Wound healing is a postharvest characteristic of potato tubers through accumulating
suberin and
lignin, which could reduce decay and water loss during storage. This study aimed to explore the impact and mechanisms of
sodium silicate on wound healing of potatoes. After being wounded, "Atlantic" potato tubers were treated with water or 50 mM
sodium silicate. The results showed that
sodium silicate treatment accelerated the formation of wound healing structures and significantly reduced the
weight loss and disease index of tubers. Furthermore,
sodium silicate induced the genes expression and
enzyme activity of
phenylalanine ammonia lyase (PAL), 4-coumarate:
coenzyme A ligase (4CL), and
cinnamyl alcohol dehydrogenase (CAD) involved in the phenylpropane metabolism, enhancing the synthesis of the main precursors of
suberin polyphenolic (SPP) and
lignin, such as
coniferyl alcohol,
sinapyl alcohol, and
cinnamyl alcohol. Meanwhile, the gene expression of StPOD and StNOX was activated, and the production of O2- and H2O2 was promoted, which could be used for injury signal transmission and oxidative crosslinking of SPP monomers and
lignin precursors. Besides, antimicrobial compounds, total phenolics, and
flavonoids were also induced. We suggest that
sodium silicate could promote wound healing by inducing the deposition of SPP,
lignin, and antimicrobial compounds in potato tubers.