S01 - Session P5 - Pathogenesis-related 10 gene associated with the defense mechanisms of banana against Ralstonia syzygii subsp. celebesensis, the causal agent of Banana Blood Disease

Authors: Jariya Nitayaros *, Thanwanit Thanyasiriwat, Aphidech Sangdee, Ladawan Rattanapolsan, Praphat Kawicha

Banana Blood Disease, caused by Ralstonia syzygii subsp. celebesensis (Rsc), currently is devastating banana production in some countries in Southeast Asia. The host response to Rsc infection is little understood. The Pathogenesis-related 10 ( Pr-10 ) gene is one of the vital defense-related genes in a banana against fungal infection. In this study, Pr-10 gene expression was compared between disease-resistant, Musa (AA Group) 'Kluai Khai Kasetsart 2', and susceptible, Musa (ABB group) 'Kluai Hin', banana infected with Rsc. A 10 8 cfu/ml cell suspension of Rsc was inoculated into 6-week-old micro-propagated bananas by soil-drenching with a root wounds method. The expression of the Pr-10 gene in the resistant and susceptible banana on 1, 3, 7 and 14 days after Rsc inoculation were evaluated by real-time PCR quantification analysis. The results showed that expression in the resistant banana was significantly upregulated at 1, 3 and 7 days after inoculation compared with the susceptible banana. At 14 days after inoculation, the expression of Pr-10 was not different between the resistant and susceptible accessions. This research points to the association of the Pr-10 gene with Rsc resistance of banana at the early stages of infection. However, the disease defense mechanisms generally rely on more than one gene. Therefore, other potential resistance genes need to be discovered in order to elucidate the defense mechanism of Banana Blood Disease resistance.