Physiological and biochemical effects of ferulic acid on watermelon seed-ling and its growth

XU Xiaojun; WU Li; ZHANG Guilan

doi:10.3969/j.issn.1673-2871.2016.07.004

Abstract：Ferulic acid is one of allelochemicals secreted by the roots of watermelon, which plays an important role in the au?totoxicity process. In this study, ferulic acid ranging from 0 to 1 000 mg·L-1 was used to treat the seeds of watermelon, subse?quently, seed germination, seedling growth, as well as the cellular physiological and biochemical changes was monitored af?ter 7 days. The results showed that ferulic acid had no significant effect on seed germination, while it significantly reduced seed vigor index, inhibited the elongation of roots and shoots along with the their fresh weight. Superoxide anion radical and lipid peroxidation both in the roots and shoots increased significantly with the increased ferulic acid concentration, at the same time, the antioxidant enzyme activities of catalase (CAT) increased accordingly, while the activities of peroxidase (POD) and superoxide dismutase (SOD) significantly increased firstly and then decreased, similar response pattern was ob?served in the activity of phenylalanine ammonia-lyase(PAL). Consequently, the concentration of phenolic acid in watermel?on seedling roots increase steadily. These results indicates that the activation of antioxidant enzyme can reduce the injure im?posed by the phenolic compound accumulated in root in watermelon seedlings, and the effect of ferulic acid on root growth and development can be attributed to excess accumulation of phenolic compound.