How Albit Works (Mechanisms of Action)
Fig. 1. Mechanisms of action of Albit (principal scheme)
The active ingredient of Albit is a microbial biopolymer poly-β-hydroxybutyrate
(PHB). PHB is a natural storage compound of beneficial soil bacteria
(like starch in plants or fat and glycogen in animals).
In the cells of bacterial producer, Bacillus megaterium,
the content of PHB reaches 77% of its dry biomass. Another bacterium, Pseudomonas
aureofaciens, enhances the synthesis of PHB by the principal producer.
Depolymerases and other enzymes excreted by P. aureofaciens also convert
PHB into a form (oligomers, β-aminobutyrate) physiologically active in plants.
Specially selected set of mineral compounds (magnesium sulphate,
dipotassium phosphate, potassium nitrate, urea) amplifies the effect of PHB
for approximately 10 times, and also acts as a preservative, saving PHB from
rapid decomposition. When Albit is being applied, this set of mineral salts
acts as a starting dose of nutrients for plants.
PHB and its derivatives interact with the receptors of NADPH oxidase system
which are located on the surface of plant cells. Enhanced activity of NADPH
oxidase in plants leads to the formation of superoxide and other reactive oxygen
species (ROS) in concentrations higher than the norm but not deleterious to
the plants. This process triggers expression of cascade of plant antioxidant
enzymes (superoxide dismutase, peroxidases, dehydroascocorbate reductase,
glutathione reductase) which are able to detoxify ROSes. Increased level of
antioxidant enzymes in plant cells brings about higher content of ascorbate
and chlorophyll (up to 100% increase to control). Since virtually any stress
in plants ultimately leads to the accumulation of ROS and impairing of chlorophyll,
plants pre-treated with Albit possess much higher stress resistance.
Under field conditions, increased stress resistance was detected towards drought,
heat, chilling, pesticidal stress, chemical contamination of soils
etc. Ascorbate may easily distribute across whole plant, amplifying stress
resistance even in those organs which were not treated with Albit.
Activation of NADPH oxidase as a response to the application of Albit leads
to the synthesis of superoxide and peroxide (which exert direct biocidal effect
on the pathogens managed to penetrate into the plant). Also, it causes the
synthesis of salicylic acid, a very active signal compound.
Salicylate immunizes the plant against diseases,
and plant tissues acquire resistance towards wide range of pathogens (Systemic
acquired resistance). Synthesis of phytoalexins (natural compound preventing
of pathogen development) increases in plant cells. For example, after Albit
treatment phytoalexins of stilbene nature are synthesized by 33% more in grapes.
As a result, the total antioxidant capacity of plant cells (the TAC) increases
in 1.4-3.6 times. Albit acts very much alike systemic fungicides,
though while they distribute across the plant and exert direct biocidal activity
towards pathogens, Albit causes wide distribution of natural signal metabolite
(salicylate), and as a result even those plant organs which have not been treated
with Albit get immunized against diseases.
In addition to immunizing action, salicylic acid causes accelerated origin
of plant shoots and generative organs of plants, i.e. stimulates their development.
Salicylate and transformation products of poly-hydroxybutyric acid have a strong
phytohormonal (auxin) action. Auxin activity of Albit in working concentrations
is equivalent to 10-6 M solution of indolylacetic acid. This leads to stretching
of the cells, the laying of new buds, flowers and shoots, and, finally, to
The last mechanism of action of Albit is its indirect effect upon
plants through rhizosphere microbial community. When seeds are treated
with Albit, PHB acts on the plant receptors, but as well gets into the rhizosphere
(soil area around plant roots) in considerable amount. The latter leads to
alterations in rhizosphere microbial community associated with plants. As
a result, such pathogenic fungi as Fusarium are suppressed, and
in contrast beneficial fungi of genera —ladosporium, Trichoderma,
and Gliocladium proliferate (increase up to 600 % to control). This
phenomenon is an analogue of exogenous application of living biofungicides.
Albit itself does not contain living microorganisms, though due to its regulatory
activity on indigenous microorganisms, the abundance of Azotobacter and
other N2-fixers increases, nitrogen fixation, phosphate solubilization,
of plants with nutritional elements are enhanced. The carry-over
of nutrition elements from soil and fertilizers into plants increases by
24-25% (N), 26-40% (P), 9-20% (K). The extra supply of plant with nutrition
elements compensates for the additional energy costs of the plant organism
to immunization, accelerated growth and development, induction of stress
To conclude, it can be stated that Albit acts as a multitask well-balanced
protective and stimulating agent embracing all vital areas of plant life.
Fig. 2. Mechanisms of action of Albit (detailed scheme)