Attachment of bacteria to the roots of higher plants. Minireview.

RODRÍGUEZ-NAVARRO, D.N., DARDANELLI, M.S., RUIZ-SAINZ, J.E.

FEMS MICROBIOLOGY LETTERS

Blackwell Publishing

Lugar: Deltf; Año: 2007 vol. 272 p. 127 - 136

0378-1097

Attachment of soil bacteria to plant cells is supposedly the very early step requiredin plant–microbe interactions. Attachment also is an initial step for the formationof microbial biofilms on plant roots. For the rhizobia–legume symbiosis, variousmechanisms and diverse surface molecules of both partners have been proposed tomediate in this process. The first phase of attachment is a weak, reversible, andunspecific binding in which plant lectins, a Ca12-binding bacterial protein(rhicadhesin), and bacterial surface polysaccharide appear to be involved. Thesecond attachment step requires the synthesis of bacterial cellulose fibrils thatcause a tight and irreversible binding of the bacteria to the roots. Cyclic glucans,capsular polysaccharide, and cellulose fibrils also appear to be involved in theattachment of Agrobacterium to plant cells. Attachment of Azospirillum brasilenseto cereals roots also can be divided in two different steps. Bacterial surface proteins,capsular polysaccharide and flagella appear to govern the first binding step whileextracellular polysaccharide is involved in the second step. Outer cell surfaceproteins and pili are implicated in the adherence of Pseudomonas species to plantroots.