Design of expression cassettes that confer drought and glufosinate tolerance to maize (Zea Mays)

Abstract

As a first approach in obtaining a transgenic drought and glufosinate ammonium tolerant maize line, genes and regulatory elements for the in silico design of the expression cassettes were selected through analysis of scientific literature and databases of genes and patents. Gene sequences were modified based on the criterion of maize codon usage to optimize their expression. The constructs designed with DNA 2.0 Software, were synthesized by a specialized company. The presence of the transgene and the expression of mRNA was demonstrated by PCR and RT-PCR in the model plant Nicotiana benthamiana transformed via Agrobacterium tumefaciens. A preliminary experiment in vitro under simulated drought conditions in MS medium with 10 % PEG (PM 6000) showed no noticeable increase in drought tolerance of the transformants, possibly because the codon usage of the design does not promote gene expression in the model plant.