Tomato gene helps plants withstand heat, improving fruit quality

Jim Crocker
12th January, 2026

Tomato gene helps plants withstand heat, improving fruit quality

Overexpression of the autophagy gene SlATG8f enhances the thermotolerance of tomato (Solanum lycopersicum) fruits, which exhibit improved internal locular gel formation and morphological resilience under heat stress compared to wild-type plants.

Image adapted from: Cheng et al. / CC BY (Source)

Key Findings

  • In tomato plants, increasing the level of the SlATG8f gene improved fruit quality and resilience to heat stress during fruit development
  • Overexpressing SlATG8f boosted the activity of autophagy, a cellular recycling process, and increased the expression of genes that help plants cope with heat
  • SlATG8f overexpression accelerated fruit ripening and improved fruit set under high-temperature conditions, leading to better overall fruit quality
Plant cells, like all cells, constantly need to recycle components and remove damaged parts to stay healthy. This process is called autophagy, and it’s essential for plant growth, development, and responding to environmental stresses like heat[2]. Autophagy involves breaking down cellular material and reusing it, a bit like a cellular cleaning and recycling service. It’s particularly important when plants face challenges, helping them reallocate nutrients and maintain energy balance[2]. Researchers at Guizhou University[1] recently investigated the role of a specific gene involved in autophagy in tomatoes, called SlATG8f. ATG8 genes are key players in the autophagy process, and SlATG8f’s exact function in tomatoes wasn’t previously well understood. The study aimed to determine how SlATG8f influences tomato fruit quality when the plants are exposed to high temperatures. The team created tomato plants that overexpressed – meaning they produced more of – the SlATG8f gene, using a technique that allowed them to control the expression. They then compared these plants to normal, unaltered tomato plants (the ‘wild-type’) under normal and high-temperature conditions. They looked at several factors, including the levels of other ATG8 genes, genes related to heat shock proteins (which help plants cope with heat stress), and indicators of fruit ripening and quality. The results showed that plants with increased SlATG8f expression had higher levels of other ATG8 genes, suggesting that boosting SlATG8f enhances the overall autophagy process. They also observed increased expression of heat shock protein genes in the SlATG8f overexpressing plants, indicating a stronger response to heat stress. Importantly, these plants ripened faster and had improved fruit quality under high-temperature conditions. These findings build upon earlier research showing that autophagy is regulated by a complex network of proteins, including those that identify and mark cellular components for degradation[2][3]. Specifically, the study[3] detailed how certain E3 ligases, called SINAT proteins, control the stability of key autophagy proteins (ATG1 and ATG13) by adding a tag called ubiquitin. This tagging process signals the cell to break down these proteins, effectively controlling the rate of autophagy. The current study doesn’t directly investigate SINAT proteins, but highlights the importance of regulating autophagy components, as SlATG8f appears to influence the expression of other ATG8 genes and, consequently, the autophagy pathway. Furthermore, the discovery of autophagy receptors that target specific cargo for degradation[4] underscores the selectivity of this process. While this study doesn’t focus on specific cargo, the observed improvements in fruit quality suggest that SlATG8f might be involved in selectively removing damaged components that negatively impact fruit development during heat stress. The LIR motif, crucial for targeting receptors to the autophagy machinery[4], could be involved in this selective degradation, though this remains to be investigated. The research demonstrates that SlATG8f plays a regulatory role in maintaining tomato fruit quality during heat stress, likely by enhancing the overall autophagy process and improving the plant’s ability to cope with the stress. This provides a foundation for developing tomato varieties that are more resilient to high temperatures and can produce better quality fruit under challenging conditions.

FruitsAgriculturePlant Science

References

Main Study

1) SlATG8f modulates tomato thermotolerance and fruit quality, correlating with changes in autophagy and heat shock-related genes

Published 9th January, 2026

https://doi.org/10.1371/journal.pone.0334005

Related Studies

2) Autophagy: The Master of Bulk and Selective Recycling.

https://doi.org/10.1146/annurev-arplant-042817-040606

3) Arabidopsis SINAT Proteins Control Autophagy by Mediating Ubiquitylation and Degradation of ATG13.

https://doi.org/10.1105/tpc.19.00413

4) The LIR motif - crucial for selective autophagy.

https://doi.org/10.1242/jcs.126128


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