Mechanisms of Gene Regulation
Baldwin, James C. , Karthikeyan, Athikkattuvalasu S. , Cao, Aiqin , Raghothama, Kashchandra G .
Biochemical and Molecular Analysis of LePS2;1- a Phosphate Starvation Induced Protein Phosphatase Gene from Tomato.
Plants adapt to phosphate (Pi) deficiency through a host of biochemical changes. Such adaptations require integration of rescue processes with the Pi starvation mediated signal transduction pathway. Many of the signaling processes are regulated by reversible protein phosphorylation directed by protein kinases and protein phosphatases. In this study, we report the characterization of a protein phosphatase gene (LePS2;1) in tomato induced during phosphate starvation. Biochemical studies using the bacterially expressed recombinant LePS2;1 protein confirmed phosphatase activity against a synthetic phospho-Ser/Thr peptide. Pharmacological analysis indicated that LePS2;1 belongs to PP2A subclass of Ser/Thr protein phosphatases. Okadaicacid, an inhibitor of Ser/Thr protein phosphatases, suppressed the enzyme activity. Western blot analysis using LePS2;1 specific polyclonal antibody showed the accumulation of protein following the induction of LePS2;1, upon Pi starvation. Over-expression of LePS2;1 in tomato plants increased anthocyanin accumulation and acid phosphatase activity under Pi sufficient condition. Transgenic plants exhibited altered morphology and delayed flower initiation. These results provide evidence that LePS2;1, a protein phosphatase, plays a key role in phosphate starvation induced processes in tomato. To our knowledge this is the first comprehensive analysis of a protein phosphatase induced during phosphate starvation.
Log in to add this item to your schedule
1 - Purdue University, Department of Horticulture and Landscape Architecture
2 - Purdue University, Department of Horticulture and Landscape Architecture, 625 Agricultural Mall Drive, West Lafayette, IN, 47907, USA
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM