TRANSIENT EXPRESSION IN LEAF MESOPHYLL PROTOPLASTS OF ARABIDOPSIS-THALIANA

Conditions for maximising transient expression of GUS in leaf mesophyl l protoplasts of Arabidopsis thaliana ecotype C24 were investigated. I t was found that the factors most influencing expression levels, with optimum levels in parenthesis, were plasmid DNA quantity (100 mug per 5 x 10(5) protoplasts), inclusion of carrier DNA (50 mug), PEG pH and amount (pH above 6, and total PEG concentration at least 9% w/w) and t he topological form of the DNA. Linearised plasmid DNA with long flank ing sequences 3' and 5' to the marker gene yielded the highest levels of GUS expression.