Types of Microbe Plant Interactions
There are too many types of microbe plant
friendly interactions to completely discuss here in
one article, but we’ll talk about a few of the main
ones.
◆ Carbon root exudate by plants
◆ Nitrogen fi xation by bacteria
◆ Phosphate solubilization by bacteria and fungi
◆ Auxin and other growth hormone production by
bacteria and fungi
Carbon Root Exudate
Plant exudate, or excrete carbon compounds
into the soil. These compounds serve to attract a vari-
ety of microorganisms. The microorganisms need the
carbon for cellular components and to reproduce.
Nitrogen Fixation
Nitrogen is needed by plants for both protein
synthesis and for DNA and RNA synthesis. Atmo-
spheric nitrogen is very abundant. The problem is
atmospheric nitrogen is not available to plants. Many
bacteria, including Paenibacillus, are capable of tak-
ing atmospheric Nitrogen and incorporating the Ni-
trogen into their cell. This process is called Nitrogen
fi xation. By use of this process, atmospheric nitrogen,
otherwise unavailable to the plant, is now avail-
able. Nitrogen fi xing bacteria are an integral part of
the Nitrogen cycle.
Phosphate Solubilization
Phosphate is required by plant cells for both DNA
synthesis and energy transport. The important chemi-
cals ATP and ADP both require phosphate. Both bac-
teria and Tric hoderma solubilize phosphate and make
it available to the plant. The phosphate cycle, while
not as well-known as the nitrogen or carbon cycles, is
vital to the plants survival.
Auxin Production
Auxins are growth hormones that stimulate plant
growth, particularly root growth. More auxins cause
plants to have healthier, better developed root sys-
tems. Better root systems, of course, mean a health-
ier, more productive plant. Several bacterial species
and Trichoderma fungi produce auxins and a myriad
of other plant growth hormones.
Microbe plant interactions are diverse and com-
plex. It is safe to say, that without benefi cial soil mi-
crobes, plants would have diffi culty growing to their
full potential. GG
Bill Baugh is a product manager for Custom Biologicals,
Inc. a manufacturer and distributor of innovative microbial
products. You can visit their website at Living-Soils.com and
he can be contacted at 561.797.3008 or
[email protected].
April 2018
www.GardenandGreenhouse.net
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