Isolation, characterization, and expression analysis of CmMLO2 in muskmelon.

The full-length cDNA sequence of the MLO gene was cloned via SMART-RACE-PCR from muskmelon (Cucumis melo L.), and was designated as CmMLO2 (GenBank Accession No. FJ713542). The gene is 1,710 bp long and encodes a 570-amino acid peptide with a seven-transmembrane domain topology, and is a typical transmembrane protein. Localization analysis in onion epidermal cells showed that CmMLO2-GFP is localized in the plasma membrane. The expression of CmMLO2 gene was analyzed in melon leaf infected with powdery mildew using a quantitative RT-PCR and it was found that CmMLO2 was mainly expressed in melon leaves in a no-tissue-specific pattern. Moreover, CmMLO2 may play a crucial role in the pathogenesis of powdery mildew.