## 1 Introduction  
Plant viruses are one of the most harmful diseases that result in significant losses in crop production worldwide [1]. Among them, tobacco mosaic virus (TMV) is the most serious plant virus, responsible for tremendous losses in crop yield quality and production [2; 3; 4]. Therefore, in order to maintain sustainable agriculture and food security, plant viral diseases must be controlled. Unfortunately, synthetic chemical treatments, including pesticides, are the widespread methods used for controlling plant diseases [5]. Such methods have negative impacts on the environment and human health. Hence, the development of alternative and effective ways to suppress plant viral infection is urgently needed. Nowadays, nanotechnology is an active field of biological sciences research [6]. It is well documented that nanoparticles (NPs) play important roles in medical applications and have successful impacts on human pathogen control [7]. Traditionally, NPs have been synthesized via different physical and chemical methods, such as microwave irradiation, ultrasonication, laser vaporization, solid-state thermal decomposition, hydrothermal, and Sol-gel [8; 9; 10; 11]. Such methods require high energy, expensive equipment, and space. In addition, the absorption of some toxic chemicals on their surface making it toxic for the environment and unsuitable for biological applications [12; 13; 14]. The green biosynthesis method of NPs is a safe alternative, low cost, and eco-friendly when compared to the conventional methods [15; 16]. Additionally, the use of nontoxic extracts as reducing and stabilizing agents is also an additive advantage [17]. Because of its contents (many bioactive molecules such as polyphenols, enzymes, polysaccharides, esters, and terpenoids), plant leaf extracts may act as reducing and stabilizing agents in the nanoparticles synthesis processes [18; 19; 20; 21]. _Mentha spicata_ L. (genus _Mentha_, family Labiatae), commonly known as spearmint, garden mint, or common mint, is frequently used as herbal tea and is considered as one of the important additive spice for many foods all over the world [22]. It is well documented that the leaves of _M. spicata_ are still used in traditional medicine to treat gastrointestinal disorders, where its essential oils possess antimicrobial and antioxidant properties [23; 24; 25]. The major chemical constituents of mentha plants were reported as pulegone, mentone, menthol, borneol, and piperitone [26; 27]. Phytochemical studies showed that phenolic, flavonoid, steroids, and terpenoid were the major components of the leaves extracts responsible for the reduction and stabilization of NPs [25; 28]. Recently, NPs, in a nanoscale range (1 nm to 100 nm), has been integrated into plant protection, as a substitution for chemical pesticides, and disease management [29; 30]. At a suitable dose, NPs have the potential to promote plant growth and inhibit pathogen infection [31]. However, their antiviral properties are still in its infancy and the corresponding mechanisms are largely unclear [32]. Many researchers reported that silver nanoparticles (Ag NPs) exhibited antiviral activities against sunhemp rosette virus (SHRV) [33], bean yellow mosaic virus (BYMV) [34], tomato mosaic virus (ToMV) and potato virus Y (PVY) [35]. They suggested that Ag NPs could bind to the virus particles and inhibit viral nucleic acid replication in the plant cell. Moreover, induction of systemic acquired resistance (SAR) and improvement releasing of reactive oxygen species (ROS), which are associate with the increase in antioxidant activity, was observed [36; 37]. Many studies showed that metal oxide NPs improved plant fertilization processes, increased plant growth parameters, yield, and quality, apart from their antimicrobial properties. Among metal oxide nanoparticles, zinc oxide nanoparticles (ZnO NPs) is a bio-safe material having a wide range of applications in medical, industrial, agricultural, and environmental fields [38; 39].