Effect of methyl jasmonate and elicitor on PAL gene expression in tobacco cultured cells

Nine PAL genomic clones from tobacco have been isolated: Restriction map analysis of these clones showed that they can be divided into two groups, gPAL A and gPAL B. Both of the genes were further subcloned and sequenced. They showed a high homology for nucleotide and deduced amino acid sequences in the coding region, gPAL B showed closer ties with other solanaceous members than to gPAL A. Gene specific probes based on the low homology region in the 5' upstream region were used to study their induction patterns with MJ and elicitor. It was found that both MJ and elicitor induced the gPAL A transcription but with different time courses. PAL A mRNA level in elicitor-treated cells peaked after 4 h of the treatment whereas in the MJ-treated cells PAL A mRNA peaked after 6-8 h of the treatment. Neither MJ nor elicitor activated the gPAL B transcription.