OVEREXPRESSION OF THE JASMONATE-INDUCIBLE 23 KDA PROTEIN (JIP-23) FROM BARLEY IN TRANSGENIC TOBACCO LEADS TO THE REPRESSION OF LEAF PROTEINS

We investigated transgenic tobacco lines which express different amoun ts of the barley JIP 23. In these plants the amount of several protein s decreased proportionally to increasing amounts of JIP 23 whereas the transcript levels were constant as determined for the small and the l arge subunit of RuBPCase, However, the translation initiation of the r bcS transcript was found to be less efficient than in the wild type. I n contrast, the jip 23 transcript was efficiently initiated, indicatin g that no unspecific impairment of initiation occurred. The data sugge st that the barley JIP 23 leads to discrimination among certain tobacc o transcripts during translation initiation. (C) 1997 Federation of Eu ropean Biochemical Societies.