Portal de Periódicos da CAPES

Effect of callose inhibition on haustorium formation by the cowpea rust fungus in the non-host, bean plant

1989; Elsevier BV; Volume: 35; Issue: 4 Linguagem: Inglês

10.1016/0885-5765(89)90042-8

1096-1178

CHRISTOPHER J. PERUMALLA, Michèle C. Health,

Mycorrhizal Fungi and Plant Interactions

The effect of callose inhibition on haustorium formation by the cowpea rust fungus in non-host bean leaves was investigated. Callose synthesis was inhibited with calcium chelator, EGTA, and glucose analogue and protein glycosylation inhibitor, 2-deoxy-d-glucose (DDG). Both treatments inhibited callose deposition in the mesophyll walls of bean plants but without any increase in the incidence of haustorium formation. Light microscopy studies revealed that callose inhibition did not have any effect on the deposition on and in the plant cell wall of either silica or phenolic material. However, electron microscopy showed that the absence of callose co-incided with a more compact appearance of the silica deposits. Injection of bean leaves with boric acid and calcium phosphate induced callose deposition but no refractive deposits typical of those containing silica. These results suggest that in the interaction between the cowpea rust fungus and non-host, bean plant: (1) callose plays little or no part in restricting fungal growth and preventing the formation of haustoria; (2) callose deposition is not a prerequisite for the deposition of silica and phenolic material and (3) the deposition of callose and silica are not interdependent and may be elicited independently.