Phytoremediation potential of seedlings: comparing heavy metal accumulation in Ailanthus, Acer, and Fraxinus species.

This study investigates the phytoremediation potential of non-productive seedlings of Ailanthus altissima, Acer pseudoplatanus, and Fraxinus excelsior for lead, cadmium, and zinc accumulation in contaminated soils of Zanjan Province, an industrial area with significant pollution. The evaluation employed a completely randomized design, with three treatment levels for each element, alongside a control treatment, replicated three times over a two-year period. A total of 810 one-year-old seedlings from the three species were involved in the study. Soil contamination levels, ranging from 0 to 2000 mg/kg for lead and zinc and from 0 to 200 mg/kg for cadmium, were administered through soil pot irrigation. Sampling of seedling stems and pot soils was conducted in November of 2021 and 2022. The absorption levels of elements in the samples were determined using the dry acid digestion method and an ICP-OES atomic absorption spectrometer. Results indicate species-specific variations in metal absorption, with Ailanthus showing the highest accumulation rates. Findings suggest Ailanthus as a promising candidate for soil improvement in polluted environments, particularly in contaminated soils of Zanjan Province.

Transcriptome analysis reveals the fruit color variation in Ailanthus altissima.

Anthocyanins are responsible for the intensity of color in plants; however, the systematic mechanisms underlying the color differences in the fruit of Ailanthus altissima remain unknown. Therefore, this study aims to analyze the transcriptomes of the white and red fruit of A. altissima by screening and validating the key genes involved in flavonoid and anthocyanin biosynthesis. Samples of A. altissima fruit were collected 30, 45, and 60 days after flowering, and their pigment and sugar content were determined. The anthocyanin content was significantly higher in red than in white fruits. Transcriptome analysis was also performed on the fruit samples, 73,807 unigenes were assembled and annotated to seven databases. Twenty-one co-expressed modules were identified via weighted gene co-expression network analysis, of which two were associated with flavonoids and anthocyanins. Furthermore, in three growth stages, 126, 30, and 124 differentially expressed genes were screened between white and red fruit. Genes involved in flavonoid and anthocyanin metabolism were identified. AaDFR (A. altissima bifunctional dihydroflavonol 4-reductase/flavanone 4-reductase) and AaANS (A. altissima anthocyanidin synthase) were associated with flavonoid and anthocyanin metabolism. Members of the AaDFR and AaANS families were also identified, and their basic physicochemical characteristics, conserved domains, motif compositions, phylogenetics, and expression levels were analyzed. The overexpression of AaDFR and AaANS in transgenic Arabidopsis significantly increased the content of seed and foliar flavonoids and anthocyanins. The study elucidated the different mechanisms underlying fruit color development and provided insight into A. altissima plants breeding with commercially desirable properties.

Wood transcriptome analysis and expression variation of lignin biosynthetic pathway transcripts in Ailanthus excelsa Roxb., a multi-purpose tropical tree species.

Safety matches are an essential consumer commodity which faces considerable shortage of raw material due to specific requirements like color, wax stability, consistent burning and splinting ability in wood. Ailanthus excelsa Roxb. is a multi-purpose tropical tree species which is predominantly used for production of match splints. It is a data deficient species with no information on molecular regulation governing the wood phenotypes. Hence, with the aim to identify the lignin biosynthetic pathway transcripts, transcriptome sequencing of pooled developing secondary wood tissues of a 22-month-old tree was conducted. The processed reads were de novo assembled and 48,493 unigenes were annotated. Quantitative real time PCR was conducted in six even-aged trees to document the natural expression profiles of nine major transcripts from the monolignol pathway. Significant differential expression of Phenylalanine ammonia-lyase (AePAL), Cinnamate 4-hydroxylase (AeC4H), Cinnamyl-alcohol dehydrogenase (AeCAD), Laccase (AeLACI) and Caffeic Acid 3-O-Methyl Transferase (AeCOMT) was documented across all genotypes studied. Transcriptome-wise microsatellites were also mined and is the first co-dominant marker resource in this species. The genomic resource generated in A. excelsa will facilitate understanding the molecular mechanisms of wood formation and accelerate trait-based breeding program through diversity assessment, population structure analysis, clonal discrimination and marker assisted selection.

Quantitative proteomics reveals the antifungal effect of canthin-6-one isolated from Ailanthus altissima against Fusarium oxysporum f. sp. cucumerinum in vitro.

