Association between virulence factors and genetic groups in Acidovorax avenae subsp. avenae isolates, the causal agent of sugarcane red stripe disease

BERTANI RP; MIELNICHUK N; CHAVES S; JOYA CM; MONACHESI MA; YARYURA PB; PERERA MF

Congreso; XXXI ISSCT Congress; 2023

International Society of Sugar Cane Technologists

Virulence factors (VFs) enable phytopathogens to proliferate, colonize and cause tissue damage or systemic infection in their hosts. For some bacterial genera, the production of virulence factors has been well described. Acidovorax avenae subsp. avenae (Aaa) is the causal agent of red stripe in sugarcane, a disease characterized by two forms: leaf stripe and top rot. Despite the importance of this disease, little is known about Aaa infection mechanisms and studies of VFs have not been reported. Previous studies on Aaa isolates obtained from sugarcane fields in Tucumán, Argentina, suggested that virulence was not related to genetic groups determined by rep-PCR and AFLP analysis. Therefore, the aim of this work was to evaluate VFs and determine their association with the virulence and the genetic groups of Aaa isolates. Cell adhesion (biofilm production), bacterial motility (sliding, swimming and twitching), H2O2-mediated oxidative stress, extracellular enzyme activities (proteases, amylases and endoglucanase) and exopolysaccharide (EPS) production were assayed in 14 Aaa isolates from different genetic groups. Significant correlations were observed among the VFs, though no clear trend was identified between them and the virulence or genetic group. This study is the first report of VFs of Aaa and further studies would be necessary to provide insight into the infection mechanism of this bacterium.