Análise ultraestrutural da interação de Curtobacterium flaccumfaciens pv. flaccumfaciens em genótipos de feijoeiro

Abstract

Observações com microscopia eletrônica de transmissão em secções ultrafinas de células de caules de feijoeiros (Phaseolus vulgaris L.), inoculados com Curtobacterium flaccumfaciens pv. flaccumfaciens (Cff), mostraram alterações nos vasos de xilema em genótipos de feijoeiros altamente resistentes, como formação de estrutura semelhante a tilose e presença de fibrilas ao redor das células bacterianas. Em genótipos suscetíveis, Cff colonizou além de vasos de xilema, células parenquimáticas e metaxilema.

Reaction and colonization of common bean genotypes by Curtobacterium flaccumfaciens pv. Flaccumfaciens

“…The authors studied the xylem vessels in stems of Cff-resistant cultivars and detected the presence of clumps in bacterial cells involved in filament and lace-like structures under marks in the walls of xylem vessels, which blocked the movement of bacteria to other parts of the xylem vessel, away from the point of inoculation. According to Souza and Maringoni (2008), protoplasmic projections are formed towards the inside of xylem vessels in Cff-resistant bean genotypes, indicating the onset of tylose formation and clogging of xylem vessels that restrict bacteria colonization.…”

Reaction of common bean lines to Xanthomonas axonopodis pv. phaseoli and Curtobacterium flaccumfaciens pv. Flaccumfaciens

“…According to Souza and Maringoni (2008), resistant genotypes involve the pathogen by protoplasmic projections, preventing its installation in the xylem vessels, while in susceptible genotypes the water transport is obstructed by the presence of bacterial cells. These results are related to the disease symptoms, e.g., plant wilting, yellowing, underdevelopment, and death, observed at different levels of aggressiveness in the 58 lines evaluated in this study.…”