Molecular Defensive Mechanism of Echinacea purpurea (L.) Moench against PAH Contaminations

Abstract

The understanding of the molecular defensive mechanism of Echinacea purpurea (L.) Moench against polycyclic aromatic hydrocarbon (PAH) contamination plays a key role in the further improvement of phytoremediation efficiency. Here, the responses of E. purpurea to a defined mixture of phenanthrene (PHE) and pyrene (PYR) at different concentrations or a natural mixture from an oilfield site with a history of several decades were studied based on transcriptomics sequencing and widely targeted metabolomics approaches. The results showed that upon 60-day PAH exposure, the growth of E. purpurea in terms of biomass (p < 0.01) and leaf area per plant (p < 0.05) was negatively correlated with total PAH concentration and significantly reduced at high PAH level. The majority of genes were switched on and metabolites were accumulated after exposure to PHE + PYR, but a larger set of genes (3964) or metabolites (208) showed a response to a natural PAH mixture in E. purpurea. The expression of genes involved in the pathways, such as chlorophyll cycle and degradation, circadian rhythm, jasmonic acid signaling, and starch and sucrose metabolism, was remarkably regulated, enhancing the ability of E. purpurea to adapt to PAH exposure. Tightly associated with transcriptional regulation, metabolites mainly including sugars and secondary metabolites, especially those produced via the phenylpropanoid pathway, such as coumarins, flavonoids, and their derivatives, were increased to fortify the adaptation of E. purpurea to PAH contamination. These results suggest that E. purpurea has a positive defense mechanism against PAHs, which opens new avenues for the research of phytoremediation mechanism and improvement of phytoremediation efficiency via a mechanism-based strategy.

Integrated Transcriptomic and Metabolomic Analysis Reveals Biochar-Induced Enhancement of Growth and Secondary Metabolism in the Medicinal Plant Echinacea purpurea

“…Uniform two-month-old E. purpurea seedlings with similar appearances, plant height, and leaf quantity were selected to ensure genetic and physiological homogeneity at the start of the experiment, thereby minimizing pre-existing variation and allowing a clearer attribution of observed effects to the biochar treatment. After transplanting, the pots (twelve replicates per treatment) were randomly arranged in the growth chamber to minimize positional effects and cultivated under a 16/8 h light/dark cycle at 18–27 °C., following the method described in Sun et al (2023) [ 65 ]. Each pot was irrigated regularly to avoid excessive drainage.…”

“…PH, LA, and SPAD were measured in accordance with the method of Sun et al (2023) [ 65 ]. Afterward, the shoot DW was determined via oven-drying at 80 °C until constant weight.…”

Analysis of Growth and Yield of Echinacea Purpurea with the Addition of Biochar and Plant Growth Regulator

“…The total accumulation rate of E.purpurea biomass cultivated in Ungaran (altitude 600 masl) was relatively lower, namely 35.4 g/plant, compared to that grown in Pacet-Cipanas (altitude 1100 masl), which could reach 75.5 g/plant [6]. E. purpurea can survive under various soil conditions and stresses, such as saline, drought, and cold, owing to its highly developed fibrous root system, vigorous growth, and significant biomass [7]. The difference in climate between the subtropics and the tropics, especially in Indonesia, will affect the growth and yield of E.purpurea.…”

Evaluation of the Effectiveness of Bioaugmentation-Assisted Phytoremediation of Soils Contaminated with Petroleum Hydrocarbons Using Echinacea purpurea

“…Phytoremediation studies conducted using Echinacea purpurea have shown that the plant has a high tolerance for petroleum and is suitable for remediating soils with petroleum concentrations exceeding 10,000 mg/kg [11]. In addition, purple coneflower has been proven to be effective in cleaning up soils polluted with PAHs and alkyl-PAHs [13][14][15][16]. A few studies also suggest that Echinacea purpurea can be used to clean up areas tainted with heavy metals [13,14].…”