Flow cytometric analysis ofBrassica junceacell and pollen cultures treated with destruxin B, a toxin produced byAlternaria brassicae

A rapid and reliable flow cytometric method of determining plant cell and pollen grain viability upon treatment with Alternaria brassicae pathotoxin (destruxin B) has been standardized on the basis of light scattering properties of cells of Brassica juncea cv. Kranti stained with fluorescein diacetate. Data on relative fluorescence of cells treated with 60 and 120 mu g destruxin B ml(-1) were collected. The frequency distribution of fluorescence and histogram statistics showed a gradual loss of fluorescence in destruxin B-treated cells. The cell viability was 81% in untreated cells and 39% in 120 mu g destruxin B ml(-1) treated cells after 96 h of culture in the Murashige and Skoog medium. These observations were similar to those obtained by manual counting with a light microscope using Evans blue. Optical sectioning with a confocal laser scanning microscope revealed plasmolysis of destruxin B-treated cells. Viability of pollen grains of B. juncea cv. Kranti treated with destruxin B was also determined on the basis of their relative fluorescence. (C) 1996 Academic Press Limited