Enhancing fruit quality of cold-stressed physalis peruviana during late-season through spraying with phenylalanine,...

Low temperatures are a significant environmental factor that can adversely impact the growth and productivity of tropical plants, such as Cape gooseberry (Physalis peruviana L.). In the current experiment, the foliar application of amino acids L-phenylalanine (Phe), L-cysteine (Cys), or sodium selenite (Se) was investigated on qualitative and biochemical properties of Cape gooseberry fruits subjected to low temperature condition in 2-year field experiment (2021 and 2022).

Our findings indicated that low temperature stress reduced membrane stability index and vitamin C content of fruits in comparison to the control plants in both years. Nonetheless, MDA, H2O2 and antioxidant enzymes activity meaningfully enhanced as a consequence of low temperature conditions. Application of Phe, Cys and Se alleviated low temperature stress by reducing MDA accumulation and significantly increasing total soluble solids, proline, total phenols, and flavonoid content. Amino acid Phe, Cys, and Se positively influenced H₂O₂ accumulation by enhancing antioxidant enzyme activities. Furthermore, these treatments stimulated the production of proline, and activities of CAT, SOD, POD, and PAL enzymes, which helped mitigate the damaging effects of cold stress and improved fruit quality. Overall, foliar application of Phe, Cys, and Se enhanced antioxidant components, enzyme activities, and proline accumulation, leading to improved fruit quality in Cape gooseberry cultivated under cold stress conditions.

Overall, the foliar application of Phe, Cys, and Se enhanced antioxidant compounds, enzyme activities, and proline accumulation, contributing to improved membrane stability and fruit quality in Cape gooseberry plants grown under cold stress conditions.