Nina Solia (Universität zu Köln)
Nina Solia's Master thesis was awarded with the Prize for the Best Plant Science Master Thesis, which was carried out at Universität zu Köln in the year 2024 with the title:
The Role of Pseudomonas putida Cip1 in Plant-Microbe Interaction
A protease inhibitor localized to the outer bacterial membrane might be involved in the colonization of maize roots by a plant-growth promoting rhizobacterium.
In Pseudomonas putida, a beneficial bacterium colonizing maize roots, the chagasin-like inhibitor Cip1 has been identified and demonstrated to inhibit maize root apoplastic Papain-like cysteine proteases (PLCPs). This Master Thesis aimed to investigate the cellular localization of Cip1 in P. putida and its potential role in root colonization. First, an in planta root colonization assay for maize was developed to evaluate root colonization by bacteria lacking Cip1. Our results show that within six days P. putida Δcip1 colonizes the root cortex as effectively as the wildtype indicating that Cip1 is not required for epiphytic colonization of maize roots. Second, we have successfully generated fluorescence-tagged P. putida strains containing a sfgfp genomic integration that can be used for further colonization studies. Finally, our localization experiments using cell fractionation and fluorescence microscopy have shown that Cip1 localizes to the outer bacterial membrane, confirming its lipoprotein prediction. These results lead us to the hypothesis that, upon endophytic colonization, Cip1 may prevent the release of microbial-associated molecular patterns from the bacterial cell surface by inhibiting PLCPs. Understanding the role of membrane-anchored Cip1 in plant colonization might provide insight into the strategies beneficial microbes use to colonize plants and might help in the application of beneficial microbes for plant protection.
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Nina Solia conducted this work at the institute of plant sciences in the working group of Prof. Dr. Gunther Döhlemann.