Universität zu Köln

Huang, Luyao (2023). Functional characterization of the Ustilago maydis effector genes UMAG_11060 and UMAG_05306. PhD thesis, Universität zu Köln.

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Abstract

Ustilago maydis causes corn smut and triggers tumor formation in all aerial parts of maize. To adapt to the host plant and promote disease progression, U. maydis uses effector proteins that exhibit organ-specific expression and adaptation during infection. This study focuses on two of these effectors, UMAG_11060 and UMAG_05306. This study characterizes UMAG_11060 (Chapter 2), which encodes the effector protein TOPLESS (TPL) interacting protein 6 (Tip6). The study shows that Tip6 interacts with the N-terminal region of ZmTPL2 through its two EAR (ethylene-responsive element binding factor-associated amphiphilic repression) motifs. These motifs are crucial for virulence function and alter the nuclear distribution pattern of ZmTPL2, disrupting host transcriptional regulation. This disruption leads to the down-regulation of 13 transcription factors in the AP2/ERF B1 subfamily. This study proposes a regulatory mechanism in which Tip6 uses repressive domains to recruit the corepressor ZmTPL2, thereby disrupting the transcriptional networks of the host plant. The second part of the thesis focuses on the characterization of UMAG_05306 (Chapter 3), which exhibits highly specific subcellular localization and appears as thick and twisted filament-like structures. The study shows that UMAG_05306 interacts with four maize dynamin related proteins (DRPs) and is able to interact with both the N- terminal and C-terminal of ZmDRP5. Three DRPs are found to interact with maize tubulin. Furthermore, UMAG_05306 directly interacts with tubulin. These findings shed light on their potential roles in U. maydis infection. In conclusion, this study provides insight into the molecular mechanisms underlying U. maydis infection and reveals the importance of UMAG_11060 and UMAG_05306 effectors for virulence and tumor formation.

Item Type:	Thesis (PhD thesis)
Creators:	Creators Email ORCID ORCID Put Code Huang, Luyao lhuang4@uni-koeln.de UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-714471
Date:	October 2023
Language:	English
Faculty:	Faculty of Mathematics and Natural Sciences
Divisions:	Faculty of Mathematics and Natural Sciences > Department of Biology > Botanical Institute
Subjects:	Natural sciences and mathematics Agriculture
Uncontrolled Keywords:	Keywords Language Ustilago maydis English effector English TOPLESS (TPL) interacting protein English
Date of oral exam:	7 August 2023
Referee:	Name Academic Title Doehlemann, Gunther Professor Thomma, Bart Professor Hofmann, Kay Professor
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/71447