Ma. Savka et Sk. Farrand, MODIFICATION OF RHIZOBACTERIAL POPULATIONS BY ENGINEERING BACTERIUM UTILIZATION OF A NOVEL PLANT-PRODUCED RESOURCE, Nature biotechnology, 15(4), 1997, pp. 363-368
The ability to catabolize distinct nutrients produced by a plant may b
e a factor in the successful colonization of that host by a bacterium
when in competition with other rhizosphere microorganisms. We tested t
his hypothesis by examining the influence of a novel substrate produce
d by a transgenic plant on root colonization by near-isogenic bacteria
, differing only in their ability to use the resource. When inoculated
alone, both bacteria colonized the roots of the normal and transgenic
plants with equal kinetics and to indistinguishable levels. When the
two bacteria were coinoculated, the catabolizer reached a population d
ensity significantly higher than that of the noncatabolizer on the roo
ts of the resource-producing plant. No such advantage was observed on
the roots of normal plants. These results support the theory that reso
urces produced and exuded by a plant host can confer a selective advan
tage to microorganisms that use the substrate.