Crop Biotech Update

Functional Stacking of Resistance Genes against Potato Late Blight

April 20, 2011

Co-evolution diversifies species and makes competitive species more adapted to the environment. Thus, transgenic resistance traits must be continuously developed in order to get rid of evolving pathogens. One of the promising strategies used by breeders is the stacking of multiple broad spectrum resistance genes into one genotype to ensure the efficacy of resistance.

To combat potato late blight caused by Phytophthora infestans, Suxian Zhu and colleagues at Wageningen University and Research Center in the Netherlands combined three broad spectrum potato resistance genes (Rpi) and inserted into the DNA of susceptible cultivar Desiree through Agrobacterium temefaciens-mediated transformation.

Twenty eight of the 550 transformants with kanamycin resistance contained the Rpi genes. Molecular analyses, disease tests, and avirulence effectors confirmed co-integration and co-functioning of the genes. No negative effects on the functions of the genes or silencing were observed in the transformants. Therefore, functional combination of the Rpi genes was achieved to confer broad resistance to potato late blight disease.

Read the abstract at http://www.springerlink.com/content/ek7183524459724p/.