Main Article Content
Phenylalanine (Phe) is the precursor for the biosynthesis of various secondary metabolites, which has crucial roles in improving plant growth and secondary metabolite production. Therefore, the objective of this research was to investigate the effect of Phe on seed germination, growth and antioxidants of sunflower (Helianthus annuus L.) sprouts. Soaking seeds in 0, 100, 200, 400, 600 and 800 mg/L Phe for 8 hours resulted in non-significantly different of seed germination percentage. However, sunflower seeds germinated earlier under 400 mg/L Phe, which showed the highest first count of germination and the lowest mean time to germination. Phe concentrations of 100, 200 and 400 mg/L were sprayed at 4 days after sowing and sprouts were harvested at 5 days after sowing. Results indicated that sprayed Phe treatments promoted the growth of sprout as shoot height, fresh and dry weight of these treatments exhibited significantly higher than those of non-sprayed treatment. The highest total phenolic content and the best DPPH radical scavenging capacity were obtained under 400 mg/L Phe. Total flavonoid content was not statically different among sprayed and non-sprayed Phe treatments.
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