Field grown transgenic Pm3e wheat lines show powdery mildew resistance and no fitness costs associated with high transgene expression

• Published in: Transgenic research Vol. 28; no. 1; pp. 9 - 20
• Main Authors: Koller, Teresa, Brunner, Susanne, Herren, Gerhard, Sanchez-Martin, Javier, Hurni, Severine, Keller, Beat
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01-02-2019; Springer Nature B.V
• Subjects: Alleles; Animal Genetics and Genomics; Ascomycota - pathogenicity; Biomedical and Life Sciences; Biomedical Engineering/Biotechnology; Disease Resistance - genetics; Fitness; Flowering; Genetic Engineering; Genetic transformation; Leucine; Life Sciences; Molecular Medicine; Original Paper; Phenotypes; Plant Breeding; Plant Diseases - genetics; Plant Diseases - microbiology; Plant Genetics and Genomics; Plant Proteins - genetics; Plants, Genetically Modified - genetics; Plants, Genetically Modified - microbiology; Powdery mildew; Somaclonal variation; Transgenes; Transgenics; Triticum - genetics; Triticum - growth & development; Triticum aestivum; Genetic engineering (GE); Disease resistance; Field trial; Wheat; Powdery mildew
• ISSN: 0962-8819; 1573-9368
• DOI: 10.1007/s11248-018-0099-5

Pm3
from wheat encodes a nucleotide-binding leucine-rich repeat type of receptor and confers resistance to powdery mildew caused by the fungal pathogen
Blumeria graminis
f.sp.
tritici
 (
Bgt
). Each of the 17 functional
Pm3
alleles identified so far confers resistance to a distinct spectrum of
Bgt
isolates. Variant Pm3e has been found in wheat donor line W150 and differs only by two amino acids from the non-functional variant Pm3CS. In order to evaluate the capability of
Pm3e
to provide powdery mildew field resistance, we generated transgenic
Pm3e
lines by biolistic transformation of the powdery mildew susceptible spring wheat cultivar Bobwhite. Field trials conducted during four field seasons in Switzerland showed significant and strong powdery mildew resistance of the
Pm3e
transgenic lines, whereas the corresponding biological sister lines, not containing the transgene, were severely powdery mildew infected. Thus
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. Line E#1 as well as sister line E#1 showed delayed flowering due to somaclonal variation. The study shows the capability of
Pm3e
in providing strong powdery mildew field resistance, making its use in wheat breeding programs very promising.