Fine structure of the giant cells induced by Meloidogyne javanica in lima bean

Abstract

Giant cells associated with egg-laying females of Meloidogyne javanica in lima bean, Phaseolus lunatus cv. L-136, were examined by light and electron microscopy. These giant cells have characteristics that are typical of nematode-induced giant cells in a wide range of hosts, but they differ in that they (i) are less closely associated with xylem vessels, (ii) contain a very large number of plastids which are devoid of starch grains, and (iii) contain several different forms of cytoplasmic crystals. One form of the crystal is associated with a large number of "spiny" vesicles. The possible role of these features, especially the crystals, in the giant cell response of lima bean is discussed.

Occurrence of paracrystalloids and their particles in resistant and susceptible carnation plants infected with Fusarium oxysporum f.sp. dianthi race 2

“…However, these bodies were larger than OPs. Fattah and Webster (1984) illustrated in nematodeinfected plants paracrystalloid bodies similar to those described here. They suggested that these bodies could have corresponded to protein crystals formed by cuboid subunits.…”

“…Unbound crystalline bodies have likewise been illustrated from plants infected by viruses, for example in oats infected with the blue dwarf virus (Zeyen and Banttari 1972), solely insect-transmitted, or by other pathogens (Fattah and Webster 1984;Sanger et al 1998). The 28-30 nm virus particles forming the crystalline bodies described by Zeyen and Banttari (1972) were equally numerous in phloem cells, even intermixed with degraded host tissue, and in this respect may show features analogous to those described here.…”

“…The present paracrystalloids were formed from apparently spherical particles that aggregated into lattices, and therefore do not correspond exactly to known icosehedral forms. Nevertheless, it is interesting to note that cylindrical crystalline structures in cells of nematode-feeding plants have been linked to the nematode-feeding tubes (in Fattah and Webster 1984). Besides the possibility that these bodies represented secretion products from the nematode, they could still have had a link with a fungal pathogen, as a companion infectious agent (Fattah and Webster 1983;Mai and Abawi 1987).…”