“Protein Phosphatases Type 2A participate in stress responses in Solanaceae”.

SILVIA MARINA PAÍS; MARINA A. GONZÁLEZ; M. TERESA TÉLLEZ-IÑÓN; DANIELA ANDREA CAPIATI

Mar del Plata, RA

Congreso; XLIII Annual Meeting of the Argentine Society for Biochemistry and Molecular Biology (SAIB).; 2007

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB)

Protein phosphorylation/dephosphorylation plays critical roles in stress responses and development in plants, being serine/threonine phosphorylation the predominant postranslational modification. Ser/Thr phosphatases in plants include members of the type 1, 2A and 2C subfamilies. PP2A contain a highly conserved catalytic subunit (C), a structural subunit (A) and a regulatory subunit (B). The aim of this study was to characterize the catalytic subunit of PP2A in potato (Solanum tuberosum) and tomato (Solanum lycopersicum) plants and its participation in the responses to diverse stress conditions and in tuber development. Sequence homology analysis revealed six isoforms in potato and five in tomato. Protein and RNA expression profiles of PP2Ac isoforms in potato and tomato under different environmental conditions were determined. The stimuli studied were related to tuber development, abiotic stress (cold, salinity and wounding) and biotic stress (fungal elicitors). These analysis together with experiments using the PP1/PP2A inhibitor okadaic acid yielded evidence on the physiological roles of different isofoms of PP2Ac in potato and tomato. The results obtained suggest that certain isoforms of PP2Ac play important roles in the response to cold, salinity, fungal elicitors, and tuber development in Solaneceae.