Characterization of the complete chloroplast genome of Pteris multifida Poir. 1804 and its phylogenetic analysis.

Pteris multifida Poir. 1804 has a long history of medicinal use in China. The chloroplast (cp) genome of P. multifida was 153,916 bp in length, with a large single-copy (LSC) region of 82,027 bp, a small single-copy (SSC) region of 21,129 bp, and a pair of inverted repeats (IRs) of 25,380 bp, forming a typical quadripartite structure. A total of 132 genes were annotated from the cp genome of P. multifida, including 89 protein-coding genes, 35 tRNA genes, and eight ribosomal RNA genes. Phylogenetic analysis indicated that P. multifida was closely related to the species of P. vittata.

Influence of low temperature on comparative arsenic accumulation and release by three Pteris hyperaccumulators.

Arsenic (As) hyperaccumulator Pteris ferns are renowned for their capacity to accumulate As and have been used to remediate As-contaminated environmental. However, there is less information on how they perform under low temperature though it is important for practical phytoremediation. The purpose of this study was to identify the effect of temperature on As accumulation by three As hyperaccumulators, Pteris multifida, Pteris cretica and Pteris vittata. Ferns were cultured with 5 mg/L As addition under 25 °C to 5 °C for 15 days. The results showed that dropping of temperatures reduced As accumulation by P. vittata moderately but not P. multifida and P. cretica until 10 °C. At 5 °C, all ferns discontinued As accumulation, and the morphology showed necrosis in P. vittata, wherein P. multifida and P. cretica kept healthy. The As distribution showed that As was mainly accumulated in fronds, while P. multifida stored partial As in its root. Both translocation factor and As efflux showed that temperate zone ferns manage As more strictly as compared to P. vittata. Our findings demonstrated that temperature should be considered when applying Pteris ferns for As phytoremediation, and P. multifida could be the most suitable fern for treating As-contaminated water in temperate zone area.

A multifunctional rhizobacterial strain with wide application in different ferns facilitates arsenic phytoremediation.

Pteris vittata and Pteris multifida are widely studied As hyperaccumulators that absorb As mainly via roots. Hence, rhizobacteria exhibit promising potential in phytoextraction owing to their immense microbial diversity and interactions with plants. Pseudomonas vancouverensis strain m318 that contains aioA-like genes was screened from P. multifida's rhizosphere through the high As resistance (minimum inhibitory concentrations (MICs) against As(III): 16 mM; MICs against As(V): 320 mM), rapid As oxidation (98% oxidation by bacterial cultures (OD600nm = 1) from 200 µL of 0.1 mM As(III) within 24 h), predominant secretion of IAA (12.45 mg L-1) and siderophores (siderophore unit: 88%). Strain m318 showed significant chemotactic response and high colonization efficiency to P. vittata roots, which suggested its wide host affinity. Interestingly, inoculation with strain m318 enhanced the proportion of aioA-like genes in the rhizosphere. And in field trials, inoculation with strain m318 increased As accumulation in P. vittata by 48-146% and in P. multifida by 42-233%. Post-transplantation inoculations also increased As accumulation in both ferns. The abilities of the isolated multifunctional strain m318 and the increase in the rhizosphere microbial aioA-like genes are thus speculated to be involved in As transformation in the rhizospheres and roots of P. vittata and P. multifida.

Arsenic-induced nutrient uptake in As-hyperaccumulator Pteris vittata and their potential role to enhance plant growth.

It is known that arsenic (As) promotes growth of As-hyperaccumulator Pteris vittata (PV), however, the associated mechanisms are unclear. Here we examined As-induced nutrient uptake in P. vittata and their potential role to enhance plant growth in sterile agar by excluding microbial effects. As-hyperaccumulator P. multifida (PM) and non-hyperaccumulator P. ensiformis (PE) belonging to the Pteris genus were used as comparisons. The results showed that, after 40 d of growth, As induced biomass increase in hyperaccumulators PV and PM by 5.2-9.4 fold whereas it caused 63% decline in PE. The data suggested that As played a beneficial role in promoting hyperaccumulator growth. In addition, hyperaccumulators PV and PM accumulated 7.5-13, 1.4-3.6, and 1.8-4.4 fold more As, Fe, and P than the non-hyperaccumulator PE. In addition, nutrient contents such as K and Zn were also increased while Ca, Mg, and Mn decreased or unaffected under As treatment. This study demonstrated that As promoted growth in hyperaccumulators and enhanced Fe, P, K, and Zn uptake. Different plant growth responses to As among hyperaccumulators PV and PM and non-hyperaccumulator PE may help to better understand why hyperaccumulators grow better under As-stress.

