Evaluating Pathogenic Potential of Fusarium oxysporum

Start date:
01 Jan 2012
End date:
31 Dec 2015
Researchers:
Liliana Rocha Matthew Laurence Victoria Ludowici Victor Puno, Candice Lim, Len Tesoriero Brett Summerell Edward Liew
Project sponsors:
The Royal Botanic Gardens and Domain Trust

Project aims

  • Evaluate the pathogenic potential of F. oxysporum from natural ecosystems of Australia by screening for putative effector genes. 
  • Understand the evolution of these genes by analysing their mode of gene transfer. 
  • Explore the phylogenetic relationships of naturally occurring effector genes with those from formae speciales recovered from agro-ecosystems. 

 

Project Summary

In addition to causing diseases in plants and animals, members of the Fusarium oxysporum species complex are also widely dispersed in natural ecosystems without any apparent evidence of disease. The study screens a representative population from natural ecosystems across the Australian continent for the putative effector genes, Pisatin Demethylase 1 (PDA1), Pectate Lyase (pelD), Secreted Gene Expression (SGE1) and Secreted in Xylem (SIX). The genes pelD and SGE1 are found to be prevalent in the natural isolates; PDA1 is present at an intermediate level whereas SIX genes are detected at low levels. Phylogenies of these putative effector genes are compared to the EF-1α species phylogeny for evidence of different modes of gene transmission: Vertical Gene Transfer (VGT) and Horizontal Gene Transfer (HGT). PDA1, pelD and SGE1 are likely to be only vertically inherited, whereas the SIX genes have evidence for both VGT and HGT between natural populations and isolates in formae speciales from agro-ecosystems.