Figure 4.

Secreted protein extracts of Alternaria brassicae. Secreted proteins were extracted from solid‐substrate fermentation cultures of two isolates of A. brassicae: QM‐1733 and ATCC 58169. Each of the six chitinase substrates were incubated either alone (left lane) or with secreted proteins (right lane). After incubation, samples were analysed by sodium dodecylsulphate‐polyacrylamide gel electrophoresis (SDS‐PAGE) and peptide staining. AtchitIV5 substrate was an equal mixture of both AtchitIV5α and AtchitIV5β. Isolate QM‐1733 (=NRRL 54668, =CBS 102.24) was originally isolated from a leaf spot of Cochlearia officinalis by P. C. Bolle (1924). Isolate ATCC 58169 was isolated from Brassica tournefortii and deposited by P. J. Cotty. Both isolates were grown as potato dextrose agar slant cultures and on autoclaved maize as described previously for other plant pathogens (Naumann and Wicklow, 2010).