Arsenic, lead and cadmium removal potential of Pteris multifida from contaminated water and soil.

The main threats to the environment from heavy metals are associated with arsenic (As), lead (Pb) and cadmium (Cd). In this study, the potential of Pteris multifida for removing As, Pb and Cd from hydroponic solution and pot soil was evaluated for the first time. Short-term (5 day) experiments were conducted to assess phytofiltration efficiency of temperate zone fern P. multifida and to compare it with mostly studied tropical zone fern P. vittata. Within 5 days, P. multifida accumulated 33% of As(III), whereas P. vittata could not accumulate that most toxic arsenic species As(III) at all. Long-term hydroponic results showed that 90% of Pb, 50% of As and 36% of Cd were removed by P. multifida. Concentration of As in the frond (22 mg/kg dw) was comparatively higher than other parts of plant and significantly higher concentration of Cd and Pb were stored in root and rhizome. Pot soil experiment of P multifida confirmed the comparative uptake and translocation of As(V), Pb and Cd from soil. Therefore, from the assessment of heavy metal accumulation capacity, translocation and healthy survival for long time, P. multifida was identified as an excellent species for the treatment of multi-metal contaminated water and soil.

Cytotoxic pterosins from Pteris multifida roots against HCT116 human colon cancer cells.

Two new pterosin glycosides, (2S,3S)-pterosin C 3-O-ß-d-(4'-(E)-caffeoyl)-glucopyranoside (1) and (2S,3S)-pterosin C 3-O-ß-d-(6'-(E)-p-coumaroyl)-glucopyranoside (2), were isolated from Pteris multifida (Pteridaceae) roots along with ten known pterosin compounds (3-12). The chemical structures of the isolated compounds were elucidated by extensive analysis of the 1D, 2D NMR, HRESIMS, and CD spectroscopic data. The cytotoxicities of 1-12 against HCT116 human colorectal cancer cell line were evaluated. Among the isolates, compound 1 showed moderate antiproliferative activity in HCT116 cells with an IC50 value of 8.0±1.7µM. Additionally, 1 induced the upregulation of the caspase-9 and procaspase-9 levels in Western blots and increased the annexin V/propidium iodide (PI)-positive cell population in flow cytometry.

Development and validation for the determination of total flavonoids and luteolin from Pteris multifida Poir / 国际中医中药杂志

Objective To determine the content of total flavonoids and luteolin from Pteris multifida Poir. Methods The content of total flavonoids was determined by gradient elution of macroporous resin D101 and ultraviolet spectrophotometry. The content of luteolin was determined by HPLC. The analysis was performed on a RP-C18 column(4.6 mm×250 mm, 5 μm) with aceconitrile-0.2% phosphoric acid (35:65) as the mobile phase at a flow rate of 1.0 ml/min, and 30 ℃ temperature. Results The detection of wave length was set at 349 nm. The content of luteolin was 0.015%, 0.019%, 0.016%, and the content of total flavonoids was 0.015%, 0.019%, 0.016%, respectively. Conclusions The method is suitable for the determination of flavonoids componets from Pteris multifida Poir.

Anti-Neuroinflammatory ent-Kaurane Diterpenoids from Pteris multifida Roots.

Activated microglia are known to be a major source of cellular neuroinflammation which causes various neurodegenerative diseases, including Alzheimer's disease. In our continuing efforts to search for new bioactive phytochemicals against neuroinflammatory diseases, the 80% methanolic extract of Pteris multifida (Pteridaceae) roots was found to exhibit significant NO inhibitory activity in lipopolysaccharide (LPS)-activated BV-2 microglia cells. Three new ent-kaurane diterpenoids, pterokaurane M1 2-O-ß-d-glucopyranoside (4), 2ß,16α-dihydroxy-ent-kaurane 2,16-di-O-ß-d-glucopyranoside (10), and 2ß,16α,17-trihydroxy-ent-kaurane 2-O-ß-d-glucopyranoside (12), were isolated along with nine other known compounds from P. multifida roots. The chemical structures of the new compounds were determined by 1D- and 2D-NMR, HR-ESI-MS, and CD spectroscopic data analysis. Among the isolates, compounds 1 and 7 significantly inhibited NO production in LPS-stimulated BV-2 cells reducing the expression of the cyclooxygenase-2 (COX-2) protein and the level of pro-inflammatory mediators such as prostaglandin E2 (PGE2), tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, and IL-6. These results suggest that ent-kaurane diterpenes from P. multifida could be potential lead compounds that act as anti-neuroinflammatory agents.

