S. Lutts et al., ETHYLENE PRODUCTION BY LEAVES OF RICE (ORYZA-SATIVA L) IN RELATION TOSALINITY TOLERANCE AND EXOGENOUS PUTRESCINE APPLICATION, PLANT SCI, 116(1), 1996, pp. 15-25
The effects of salt stress on the production of ethylene in leaves of
five rice cultivars differing in salinity tolerance were investigated
after 15 and 30 days of stress exposure in plants sprayed every 2 days
with deionised water or putrescine 100 mu M. NaCl induced an increase
in ethylene synthesis which was higher in salt-tolerant than in salt-
sensitive cultivars (cvs.), Salt-stress also induced an increase in 1-
aminocyclopropane-1-carboxylic acid (ACC) content which was larger in
salt-tolerant cvs, whereas a decrease in ACC conversion to ethylene su
ggested a reduction in ACC oxidase activity. Putrescine increased the
growth and the leaf tissue viability (as indicated by the reduction of
2,3,5-triphenyltetrazolium chloride (TTC) to formazan) of salt-treate
d plants in all cvs. This positive effect was associated with an incre
ase in ethylene biosynthesis through an increase in ACC content and a
suppression of NaCl-induced inhibition of ACC conversion to ethylene.
These data suggest that putrescine could be involved in salinity toler
ance in rice.