Abstract: 【Objective】This study aim to investigate the effect and related mechanism of p-CA treatment on the accumulation of suberin polyphenolic and lignin at wound sites of potato tubers.【Method】The half cut potato tubers ‘cv. Atlantic’ were soaked with 0.5 mmol?L^-1 p-CA for 10 min and stored at room temperature and protected from light for healing. The weight loss and the disease index of wounded tubers inoculated with Fusarium sulphureum were determined, the deposition of suberin polyphenolic and lignin at wounded sites were observed, the activity of the key enzymes of phenylpropane metabolism and peroxidase as well as the content of phenylpropane metabolism products and H₂O₂ at wounded sites were measured.【Result】The weight loss and the disease index of wounded tubers were significantly reduced by p-CA treatment, and were 38.46% and 43.18% lower than those of control on the 14 day of healing, respectively. p-CA treatment accelerated the deposition of suberin polyphenolic and lignin at wound sites of potato tubers, and the thickness of cell layers in treated tubers were 26.43% and 30.26% higher than the control on the 14 day of healing, respectively. p-CA treatment also significantly increased the activities of phenylalanine ammonia lyase, cinnamic acid-4-hydroxylase, 4-coumaryl coenzyme A ligase and cinnamyl alcohol dehydrogenase at wounde sites of tubers, with the enzyme activities of the treated tubers being 32.17%, 23.51%, 25.09% and 23.08% higher than the control on 7 day, respectively. p-CA treatment also promoted the synthesis of cinnamic acid, p-coumaric acid, caffeic acid, ferulic acid, sinapic acid and total phenolics, with the contents of cinnamic acid, p-coumaric acid, caffeic acid and total phenolics in the treated tubers on 14 day being 34.26%, 38.29%, 19.31% and 41.04% higher than the control respectively, and the contents of ferulic acid, sinapic acid in the treated tubers being 38.33% and 20.47% higher than the control on 21 day, respectively. In addition, p-CA treatment promoted the accumulation of cinnamyl alcohol, coniferyl alcohol, sinapis alcohol and lignin at wound sites, with the contents of cinnamyl alcohol and lignin in the treated tubers being 36.93% and 31.66% higher than the control on 14 day, respectively, and the contents of coniferyl alcohol and sinapis alcohol in the treated tubers were 41.43% and 34.05% higher than the control on 21 day, respectively. The p-CA treatment also increased the H2O2 content and peroxidase activity at the wound sites, with the H₂O₂ content and peroxidase activity of the treated tubers being 40.25% and 27.01% higher than the control on 7 day, respectively.【Conclusion】The p-CA treatment accelerated wound healing of potato tubers by activating phenylpropanoid metabolism, increasing H₂O₂ content and peroxidase activity, and promoting the accumulation of suberin polyphenolic and lignin in potato tuber wound sites. 

Key words: p-CA, potato tuber, wound healing, phenylpropanoid metabolism