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The essential oil of Cinnamomum camphora is the most widely consumed and used spice in the world today. It has therapeutic effects in medicine and has been shown to have good antibacterial and bacteriostatic effects in agriculture. This study found that C. camphora oil significantly induced plant disease resistance activity. Linalool, its main active component, significantly induced plant disease resistance activity (67.49% at a concentration of 800 μg/ml) over the same concentration of the chitosan oligosaccharide positive control, but had no direct effect on TMV. In this study of its antiviral mechanism, linalool induced hypersensitive reaction (HR), the overexpression of related defense enzymes SOD, CAT, POD and PAL, the accumulation of H2O2 and SA content in N. glutnosa. Besides, linalool induced crops resistance against Colletotrichum lagenarium, Botrytis cinerea, Sclerotinia sclerotiorum and Phytophthora capsica. Taken together, the anti-TMV mechanism of linalool involved the induction of plant disease resistance through activation of a plant immune response mediated by salicylic acid. Linalool-induced plant disease resistance activity has a long duration, broad spectrum, and rich resources; linalool thus has the potential to be developed as a new plant-derived antiviral agent and plant immune activator.

Cherry tomatoes (Solanum lycopersicum) are becoming increasingly popular due to their nutrition and delicious flavor. However, cherry tomatoes are highly perishable and susceptible to various pathogenic microorganisms after harvest, such as Botrytis cinerea. In the pretest experiment, we screened out 3 kinds of plant essential oils (Torreya grandis oil, Eriobotrya japonica oil, and Citrus medica oil) that have strong fungicidal activity on B. cinerea from cherry tomatoes. To further evaluate the postharvest preservation application prospect of these three oils for cherry tomatoes, these three oils were extracted from different parts of three plants by hydrodistillation, and their chemical constituents were analyzed by Gas Chromatography - Mass Spectrometry (GC–MS). The main representative components of T. grandis oil, E. japonica oil, and C. medica oil were δ-cadinene (11.76%), trans-nerolidol (9.70%), and 5,7-dimethoxycoumarin (23.22%), respectively. These three EOs effectively inhibited the mycelial growth of B. cinerea in vitro, with EC50 values of 81.672, 144.046, and 221.500 μL/L, respectively. Compared with the blank control and other oil treatments, T. grandis oil (at a concentration of 200 µL/L) fumigation treatment was more effective at inhibiting the growth rate of the pathogen. In addition, the phenolic content and phenylalanine ammonia lyase (PAL), β-1,3-glucanase, chitinase, and peroxidase (POD) activities of tomatoes significantly increased on the 7th day due to T. grandis oil treatment. The present study shows that these three oils with high extraction rates have preservation potential for cherry tomatoes. Among these three essential oils (EOs), T. grandis oil can be used to further develop preservative products as a fumigant.