Bacteriophages: an overview of the control strategies against phytopathogens

Nawaz et al. Egyptian Journal of Biological Pest Control (2023) 33:108 https://doi.org/10.1186/s41938-023-00751-7 Egyptian Journal of Biological Pest Control Open Access REVIEW ARTICLE Bacteriophages: an overview of the control strategies against phytopathogens Aneela Nawaz1, Sabeena Zafar1, Muqaddas Shahzadi1, Sayed Muhammad Ata Ullah Shah Bukhari1, Nasir Khan1, Aamer Ali Shah1, Malik Badshah1 and Samiullah Khan1*    Abstract Food demand is directly associated with the human population. Due to various plant diseases, there has been a reduction in crop yield. There is an extreme necessity to low such losses in crop yield to meet the rising demand for food. Novel and eco-friendly control approaches should be developed for combating bacterial diseases of crops. Recent control strategies that involve the usage of antibiotics or chemicals are no more effective because of resistance developed by bacterial species. Furthermore, the usage of such agents has proven to be not environmentally friendly. To overcome these issues, bacteriophages are used as an alternative solution. Phages are viruses that attack specific bacterial species, and within current years much consideration is received by them in controlling different diseases caused by bacteria. Phages can be used for controlling different crop-related diseases. Several phage-based products are accessible in the market. Compared to chemical control methods, phage biocontrol offers several advantages. Mixtures of phages can be employed to target pathogenic bacteria. Unlike chemical control strategies, phage mixtures can be readily adjusted to counter any potential resistance. This review summarizes the use of phages as a biocontrol agent against phytopathogens. Keywords Bacteriophages, Phytopathogens, Biocontrol Background The global population is expected to grow about 9.6 billion by the year 2050, which projects the emergence of scarcities of agricultural and food resources. To meet the demands of a growing food supply, crop production is likely to increase by about 70–80% by improving the efficiency of agricultural units (Raina et al. 2022). Normally, the crops are largely subjected to several factors like climate change, the gap in technology, pests, and plant diseases that lower the pace of production (Wang et al. 2022a, b). Specifically, plant diseases affect about 10% of global food in developing and emerging countries. The major plant pathogens include several parasitic *Correspondence: Samiullah Khan 1 Department of Microbiology, Faculty of Biological Sciences, Quaid-iAzam University, Islamabad 45320, Pakistan plants, fungi, viruses, nematodes, and bacteria that are also known as phytopathogens (Daulagala 2021). Two hundred bacterial phytopathogens have been reported yet, and the most important genera of these pathogens are Xanthomonas, Ralstonia, Erwinia, Pseudomonas, and Pectobacterium. These pathogens are very high in virulence and can adapt to changing environments and are difficult to handle. Efficient disease control management is very crucial for a stable and effective food supply to consumers. Antibiotics and copper compounds are considered the best antibacterial agents for the control of phytopathogenic bacteria. They are readily available and often used worldwide to control pests’ attacks on several crops and affect productivity (Pereira et al. 2021). Antibiotics that are used widely include tetracycline, streptomycin, and kasugamycin, but they have some risks associated with them like emergence of resistant species, which cause hindrance in the management of plant diseases (Miller © The Author(s) 2023. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. Nawaz et al. Egyptian Journal of Biological Pest Control (2023) 33:108 Page 2 of 10 et al. 2022). The application of copper-based compounds as pesticide affects both the environment and the agricultural system. They cause phytotoxicity and bioaccumulation of these compounds on the surface of soil also occurs that leads to a reduction in microbial diversity (Tudi et al. 2021). Recently, several classes of control agents like pesticides and antibiotics have been completely banned in western countries due to their undesirable toxic characteristics (Alengebawy et al. 2021). While taking into consideration all the damaging effects of pesticides on crop productivity, the alternative control agents of plant diseases having desirable characteristics are needed to be synthesized urgently (Elnahal et al. 2022). The best possible way to achieve this target is by using new tools and machinery based on biocontrol agents (BCAs) that synthesize a pest control agent with minimal negative impact on the environment. Biocontrol of plant diseases mainly includes the use of microorganisms (Izraeli et al. 2021). Biological control means utilizing the living entity for the control of any pathogens and parasites of plants. Biocontrol agents are capable to suppress the activities of pathogenic bacteria as well as their reproduction. Moreover, the basic idea of biocontrol agents majorly involves the strategy to reduce the incidence of disease by either direct or indirect manipulations of the microbial population (Bhardwaj et al. 2022). The use of bacteriophage as a biocontrol agent (BCA) has become a major growing interest to deal with phytopathogens (Pandit et al. 2022). Phages are viruses that infect bacteria only with no harmful effect on plants and animals. Bacteriophages have been discovered in the twentieth century and are considered as most abundant and diverse in the natural environment and affect various ecological and biological processes having their role in bacterial mortality and genetic exchange (Chevallereau et al. 2022). They can be found in every domain or habitat, mainly in the soil and oceans. They infect the bacteria by using lysogenic or lytic cycles (Jamal et al. 2019). In the case of the lysogenic cycle, a bacteriophage integrates its genome directly into bacterial cell chromosomes after which they replicate and form daughter cells (Abedon 2022). They initiate the infection by attaching themselves to specific bacteria by adsorption and inserting their genome i (...truncated)