Abstract

Autophagy is an evolutionarily conserved catabolic pathway in eukaryotes, mediated by AuTophaGy related proteins (ATGs). It serves as a housekeeping mechanism by degrading diverse cellular components ranging from protein aggregates to entire organelles. Autophagy can either execute bulk degradation or exhibit high selectivity in targeting its cargo in response to the prevailing environmental conditions. In this thesis, we began by investigating adaptations of autophagy in the autotrophic and heterotrophic organs of plants. Our study revealed organ-specific dynamics of autophagic response in Arabidopsis thaliana under different stress conditions, with roots consistently exhibiting an earlier and more robust activity than shoots. We further identified the spatiotemporal autophagic selectivity towards different organelles under bulk autophagy-inducing conditions. In an effort to uncover distinctions in the autophagy machinery responsible for these plant-specific autophagic responses, we discovered that the ATG4-mediated delipidation of ATG8, previously considered a fundamental step in all eukaryotes, is dispensable in Arabidopsis thaliana. Further investigation into the plant ATG proteins led to the discovery of their potential roles beyond autophagy, as exemplified by the interactome of ATG5 which includes, among others, proteins involved in the endomembrane trafficking system and components of the ubiquitin-proteasome system. We developed two specialized tools to enable the above studies: SPIRO, an automated time-lapse imaging system designed for conducting phenotypical assays, and RoPod, dedicated microscopy chambers that aid in low-stress imaging of Arabidopsis roots.

Keywords

Arabidopsis; roots; shoots; autophagy; stress; selectivity; ATG4; ATG8; ATG5; tools

Published in

Acta Universitatis Agriculturae Sueciae
2023, number: 2023:91
ISBN: 978-91-8046-236-5, eISBN: 978-91-8046-237-2
Publisher: Swedish University of Agricultural Sciences

SLU Authors

• Holla, Sanjana

  • Department of Molecular Sciences, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Biochemistry and Molecular Biology


Publication identifier

DOI: https://doi.org/10.54612/a.4n27me0ojg

Permanent link to this page (URI)

https://res.slu.se/id/publ/126464