Phytocytotoxicity of volatile constituents of essential oils from Sparattanthelium Mart. species (Hernandiaceae)

Abstract

praça-fontes 1,3* the intensive application of agrochemicals in crops has negatively impacted the environment and other organisms. The use of naturally occurring compounds may be an alternative to mitigate these effects. Plants are secondary metabolite reservoirs and may present allelopathic activity, which is potentially interesting to be used in bioherbicide formulations. In this context, the present work aimed to evaluate the phytotoxic and cytotoxic effects of essential oils extracted from leaves of Sparattanthelium botocudorum and Sparattanthelium tupiniquinorum in bioassays with the plant models Lactuca sativa L. and Sorghum bicolor L. Moench. The essential oils were applied at concentrations of 3,000, 1,500, 750, 375 and 187.5 ppm. Chemical characterization of the oils was performed, and their impact on the percentage of germinated seeds, initial development of L. sativa and S. bicolor seedlings, and changes in the mitotic cycle of meristematic cells from L. sativa roots was evaluated. The major compound of the essential oils was germacrene D, followed by bicyclogermacrene, β-elemene and germacrene A. The phytotoxicity assay showed that the essential oils of both species reduced the root and shoot growth in L. sativa and decreased the germination and shoot growth in S. bicolor. Inhibition was dependent on the tested oil concentration. In the cytotoxicity assay, a decrease in mitotic index and chromosomal and nuclear alterations were observed, which resulted from aneugenic and clastogenic action. Herbicides, which are used for weed control 1 , are among the most applied agrochemicals in crop fields. However, the use of these compounds has led to problems related to plant resistance, environmental contamination, and risks to human and animal health. Therefore, it is necessary to find alternative methods for agricultural pest control 2,3. In this context, secondary metabolites may be of particular interest, as they can be directly or indirectly used in the development of new herbicides. These compounds are produced by plants and comprise three major groups, which are found in extracts and essential oils: terpenoids, alkaloids and phenolic compounds 4,5. Essential oils play an important role in protecting the plant during the competition with other species as well as against herbivore and pest attacks, and are produced variably according to the plant's interactions with the environment 6. Essential oils are volatile products, found in all plant organs, and are obtained by extraction processes such as hydrodistillation and cold pressing, depending on plant location, quantity and characteristics required for the final product 7-9. The identification and phytochemical classification of these oils enable the investigation of biologically active substances 10-12. Known as allelochemicals, these substances can be a favorable source for the development of natural herbicides, which may contribute to reduce the environmental impact caused by commercial herbicides, and additionally serve as plant growth stimulants 13-16 .

Membrane Disruption Properties of Essential Oils—A Double-Edged Sword?

“…Although EOs are generally viewed as safe for the environment, their inevitable impact on non-target organisms, such as beneficial soil microbes, crops and humans, should be carefully considered before largescale introduction. Phytocytotoxicity and cytotoxic activities of EOs associated with the presence of terpenoids as major constituents have been reported, leading to membrane phospholipids inhibiting shoot and root growth [61]. Thus, the phytotoxicity of EOs warrants serious attention, especially when developing products for agricultural and environmental applications.…”

Characterization of SchTPSs Enables Construction of Yeast for the Bioproduction of α-Cadinol and the Related Sesquiterpenes

“…Intriguingly, seven out of eight products of SchTPS6 in S. cerevisiae were reported to have insecticidal, fungicidal, and/or herbicidal activities. ,,− We next constructed an engineered S. cerevisiae in which the titers of two major products α-cadinol and τ-muurolol reached 46.2 ± 4.0 and 11.2 ± 1.4 mg/L, respectively.…”

Phytotoxic, insecticidal, and antimicrobial activities of Ajania tibetica essential oil

“…Most aromatic plants produce a large quantity of EOs, which can kill pests and sterilize or suppress the growth of weeds (Insawang et al, 2019;Saleh et al, 2020;Aungtikun et al, 2021;Sousa et al, 2021). Previous reports have demonstrated that certain EOs can produce phytotoxic activity against plants, affecting their seed germination as well as root and shoot growth of seedlings (Dutra et al, 2020;Vasconcelos et al, 2022), causing changes of their protective enzymes' activity and chlorophyll content (Kong et al, 2021;Han et al, 2021); in addition, the cytotoxicity and aneugenic potential of EOs were evidenced by the reduction of the mitotic index and the presence of chromosomal and nuclear alterations (Singh et al, 2020;Valente et al, 2022). Owing to these properties, some EOs, which are extracted from aromatic plants, have the potential value to be further used as environmentally friendly alternatives to synthesized insecticides, weedicides, or bactericides.…”