Cloning and expression of an alternative oxidase gene from Lycopersicon esculentum.

A full-length cDNA gene (LeAox1au) was isolated from a cDNA library made from ripening fruit of tomato "UC-82B" (Lycopersicon esculentum), after probing with alternative oxidase (AOX) gene fragments, obtained by degenerate primer PCR. Sequence analysis showed that LeAox1au was 1418 bp long and contained a 1077-bp open reading frame encoding a about 40 kD precursor protein which is processed to a mature protein of 32 kD. Southern blot analysis suggested LeAox1au is present as a single copy in the genome of tomato. RT-PCR analysis indicated LeAox1au was expressed in roots, stems, leaves and cotyledons of tomato plants. A recombinant construct containing the open reading frame sequence of the LeAox1au was transformed into Escherichia coli to express the alternative oxidase precursor protein.