Immunodiagnostic potential of a 27 kDa protein of Fusarium xylarioides, the cause of coffee wilt disease in Robusta coffee in Uganda

Abstract

Several Fusarium species infect Robusta coffee; these Fusarium xylarioides Steyaert (Gibberella xylarioides Heim and Saccas) are the most virulent and responsible for the destructive Robusta coffee wilt disease in Uganda. To date, F. xylarioides has not been isolated directly from soil, though the pathogen can persist in soil for a short time. In this study, a promising diagnostic target which can be developed into a serological test for F. xylarioides in coffee plants and soil has been identified and validated for identification. Water-soluble extracts of mycelia from six Fusaruim species were resolved by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The different protein profiles from the other five Fusarium species were compared and contrasted with that of F. xylarioides. Protein bands that appeared peculiar to F. xylarioides were cut and injected into rabbits to produce polyclonal antibodies. Dot blot and Western blot analyses showed one immunodominant antigen (27 kDa) common to all F. xylarioides isolates analyzed. No cross-reactivity of anti-27 kDa antibodies were observed in the entire test Fusarium species. The results suggest that polyclonal antibodies raised against the endoantigens from F. xylarioides of 27 kDa, is a promising tool for the rapid, sensitive, and accurate detection of pathogen in soil and plant parts.

Using Translation Elongation Factor Gene to Specifically Detect and Diagnose Fusarium xylaroides, a Causative Agent of Coffee Wilt Disease in Ethiopia, East and Central Africa.

“…Detection of CWD pathogen from disease plant tissue has been mainly done microscopically after culturing and has since failed to detect the pathogen from the soil and asymptomatic plants [6], it is expensive, slow, and requires high taxonomic expertise [7], On the other hand, field identification basing on symptoms is confusing with other effects like stem borer, drought and other physiological problems, which produce similar symptoms to CWD [6]. A fast and reliable method for detection and identification of the pathogen is therefore needed.…”