Phyllosphere colonization strategies related to successful infection in Xanthomonas vesicatoria

ROMERO A. M.; FELIPE, V; MONTECCHIA, M. S.; BIANCO, MI; YARYURA, P. M.

Boston

Congreso; International Congress of Plant Pathology (ICPP) 2018: Plant Health in A Global Economy.; 2018

Phyllospherecolonization strategies related to successful infection in Xanthomonas vesicatoriaBacterialspot, induced by Xanthomonas vesicatoria,is a serious constrain of field grown tomatoes in Argentina. To better understandstrains aggressiveness, several characteristics of 3 local strains that inducedifferent levels of disease were evaluated. Swarming and twitching motility,biofilm formation and xanthan production and viscosity of each strain weredetermined in vitro; the assays wereperformed in triplicate. The number and size of the lesions induced by eachstrain and bacterial multiplication inplanta were also evaluated; there were 4 plants per strain. Strain BNM208was the most aggressive: it induced more and bigger lesions than BNM216; BNM214showed intermediate values. All strains reached similar population sizes wheninoculated by infiltration, surpassing the need for phyllosphere colonization.Twitching and swarming motility was greatly reduced in BNM214 and BNM216,compared to BNM208. Only BNM208 developed a mature biofilm: it had asignificantly higher surface coverage (%) and biomass (µm3/ µm2)than the other two strains, and a lower roughness coefficient, indicative of amore homogeneous thickness. The 3 strains produced similar amounts of xanthan,although that of BNM208 was the most viscous, which possibly relates to thebetter characteristics of its biofilm. The ability of BNM208 to move and formmature biofilms may allow a better colonization of the phyllosphere, resultingin a high infection success of this strain.