D. Skalamera et Mc. Heath, CHANGES IN THE CYTOSKELETON ACCOMPANYING INFECTION-INDUCED NUCLEAR-MOVEMENTS AND THE HYPERSENSITIVE RESPONSE IN PLANT-CELLS INVADED BY RUSTFUNGI, Plant journal, 16(2), 1998, pp. 191-200
During the infection of cowpea (Vigna unguiculata) by the cowpea rust
fungus (Uromyces vignae, race 1) the plant nucleus moves towards and a
way from the invading hypha and eventually moves close to the fungus i
n the susceptible cultivar while it remains away in two cultivars whic
h subsequently respond by resistance gene-dependent plant cell death (
the hypersensitive response, HR). The role of plant cytoskeleton in th
ese responses was investigated by fluorescent microscopy and treatment
s with anticytoskeletal drugs. Observations of microtubule organizatio
n prior to cell death revealed that the sequence of events leading to
protoplast collapse differed between the two resistant cultivars, sugg
esting a possibility of multiple pathways for cellular degradation dur
ing the HR. Different fixations produced two different microfilament p
atterns: a filament network and cables. Microfilament network remained
visible even at later stages of cell death. Oryzalin and taxol reduce
d the incidence of autofluorescence that develops late in the death pr
ocess, indicating a role of microtubules in the deposition of phenolic
s by adjacent living cells. Cell death and nuclear movements were not
affected by oryzalin and taxol but were inhibited by cytochalasin E, s
uggesting that the microfilaments are required for the HR.