Canthin-6-one, one of the main alkaloid compounds extracted from Ailanthus altissima, has recently attracted increasing interest for its antifungal activity. To evaluate the potential of canthin-6-one in controlling plant fungal diseases, we investigated the antifungal activity of canthin-6-one isolated from A. altissima against Fusarium oxysporum f. sp. cucumerinum (Foc) in vitro. The mycelial growth rate and micro-broth dilution were used to test antifungal activity. Furthermore, label-free quantitative proteomics and parallel reaction monitoring (PRM) techniques were applied to analyze the antifungal mechanism. It was found that canthin-6-one significantly inhibited the growth of Foc, and had higher inhibitory action than chlorothalonil at the same concentration. Proteomic analysis showed that the expression of 203 proteins altered significantly after canthin-6-one treatment. These differentially expressed proteins were mainly involved in amino acid biosynthesis and nitrogen metabolism pathways. These results suggest that canthin-6-one significantly interferes with the metabolism of amino acids. Therefore, it affects nitrogen nutrients and disturbs the normal physiological processes of fungi, and ultimately leads to the death of pathogens. This study provides a natural plant antifungal agent and a new perspective for the study of antifungal mechanisms.

9-Hydroxycanthin-6-one isolated from stem bark of Ailanthus altissima induces ovarian cancer cell apoptosis and inhibits the activation of tumor-associated macrophages.

The stem bark of Ailanthus altissima is used in traditional medicine in Asia to treat a variety of diseases, including cancer. The aim of this study was to identify compounds with tumoricidal activity from A. altissima stem bark and to investigate their mechanisms of action. Among the 13 compounds isolated from the ethyl acetate fraction of A. altissima stem bark, the ß-carboline alkaloid 9-hydroxycanthin-6-one had potent cytotoxicity in all three ovarian cancer cell types examined. 9-Hydroxycanthin-6-one induced apoptosis through the activation of caspases-3, -8, and -9. 9-Hydroxycanthin-6-one increased the intracellular levels of reactive oxygen species (ROS), and pre-treatment with the antioxidant N-acetyl-l-cysteine (NAC) attenuated the pro-apoptotic activity of 9-hydroxycanthin-6-one. Additionally, 9-hydroxycanthin-6-one was found to decrease the expressions of MCP-1 and RANTES, major determinants of macrophage recruitment at tumor sites, in ovarian cancer cells. Treatment with 9-hydroxycanthin-6-one inhibited the levels of M2 phenotype markers and some cancer-promoting factors, such as MMP-2, MMP-9, and VEGF, in macrophages educated in ovarian cancer conditioned medium. Taken together, these data suggest that 9-hydroxycanthin-6-one isolated from A. altissima stem bark induces apoptosis in human ovarian cancer cells through the caspase- and ROS-dependent pathways and inhibits the activation of tumor-associated macrophages.

Photocatalytic degradation of synthetic food dye, sunset yellow FCF (FD&C yellow no. 6) by Ailanthus excelsa Roxb. possessing antioxidant and cytotoxic activity.

The purpose of our work is to identify the bioactive compounds of bark and leaves extract from Ailanthus excelsa Roxb. and to explore its effectiveness against synthetic food dye. The presence of primary and secondary metabolites was confirmed by carrying out phytochemicals analysis. With the prior knowledge accessible on the indispensable secondary metabolites holding antioxidant and cytotoxicity activity, the quantitative screening of total phenolic and flavonoid content in methanolic and aqueous extract of bark and leaves from Ailanthus excelsa were done. Comparatively, a higher value of flavonoid (161±0.3µg/mg) and phenolic acid content (152.4±0.14µg/mg) was found in bark extract. By FTIR analysis, the characteristic peak was obtained at 1581.63 and 1598.99cm-1 confirmed the presence of functional groups associated to flavonoids and other phenolic groups respectively. In bark extract, 81% of DPPH inhibition was observed when compared to ascorbic acid (standard) 92% of free radical scavenging activity. Bark extract from Ailanthus excelsa exhibited 71% cytotoxicity against HeLa cell line (cervical cancer). In examining the toxicity level of crude extracts with red blood cells (RBC), the bark extract was showed a very less (2.8%) haemolytic activity. They also showed maximum zone of inhibition in antibacterial activity i.e. 13±0.5mm against Escherichia coli culture. At a concentration of 10mg/mL of crude extract from A. excelsa, 55% degradation of sunset yellow dye was observed. It concludes that, the compounds present in the A. excelsa, especially the bark extract showed better photocatalytic, haemolytic, antioxidant, cytotoxicity and antibacterial activity when compared to leaves extract.

