A new study published in Nature by Zhou et al. has found that above-optimal growth temperatures, usually referred to as heat stress (HS), pose a challenge to the survival of organisms by interfering with essential physiological functions and disrupting the cellular organization. While previous studies have elucidated the complex transcriptional regulatory networks involved in plant HS responses, organellar remodeling and homeostasis mechanisms during plant HS adaptations have remained elusive.
The study reports a non-canonical function of ATG8 in regulating the restoration of plant Golgi damaged by HS. Short-term acute HS causes vacuolation of the Golgi apparatus and translocation of ATG8 to the dilated Golgi membrane. The inactivation of the ATG conjugation system, but not of the upstream autophagic initiators, abolishes the targeting of ATG8 to the swollen Golgi, causing a delay in Golgi recovery after HS.
Using TurboID-based proximity labeling, the study identified CLATHRIN LIGHT CHAIN 2 (CLC2) as an interacting partner of ATG8 via the AIM–LDS interface. CLC2 is recruited to the cisternal membrane by ATG8 to facilitate Golgi reassembly.
The study’s findings reveal a hitherto unanticipated process of Golgi stack recovery from HS in plant cells and uncover a previously unknown mechanism of organelle resilience involving ATG8. By understanding the mechanisms of organellar remodeling and homeostasis during plant HS adaptations, researchers can develop new approaches for breeding plants with improved heat stress tolerance, ultimately improving crop yields and food security.
The study’s findings provide important insights into the fundamental mechanisms underlying plant resilience to heat stress, highlighting the importance of scientific research in understanding the complex processes that underlie plant growth and development.
As global temperatures continue to rise, ensuring the resilience of plants to heat stress will become increasingly important for maintaining food security and sustainability. The findings of this study offer a promising new approach for improving plant resilience to heat stress, providing new opportunities for breeding plants that can better adapt to changing environmental conditions.
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