Essential oil composition and total phenolic content in Cupressus arizonica G. in response to microbial inoculation under water stress conditions

Abstract

Arizona Cypress is one of the drought-resistant, aromatic, and aesthetically pleasing trees having several pharmacological uses. Certain microorganisms contribute to the secondary metabolism and synthesis of bioactive compounds in aromatic and medicinal plants. This study aimed to determine the photosynthetic pigments, total phenolic content, antioxidant capacity, and essential oil composition of Arizona cypress under two irrigation regimes and microbial inoculations. We established a factorial experiment with three mycorrhizae inoculations (Rhizophagusirregularis, Funneliformismosseae, and a mixture of R.irregularis and F.mosseae), a rhizobacterium inoculation (Pseudomonasfluorescens), and two irrigation regimes (well-watered and water stress). Under the water stress regime, seedlings inoculated with F.mosseae (0.46%) and non-inoculated control plants (0.29%) had the highest and lowest essential oil contents, respectively. GC–MS analysis revealed that limonen, a-pinene, terpinen-4-ol, and umbellulone were the most abundant compounds in the seedlings and treatments under study. The water stress regime had a significant and dominant effect on essential oil and antioxidant capacity, whereas seedling growth and photosynthetic pigments tended to decrease under stress conditions. However, co-inoculation of seedlings with mycorrhizae and the bacterium resulted in an increase in phenolic compounds and carotenoids. Under conditions of water stress and mycorrhizal symbiosis, the results of the current study may help increase the level of valuable compounds in Arizona cypress for further pharmaceutical applications.

Arbuscular Mycorrhizal Fungi and Higher Plants

“…Qian et al (2023) reported higher saponin VI accumulation in Paris polyphylla when inoculated with Rhizophagus irregularis in water-deficit condition. Similarly, greater carotenoid content was observed in mycorrhizal Brassica juncea, Lactuca sativa, and Cupressus arizonica (Srivastava et al 2022;Ouhaddou et al 2022;Aalipour et al 2023). In addition, Funneliformis mosseae colonization improved coumarin, phenolic compounds, and flavonoids in Olea europaea, Poncirus trifoliata, and Mentha piperita (Tekaya et al 2022;Ostadi et al 2023).…”

Microbial inoculants alter resilience towards drought stress in wheat plants

“…This suggests that microbial inoculation reduces the impact of drought on wheat. In a similar study, an AMF substantially increased the chlorophyll and carotenoid content of Cupressus arizonica (Aalipour et al 2023) Vesicle formation was more in microbial inoculated as compared to uninoculated plants. Vesicle formation increases under stress conditions (Karim et al 2014).…”

Screening some pine species from North America and dried zones of western Asia for drought stress tolerance in terms of nutrients status, biochemical and physiological characteristics

“…and P. brutia Ten. ( Deligöz and Cankara, 2020 ), and Cupressus arizonica G. ( Aalipour et al., 2023 ). This study also revealed that resistant genotypes have higher levels of carotenoids and chlorophyll ( Table 3 ), which likely contributed to a more effective defensive system that preserves higher visual quality ( Table 7 ).…”

“…Carotenoids have a protective impact against oxidative stress, contribute to chlorophyll detoxification, and mitigate the toxicity of free radicals ( Zhang et al., 2021 ). Plants with a higher carotenoid content have a more effective defense against reactive oxygen species and exhibit greater water stress tolerance ( Noctor et al., 2016 ; Aalipour et al., 2023 ).…”