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

27. PAÍS SM, GONZÁLEZ MA, TÉLLEZ-IÑÓN MT, CAPIATI DA

Mérida, México

Congreso; Plant Biology 2008.American Society of Plant Biologists, ASPB; 2008

Asoc Plant Biol USA

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 Solanaceae. Broader Impacts The aim of this study was to characterize the catalytic subunit of PP2A in Solanum tuberosum and Solanum lycopersicum, two economically important food crops of the Solanaceae family, and to study its participation in the responses to diverse stress conditions and in tuber development. Understanding the mechanisms by which plants perceive stress and transmit the signal to activate adaptive responses as well as the molecular processes underlying tuberization is of great importance to biology and vital for generating transgenic strategies to improve stress tolerance and yield in crops.