PROMOTERLESS GUSA EXPRESSION IN A LARGE NUMBER OF ARABIDOPSIS-THALIANA TRANSFORMANTS OBTAINED BY THE IN PLANTA INFILTRATION METHOD

A large number of Arabidopsis thaliana transformant T2 families were o btained using in planta infiltration method. A T-DNA containing 2 resi stance genes for the selection of the transformants and the promoterle ss gus gene for promoter-trapping was transferred from the Agrobacteri um cells to the plant genome. The GUS activity of each transformant wa s tested histochemically an 15-day-old seedlings grown in vitro either under light or dark conditions. For each transformant, the GUS activi ty spatial pattern in plant organs and tissues and the light influence on the GUS activity were studied. Vast variation of GUS activity spat ial patterns was observed. A majority of transformants displayed a str ictly light-dependent GUS activity Lastly, it was seen that certain tr ansformants could give variable GUS patterns at different stages of de velopment. These spatial, temporal and light-dependent GUS activity fe atures allowed us to characterize the activity of the putative corresp onding promoter.