Invertase Plays a Vital Role in Regulating Wound-Induced Accumulation of Phenolic Compounds in Carrot Tissue

Abstract

The application of wounding stress can induce the accumulation of phenolic antioxidants in carrots. This study aimed to investigate the possible regulation role of invertase (INV) on the biosynthesis of phenolics in wounded carrots. In this study, carrots were cut into two different wounding intensities of slices and cubes, then stored at 20 °C for 2 days. The results showed that wounding stress caused an obvious increase in phenolic content and antioxidant capacity in carrot tissues, and a positive correlation was observed between the biosynthesis of phenolic compounds and the degradation of sucrose. Simultaneously, wounding activated the sucrose-cleaving enzymes of INVs, including acid INV (AI) and neutral INV (NI), and up-regulated the expressions of most encoding genes of INVs. In addition, treatment with INV activators accelerated the accumulation of phenolic antioxidants, while treatment with INV inhibitors suppressed this process, suggesting that the synthesis of phenolic compounds in wounded carrots is closely related to the availability of sugars. Our findings provide new insights into the regulation role of INV on the wound-induced accumulation of phenolic compounds in carrots, which may be helpful in using wounded plants to produce more phenolic antioxidants.