The target of rapamycin (TOR) kinase is a central signaling hub that plays a crucial role in precisely orchestrating plant growth, development, and stress responses. This suggests that TOR is intricately involved in maintaining the balance between plant growth and stress responses. Nevertheless, despite the observed effects, the specific mechanisms through which TOR operates in these processes remain obscure. In this study, we investigated how the tomato (Solanum lycopersicum) TOR (SlTOR) affects plant growth and cold responses. We demonstrated that SlTOR inhibition transcriptionally primes cold stress responses, consequently enhancing tomato cold tolerance. A widely targeted metabolomics analysis revealed the disruption of amino acid metabolism homeostasis under cold stress upon SlTOR inhibition, which led to the accumulation of two important cryoprotective metabolites: salicylic acid (SA) and putrescine (Put). Next, we discovered SlPGH1 (2-PHOSPHO-D-GLYCERATE HYDRO-LYASE) as a direct substrate of SlTOR. Inhibiting SlTOR led to increased SlCBF1 (C-REPEAT-BINDING FACTOR 1) expression via SlPGH1, potentially triggering the activation of cold-responsive genes and subsequent metabolic alterations. Our study provides a mechanistic framework that elucidates how SlTOR modulates amino acid-related metabolism to enhance tomato cold tolerance, which sheds light on the complex interplay between growth and stress responses orchestrated by TOR.

Global warming is leading to an increase in extreme-temperature events, posing a significant threat to crop productivity and global food security. Plants have evolved sophisticated mechanisms to perceive and respond to both heat and cold stress. While these mechanisms share certain similarities, they also exhibit distinct differences, enabling plants to effectively cope with extreme temperatures. This review summarizes recent findings on the mechanisms underlying plant perception and response to extreme temperature stresses. Additionally, we compare the signaling pathways for heat and cold stress in plants and discuss the remaining challenges in the field. Finally, we address unresolved issues and propose future directions.

The target of rapamycin (TOR) kinase is an evolutionarily conserved atypical Ser/Thr protein kinase present in yeasts, plants, and mammals. In plants, TOR acts as a central signaling hub, playing a pivotal role in the precise orchestration of growth and development. Extensive studies have underscored its significant role in these processes. Recent research has further elucidated TOR’s multifaceted roles in plant stress adaptation. Furthermore, mounting evidence indicates TOR’s role in mediating the plant metabolome. In this review, we will discuss recent findings on the involvement of TOR signaling in plant adaptation to various abiotic and biotic stresses, with a specific focus on TOR-regulated metabolome reprogramming in response to different stresses.

The target of rapamycin (TOR) kinase is an evolutionarily conserved atypical Ser/Thr protein kinase found in yeasts, plants, and mammals. In plants, TOR functions as a central signaling hub, playing a crucial role in the precise orchestration of growth and development. Extensive studies have underscored its significance in plant signaling by highlighting its integral role in these processes. Recent research has further elucidated TOR's multifaceted roles in plant responses to environmental stresses, emphasizing its importance in stress adaptation. In this review, we will discuss recent findings on the involvement of TOR signaling in plant adaptation to various abiotic and biotic stresses. Moreover, mounting evidence indicates TOR’s role in mediating the plant transcriptome. Therefore, we will specifically discuss TOR-regulated metabolome reprogramming in plant response to different stresses.