Effect of BR and ACC on seed germination
To test whether BRs and ethylene play a role in germination
of cucumber seeds suffering from salt stress, the dose
response of seed germination to BR and ethylene precursor
ACC in the presence of NaCl was investigated. As shown
in Fig. 1a, the cucumber seeds used in the present study
had an average germination rate of 97% after 48 h imbibition
in control solutions, and the germination was
reduced to about 20% when 250 mM NaCl was present in
the incubation medium. The inhibitory effect of NaCl on
seed germination was significantly ameliorated by addition
of EBR into the incubation medium with the optimal
concentration being 5 lM EBR. Given that 5 lM EBR was
optimal in terms of its effect on seed germination under
conditions of salt stress, this concentration was used to
study the role of BR in seed germination under salt stress
throughout the study. Similar to EBR, the reduction in seed
germination induced by NaCl was also alleviated when
ACC at concentrations greater than 1 lM was present in
the incubation medium, and the ameliorative effect of ACC