Defensive functions of volatile organic compounds and essential oils from northern white-cedar in China

Abstract

Background Plants are known to emit diverse volatile organic compounds (VOCs), which may function as signaling substances in plant communication with other organisms. Thuja occidentalis, which is widely cultivated throughout China, releases aromatic VOCs into the air in winter and early spring. The relationship of this cultivated plant with its neighboring plants is necessary for the conservation of biodiversity. Results (−)-α-thujone (60.34 ± 5.58%) was found to be the major component in VOCs from the Shenyang population. The essential oils (EOs) from the Kunming and Shenyang populations included the major components (−)-α-thujone, fenchone, (+)-β-thujone, and (+)-hibaene, identified using GC-MS analyses. (−)-α-thujone and (+)-hibaene were purified and identified by NMR identification. EOs and (−)-α-thujone exhibited valuable phytotoxic activities against seed germination and seedling growth of the plants Taraxacum mongolicum and Arabidopsis thaliana. Moreover, the EOs displayed potent inhibitory activity against pathogenic fungi of maize, including Fusarium graminearum, Curvularia lunata, and Bipolaris maydis, as well as one human fungal pathogen, Candida albicans. Quantitative analyses revealed high concentrations of (−)-α-thujone in the leaves of T. occidentalis individuals from both the Shenyang and Kunming populations. However, (−)-α-thujone (0.18 ± 0.17 μg/g) was only detected in the rhizosphere soil to a distance of 0.5 m from the plant. Conclusions Taken together, our results suggest that the phytotoxic effects and antifungal activities of the EOs and (−)-α-thujone in T. occidentalis certainly increased the adaptability of this plant to the environment. Nevertheless, low concentrations of released (−)-α-thujone indicated that reasonable distance of T. occidentalis with other plant species will impair the effects of allelochemical of T. occidentalis.

Insecticidal Terpenes From the Essential Oils of Artemisia nakaii and Their Inhibitory Effects on Acetylcholinesterase

“…The EOs of Tanacetum balsamita L. were found to contain β-thujone (84.43%), α-thujone (4.68%), eucalyptol (4.07%), and aliphatics (1.82%). Our previous studies have shown terpenes to be the major components of the EOs of Thuja occidentalis (Bai et al, 2020). The EOs obtained from A. nakaii comprised mostly monoterpenes and sesquiterpenes, including feropodin (26.01%), (+)-camphor (24.42%), 1,8-cineole (17.77%), rishitin (10.53%), borneol (6.82%), and β-selinene (4.24%).…”

“…The EOs were obtained by the hydro-distillation of 20 g of A. nakaii aerial parts using a Clevenger-type apparatus for 2 h (Bai et al, 2020). The oil/water mixtures were extracted with hexane, and the hexane layer was washed with anhydrous sodium sulfate, dried, and concentrated.…”

Occurrence of Marine Ingredients in Fragrance: Update on the State of Knowledge

“…They are secondary metabolites and are undoubtedly involved in allelopathic interactions and, generally, in the chemical communication of the species [35,36]. Thus, they play an important role in plant defense against insects, herbivores, microorganisms, and also in the pollination process [37]. Some natural fragrances' ingredients are difficult to extract in a sufficient quantity; therefore, chemists have successfully produced them synthetically.…”

Solanum linnaeanum Leaves: Chemical Profiling of VOCs and Effects on Seed Germination and Early Growth of Monocots and Dicots

“…The effects of allelochemicals are detected at the biochemical, molecular, physiological and structural level of the plant organization. [9] The role of volatile organic compounds (VOCs) in chemical communications between plants was reported, [10] and their phytotoxicity demonstrated, although the mechanisms of action need to be further investigated. [11][12][13] Different members of the Solanaceae family including some belonging to the Solanum genus are rich sources of sesquiterpenoid phytoalexins able to inhibit, reduce or delay the seed germination and seedling growth of several treated species.…”