Transgenic Pm3e Wheat Show High Resistance to Powdery Mildew

Pm3 from wheat confers resistance to powdery mildew caused by fungal pathogen Blumeria graminis f.sp. tritici (Bgt). Researchers have identified 17 working Pm3 alleles that confer resistance to Bgt isolates. One of the variants, Pm3e, was found in wheat donor line W150 and similar to non-functional variant Pm3CS except for two amino acids. To evaluate the capability of Pm3e to confer powdery mildew resistance, scientists from the University of Zurich and Agroscope in Switzerland developed transgenic Pm3e lines by biolistic transformation of the powdery mildew susceptible spring wheat cultivar Bobwhite.

Results of the field trials showed significant and strong powdery mildew resistance of the Pm3e transgenic lines, while the non-transformed lines were severely powdery mildew infected. Thus, it was confirmed that Pm3e alone is responsible for the strong resistance phenotype. The field grown transgenic lines showed high transgene expression and Pm3e protein accumulation with no fitness costs on plant development and yield associated with Pm3e abundance.

Based on the study, Pm3e can provide strong powdery mildew field resistance, making its use in wheat breeding programs very promising.

Read more from Transgenic Research.