Germination Pattern and Behavior of Antioxidant Enzymes in Spinacia oleracea Seedlings in Saline Environment

Spinach (Spinacia oleracea L.) is widely considered as a functional food mainly due to its various beneficial components including vitamins, minerals, phyto-chemicals, bioactive and antioxidant compounds that stimulate health beyond basic nutrition. The overwhelming agricultural crop at salinity conditions faces several abiotic and biotic stresses that unfortunately reduce the potential applicability of highly nutritious plants. As major area utilized for vegetables cultivation in Karachi, Pakistan is saline, the study was conducted to get information of how the spinach plant seedlings ensure the salinity tolerance and healthy growth. Antioxidant enzymes present in spinach are targeted to check their responses at different germination stages of the seedlings. Results found were amazing and crucial key of plant behavior during oxidative stress in harsh saline environment. Spinach seedlings have the potential to germinate remarkably up to 800 mM NaCl concentration with efficient increase in the average weight and soluble protein content of seedlings. During oxidative stress in saline environment, the tolerance of enzymes like catalase, ascorbate peroxidase, guaiacol peroxidase, superoxide dismutase, and glutathione reductase is increased. Among these, ascorbate Peroxidase is active even at 600 mM of NaCl in germination stage 1. The activation of antioxidant defense mechanism in Spinacia oleracea at the very early stage of germination possibly helps the plant to survive under harsh conditions and thus preserves the nutritional quality of the plant.