are quantified within the same run. We also investigate the enzymatic function of BXL4 which belongs to a seven-member betaxylosidase gene family in Arabidopsis. By expressing BXL4 in the seed coat of a bxl1 mutant, we can rescue the mucilage extrusion phenotype of bxl1. Monosaccharide analysis of the complemented bxl1 and over expression lines in Col-0 show that BXL4 acts on both xylose and arabinose in the cell walls. The bxl4 mutants exhibit higher amounts of arabinose in the leaf cell walls but this does not affect the general development of the plants. Wounding and Botrytis cinerea infection of Arabidopsis show that BXL4 is a stress induced gene and its expression is JA-Ile dependant. Whilst BXL4 was acting downstream of JA-Ile the bxl4 mutants show a reduction in the expression of JA-Ile marker genes JAZ10 and PDF1.2 upon infection and mechanical wounding, compared to wild type. The expression of PAD3 is also reduced in the bxl4 mutant compared to wild type after B. cinerea infection. Accumulation of JA-Ile and camalexin is reduced in the bxl4 mutants after infection with B. cinerea as compared to wild type plants. Infection of the plants with B. cinerea shows that the bxl4 mutants have an enhanced susceptibility to the pathogen. The post secretion remodelling of pectin by BXL4 is thus an important component of plant immunity against B. cinerea, and this is likely due to its role in JA-Ile signalling and camalexin biosynthesis. | de |
| dc.contributor.coReferee | Lipka, Volker Prof. Dr. | |
| dc.contributor.thirdReferee | Karlovsky, Petr Prof. Dr. | |
| dc.contributor.thirdReferee | Heimel, Kai Prof. Dr. | |
| dc.contributor.thirdReferee | Wiermer, Marcel Dr. | |
| dc.subject.eng | Pectin | de |
| dc.subject.eng | Rhamnogalacturonan I | de |
| dc.subject.eng | Plant defence | de |
| dc.subject.eng | mucilage | de |
| dc.subject.eng | JA-isoleucine | de |
| dc.subject.eng | Camalexin | de |
| dc.subject.eng | Botrytis cinerea | de |
| dc.identifier.urn | urn:nbn:de:gbv:7-21.11130/00-1735-0000-0005-1375-2-6 | |
| dc.affiliation.institute | Göttinger Graduiertenschule für Neurowissenschaften, Biophysik und molekulare Biowissenschaften (GGNB) | de |
| dc.subject.gokfull | Biologie (PPN619462639) | de |
| dc.identifier.ppn | 1693990962 | |