Photosynthetic electron-transfer reactions in the gametophyte of Pteris multifida reveal the presence of allelopathic interference from the invasive plant species Bidens pilosa.

To date, the response of the fern gametophyte to its environment has received considerable attention. However, studies on the influence of plant invasion on the fern gametophyte are fewer. Allelopathy has been hypothesized to play an important role in biological invasion. Hence, it is necessary to study the allelopathy of invasive plant species to the fern gametophyte and elucidate the mechanisms by which invasive plants cause phytotoxicity. As one of the main invasive plants in China, Bidens pilosa exhibits allelopathic effects on the gametophytic growth of Pteris multifida. The root exudate plays an important role among various allelochemical delivery mechanisms in B. pilosa. The effect invasive plant species has on photosynthesis in native species is poorly understood. To elucidate this effect, the changes in photosynthesis in the gametophytes of P. multifida are analyzed to examine the mechanisms of the root exudates of B. pilosa. Meanwhile, a non-invasive plant, Coreopsis basalis, was also applied to investigate the effects on fluorescence and pigments in P. multifida gametophytes. We found that gametophytes exposed to both B. pilosa and C. basalis had decreased fluorescence parameters in comparison with the control, except for non-photochemical quenching. Furthermore, it was found that these parameters were markedly affected from day 2 to day 10 in the presence of both exudates at a concentration of 25% or above. B. pilosa exudate had a negative dose-dependent effect on chlorophyll a, chlorophyll b, carotenoid, and the total chlorophyll in the gametophyte. The inhibitory effects increased with increasing exudate concentrations of both species, exhibiting the greatest inhibition at day 10. In conclusion, B. pilosa irreversibly affected the photosynthesis of P. multifida on both PS I and PS II. Root exudates caused the primary damage with respect to the decrease of the acceptors and donors of photon and electron in photosynthetic units and the production and the relative yield of photochemical quantum in PS II. With the effects of exudates, part of the energy is released as heat in chloroplasts. The comparison of invasive and non-invasive plants in allelopathic experiments demonstrated that invasive plants were responsible for the critical damage to the photosynthetic process in local species.

Changes in gametophyte physiology of Pteris multifida induced by the leaf leachate treatment of the invasive Bidens pilosa.

In recent years, the response of fern gametophytes to environment has raised much attention. However, studies on the influence of plant invasion to fern gametophytes are scarce. Allelopathy plays an important role in biological invasion. Hence, it is necessary to study the allelopathic effects of invasive plants on fern gametophytes and elucidate the mechanisms by which invasive plants cause phytotoxicity. As one of the main invasive plants in China, Bidens pilosa exhibits allelopathic effects on spermatophyte growth. Field investigation shows that many ferns are threatened by the invasion of B. pilosa. The distribution of Pteris multifida overlaps with that of B. pilosa in China. To examine the potential involvement of allelopathic mechanisms of B. pilosa leaves, changes in the physiology in P. multifida gametophytes are analyzed. We found that cell membrane and antioxidant enzyme activities as well as photosynthesis pigment contents of the gametophytes were affected by B. pilosa leachates. Gametophytes of P. multifida exposed to B. pilosa had increased damages to cell membranes, expressed in thiobarbituric acid reacting substance (TBARS) concentrations, malondialdehyde (MDA), electrolyte leakage (membrane permeability), and degree of injury. Enzyme activities, assessed by superoxide dismutase (SOD) and catalase (CAT) as well as guaiacol peroxidase (GPX) enhanced with the increase in leachate concentration after 2-day exposure. Meanwhile, lower chlorophyll a (Chl a), chlorophyll b (Chl b), carotenoid (Car), and the total chlorophyll were measured as leachate concentrations increased. At day 10, leaf leachates of B. pilosa exhibited the greatest inhibition. These results suggest that the observed inhibitory or stimulatory effects on the physiology studied can have an adverse effect on P. multifida and that allelopathic interference seems to have involved in this process.

[Chemical constituents from Pteris multifida and cytotoxic activity].

