Sodium silicate accelerates the deposition of lignin and silicon by activating the biosynthesis of lignin monolignols and increasing the relative silicon content in muskmelon wounds

Silicate is the main constituent of soil and is widely distributed throughout the Earth's. Sodium silicate (SS) is a common water-soluble silicate. Our previous research found that SS could prevent water evaporation and pathogen infection by promoting the deposition of suberin polyphenols on muskmelon fruit wounds, bur few reports are available on the effect of SS on the deposition of lignin and silicon on muskmelon wounds. In this study, SS treatment enhanced the activities of enzymes related to lignin synthesis, increased ρ-coumaryl, coniferyl, and sinapyl alcohols, and lignin levels, increased peroxidase activity and H2O2 content, and accelerated the deposition of lignin on wounds. In addition, SS treatment increased the relative silicon content to increase the rate of silicon deposition, which altered the morphological layer of cells compared to the control. These results suggest that SS accelerated lignin deposition on muskmelon wounds by activating lignin biosynthesis. SS also improved silicon deposition by increasing relative silicon content of the wounds. Since SS promotes lignin and silicon deposition at muskmelon wounds, the chemical can be used for wound healing of muskmelon fruit.