Bean common mosaic virus (BCMV) infection has bean shown to influence
the anatomical and cytological characters of infected bean plants. The thickness of
leaflet blades, palisade and spongy tissues were increased than the healthy plants. In
contrast the thickness of upper and lower epidermis layers were reduced. Also the
thickness of midrib zone was slightly reduced. Moreover, vascular tissues lost their
normal shape and arrangement as xylem arms. The most interesting finding, lengths
of both , protoxylem and metaxylem were reduced while their widths were increased.
Ultrathin sections of symptomatic leaf tissue showed several cytological changes
characteristic of Potyviruses. The thlakoidal structure of the chloroplastes becomes
disorganized, abnormally distributed and dilated . The number of plastoglobulis
increased and clumped together, their starch content was decreased. Clumping of
mitochondria , chloroplastes and degeneration of grana were also observed. Pinwheel
inclusions and associated virus particles are frequently found in the cytoplasm of
infected leaf cells.