Proteomic identification of differentially expressed proteins in Gossypium thurberi inoculated with cotton Verticillium dahliae.

Thurber's cotton (Gossypium thurberi) is the wild relative of cultivated cotton. It is highly resistant to cotton Verticillium wilt, a disease that significantly affects cotton yield and quality. To reveal the mechanism of disease resistance in G. thurberi and to clone resistance-related genes, we used two-dimensional electrophoresis (2-DE) and tandem time-of-flight mass spectrometry (MALDI-TOF-MS) to identify differentially expressed proteins in Thurber's cotton after inoculation with Verticillium dahliae. A total of 57 different protein spots were upregulated, including 52 known proteins representing 11% of the total protein spots. These proteins are involved in resistance to stress and disease, transcriptional regulation, signal transduction, protein processing and degradation, photosynthesis, production capacity, basic metabolism, and other processes. In addition, five disease resistance proteins showed intense upregulation, indicating that resistance genes (R genes) may play a critical role in resistance to Verticillium wilt in Thurber's cotton. Our results suggest that disease and stress resistance are the combined effects of multiple co-expressed genes. This provides a basis for further, detailed investigation into the mechanisms underlying Verticillium wilt resistance of G. thurberi and for cloning essential genes into cotton cultivars to produce Verticillium wilt resistant plants.