Title |
Effect of exopolysaccharides of Paenibacillus polymyxa rhizobacteria on physiological and morphological variables of wheat seedlings |
Author |
Irina V. Yegorenkova*, Kristina V. Tregubova, Alexander I. Krasov, Nina V. Evseeva, and Larisa Yu. Matora |
Address |
Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences (IBPPM RAS), Saratov 410049, Russian Federation |
Bibliography |
Journal of Microbiology, 59(8),729–735, 2021,
|
DOI |
10.1007/s12275-021-0623-9
|
Key Words |
Paenibacillus polymyxa, exopolysaccharides, mitotic
index, plant-growth-promoting activity, root colonization,
Triticum aestivum L. |
Abstract |
Paenibacillus polymyxa is a promising plant-growth-promoting
rhizobacterium that associates with a wide range of host
plants, including agronomically important ones. Inoculation
of wheat seedlings with P. polymyxa strains CCM 1465 and
92 was found to increase the mitotic index of the root cells
1.2- and 1.6-fold, respectively. Treatment of seedlings with
the exopolysaccharides (EPSs) of these strains increased the
mitotic index 1.9-fold (P. polymyxa CCM 1465) and 2.8-fold
(P. polymyxa 92). These increases indicate activation of cell
division in the root meristems. Analysis of the morphometric
variables of the seedlings showed that P. polymyxa CCM
1465, P. polymyxa 92, and their EPSs promoted wheat growth,
increasing root and shoot length up to 22% and root and
shoot dry weight up to 28%, as compared with the control.
In addition, both strains were found to intensely colonize the
seedling root surface. Thus, P. polymyxa EPSs are active metabolites
that, along with whole cells, are responsible for the
contact interactions of the bacteria with wheat roots and are
implicated in the induction of plant responses to these interactions.
The strains used in this work are of interest for
further study to broaden the existing understanding of the
mechanisms of plant–bacterial interactions and to develop
effective biofertilizers for agricultural purposes. |