Interference Expression of StMSD Inhibited the Deposition of Suberin and Lignin at Wounds of Potato Tubers by Reducing the Production of H 2 O 2 .

Superoxide dismutase (SOD) actively participates in the wound stress of plants. However, whether StMSD mediates the generation of H 2 O 2 and the deposition of suberin polyphenolic and lignin at potato tuber wounds is elusive. In this study, we developed the StMSD interference expression of potato plants and tubers by Agrobacterium tumefaciens -mediated transformation. The StSOD expression showed a marked downregulation in StMSD -interference tubers, especially StCSD2 and StCSD3 . The content of O 2 • - exhibited a noticeable increase together with the inhibition in H 2 O 2 accumulation. Moreover, the gene expression levels of StPAL ( phenylalanine ammonia-lyase ) and StC4H ( cinnamate-4-hydroxylase ) were downregulated in StMSD -interference tubers, and less suberin polyphenolic and lignin depositions at the wounds were observed. Taken together, the interference expression of StMSD can result in less suberin polyphenolic and lignin deposition by inhibiting the disproportionation of O 2 •- to H 2 O 2 and restraining phenylpropanoid metabolism in tubers.