The GAIN4CROPS partners at CEPLAS (Centre for Plant Genome Engineering of Heinrich Heine University Düsseldorf) are currently testing and establishing the transformation for different sunflower varieties selected to fit the needs of the project. “The field trials will happen in Switzerland, and for this reason, we have preferred cultivars with a short life cycle, suitable also to the shorter warm season,” explains Dr. Götz Hensel, Head of CPGE.
The task of Hensel’s lab is to establish a transformation protocol for some of the varieties by selecting the best conditions that ensure an effective transformation, e.g., the agrobacteria strain, the selectable marker gene, promoter sequence, the part of the plant used as explant, etc. Scientists use the so-called reporter genes to assess the transformation’s success: besides the target changes, the transformation vector also carries a gene responsible for a visible marker, e.g., the protein RUBY, which confers a dark purple color to the tissue easily detected by the naked eye. Successful transformations are then easily identified because the starting material becomes purplish. But the transformation efficiency is generally relatively low at the beginning – around 1%. “We started with 100 sunflower seeds, which is a meager number for transformation experiments if only one out of 100 is successful,” says Dr. Hensel. Thus, the lab also had to expand the starting material with field multiplication at the Botanical Garden of the HHU, obtaining thousands of seeds for more comprehensive experiments.