Ailanthone induces G2/M cell cycle arrest and apoptosis of SGC­7901 human gastric cancer cells.

Ailanthone is a major quassinoid extracted from the Chinese medicinal herb Ailanthus altissima, which has been reported to exert antiproliferative effects on various cancer cells. The present study aimed to investigate the antitumor effects of ailanthone on SGC­7901 cells, and to analyze its underlying molecular mechanisms. Following treatment with ailanthone, Cell Counting kit­8 was used to detect the cytotoxic effects of ailanthone on SGC­7901 cells in vitro. The typical apoptotic morphology of SGC­7901 cells was observed by Hoechst 33258 staining. Cell cycle progression and apoptosis were measured by flow cytometry, and the protein and mRNA expression levels of Bcl­2 and Bax were analyzed by western blot analysis and reverse transcription­quantitative polymerase chain reaction (RT­qPCR) respectively, in SGC­7901 cells. The results of the present study indicated that ailanthone inhibited the proliferation of SGC­7901 cells in a dose­ and time­dependent manner in vitro, and also demonstrated that ailanthone induced G2/M phase cell cycle arrest and apoptosis of SGC­7901 cells. Furthermore, analysis of the underlying molecular mechanisms revealed that ailanthone downregulated the expression levels of Bcl­2, whereas the expression levels of Bax were upregulated at the protein and mRNA levels. In conclusion, ailanthone may inhibit the proliferation of SGC­7901 cells by inducing G2/M phase cell cycle arrest and apoptosis via altering the protein and mRNA expression levels of Bcl­2 and Bax in SGC­7901 cells.

Phytoremediation potential of wild plants growing on soil contaminated with heavy metals.

Phytoremediation is an emerging technology that employs higher plants to cleanup contaminated environments, including metal-polluted soils. Because it produces a biomass rich in extracted toxic metals, further treatment of this biomass is necessary. The aim of our study was to assess the five-year potential of the following native wild plants to produce biomass and remove heavy metals from a polluted site: poplar (Populus ssp.), ailanthus (Ailanthus glandulosa L.), false acacia (Robinia pseudoacacia L.), ragweed (Artemisia artemisiifolia L.), and mullein (Verbascum thapsus L). Average soil contamination with Pb, Cd, Zn, Cu, Ni, Cr, and As in the root zone was 22,948.6 mg kg-1, 865.4 mg kg-1, 85,301.7 mg kg-1, 3,193.3 mg kg-1, 50.7 mg kg-1, 41.7 mg kg-1,and 617.9 mg kg-1, respectively. We measured moisture and ash content, concentrations of Pb, Cd, Zn, Cu, Ni, Cr, and As in the above-ground parts of the plants and in ash produced by combustion of the plants, plus gross calorific values. The plants' phytoextraction and phytostabilisation potential was evaluated based on their bioconcentration factor (BCF) and translocation factor (TF). Mullein was identified as a hyperaccumulator for Cd. It also showed a higher gross calorific value (19,735 kJ kg-1) than ragweed (16,469 kJ kg-1).The results of this study suggest that mullein has a great potential for phytoextraction and for biomass generation, and that ragweed could be an effective tool of phytostabilisation.

Ailanthus Altissima and Phragmites Australis for chromium removal from a contaminated soil.

The comparative effectiveness for hexavalent chromium removal from irrigation water, using two selected plant species (Phragmites australis and Ailanthus altissima) planted in soil contaminated with hexavalent chromium, has been studied in the present work. Total chromium removal from water was ranging from 55 % (Phragmites) to 61 % (Ailanthus). After 360 days, the contaminated soil dropped from 70 (initial) to 36 and 41 mg Cr/kg (dry soil), for Phragmites and Ailanthus, respectively. Phragmites accumulated the highest amount of chromium in the roots (1910 mg Cr/kg(dry tissue)), compared with 358 mg Cr/kg(dry tissue) for Ailanthus roots. Most of chromium was found in trivalent form in all plant tissues. Ailanthus had the lowest affinity for Cr(VI) reduction in the root tissues. Phragmites indicated the highest chromium translocation potential, from roots to stems. Both plant species showed good potentialities to be used in phytoremediation installations for chromium removal.

Ailanthone Inhibits Huh7 Cancer Cell Growth via Cell Cycle Arrest and Apoptosis In Vitro and In Vivo.

