Proteomic Analysis of Potato Traumatic Tubers in Response to Exogenous Nitric Oxide (NO)

Purpose To analyze the mechanism of exogenous NO effect on potato wound suberization from a proteomic perspective.

Methods Using potato variety ‘Dianshu 47’ as the material and distilled water as the control (CK), the wounded tubers were soaked with 0.5 mmol/L sodium nitroprusside (SNP, as a NO donor) and 1.3 mmol/L carboxy-PTIO (C-PTIO, as a NO scavenger) under artificial wounding in an incubator. The wound healing response was performed, and samples were taken at 0, 27, and 54 h after wound for proteomic analysis.

Results At 27 h after wound, there were 147 differentially expressed proteins (DEPs) in the SNP vs. CK group, 113 DEPs in the C-PTIO vs. CK group, and 176 DEPs in the SNP vs. C-PTIO group; GO analysis showed that DEPs were mainly enriched in the pectin metabolism process, cell wall organization, cytokinin activity signaling pathway, and phenylpropane metabolism process; KEGG analysis showed that DEPs were mainly involved in phenylpropane biosynthesis, glutathione metabolism, and phytohormone signaling pathways. At 54 h after wound, there were 120 DEPs in the SNP vs. CK group, 164 DEPs in the C-PTIO vs. CK group, and 144 DEPs in the SNP vs. C-PTIO group; GO analysis showed that the DEPs were mainly enriched in the processes of suberin biosynthesis, phenylpropane biosynthesis, and cellular water homeostasis; KEGG analysis revealed that the DEPs were mainly involved in the phenylpropane biosynthesis, fatty acid metabolism and keratin, and cork lipid and wax biosynthesis pathways. Meanwhile, SNP treatment increased 16 peroxidase proteins, four phenylalanine ammonia lyase proteins, two 4-coumaroyl-CoA-ligase proteins, 14 fatty acid metabolism-related proteins, three cis-zeatin proteins, and one ethylene receptor protein were expressed.

Conclusion Exogenous increase of NO donor (SNP treatment) up-regulates the expression of proteins related to phenylpropane biosynthesis, glutathione metabolism, fatty acid metabolism and signaling transduction pathways in potato wounded tubers, and thus accelerates the wound suberization. This study provides a new idea for analyzing the molecular mechanism of NO-promoted wound healing in potato tubers.