Effect of shading and nitrogen fertilization on nitrogen metabolism, essential oil content and antimicrobial activity of Achillea millefolium

Abstract

The Achillea millefolium L. is a perennial herb with important antibacterial, antifungal, anti-inflammatory, antitumoral, and antioxidant properties. This research aimed to investigate the effect of shading (75%; black net) and nitrogen fertilization (0, 75 and 150 kg urea ha-1) on the nitrogen metabolism, essential oil yield and antimicrobial activity of A. millefolium at vegetative- and reproductive-stage. The evaluated parameters varied depending on the organ and the phenological stage of the plant considered. Overall, our findings indicated that shading decreased nitrogen assimilation. Decreased activities of nitrate reductase and glutamine synthetase were observed on shaded plants during reproductive and vegetative stages, respectively. Nitrate and total amino acid levels increased in shaded plants at the vegetative stage. Regarding nitrogen supply, the improved nitrogen metabolism and essential oil yield values were accompanied by intermediate concentrations of urea (75 kg ha-1). Plants fertilized with 75 kg urea ha-1 produced the highest amino acids concentration (vegetative stage), ammonium concentration (vegetative stage) and essential oil yield (reproductive stage). Shading or nitrogen supply did not influence the microbial activity of A. millefolium essential oil. However, the essential oil of leaves and flowers were highly effective against fungi and bacteria, especially gram-positive bacteria. In conclusion, the current study showed that full light and 75 kg urea ha-1 enhanced the nitrogen metabolism of A. millefolium in both vegetative and reproductive stages.

Chemical Profiling and Antioxidant Activity of Wild and Cultivated Sage (Salvia officinalis L.) Essential Oil

“…Several groups have addressed the influence of light modification on EO metabolism in different plant species [40,60,61]. The EO content of marigold [62], chamomile [63] and yarrow [64] decreased with shading level, whereas sage [39] and oregano [29] were improved by limited light intensity.…”

Role of organic and inorganic fertilizers in enhancing biomass yield and eugenol content of ornamental basil (Ocimum gratissimum L.)

“…Several literatures reported that the plants grown under low light intensity in closed environments exhibited better growth, yield, and enhancement of the secondary metabolites such as essential oils because of the reduction in the photosynthetic activity [ 13 ]. The enhanced essential oil content under low intensities was reported in yarrow ( Achillea millefolium L.) [ 14 ] and oregano ( Origanum vulgare L.) [ 15 ]. Thus, cultivation of medicinal and aromatic plants under controlled environments such as greenhouses, growth chambers, and playhouses provides a sustainable opportunity to enhance the principal chief phytochemicals, maximize the biomass yield, and in addition help to prevent the loss through insects and pests, and regulate both productivity and its production [ 16 ].…”

Potential use of lemongrass essential oil as fungicide against Aspergillus brasiliensis and as post-harvest protectant of wheat

“…Native to India, lemongrass is a perennial aromatic herb grown to obtain its essential oil, which is rich in citral, a substance used by the perfumery, cosmetics and pharmaceutical industries (May et al, 2008). Studies such as Pandey, Rai, and Acharya (2003), Jaramillo-Colorado, Palacio-Herrera, and Duarte-Restrepo (2020), Lima et al (2020), Lee, Garcia, Matinazzo, and Teodoro (2020), have demonstrated intense antimicrobial, antifungal, antiviral, and insecticidal activity of the essential oils. The objective in this study was to analyze the antifungal activity of lemongrass (Cymbopogon flexuosus) essential oil and citral for the control of the fungus Aspergillus flavus in in vitro tests and its proliferation in contaminated grains of wheat (Triticum aestivum).…”