Impact of metal stress on the production of secondary metabolites in Pteris vittata L. and associated rhizosphere bacterial communities

Abstract

Plants adapt to metal stress by modifying their metabolism including the production of secondary metabolites in plant tissues. Such changes may impact the diversity and functions of plant associated microbial communities. Our study aimed to evaluate the influence of metals on the secondary metabolism of plants and the indirect impact on rhizosphere bacterial communities. We then compared the secondary metabolites of the hyperaccumulator Pteris vittata L. collected from a contaminated mining site to a non-contaminated site in Vietnam and identified the discriminant metabolites. Our data showed a significant increase in chlorogenic acid derivatives and A-type procyanidin in plant roots at the contaminated site. We hypothesized that the intensive production of these compounds could be part of the antioxidant defense mechanism in response to metals. In parallel, the structure and diversity of bulk soil and rhizosphere communities was studied using high-throughput sequencing. The results showed strong differences in bacterial composition, characterized by the dominance of Proteobacteria and Nitrospira in the contaminated bulk soil, and the enrichment of some potential human pathogens, i.e., Acinetobacter, Mycobacterium, and Cupriavidus in P. vittata's rhizosphere at the mining site. Overall, metal pollution modified the production of P. vittata secondary metabolites and altered the diversity and structure of bacterial communities. Further investigations are needed to understand whether the plant recruits specific bacteria to adapt to metal stress.

Combined Kinetin and Spermidine Treatments Ameliorate Growth and Photosynthetic Inhibition in Vigna angularis by Up-Regulating Antioxidant and Nitrogen Metabolism under Cadmium Stress

“…The increased accumulation of phenols and flavonoids has been also reported by Ibrahim et al [75] in Gynura procumbens. The increased accumulation of secondary metabolites has been reported to result in improved tolerance to toxic metals [76], and in the present study, Kn + Spd-mediated enhancement in the accumulation of secondary metabolites may have significantly contributed to avoid the deleterious effects of Cd. Secondary metabolites mediate stress signals for the elicitation of a better stress response [77].…”

Secondary Metabolites in the Green Synthesis of Metallic Nanoparticles

“…Stimulation of key enzymes of the phenylpropanoid pathway, such as phenylalanine ammonia-lyase (PAL) and chalcone synthase (CHS), has been observed in plants upon exposure to Cu, Cd, Al, Pb, and Ni [ 28 ]. Pteris vittata, a hyperaccumulator, produces high concentrations of chlorogenic acid derivatives and a-type procyanidin upon Cu stress [ 29 ]. Similarly, elevation of phenolic content in maize exposed to Al [ 30 ] and Phaseolus vulgaris exposed to Cu [ 31 ] has been reported.…”

Impact of metal contamination to the emergence of (multi) antibiotic resistant bacteria in Thai Nguyen, Vietnam

“…So far, our report is among the first ones evaluating the impact of Pb contamination on antibiotic resistant bacterial population in Thai Nguyen province. Recent study by Pham et al (2017) (Pham et al, 2018). Deredjian et al (2010) also detected the high prevalence of Stenotrophomonas and Pseudomonas among the MAR isolated from various French agricultural soils contaminated with Pb and Zn.…”

“…Although metal mining brings economic benefits, the environmental impact including contamination of soil and ground water together with the loss of biodiversity is inevitable with the use of obsolete technology and the lack of preliminary treatment (Dang et al, 2010). In Ha Thuong, Dai Tu (Thai Nguyen Province), the measured concentration of As in soils was found in between 3102 and 6754 mg/kg, the highest contamination level of As in Vietnam (Anh et al, 2011), and the Cu level in soil reached 3150 mg/kg (Pham et al, 2017). High levels of Pb, Cd, and Zn was found in Dong Hy, an active mining site in Tan Long, at 4337, 419 and 17565 mg/kg, respectively (Dang et al, 2010).…”