Abstract

Litchi fruit is highly susceptible to browning after harvest, which significantly reduces its commercial value. Methyl jasmonate (MeJA) is crucial to the quality of the harvested fruit, but its molecular mechanism remains unclear. This study systematically investigated the physiological and molecular mechanisms by which MeJA delays browning in litchi. Results indicated that treatment with 50 μM MeJA effectively delayed browning, mitigated the increase in relative electrical conductivity, increased anthocyanin content and total phenolic content. Transcriptome analysis revealed differentially expressed genes predominantly enriched in redox balance, phenolic metabolism and membrane metabolism pathways. Further research identified that MeJA activated LcPAL1 and LcMYBs during litchi browning. Yeast one-hybrid and dual luciferase reporter assays demonstrated that LcMYB113 and LcDIV1 directly bind to the LcPAL1 promoter and activate its transcription. Finally, a comprehensive regulatory network mediated by MeJA for delaying litchi browning was constructed. These findings suggested that MeJA may mitigate litchi browning by activating the expression of LcPAL1 , and provide a theoretical basis for elucidating the molecular mechanism of LcMYB113 and LcDIV1 module.