Abstract Potato plays a crucial part in meeting the energy and dietary requirements of the global population. It is imperative to acquire PEG-resistant and productive strains by comprehending the physiological and molecular processes underlying potato’s ability to withstand water scarcity. In order to evaluate the significance of antioxidant response and potential participation of resilient genes in coping with PEG-treatment, we examined the leaves and roots of five distinct potato cultivars varying in their sensitivity to water stress. The levels of chlorophyll and anthocyanin, as well as sugar and antioxidant enzyme activity, were utilized as markers to categorize the genotypes as either tolerant or sensitive to PEG-treatment. These results showed that physiological traits were differentially affected by PEG-treatment in the genotypes. Among the five contrasting Solanum tuberosum genotypes analyzed under PEG-induced osmotic stress, D220 exhibited the highest number of up-regulated tolerance genes, distinguishing it as the most responsive genotype at the transcriptional level (Bahar, Avin, D394, and KG911-91). The highest antioxidant enzyme activity in the leaves and roots were observed in the genotypes D220 and Bahar. Although, StANN1 and StNRTs are traditionally considered negative regulators of ABA signaling and drought resistance, in our study, gene expression levels of StANN1 and StNRTs were found to be highest in both leaves and roots of genotype D220, which also exhibited superior physiological resilience under PEG-induced drought stress. This may be associated with increased tolerant mechanism to PEG-treatment. Further, the modification in the anthocyanin content showed close positive correlations with roots sugar content alterations in response to PEG-treatment. The discovery of genotype-specific physiological and transcriptional responses to PEG-induced osmotic stress provides valuable insights into the molecular mechanisms underlying drought tolerance in Solanum tuberosum. By identifying key regulatory genes—such as StANN1 and StNRTs—and mapping their expression patterns across contrasting genotypes, this study contributes to a deeper understanding of stress adaptation pathways.
Hajibarat et al. (Wed,) studied this question.