Figure 5.
Elicitation of ROS by mutant virus particles. Epidermal peels from N. tabacum cv Samsun nn (A–F) or N. tabacum cv Samsun EN (F) were loaded with DCFH-DA and monitored using fluorometry. Peels were exposed to 100 ng of TMV virus containing wild-type CP (U1) or mutant type CP as indicated. l-Arg (1 mm) was added as a control at the end of each experiment. Viruses used wereas follows: A, wild-type CP; B, CP E50Q; C, CP P20L; D, CP R46G; and E, CP P20L/Y72F. F, The mean increase in DCF fluorescence is shown after elicitation with each CP mutant in either N. tabacum cv Samsun NN or EN cells. The increase is expressed as the percentage of the maximal response obtained after the addition of 5 mm H2O2.