[Maize transformation using xylose isomerase gene as a selection marker]

Area of Science:

• Molecular Biology
• Plant Biotechnology
• Genetics

Context:

• The xylA gene, encoding xylose isomerase, was cloned from E. coli.
• A novel vector, pBAC413, was engineered to facilitate gene integration and prevent specific gene expression in maize.
• Maize calli from elite inbred lines were used for transformation experiments.

Purpose:

• To establish a bio-safe method for genetically transforming maize using xylose as a selection marker.
• To investigate the efficacy of xylose concentrations for selecting transformed maize cells.
• To confirm the successful integration of the xylA gene into the maize genome.

Summary:

• The bacterial xylA gene was cloned and integrated into a vector (pBAC413) designed for maize transformation.
• Maize calli were bombarded with the vector, and transformed cells were selected on media containing 50-100% D-xylose, with optimal concentrations varying by maize genotype.
• Successful gene integration was verified using DNA dot blotting, PCR, and PCR-Southern hybridization.

Impact:

• A bio-safe screening method for transformed maize cells was developed, replacing traditional antibiotic or herbicide selection.
• This approach enhances biosafety in plant genetic engineering.
• The findings provide a foundation for developing improved methods for maize genetic modification.