Response of OocE and OocO gene expression levels in Serratia plymuthica UBCF_13 to the presence of pathogenic fungus Colletotrichum gloeosporioides.

The bacterium Serratia plymuthica strain UBCF_13 is a biocontrol agent that has the potential to inhibit the pathogenic fungus C. gloeosporioides. S. plymuthica produces several antifungal compounds, such as oocydin A. The biosynthesis of oocydin A involves 23 genes, namely oocA to oocW genes. However, only a few genes play a crucial role in the biosynthesis of oocydin A, such as oocE and oocO genes. This study was conducted to determine the changes in the expression levels of the oocE and oocO genes of S. plymuthica strain UBCF_13 against the presence of C. gloeosporioides. The method used is qRT-PCR. The culture treatment consisted of single culture and co-culture with the age of bacteria from each culture was 4, 8 and 12 days. The results showed that the presence of the pathogenic fungus C. gloeosporioides could increase the expression of the oocE gene and decrease the expression of the oocO gene in S. plymuthica UBCF_13 because the oocE and oocO genes have different regulatory pathways. The expression of the oocO gene is under the control of Quorum Sensing (QS) and its regulation is regulated by the RpoS gene, while the regulation of the oocE gene is still unknown. [ABSTRACT FROM AUTHOR]