Changes in water stress indicators and antioxidant systems in chilli by chemical seed priming under water stress condition

One of the most significant abiotic stresses impacting agricultural productivity is water stress. Plant responses to water stress and its survival mechanism is very decisive in the present changing climatic conditions. Seed priming is an important stress management practice for conferring tolerance when plants are subjected to water stress. We tested the effects of 3% silicon dioxide (SiO2), 2.5% potassium nitrate (KNO3), and distilled water for 12 h at two different stages: at the seedling stage under in vitro conditions by subjecting to three different stress levels, namely control, mild stress (5%—PEG 6000), and moderate stress (10%—PEG 6000), and at the flowering stage under greenhouse conditions by withholding irrigation for 4 days. The results at the seedling stage under water stress conditions revealed that in primed seed, there is an increased Seedling Vigour Index I (SVI I), Seedling Vigour Index II (SVI II), and proline content with decrease of Malondialdehyde (MDA) and Hydrogen peroxide (H2O2) when compared to unprimed seeds, while results at flowering stage disclosed that reduced Cell Membrane Stability Index, relative water content, fruit yield plant −1, number of seeds fruit −1 and seed yield plant −1 under water stress conditions with respective of control condition but seeds primed with 3% SiO2 and 2.5% KNO3 showed significantly increased value when compared to unprimed seeds. The antioxidant activity levels like peroxidase (POD), catalase (CAT) and superoxide dismutase (SOD) were increased under drought conditions compared to the control condition, even though primed seeds marked a significant difference. The findings revealed that the seeds primed with 2.5% KNO3 recorded high antioxidant levels with maximum water absorption capacity, while seeds with 3% SiO2 can be suggested for seed production when there is water stress. © 2023, The Author(s) under exclusive licence to Society for Plant Research.