Application of plant biostimulants as new approach to improve the biological responses of medicinal plants- a critical review

The aim of this review was to represent a category of applied plant biostimulants and to highlight the effect of their application on morphological and phytochemical properties of medicinal plants in in vivo and in vitro conditions and their mechanism of action. Plant biostimulants, safe for both human beings and the environment, are substances or materials, except for nutrients and pesticides, which have the ability to beneficially modify plant growth and have been accepted over the past decade. Plant biostimulants have natural and synthetic origin. The natural biostimulants contain amino acids, bacteria, seaweed, yeast, chitosan, phytohormones, and also plant growth regulators [synthetic hormones], phenolic compounds, inorganic salts, essential elements, and other different substances are some examples of synthetic biostimulants. The plant biostimulants through different mechanisms of action [such as nitrogen assimilation] are sustainable management practice for production of medicinal plants, increasing biomass production, and enhancing secondary metabolites synthesis and it is investigated and shown in many studies in recent years. Furthermore, there are many reports on positive effects of biostimulants and elicitors application on medicinal plants in in vitro culture condition. Some products of companies active in the formulation of biostimulants in Iran are mentioned in this review. In conclusion, yield response in medicinal plants to biostimulants application showed that each medicinal plant responds in a different way based on the chemical composition and components of biostimulants, the timing and rate of application

Bio-elicitation of beta-carboline alkaloids in cell suspension culture of Peganum Harmala L.

Background: Sustainable and commercial production of secondary metabolites is a critical issue when dealing with its clinical application. Efforts are still being made to look for biotic or abiotic elicitors with more efficient and universal effects on the improvement of secondary metabolites

Objective: In order to evaluate the suitability of different biotic elicitors on P. harmala L. cell suspension cultures was established to enhance the beta-carboline alkaloids [harmaline and harmine] production

Methods: The elicitation of cell suspension cultures of Peganum harmala L. was done by adding various fungal mycelium homogenates [Aspergillus flavus, Alternaria alternate, Coriolus versicolor, Fusarium oxysporum, Mucor sp, Penicillium notatum, and Rhizopus stonifer], Casein hydrolysate and Saccharomyces cerevisiae at different concentrations. The cell cultures of P. harmala L. were subcultured on MS medium with optimal treatment of biotic elicitor. CAMAG analytical HPTLC system was used for estimation of harmaline and harmine after extraction of beta-carboline alkaloids

Results: The maximum harmine production [91.2 +/- 1.8 microg g[-1] DW] was observed at 1000 mg l[-1] S. cerevisiae in cell suspension culture of P. harmala L. [1.68 fold over than the control]. Also the results showed that supplement of 75-100 mg l-1 casein hydrolysate in cell cultures media increased biomass of cell culture and harmaline and harmine production [1.61 and 1.46 times over than the control, respectively]

Conclusion: The conclusion of the research showed that by applying biotic elicitors, we can reach to higher secondary metabolites [harmaline and harmine] in cell suspension culture of P. harmala L. We suggest future investigation on using other elicitors like bacterial extract or signal transduction compounds in cell suspension culture of P. harmala L. in order to increase the production of different kind of secondary metabolites

[Effect of bio-stimulators compounds on quantitative and qualitative yield of German chamomile [Matricaria recutita L.]]

In order to ecological agriculture, application of bio-stimulators compounds can be increase the quantitative and qualitative yield of crops in company with reducing environmental stresses. To determine the effects of bio-stimulators compounds on quantitative and qualitative yield of German chamomile [Matricaria recutita L.], this experiment was conducted. This study was done in research farm of ACECR, Institute of Medicinal Plants in a randomized complete block design with three replications and ten treatments in 2010. The treatments were C [Control/no fertilizer], CF [Chemical fertilizer], A[1] [Aminolforte 0.75 L.ha[-1]], A[2] [Aminolforte 1.5 L.ha[-1]], K[1] [Kadostim 0.75 L.ha[-1]], K[2] [Kadostim 1.5 L.ha[-1]], H[1] [Humiforte 0.75 L.ha[-1]], H[2] [Humiforte 1.5 L.ha[-1]], F[1] [Fosnutren 0.75 L.ha[-1]], and F[2] [Fosnutren 1.5 L.ha[-1]]. The results showed that the different treatments had significant effects on plant height, capitule diameter, capitule number per plant, fresh and dry matter yield of capitule per hectare, essential oil yield per hectare, chamazulene content, total flavonoid content [p<0.01] and plant harvest index [p<0.05]. Also, the treatments didn't have significant effects on plant water content. Application of bio-stimulators could be increased the quantitative and qualitative yield of German chamomile. However, treatments of A[2] and F[2] [Aminolforte and Fosnutren 1.5 L.ha[-1]] were the best treatments in respect of yield of capitule and essential oil per hectare. Also, the application of the bio-stimulators can lead to increasing crop production in company with minimizing of environmental pollution and sustainable agriculture