Differentially expressed genes in incompatible interactions of Pratylenchus coffeae with Musa using suppression subtractive hybridization

A cDNA library enriched with differentially expressed transcripts was constructed from Pratylenchus coffeae challenged resistant banana cultivar (Karthobiumtham-ABB) through suppression subtractive hybridization (SSH) technique to elucidate the nematode resistance mechanisms. A total of 256 unique genes of this SSH library were sorted into eight functional categories. Of these, 26.8% were unigenes involved in defense and/or signal transduction including resistant gene homologues, disease resistance response proteins and transcripts associated with disease related proteins and protein kinase signaling. These findings imply that invasion of nematode triggers multiple signaling pathways both through tissue damage caused by nematode invasion and recognition of nematode elicitors by R genes. Confirmation of defense specific representative genes through semi quantitative RT-PCR revealed their increased expression levels in resistant than in susceptible cultivar and the resistant cultivar triggered response much earlier than the susceptible cultivar.