Difference in defense mechanism of two cassava cultivars to bacterial blight disease inferred by analysis of interspecies protein-protein interaction networks

Cassava (Manihot esculenta Crantz), is an important economic crop of the world and especially Thailand. One of the major problems resulting in its yield loss is cassava bacterial blight (CBB) disease caused by Xanthomonas axonopodis (XAM). Unfortunately, the basic knowledge of cultivar-specific defense mechanism is limited. Therefore, in this work protein-protein interaction (PPI) networks of two cassava cultivars; KU50 and AM560, and XAM were reconstructed using domain-domain interaction method (DDI) to study interactions between XAM and cassava. The PPIXAM-KU50 consisted of 24,509 interactions from 4,754 proteins while PPIXAM-AM560 contained 28,962 interactions from 6,153 proteins. The results demonstrated that XAM used different mechanisms to invade specific cassava cultivar. This study would enable us to comprehend the protein-protein relationship between bacterial pathogen and cassava.