## 1 Introduction  
There are only two species of flowering plants in the Antarctic Peninsula, Antarctic hairgrass (_Deschampsia antarctica_) and Antarctic pearlwort (_Colobanthus quitensis_). During their entire life cycle, Antarctic plants are exposed to multiple abiotic stresses, including extreme temperatures, varying oxygen concentrations, water and nutrient deficiency, extremely short growing seasons, common summer frosts, strong winds, low light quality, and photoperiod changes [1; 2; 3; 4]. Low temperatures, particularly freezing temperatures, can dramatically affect plants from the cellular level to ecosystem scales [5]. To overcome extreme temperature conditions, these Antarctic plant species have evolved a wide range of cell rescue systems involved in physiological and molecular functions for increasing their cold resistance through enhanced metabolic rate upon cold acclimation [4; 6; 7]. For example, plants in the Antarctic region have long life cycles, extended leaf and flower primordia development, well-developed root systems, and efficient photosynthetic and respiratory systems at \(\leq\)10 \({}^{\circ}\)C [2; 6; 8; 9]. Various cellular changes induced by low-temperature lead to the excess accumulation of toxic compounds, particularly reactive oxygen species (ROS) [2; 10]. The high accumulation of ROS generates oxidative stress [11]. ROS can induce DNA damage, protein oxidation, membrane lipid peroxidation and pigment destruction [2; 6; 12]. Therefore, a considerable amount of research has been conducted to explore the correlation between ROS scavenging and plant stress tolerance under extreme temperatures [13; 14; 15]. To neutralize ROS generated by cold stress, plants, including those in the Antarctic, have developed a wide range of cell rescue systems such as antioxidant systems [15; 16; 17]. One includes enzymatic components, such as superoxide dismutase, catalase (CAT), glutathione (GSH) peroxidase, and peroxideroxins, and especially the ascorbate (AsA)-GSH cycle in plants [18; 19]. The other component includes non-enzymatic antioxidants, including ascorbic acid (AsA; vitamin C), GSH, flavonoids, and polyphenol-derived compounds [20]. Among them, AsA, an abundant component of plants, plays an important role as a strong and active ROS scavenger [11]. Under oxidative stress, AsA directly participates in detoxifying excess ROS and leads to oxidized forms [21]. In this process, AsA is oxidized to monodehydroascorbate (MDHA), and MDHA is further oxidized to dehydroacorbate (DHA) via spontaneous reaction [19]. To enhance the antioxidative capacity and redox state of AsA after an increased AsA pool, oxidized AsA is required to reduce AsA via rapid, effective recycling mediated by DHA reductase (DHAR) and MDHA reductase (MDHAR) in the presence of GSH [11; 22]. Several studies have reported that overexpression of either _DHAR_ or _MDHAR_ enhanced plant resistance against various abiotic stresses [23; 24; 25]. It is particularly suggested that the role of MDHAR in AsA regeneration is more efficient than that of DHAR under oxidative stress [21; 26]. Therefore, the improvement of acquired tolerance to extreme temperatures is often related to enhanced activities of enzymes involved in the antioxidant systems of plants [11; 27]. _Saccharomyces cerevisiae_ is a eukaryotic unicellular budding yeast widely distributed in natural environments as well as found in association with various insects, animals, and plants [28; 29]. _S. cerevisiae_ plays an important role in food chains and nutrient cycles such as nitrogen and sulfur and is used to produce food, beverages, chemicals, pharmaceuticals, biocontrol agents, and industrial enzymes as well as in agriculture [30; 31]. Moreover, _S. cerevisiae_ is the main yeast responsible for biomass-based alcoholic fermentation using hydrolyzed glucose derived from rice, wheat, barley, corn, and grape in a commercially important plant-based agriculture field [32; 33].