Proteomic Insights into Solanum torvum Responses to Verticillium dahliae Infection and Functional Validation of StoAOS1

Eggplant (Solanum melongena L.) is an important solanaceous vegetable crop cultivated worldwide. Verticillium wilt, caused by Verticillium dahliae, severely restricts eggplant growth and yield, while most cultivated eggplant varieties show only limited resistance to this disease. In contrast, Solanum torvum, a wild relative of eggplant, exhibits strong natural resistance to Verticillium wilt. The molecular mechanisms underlying the contrasting responses of cultivated eggplant and S. torvum to V. dahliae infection remain poorly understood. In this study, high-throughput iTRAQ-based quantitative proteomics was used to analyze root protein profiles of S. torvum after V. dahliae inoculation. A differentially expressed protein, StoAOS1, was identified in S. torvum and was strongly induced by V. dahliae infection. StoAOS1 encodes a key enzyme in the jasmonic acid (JA) biosynthetic pathway. Further analysis showed that exogenous methyl jasmonate (MeJA) treatment markedly induced StoAOS1 expression. Virus-induced gene silencing of StoAOS1 significantly compromised Verticillium wilt resistance in S. torvum, accompanied by reduced acid-insoluble lignin accumulation and decreased transcript levels of the defense-related marker genes StoPDF1.2, StoVSP2, and StoThi2.1. Conversely, transient overexpression of StoAOS1 in Nicotiana benthamiana enhanced resistance to V. dahliae. Together, these findings suggest that StoAOS1 positively regulates Verticillium wilt resistance in S. torvum, likely through a JA-dependent defense pathway.