Method for isolation of transcription termination sequences

A method for identification and isolation of transcription termination sequences from a plant comprising the steps of:

• i) providing a screening construct or screening vector comprising
• a) a promoter sequence,
• b) one or more insertion sites for insertion of DNA sequences, and
• c) at least one additional sequence which causes upon expression under said promoter sequence a readily detectable characteristic,
• wherein insertion of an efficient transcription terminator into said insertion site changes expression of said additional sequence by said promoter sequence in comparison to no insertion,
• ii) providing one or more DNA sequences to be assessed for their transcription termination capability by
• a) identifying intergenic regions between paired genes having an intergenic distance of about 400 to 3,000 base pairs from a plant,
• b) identifying one or more DNA sequences which are flanked on both sides by genes having at least 5% of expression level of actin in said plant, and
• c) isolating the one or more DNA sequences identified in step b),
• iii) inserting one or more copies of said DNA sequences obtained from step ii) into said insertion site of said screening construct or screening vector,
• iv) introducing said screening construct or screening vector with said inserted DNA sequences into an in vitro or in vivo transcription system suitable to induce expression from said promoter sequence,
• v) identifying and/or selecting screening construct or screening vector with a changed readily detectable characteristic in comparison to no insertion, and
• vi) isolating the inserted DNA sequences from said identified and/or selected screening construct or screening vector for use as transcription termination sequences and, optionally, determining their sequence.