involved in iron bioavailability and the inhibition of ferritin degradation, protecting from anemia, in the biosynthesis of many signaling peptides, in cytochrome P450 dependent hydroxylation, in collagen formation, while it also serves as a co-factor of hydroxylases [8]. Severe AsA deficiency may cause scurvy [9; 10]. Due to its ability to modulate epigenome, AsA has been recently proposed as an effective anti-cancer molecule [11]. An average requirement of 90 mg/day for men and 80 mg/day for women, has been recommended by the European Food Safety Authority, but this recommended intake can be significantly higher for pregnant women or when adults are exposed to stress, smoking, or alcoholism, which cause a rapid decline in plasma ascorbate concentration ([[https://efsa.onlinelibrary.wiley.com/doi/pdf/10.2903/sp.efsa.2017.e15121](https://efsa.onlinelibrary.wiley.com/doi/pdf/10.2903/sp.efsa.2017.e15121)]([https://efsa.onlinelibrary.wiley.com/doi/pdf/10.2903/sp.efsa.2017.e15121](https://efsa.onlinelibrary.wiley.com/doi/pdf/10.2903/sp.efsa.2017.e15121)), accessed on 5 May 2021). Although vitC-deficiency has declined throughout time, especially in developing countries, the recent fatal human coronavirus disease (named COVID-19), necessitates a diet rich in vitC for good health. In particular, vitC has been recently demonstrated to act beneficially not only as prophylaxis (at low doses) but also in cases of severe COVID-19, as vitC can reduce inflammatory mediators including interleukin-6 and endothelin-1, which drive pneumonia and respiratory failure in hypertensive and diabetic adult patients [12].  
In spite of the fact that chemically synthesized AsA is nearly indistinguishable from the plant-derived one, fresh fruits and vegetables serve as the main source of vitC for humans [3]. Interactions with other phytonutrients, especially vitamin E, should be also taken into consideration when studying the bioavailability of ascorbate [6], although findings so far dictate whether bioavailability is higher or lower in plant-derived resources compared to synthetic supplements [8].  
Due to its remarkable functions in plant growth and development, in plant abiotic stress responses, as well as its nutritional benefits in the human diet, genetic regulation of AsA in plant species with edible organs, and in particular tomato (_Solanum Lycopersicum_ L.), has received considerable attention over the last years. Tomato is one of the most pronounced vegetable crops worldwide, being considered as a model species to investigate ripening and quality attributes in fruit species. Despite accumulating moderate levels of AsA in fruits, tomato has been employed extensively to study AsA metabolic pathways in fruits, probably due to its significance in the human diet, as well as its high levels of consumption [13; 14; 15].  
Currently, commercial varieties and hybrids seem to possess lower amounts of AsA in many fruit crop species, including tomato, compared to wild relatives, probably as a joint result of the dilution effect and the optimum-devoid of stress-greenhouse growing conditions [3]. Conceptually, the enhancement of AsA in plants represents a strategic goal for improved human health. On the basis of these considerations, this review attempts to elucidate recent findings in the genetic factors underlying AsA accumulation in fruit species, focusing on tomato, for improved fruit quality and alleviation of abiotic stress.