While searching for natural anti-hepatocellular carcinoma (HCC) components in Ailanthus altissima, we discovered that ailanthone had potent antineoplastic activity against HCC. However, the molecular mechanisms underlying the antitumor effect of ailanthone on HCC have not been examined. In this study, the antitumor activity and the underlying mechanisms of ailanthone were evaluated in vitro and in vivo. Mechanistic studies showed that ailanthone induced G0/G1-phase cell cycle arrest, as indicated by decreased expression of cyclins and CDKs and increased expression of p21 and p27. Our results demonstrated that ailanthone triggered DNA damage characterized by activation of the ATM/ATR pathway. Moreover, ailanthone-induced cell death was associated with apoptosis, as evidenced by an increased ratio of cells in the subG1 phase and by PARP cleavage and caspase activation. Ailanthone-induced apoptosis was mitochondrion-mediated and involved the PI3K/AKT signaling pathway in Huh7 cells. In vivo studies demonstrated that ailanthone inhibited the growth and angiogenesis of tumor xenografts without significant secondary adverse effects, indicating its safety for treating HCC. In conclusion, our study is the first to report the efficacy of ailanthone against Huh7 cells and to elucidate its underlying molecular mechanisms. These findings suggest that ailanthone is a potential agent for the treatment of liver cancer.

The effects of iron deficiency on lead accumulation in Ailanthus altissima (Mill.) Swingle seedlings.

Understanding the effects of root Fe deficiency on the uptake and translocation of toxic metals can be important for improving the phytoremediation strategies of polluted soils. The present study investigated how Fe nutritional status affects the uptake and root-to-shoot-translocation of Pb in hydroponically grown seedlings of (Mill.) Swingle. The interactions of Fe deficiency and Pb were assessed by measuring the root Fe(III) reductase activity, carboxylic acids concentration in root exudates, root and shoot biomass, and accumulation of Pb and other metals (Fe, Zn, Mn, and Cu) in roots and leaves of Fe-sufficient (+Fe) and Fe-deficient (-Fe) plants. The results indicate that Fe deficiency induced 18-fold higher Fe(III) reductase activity in roots compared with +Fe plants, which was followed by increased root exudation of citric acid (28.2 ± 1.39 in +Fe and 498 ± 256.4 µmol g DW 2 h in -Fe plants). Iron deficiency also induces a significant decrease of root and shoot dry weight compared with the control +Fe plants, whereas 2-wk Pb (20 µM) treatment did not influence root and shoot growth. Iron-sufficient plants accumulated more Pb (56.8 ± 17.29 µg g) in leaves than -Fe plants (21.5 ± 8.10 µg g). Two weeks of exposure to Pb significantly decreased Fe(III) reductase activity and accumulation of Fe, Zn, and Mn in the roots of -Fe plants. It is hypothesized that 2 wk of root exposure to Pb blocks functioning of a specific Fe transport system activated under Fe deficiency.

High biological variability of plastids, photosynthetic pigments and pigment forms of leaf primordia in buds.

To study the formation of the photosynthetic apparatus in nature, the carotenoid and chlorophyllous pigment compositions of differently developed leaf primordia in closed and opening buds of common ash (Fraxinus excelsior L.) and horse chestnut (Aesculus hippocastanum L.) as well as in closed buds of tree of heaven (Ailanthus altissima P. Mill.) were analyzed with HPLC. The native organization of the chlorophyllous pigments was studied using 77 K fluorescence spectroscopy, and plastid ultrastructure was investigated with electron microscopy. Complete etiolation, i.e., accumulation of protochlorophyllide, and absence of chlorophylls occurred in the innermost leaf primordia of common ash buds. The other leaf primordia were partially etiolated in the buds and contained protochlorophyllide (0.5-1 µg g(-1) fresh mass), chlorophyllides (0.2-27 µg g(-1) fresh mass) and chlorophylls (0.9-643 µg g(-1) fresh mass). Etio-chloroplasts with prolamellar bodies and either regular or only low grana were found in leaves having high or low amounts of chlorophyll a and b, respectively. After bud break, etioplast-chloroplast conversion proceeded and the pigment contents increased in the leaves, similarly to the greening processes observed in illuminated etiolated seedlings under laboratory conditions. The pigment contents and the ratio of the different spectral forms had a high biological variability that could be attributed to (i) various light conditions due to light filtering in the buds resulting in differently etiolated leaf primordia, (ii) to differences in the light-exposed and inner regions of the same primordia in opening buds due to various leaf folding, and (iii) to tissue-specific slight variations of plastid ultrastructure.