A study on optimization of pat gene expression cassette for maize transformation.

Phosphinothricin acetyltransferase gene (pat) is an important selectable marker and also a key herbicide trait gene in several commercial products. In maize, the transformation frequency (TF) using pat as a selectable marker is the lowest among the commonly used marker options including epsps, pmi or ppo. Low pat transformation efficiency can become a major bottleneck in our ability to efficiently produce large numbers of events, especially for large molecular stack vectors with multiple trait gene cassettes.

MATRILINEAL, a sperm-specific phospholipase, triggers maize haploid induction.

Sexual reproduction in flowering plants involves double fertilization, the union of two sperm from pollen with two sex cells in the female embryo sac. Modern plant breeders increasingly seek to circumvent this process to produce doubled haploid individuals, which derive from the chromosome-doubled cells of the haploid gametophyte. Doubled haploid production fixes recombinant haploid genomes in inbred lines, shaving years off the breeding process.