Insight into polyethylene glycol-mediated physiochemical, nutritional, and antioxidative defense modulations in salt-stressed Raphanus sativus L.

Abstract

Salinity is one of the most crucial factors that impede various morphological and physiological parameters, eventually reducing crop production. Chemical and physical weathering, in addition to poor irrigation practices, enhances soil salinity. Radish (Raphanus sativus L.), a leafy and root vegetable, is cultivated worldwide because of its nutritional value. However, salinity poses a serious threat to its productivity. Polyethylene glycol (PEG) is mainly used to induce and study osmotic stress in plants. However, our novel research work was designed to observe the stress-mitigating potential of PEG (10%, 20%, 30%, and 40% PEG) in R. sativus subjected to salinity stress (200 mM NaCl). Salt toxicity significantly reduced the seed germination (61.03%), seedling vigor index (54.25%), total soluble protein (69.23%), and biomass accumulation (42.25%) of R. sativus plants. Similarly, stressed plants presented a reduced synthesis of photosynthetic pigments and poor nutrition. However, seed priming with PEG-30% significantly alleviated salt stress by promoting growth attributes, mineral uptake, and the antioxidative defence system of R. sativus under salinity regimes. Plants raised from seeds treated with 30% PEG alleviated NaCl-induced oxidative stress by modulating the activity of antioxidative enzymes such as peroxidase, ascorbate peroxidase, glutathione peroxidase, glutathione S-transferase, ascorbic acid, superoxide dismutase, and catalase. Furthermore, PEG-30% significantly improved photosynthetic pigment biosynthesis, although there was a decrease in electrolyte leakage and lipid peroxidation in plants under saline conditions. Furthermore, 30% PEG improved the shoot length (41.46%), root length (46.57%), and biomass production (53.93%) of salt-stressed plants. This study revealed that 30% PEG is beneficial for reversing salt stress. However, extensive field studies are required to assess the potential of PEG for mitigating salt stress in various geographical regions.

Supplementary information: The online version contains supplementary material available at 10.1007/s12298-025-01585-3.