A tool for monitoring trichoderma and fusarium oxysporum f.Sp. Elaeidis oil palm interactions, using constitutive and inducible green fluorescent protein (GFP) and red fluorescent protein (DsRED) reporter system

Vascular wilt disease of oil palm is cause by Fusarium oxysporum f.sp elaeidis. The pathogen normally invades intact roots of palms or wounds and colonises the xylem vessels where it causes water stress, and hormonal imbalance result in severe yield loss and possible palm death. This study attempted to visualise the stages of colonisation and penetration into roots by Fusarium oxysporum f.sp elaeidis expressing Red Flourescent Protein (DsRed) in susceptible oil palm line and it's interactions with Trichoderma TPP4 expressing Green Fluorescent Protein (GFP). Trichoderma TPP4 and Fusarium oxysporum f.sp elaeidis were successfully transformed using Agrobacterium tumefaciens-mediated transformation with both GFP and DsRed respectively using vectors pCAMDsRed and pCAMBgfp whereby this is the first report that Fusarium oxysporum f.sp. elaeidis has been genetically modified. Analysis showed that early colonisation of Foe hyphae on the surface of secondary roots while colonisation by Trichoderma was observed at early stages after inoculation and became denser with time. Trichoderma TPP4 also was seen coiling around the Foe when inoculated together showing potential mycoparasitisic action.