PT  - JOURNAL ARTICLE
AU  - Kumaran, Girishkumar
AU  - Pathak, Pradeep Kumar
AU  - Quandoh, Ebenezer
AU  - Mursalimov, Sergey
AU  - Devi, Jyoti
AU  - Alkalai-Tuvia, Sharon
AU  - Leong, Jia Xuan
AU  - Schenstnyi, Kyrylo
AU  - Levin, Elena
AU  - Üstün, Suayib
AU  - Michaeli, Simon
TI  - Autophagy Restricts Tomato Fruit Ripening Via a General Role in Ethylene Repression
AID  - 10.1101/2023.12.20.572633
DP  - 2024 Jan 01
TA  - bioRxiv
PG  - 2023.12.20.572633
4099  - http://biorxiv.org/content/early/2024/01/02/2023.12.20.572633.short
4100  - http://biorxiv.org/content/early/2024/01/02/2023.12.20.572633.full
AB  - Autophagy, a cellular degradation pathway, and the phytohormone ethylene function in plant development, senescence, and stress responses. However, the manner of their interaction is mostly unknown. We reasoned that this may be revealed by studying autophagy in a climacteric fruit ripening context, for which ethylene is crucial. During ripening, fruits undergo softening, color change, toxic compound degradation, volatile production, and sugar assembly by fine-tuning synthesis and degradation of their cellular content. For autophagy activity assessment, we analyzed autophagy-related 8 (ATG8) lipidation and GFP-ATG8-labeled autophagosome flux in tomato fruit cells. Autophagy activity increased sharply from ripening initiation, climaxed at its middle stage, and declined towards its end, resembling ethylene production dynamics. Silencing the core-autophagy genes SlATG2, SlATG7, and SlATG4 separately in mature fruits resulted in early ethylene production and ripening onset, which was abrogated by 1-methylcyclopropene (1-MCP), an ethylene signaling inhibitor. Beyond ripening, Arabidopsis atg5 and atg7 mutant seedlings exhibited elevated ethylene production and sensitivity to 1-Aminocyclopropane 1-carboxylic acid (ACC), ethylenès precursor, which induces autophagy. This research demonstrates that autophagy limits tomato fruit ripening via a general role in ethylene restriction, opening the path for a mechanistic understanding of autophagy-ethylene crosstalk and harnessing autophagy for fruit shelf-life extension.Competing Interest StatementThe authors have declared no competing interest.