DIFFERENTIAL SCREENING USING HIGH-DENSITY FILTERS REVEALS A DRAMATIC CHANGE IN GENE-EXPRESSION AT DIFFERENT GROWTH-PHASE IN ARABIDOPSIS CELL-SUSPENSION CULTURES

Differential screening using high density filters prepared from ordere d cDNA libraries has been tested in order to obtain an overall view of plant genes expressed in different tissues or under particular physio logical conditions. Arabidopsis thaliana cell suspension cultures at d ifferent growth phases were used for this approach. Our results indica te that there are dramatic changes in gene expression during the diffe rent growth phases of these cell suspension cultures. The analysis by partial sequencing of a sample of 61 cDNA clones specifically or prefe rentially expressed in the stationary phase, reveals that most of thes e clones correspond to genes having a putative relationship with mecha nisms involved in response to stress, in defence against pathogens or in senescence processes.