TRANSCRIPT-PROFILING OF A RESISTANT CUCUMBER GENOTYPE DURING INFECTION WITH Podosphaera fusca (A PHYTOPATHOGEN)

Cucurbits powdery mildew caused by P. fusca is an extremely damaging disease of cucumbers throughout the world. Using cDNA-AFLP transcript profiling, gene expression pattern of a powdery mildew resistant cucumber (Cucumis sativus) genotype was assayed during infection with P. fusca and 22 transcription derived factors (TDFs) showing differential expression patterns were sequenced and further analyzed using BLAST homology search and bioinformatics analyses. The results showed that 11.4% of TDFs displayed altered expression in comparing between different times of infection together and with non-infected plants and majority of TDFs were upregulated during infection. The majority of the sequences were homolog to plant functionally known genes controlling resistance, signaling, regulatory and metabolism functions. Two cucumber disease resistance genes with GenBank accession numbers of “XR_970128.1” and “XM_004141879.2’ were significantly homolog to ESTs “JZ948665” and “JZ948667’ respectively which can be considered as possible resistance candidate genes against the pathogen. The results of the present study give more insights into factors and mechanisms underlying the responses of cucumber to powdery mildew caused by P. fusca and would be useful in cucumber breeding programs for resistance against the pathogen.