The Impact Of Foliar Salicylic Acid In Salt-Exposed Guava (Psidium Guajava L.) Seedlings

Abstract

The rising demand for guava fruit worldwide is due to its richness in vitamin C, high yielding and two bearing seasons. Given the salt stress threat to guavas and the necessity of protective strategies, in the present research guava seedlings were subjected to sodium chloride (0 and 50 mM) and salicylic acid (0 and 1 mM). To ascertain a logical conclusion, the activity of antioxidant enzymes, antioxidant capacity of DPPH, ferric reducing antioxidant power, total flavonoid and phenol contents were monitored in salt-exposed guava seedlings. Based on our findings, the most superoxide dismutase (87.46 µmol min−1g−1DW) activity, ferric reducing antioxidant power (408.82 mmol g−1 DW), DPPH scavenging activity (80.65%), flavonoid (14.15 mg QE−1 g DW) and phenol (34.02 mg GAE g−1 DW) contents were found in 50 mM NaCl-exposed plants, which were enriched by 1 mM salicylic acid. A high correlation was observed among non-enzymatic antioxidant parameters (DPPH scavenging activity, ferric reducing antioxidant power, total flavonoid content and total phenol content). In conclusion, salicylic acid improved guavas salt tolerance by increasing both enzymatic (peroxidase and superoxide dismutase) and non-enzymatic (ferric reducing antioxidant power, DPPH scavenging activity, total phenol and flavonoid contents) pathways.