DisplayTitle

A Highly Efficient Transposon Mutagenesis System for the Tomato Pathogen Clavibacter michiganensis subsp. michiganensis

A transposon mutagenesis system for Clavibacter michiganensis subsp. michiganensis was developed based on antibiotic resistance transposons that were derived from the insertion element IS1409 from Arthrobacter sp. strain TM1 NCIB12013. As a prerequisite, the electroporation efficiency was optimized by using unmethylated DNA and treatment of the cells with glycine such that about 5 × 10⁶ transformants per μg of DNA were generally obtained. Electroporation of C. michiganensis subsp. michiganensis with a suicide vector carrying transposon Tn1409C resulted in approximately 1 × 10³ transposon mutants per μg of DNA and thus is suitable for saturation mutagenesis. Analysis of Tn1409C insertion sites suggests a random mode of transposition. Transposition of Tn1409C was also demonstrated for other subspecies of C. michiganensis.