„X Isolation of cDNA clones that express differentially in leaves of Ilex paraguariensis under soil water stress

SANSBERRO, P.; LASPINA, N; PESSINO, S; BOTTINI, R.; MROGINSKI, L.

Boston (MA), USA

Congreso; Plant Biology 2006. Joint Annual Meeting of the American Society of Plant Biologist and Canadian Society of Plant Physiologists; 2006

Amercian Society of Plant Biologists

To identify genes of drought tolerance in Ilex paraguariensis, differential display was performed in plants grown at different Ysoil (-0.4, -1, -2, -3 MPa, and re-watering at -3 MPa). Approximately 400 transcript-derived fragments (TDFs) were screened. Three TDFs with differential expression between non-stressed and stressed plants were identified, isolated and cloned. Two TDFs sequences showed significant homology (Evalue: 1 e-56) with SDH1 genes encoding succinate dehydrogenase. Transcriptome profiling showed that one of the TDFs was repressed, while the other was induced during the stress period, suggesting an specific expression of different alleles. The third TDF did not match any sequence of public databases. During a drying cycle, predawn Yleaf and Yp100 in stressed plants declined from -1.75 and -1.05 MPa to -2.85 and -1.6 MPa respectively, with a decrease in relative water content (RWC) of 42%. On re-watering, pre-dawn Yleaf and RWC fully recovered, but Yp100 remained depressed by 0.3 MPa relative to control, indicating that solute concentration had changed during drought. Simultaneously, endogenous ABA increased 3.16-folds respect the non-stressed plants. The results reported ground future studies of the physiology of water stress tolerance of I. paraguariensis.