Microbial Biochemistry and Plant Biotechnology

Impact of new Microbial Plant Resistance/Plant Growth Protection (PR/PGP) Inducers for increasing tolerance of Brassica rapa subsp. pekinensis (Chinese cabbage) to parasitic nematode Heterodera schachtii Schmidt was studied. In the greenhouse conditions on the artificial invasive nematode background the accumulation of Chinese cabbage biomass was increased as follows: under impact of Avercom nova-2-up to 94%, Phytovit-up to 55%, Violar-up to 32% and Avercom-up to 17%, accordingly as compared to control. In the laboratory conditions the biomass of affected by nematode and treated by microbial PR/PGP inducers plants was increased up to 26-43 % as compared to biomass of control affected by nematode plants. Influence of Microbial PR/PGP Inducers on molecular-genetic indexes of Chinese cabbage resistance to nematode Heterodera schachtii was investigated. The increase in the difference of Dot-blot hybridization index up to 27-49% between cytoplasmic mRNA and small regulatory RNA (si/miRNA), isolated from control and affected by nematode and treated by microbial PR/PGP inducers plants was shown. Silencing activity of si/miRNA isolated from affected by nematode and treated by microbial PR/PGP inducers plants was increased up to 32-67 % in the wheat embryo cell free system. Obtained data testify that microbial PR/PGP inducers stimulate synthesis in the plant cells of immune-protective si/miRNA. As a result of this, plant tolerance against this parasitic nematode is increased.

Impact of microbial biostimulants on the increase (up to 75-87%) of resistance of wheat plants of two varieties Yatran 60 and Zimoyarka to the cereal cyst nematode Heterodera avenae was found. The increase of difference in the index of Dot-blot hybridization (up to 37-65%) between cytoplasmic mRNA and si/miRNA isolated from control and experimental (affected by nematode and treated with biostimulants) plants was observed. In the wheat-embryo cell-free system the increase of silencing activity (up to 48-78%) of si/miRNA isolated from experimental as compared to control wheat plants was revealed. These data indicate that microbial biostimulants cause reprogramming wheat genome by inducing synthesis si/miRNA with immune-protective properties against nematode; as a result the wheat resistance to nematode invasion is increased. To obtain new lines of wheat cells resistant to nematode. H. avenae the microbial biostimulants were used for preparing of MS media for cultivation of isolated wheat tissues in vitro. The indirect and direct shoot organogenesis was observed on the apical meristem of shoot and root on the MS media supplemented with each microbial biostimulant at the concentrations 10-50 µl/l in combination with either 1-2 mg/l axing 2.4-D or 1-2 mg/l c ytokinin BAP. The obtained wheat plants will be further tested on the resistance to nematode H. avenae in greenhouse conditions.

The present study was undertaken to investigate the phytochemical constituents of two Nigerian grown kolanut and their antimicrobial properties. Extract of the seed of Cola nitida and Cola acuminata were used to determine the phytochemical constituent of aqueous and methanol nut extract and their solubility in the two solvents. Aqueous and methanol used reveals the solubility of these exrtacts in different solvent and the presence of secondary metabolites in the kola nut. Qualitative screening of the extracts of C. acuminata and C. nitida for phytochemicals revealed the presence of alkaloid, saponins, tannins, flavonoids, glycoside, steroid, saponins glycoside, cardiac glycoside and the absence of anthraquinones in all the extracts. Quantitative analysis shows that the methanolic extracts C. acuminata and C. nitida have the highest percentage of Saponins: (>10%) than the aqueous extract of the preparations. The disc method was used to determine the inhibitory effect of kolanut on the test microorganisms. Sensitivity patterns of zones of inhibition exhibited by the crude methanol and aqueous extract of Cola nitida and Cola acuminata shows that the nut possess relative degree of inhibitory effects against the test microorganisms: Staphylococcus aureus, Esherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia and Lactobacillus respectively.. The zones of inhibition for K. pnemonia was the highest with 4mg/ml methanol extract of C. nitida and least for E.coli. As for C. acumunata, zones of inhibition for Lactobacillus was the highest with 4mg/ml methanol extract and least for P. aeruginosa. Highest zones of inhibition progressively increase from methanol to aqueous extract as their diameter of inhibition increases with increase in their concentration. The overall implication of the antimicrobial potentials of C.nitida and C. acuminata in the development of drugs against infectious diseases and subsequent health improvement was highlighted.