Biotech Updates

MdMLO19 Gene Knockdown in Apple Reduces Susceptibility to Powdery Mildew

May 18, 2016

Varieties resistant to powdery mildew (PM) caused by Podosphaera leucotricha are a major component of sustainable apple (Malus domestica) production. Resistance can be achieved by knocking-out susceptibility S-genes, which can be singled out from members of the MLO (Mildew Locus O) gene family. Candidate genes include the MLO S-genes MdMLO11, MdMLO18 and MdMLO19, which were found upregulated upon PM inoculation.

Scientists from the Fondazione Edmund Mach in Italy and Wageningen University and Research Centre in the Netherlands report on the RNA interference knockdown of MdMLO11 and 19, as well as the complementation of resistance with MdMLO18 in the Arabidopsis thaliana triple mlo mutant.

The knockdown of MdMLO19 reduced PM severity by 75%, while the knockdown of MdMLO11, alone or in combination with MdMLO19, did not result in any reduction or additional reduction of susceptibility. The test in Arabidopsis excluded a role for MdMLO18 in PM susceptibility.

MdMLO19 plays an important role in apple PM susceptibility and its knockdown induces a very significant level of resistance.

For more information, read the full article in Plant Biotechnology Journal.