Identification of Powdery Mildew Susceptibility Genes in Cultivated Solanaceous Crops

Specific homologs of the plant Mildew Locus O (MLO) gene confer susceptibility towards the powdery mildew (PM) disease. In order to develop PM resistant plants, a breeding based on the inactivation of MLO genes in cultivated species was proposed.

Michela Appiano from the Wageningen University used PCR-based methodologies to isolate MLO genes from cultivated solanaceous crops that host PM fungi, namely eggplant, potato, and tobacco, which were named SmMLO1, StMLO1, and NtMLO1, respectively.

Analysis revealed that these genes are orthologs of tomato SlMLO1 and pepper CaMLO2, which were required for PM pathogenesis. Characterization of the tobacco homolog NtMLO1 revealed it as a PM susceptibility gene. Researchers also found that a single nucleotide change in the NtMLO1 allele leads to complete gene loss-of-function.

The results presented in the study will be valuable in the study of MLO gene evolution and for molecular breeding approaches of developing PM resistant solanaceous crops.

For more information, read the full article on Transgenic Research.