Universität zu Köln

Sengupta, Priyamedha ORCID: 0000-0001-9728-8503 (2023). Elucidating the role of Glycoside Hydrolase 25 in microbial antagonsim. PhD thesis, Universität zu Köln.

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Abstract

Plant organs are colonized by microorganisms, ranging from beneficial, commensals and pathogenic, which interact among themselves to establish a community. Rhizosphere microbiota is extensively characterized regarding their roles in protection of host plant against pathogenic microbes and in overall plant growth and development. However, the phyllosphere is also enriched with microbial interactions, aiding in plant immunity and protection. In this study, it was shown how a basidiomycete yeast Moesziomyces bullatus ex Albugo on Arabidopsis (MbA) antagonizes the white rust pathogen Albugo laibachii by expressing Glycoside Hydrolase 25 (GH25) protein on Arabidopsis thaliana. Recombinantly produced MbA_GH25 also reduced A. laibachii growth in-planta, identifying the hydrolase gene to be a major effector of MbA mediated antagonism. GH25 proteins are present in various plant�associated fungi, however, their mechanism of action is unknown. To elucidate the mechanism behind MbA_GH25 activity, two strategies were employed: firstly, testing purified MbA_GH25 as an elicitor of plant immunity and secondly, analyzing the impact of MbA_GH25 on bacterial associations of A. laibachii. The potential antagonistic activity of MbA_GH25 towards the oomycetes Hyaloperenospora arabidopsidis and Phytophthora infestans have been investigated as well. Alongside the role of GH25 in related smut pathogen, U. maydis has been explored in this study to understand the impact of the hydrolase gene expression on fungal pathogenicity. Taken together, we functionally characterize the role of fungal GH25 proteins to deepen our understanding of microbial interactions in the phyllosphere and carve a path for the development of newer antimicrobials for plant protection.

Item Type:	Thesis (PhD thesis)
Creators:	Creators Email ORCID ORCID Put Code Sengupta, Priyamedha priyamedhasg@gmail.com orcid.org/0000-0001-9728-8503 UNSPECIFIED
URN:	urn:nbn:de:hbz:38-647558
Date:	6 February 2023
Language:	English
Faculty:	Faculty of Mathematics and Natural Sciences
Divisions:	CEPLAS - Cluster of Excellence on Plant Sciences
Subjects:	Natural sciences and mathematics
Uncontrolled Keywords:	Keywords Language plant-microbe English antagonsim English Glycoside Hydrolase UNSPECIFIED
Date of oral exam:	23 January 2023
Referee:	Name Academic Title Doehlemann, Gunther Prof. Dr. Thomma, Bart Prof. Dr.
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/64755