BSMV infection inhibits chlorophyll biosynthesis in barley plants

Protochlorophyllide forms: their phototransformation in the greening proces s and the ultrastructure of the etioplasts were studied in BSMV-infected ba rley plants. The aim of this work was to determine whether the chlorotic sy mptoms caused hy the infection of this virus result from inhibition of chlo rophyll biosynthesis. 77 K fluorescence emission spectra of dark-grown, fla sh-illuminated and re-darkened leaves and transmission electron micrographs suggested that the BSMV infection did not cause specific changes in chloro phyll biosynthesis or in chloroplast development. However, infection accele rated senescence and inhibited or delayed chlorophyll biosynthesis similar to general stress effects. (C) 2000 Academic Press.