ارزیابی اثر ضد باکتریایی پپتید نوترکیب Tachyplesin در باکتری‌های بیمارگر گیاهی

Plant pathogenic bacterial cause significant losses to farmers in the production of horticultural crops in Iran every year. Among the most important bacterial pathogens, we can mention the fire blight disease caused by Erwinia amylovora and the bacterial canker disease caused by Pseudomonas syringe, which cause economic losses in pome fruits (pears and quince) and stone fruit (cherries and apricots), respectively. Since only copper compounds are effective on bacterial pathogens, due to the resistance of plant pathogenic bacterial to the copper compounds available in the market, contact effect and plant burning in spring (when the trees are blooming) there is need to assay and use compounds obtained from nature that have a high antibacterial effect. In recent years, the use of new compounds with high antibacterial effect, such as antimicrobial peptides, has become very important in medical and agricultural sciences. These peptides are found naturally in various organisms, from bacteria, fungi and viruses to plant and animal species. The lack of these peptides in natural sources, along with the extraction and purification costs, have led researchers to try to replace recombinant DNA technology to obtain these valuable biological products. In this research, the antibacterial effect of Tachyplesin peptide on four bacterial pathogens E. amylovora D43, P. syringe, Xanthomonas oryzae pv. oryzae and Agrobacterium rhizogenes found in the microbial collection of the Agricultural and Natural Resources Research Center of Semnan Province (Shahrood) were investigated. Tachyplesin peptide is derived from a type of marine crustacean that lives in Southeast Asia. HEK 293 (Human Embryonic Kidney) cell line was used to produce the peptide in laboratory scale. Peptide purification from cell culture medium was done by adding His-tag extension and using a pure nickel column. In order to investigate the antibacterial effect, the culture method was used in Muller-Hinton agar liquid medium. The peptide showed effective antibacterial effects at very low concentrations (less than 100 μg/mL). The best effect for P. syringe was obtained with 1.68 μg/mL. Antimicrobial effect on E. amylovora D43, X. oryzae pv. oryzae and A. rhizogenes was obtained with 37.3 μg/mL, 48.13 μg/mL and 74.6 μg/mL, respectively. Considering the effect obtained from Tachyplesin recombinant peptide in controlling plant pathogenic bacterial and its ability to be used in low doses and its ability to be used in tissues sensitive to copper compounds such as flowers and immature fruits, the above peptide can be used to control plant pathogenic bacteria, considered as a new and effective solution