Constitutive Expression of the Inositol Polyphosphate 5- Phosphatase Gene Alters Plant Development and Enhances Abiotic Stress Tolerance in Creeping Bentgrass

Inositol-1,4,5-triphosphate (IP3), a second messenger molecule and a very important component of phosphoinositide (PI) signaling, participates in plant growth and response to various abiotic stresses. Strict control of the IP3 balance is critical for normal plant development. Type I Inositol polyphosphate 5-phosphatase (InsP 5-ptase) functions to hydrolyze soluble inositol phosphates, such as IP3. It has previously been reported that transgenic Arabidopsis, a dicotyledonous plant species overexpressing InsP 5-ptase exhibit a sharply declined IP3 level, but enhanced tolerance to various environmental adversities, indicating an important role the InsP 5-ptase plays in regulating phosphoinositide (PI) signaling to mediate plant stress responses. To investigate how InsP 5-ptase is involved in stress responses in monocots, we have generated transgenic creeping bentgrass (Agrostis stolonifera L.), an important C3 cool-season turfgrass that constitutively expresses a mammal type I InsP 5-ptase. Data obtained revealed that overexpression of InsP 5-ptase gene alters plant development and leads to enhanced plant tolerance to drought, salt and heat stresses associated with improved physiological parameters. Further characterization of the InsP 5-ptase transgenic plants will allow a better understanding of InsP 5-ptase-mediated plant stress response, providing information to develop novel biotechnology approaches for crop genetic improvement