Plants under attack from pathogens have a range of defence responses a
t their disposal to fight off the infecting organism. The fungus Fusic
occum amygdabi, however, appears to have found a major weakness in the
plant defence barrier. A key role in the fungal attack is played by a
molecule produced by and named after the fungus: fusicoccin. Recently
, it has become clear that fusicoccin targets 14-3-3 proteins, which a
re at the cross-point of a huge array of signalling and regulatory pat
hways. Progress has now been made in understanding how 14-3-3 proteins
and fusicoccin are involved in the regulation of key enzymes, such as
the plasma membrane H+-ATPase and soluble nitrate reductase. Research
on the in vivo effects of fusicoccin may lead to the identification o
f new 14-3-3 target proteins.