Overexpression of a heat-inducible apx gene confers chilling tolerance to rice plants.

This paper examines the effect of prior high-temperature exposure on the susceptibility of rice (cv. Kirara 397) seedlings to chilling injury, and evaluates the changes in L-ascorbate peroxidase (APX) activity and induction of transcription after exposure to high temperature in order to determine the possible role of APX in increasing the chilling tolerance to plants previously subjected to high temperature. The heat-inducible apx gene promoter sequences are characterized and chilling tolerance of transgenic rice with elevated levels of APX are examined.