Differential Changes in Growth and Enzyme Activities of Chilling Induced Wheat Seedlings by Nitric Oxide Priming

Wheat reportedly has a positive response to seed priming in any environmental condition. The present study evaluates the changes in germination, seedling growth and antioxidant enzyme activities by nitric oxide priming (NO) in seedlings of seven wheat genotypes under normal and chilling stress. Priming was achieved by exposing the seeds of NARC-2011, AAS-2011, Punjab-2011, Faisalabad-2008, Uqab-2002, Chakwal-50 and Lasani to 10(-4) and 10(-5) M aerated sodium nitroprusside (SNP, as nitric oxide donor) solutions for 7 h. Genotypes behaved differentially in terms of growth and antioxidant response to stress and priming. Seedling growth was increased in primed seeds compared to dry seeds under control and stress conditions. The activities of superoxide dismutase, indole acetic acid oxidase, ascorbate peroxidase and guaiacol peroxidase were affected differently in almost all genotypes under stress conditions. Maximum seedling growth was revealed by SNP primed NARC-2011 and Uqab-2002 in both growth conditions. Faisalabad-2008 revealed higher antioxidant enzyme activities by SNP priming. It was concluded that response of genotypes vary under different growth conditions and different levels of SNP priming. Oxidative species scavenging system was more actively involved in detoxification of oxidative stress induced by chilling and subsequently enhanced the growth of wheat seedlings. (C) 2020 Friends Science Publishers