The materials were extracted by 95% ethanol, and the extracting solution was isolated by kinds of chromatographic columns including polyamide, MCI, preparative MPLC, and preparative HPLC. Eight diterpenes and two sesquiterpenes were isolated from the plant. On analysis of ESI-MS and NMR spectroscopic data, the structures were established as ent-3ß-hydroxy-kaur-16-en-19-al (1), 4-epi-kaurenic acid (2), mitrekaurenone (3), 7ß,16α,17-trihydroxy-ent-kauran-19-oic acid (4), crotonkinin E (5), crotonkinin F (6), pterisolic acid A (7), pterisolic acid C (8), (2R)-pterosin P (9), and dehydropterosin B (10). Compounds 1-6 were obtained from Pteris for the first time, and compounds 7-10 were obtained from P. ensiformis for the first time. Compounds 5-8 showed moderate activity against HCT-116, HepG2 and BGC-823 cell lines, separately.

Chemical constituents from Pteris multifida and cytotoxic activity / 中国中药杂志

The materials were extracted by 95% ethanol, and the extracting solution was isolated by kinds of chromatographic columns including polyamide, MCI, preparative MPLC, and preparative HPLC. Eight diterpenes and two sesquiterpenes were isolated from the plant. On analysis of ESI-MS and NMR spectroscopic data, the structures were established as ent-3β-hydroxy-kaur-16-en-19-al (1), 4-epi-kaurenic acid (2), mitrekaurenone (3), 7β,16α,17-trihydroxy-ent-kauran-19-oic acid (4), crotonkinin E (5), crotonkinin F (6), pterisolic acid A (7), pterisolic acid C (8), (2R)-pterosin P (9), and dehydropterosin B (10). Compounds 1-6 were obtained from Pteris for the first time, and compounds 7-10 were obtained from P. ensiformis for the first time. Compounds 5-8 showed moderate activity against HCT-116, HepG2 and BGC-823 cell lines, separately.

An unusual dihydrobenzofuroisocoumarin and ent-kaurane diterpenoids from Pteris multifida.

An unusual 5-C-methylated-dihydrobenzofuroisocoumarin, named multifidarin A (1), and two new ent-kaurane diterpenoids, named multikauranes A (2) and B (3), together with three known ent-kaurane diterpenoids, were isolated from the whole plants of Pteris multifida. The structures of 1-3 were elucidated by spectroscopic methods. The cytotoxic activities of all new compounds were evaluated against five human tumor cell lines. A possible biosynthetic process for the formation of 1 is proposed.

Characterization of arsenic-resistant endophytic bacteria from hyperaccumulators Pteris vittata and Pteris multifida.

We isolated and characterized As-resistant endophytic bacteria (AEB) from two arsenic hyperaccumulators. Their plant growth promoting traits and the relation between As tolerance and transformation were evaluated. A total of 41 and 33 AEB were isolated from Pteris vittata (PV) and Pteris multifida (PM) respectively. PV AEB represented 2genera while PM AEB comprised of 12 genera, with Bacillus sp. being the most dominant bacteria from both plants. All AEB had limited ability in solubilizing P and producing indole acetic acid (IAA) and siderophore. All isolates tolerated 10mM arsenate (As(V)), with PV isolates being more tolerant to As(V) and PM more tolerant to arsenite (As(III)). Bacterial arsenic tolerance was related to their ability in As(III) oxidation and As(V) reduction as well as their ability to retain As in the biomass to a varying extent. Though AEB showed limited plant growth promoting traits, they were important in arsenic tolerance and speciation in plants.

A study on the antitumour effect of total flavonoids from Pteris multifida Poir in H22 tumour-bearing mice.

The objective of this paper was to investigate the inhibitory effect of total flavonoids from Pteris multifida Poir on growth of transplanted H22 tumour in mice. H22 tumour-bearing mice model was established; the experimental animals were divide/d into the model group, Pteris multifida Poir total flavonoids high-, low-dose groups, and CTX group. Pteris multifida Poir groups were administered continuously for 10d, and CTX group was administered every other day. Tumour inhibition rate, thymus index and spleen index were calculated. Serum levels of TNF-α and IL-2 were determined, as well as total antioxidant capacity (T-AOC) and malondialdehyde (MDA) levels in serum. Compared with the model group, the total flavonoids of Pteris multifida Poir can significantly inhibit tumour growth, with tumour inhibition rates of high-and low-dose groups 49.36% and 33.97%, respectively. They can also evidently increase the spleen and thymus indices of tumour-bearing mice, elevate serum TNF-α and IL-2 levels increase serum T-AOC level and reduce serum MDA level in tumour-bearing mice. The study concluded that total flavonoids from Pteris multifida Poir has an obvious inhibitory effect on transplanted H22 tumours; its mechanism of action may be associated with the improvement of immune function and enhancement of antioxidant capacity in mice.