Application of Beta-Glucuronidase Transient Expression for Selection of Maize Genotypes Competent for Genetic Transformation

Abstract

Genetic transformation of inbred maize lines and F₁ hybrids registered in Ukraine has been carried out. The study employed a biolistic method for genetic transformation of immature maize embryos that formed callus tissue and the pAHC25 vector containing the genes of phosphinothricin-N-acetyltransferase (bar) and β-glucuronidase (uidA). As a result of the transformation of callus tissue of maize genotypes, lines resistant to phosphinothricin and regenerated plants were obtained. The activity of β-glucuronidase in herbicide-resistant calli was detected. The presence of the bar gene in callus DNA was demonstrated by the PCR method. The rate of stable transformation ranged from 2.2 to 30% depending on the genotype. The relationship between the results of transient expression of the β-glucuronidase gene and stable genetic transformation was observed. The proposed protocol for genetic transformation of maize using the study of transient expression of the β-glucuronidase gene makes it possible to significantly simplify the process of selecting genotypes competent for genetic transformation and create transgenic organisms with new traits.