Abstract:

Mildew resistance locus o（MLO）genes are new type of disease resistance. In dicots，loss-of-function mutations in MLO genes confer high levels of broad-spectrum resistance in powdery mildew. In this study，we analyzed subcellular localization of MLO genes from rose using bioinformatics software combined with subcellular localization experiment. The results showed that RhMLO1 and RhMLO2 were both transmembrane proteins mainly distributed in plasma membrane，vacuole membrane and nucleus，which were basically in line with the prediction. We constructed the plant expression vector with sense RhMLO1 gene based on digestion and connection methods，which was introduced into embryogenic callus of‘Baiyu’by Agrobacterium-meidiated transformation. The transgenic lines were confirmed integration based on PCR and FQ-PCR. We compared the difference of powdery mildew resistance level between control plants and transgenic plants by isolated identification and microscope observation. The results showed that RhMLO1-transgenic lines decreased resistance against the pathogen.

Key words: Rosa, powdery mildew, mildew resistance locus o, subcellular localization, functional analysis