Rf. Ransom et al., PURIFICATION AND DISTRIBUTION OF PATHOTOXIN-ENHANCED PROTEINS IN SORGHUM, Physiological and molecular plant pathology, 45(5), 1994, pp. 385-395
The synthesis of a group of four 16 kDa proteins in sorghum [Sorghum b
icolor (L.) Moench] roots is enhanced by treatment with peritoxin, the
host-selective toxin produced by the root rot fungus Periconia circin
ata (Mangin) Sacc. The proteins were purified by two-dimensional gel e
lectrophoresis and partially characterized, and their distribution wit
hin the sorghum plant and in other plant species was determined. The f
our proteins were found to be charge isomers indistinguishable by elec
trophoretic analysis of the products of protease digestion and CNBr cl
eavage. In Western blots with polyclonal antibodies, the proteins were
detected in all organs of mature sorghum plants in quantities that de
creased from the roots upward toward the inflorescence. Multiple cross
-reacting proteins from 15-21 kDa were also detected in all grass spec
ies tested and in some other monocotyledons. None of the dicotyledons
analysed contained cross-reacting proteins. The results suggest that t
he 16 kDa proteins are conserved proteins whose constitutive synthesis
is regulated and whose function is important in several plant species
, especially grasses. The presence of these proteins in other plant sp
ecies suggests that they are not the direct cause of disease symptoms
and plant cell death in peritoxin-treated sorghum plants.