Poster: Mineral nutrition
Abs #
208: FUNCTIONAL CHARACTERIZATION AND GENOMIC ANALYSIS OF A PHOSPHATE STARVATION INDUCED PHOSPHATASE GENE FAMILY IN ARABIDOPSIS (AtPS2) AND TOMATO (LePS2).
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Presenter: |
Raghothama, Kashchandra G, ragu@hort.purdue.edu |
Authors | Baldwin, James C (A) Karthikeyan, Athikkattuvalasu S (A) Cao, Aiqin (A) Raghothama, Kashchandra G (A) | | Affiliations: |
(A): Purdue University
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Plants adapt to phosphate (Pi) deficiency through a host of biochemical changes. Such changes require the coordination of both Pi starvation mediated rescue processes and the signal cascade that regulates them. Protein phosphorylation and dephosphorylation are among the biochemical events associated with plants’ response to many environmental signals including nutrient deficiency. In this study, members of a putative protein phosphatase gene family (PS2) in Arabidopsis (AtPS2) and tomato (LePS2) were analyzed. Three members of the family were identified within the Arabidopsis genome. The deduced AtPS2 proteins shares a significant level of amino acid sequence homology (>80%) with LePS2, a putative acid phosphatase gene induced under Pi deficiency in tomato. These peptides also share significant identity with the members of HAD and DDDD super families of phosphohydrolases. All three members of the AtPS2 family are rapidly and specifically induced in response to Pi starvation. Western blot analysis showed that the expression LePS2 gene is linked with the accumulation of the protein. The PS2 proteins are most similar to serine/threonine phosphoprotein phosphatases. In addition, bacterially expressed LePS2 protein exhibits phosphatase activity against a synthetic phospho-Ser/Thr peptide. The transgenic plants over expressing LePS2:1 showed minor phenotypic changes including accumulation of higher levels of anthocyanins and delayed flowering. These observation strongly points to the potential protein phosphatase function of PS2 family members. Such enzymes could be involved in the signal cascade caused by Pi starvation and its subsequent adaptation to Pi stress.
