Phytotoxicity on cotton ex-plants of an 18.5 kDa protein from culture filtrates of Verticillium dahliae

摘要: Abstract A phytotoxic protein that evokes the typical symptoms of Verticillium wilt disease in seedlings Gossypium hirsutum L. (Upland cotton) was isolated from culture filtrates dahliae . The purified by ammonium sulfate precipitation, Sephadex-G100 fractionation, and native PAGE. 18.5 kDa protein, designated VD18.5, appears to be a single subunit with an isoelectric point between 3 5. VD18.5 induces leaf dehydration, chlorosis, necrosis stem discoloration susceptible cotton cultivar Siokra 1–4. LD 50 on protoplasts 1–4 18 μg mL −1 had no noticeable effect Pima S-7, which is resistant cultivar. Phytotoxic activity partially destroyed at high temperature abolished digestion proteinase K. Mass spectrometry fingerprinting sequence data yielded significant matches when submitted Mascot search engine NCBI non-redundant databases, respectively. These results suggest novel may involved development some associated plant.