For plant cells in the early phases of water stress exposure, the genes induced under such conditions play a key role in detecting and responding to water deficit. In this study, potato cell suspensions were used as a sim- plified model system to dissect early molecular changes upon low water potential. In particular, the cDNA-ampli- fied fragment length polymorphism approach was used to capture genes rapidly activated in potato cell cultures in response to water deficit induced by short-term exposure (up to 1 h) to polyethylene glycol. Selective amplifications with 38 primer combinations allowed the visualization of about 167 transcript-derived fragments (TDFs) differen- tially expressed upon exposure to low water potential. The gene expression pattern of 18 up-regulated genes was further investigated by semi-quantitative reverse trans- criptase polymerase chain reaction analysis. Sequencing and similarity analysis revealed that TDFs present homol- ogies chiefly with proteins involved in chaperone activity and protein degradation (hsps, proteinase precursor), in protein synthesis (elongation factor, ribosomal proteins) and in the ROS scavenging pathway (phenylalanine ammonia-lyase, peroxidase). Our findings might contribute to describe the potential role of genes activated in the early phases of plant response to drought.
