Effect of PEG-Mediated Water Deficit on Morphometric Traits and Antioxidants Activity in Chickpea Plants

Abstract

Drought stress is a major constraint to chickpea (Cicer arietinum L.) production, particularly in semi-arid regions, where water scarcity adversely affects seed germination, seedling establishment, and overall plant growth. The present study evaluated the effect of polyethylene glycol (PEG)–induced water deficit on morphometric traits and antioxidant enzyme activities in chickpea seedlings under laboratory conditions. Seeds were subjected to osmotic stress using PEG solutions at concentrations of 2%, 4%, and 6%, while distilled water–soaked seeds served as the control. Germination percentage, seedling growth parameters (root length, shoot length, seedling length, leaf number), seedling vigour index (SVI), and antioxidant enzyme activities (peroxidase and polyphenol oxidase) were assessed. Results revealed a progressive decline in germination percentage, seedling length, root and shoot growth, leaf number, and SVI with increasing PEG concentration. Germination decreased from 100% in the control to 88% at 6% PEG, indicating the inhibitory effect of osmotic stress on early seedling development. In contrast, antioxidant enzyme activities showed a marked increase under stress conditions, with the highest peroxidase and polyphenol oxidase activities recorded at 6% PEG. The enhanced activity of these enzymes suggests activation of antioxidative defense mechanisms to counteract PEG-induced oxidative stress. Overall, PEG-mediated osmotic stress negatively affected morphometric traits of chickpea seedlings while stimulating antioxidant enzyme responses. These findings highlight the sensitivity of chickpea to water deficit during early growth stages and underscore the role of antioxidant systems in stress tolerance. The study provides valuable insights for screening drought-tolerant chickpea genotypes and developing strategies to improve crop resilience under water-limited conditions.