Participation of protein phosphatases type 2A in stress responses and development in Solanaceae

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

Mérida (México)

Congreso; Plant Biology 2008 (American Society of Plant Biologists, ASPB); 2008

American Society of Plant Biologists (ASPB)

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 clustered into two subfamilies. Alternative polyadenylation sites were found for StPP2Ac-5 and SlPP2Ac-1. 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.