Promowanie wzrostu roślin przez bakterie z rodzaju azospirillum oraz ich zastosowanie w rolnictwie

Abstract

Azospirillum represents the best characterized genus of plant
growth-promoting rhizobacteria. Four aspects of the Azospirillum
plant root interaction are highlighted: associations, plant root in-
teraction, nitrogen fixation and biosynthesis of plant growth hor-
mones. Each of these aspects is dealt with in a comparative way.
Azospirilla are predominantly surface colonizing bacteria. The at-
tachment of Azospirillum cells to plant roots occurs in two steps.
The polar flagellum, of which the flagellin was shown to be a gly-
coprotein, mediates the adsorption step. Nitrogen fixation structural
genes (nif) are highly conserved among all nitrogen-fixing bacteria.
The transcriptional activator NifA is required for expression of oth-
er nif genes in response to two major environmental signals. Many
genes are involved in colonization of plant roots, plant-growth
promotion, and properties related to rhizosphere adaptation. Those
bacteria have been in the centre of scientific interest for the last
two decades because under appropriate conditions members of this
genus can enhance plant development and promote the yield of
several agriculturally important crop plants.