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Polyamines have been discovered for hundreds of years and once considered as a class of phytohormones. Polyamines play critical roles in a range of developmental processes. However, the molecular mechanisms of polyamine signaling pathways remain poorly understood. Here, we measured the contents of main types of polyamines, and found that endogenous level of thermospermine (T-Spm) in Arabidopsis thaliana is comparable to those of classic phytohormones and is significantly lower than those of putrescine (Put), spermidine (Spd), and spermine (Spm). We further found a nodule-like structure around the junction area connecting the shoot and root of the T-Spm biosynthetic mutant acl5 and obtained more than 50 suppressors of acl5nodule structure (san) through suppressor screening. An in-depth study of two san suppressors revealed that NAP57 and NOP56, core components of box H/ACA and C/D snoRNPs, were essential for T-Spm-mediated nodule-like structure formation and plant height. Furthermore, analyses of rRNA modifications showed that the overall levels of pseudouridylation and 2'-O-methylation were compromised in san1 and san2 respectively. Taken together, these results establish a strong genetic relationship between rRNA modification and T-Spm-mediated growth and development, which was previously undiscovered in all organisms.

Background: To explore the effect of continuous renal replacement therapy (CRRT) in patients with sepsis-associated acute kidney injury (SA-AKI) with the Acute Kidney Injury Network Classification III and its effect on inflammatory mediators and coagulation function. Methods: We evaluated 90 patients who were diagnosed with sepsis and treated at our hospital. Forty patients received CRRT (group A) and the remainder received routine therapy (group B). We compared the renal function indices, represented by blood urea nitrogen (BUN) and serum creatinine (Scr), the urinary levels of kidney injury molecule 1, and the curative effect indices between the two groups. The incidence of major adverse cardiovascular events was compared between both groups. Further, the therapeutic effect (total effective rate) was evaluated and compared. Results: After treatment, the levels of BUN and Scr in group A were significantly lower than those in group B (p

The neutralization of strongly alkaline pH conditions and acceleration of mineral weathering in alkaline Fe ore tailings have been identified as key prerequisites for eco-engineering tailings-soil formation for sustainable mine site rehabilitation. Acidithiobacillus ferrooxidans has great potential in neutralizing alkaline pH and accelerating primary mineral weathering in the tailings but little information is available. This study aimed to investigate the colonization of A. ferrooxidans in alkaline Fe ore tailings and its role in elemental sulfur (S0) oxidation, tailings neutralization, and Fe-bearing mineral weathering through a microcosm experiment. The effects of biological S0 oxidation on the weathering of alkaline Fe ore tailings were examined via various microspectroscopic analyses. It is found that (1) the A. ferrooxidans inoculum combined with the S0 amendment rapidly neutralized the alkaline Fe ore tailings; (2) A. ferrooxidans activities induced Fe-bearing primary mineral (e.g., biotite) weathering and secondary mineral (e.g., ferrihydrite and jarosite) formation; and (3) the association between bacterial cells and tailings minerals were likely facilitated by extracellular polymeric substances (EPS). The behavior and biogeochemical functionality of A. ferrooxidans in the tailings provide a fundamental basis for developing microbial-based technologies toward eco-engineering soil formation in Fe ore tailings.

Eukaryotic rRNAs and snRNAs are decorated with abundant 2′-O-methylated nucleotides (Nm) that are predominantly synthesized by box C/D snoRNA-guided enzymes. In the model plant Arabidopsis thaliana, C/D snoRNAs have been well categorized, but there is a lack of systematic mapping of Nm. Here, we applied RiboMeth-seq to profile Nm in cytoplasmic, chloroplast and mitochondrial rRNAs and snRNAs. We identified 111 Nm in cytoplasmic rRNAs and 19 Nm in snRNAs and assigned guide for majority of the detected sites using an updated snoRNA list. At least four sites are directed by guides with multiple specificities as shown in yeast. We found that C/D snoRNAs frequently form extra pairs with nearby sequences of methylation sites, potentially facilitating the substrate binding. Chloroplast and mitochondrial rRNAs contain five almost identical methylation sites, including two novel sites mediating ribosomal subunit joining. Deletion of FIB1 or FIB2 gene reduced the accumulation of C/D snoRNA and rRNA methylation with FIB1 playing a bigger role in methylation. Our data reveal the comprehensive 2′-O-methylation maps for Arabidopsis rRNAs and snRNAs and would facilitate study of their function and biosynthesis.

Pioneer plants play an important role in eco-engineering Fe ore tailings into soil for sustainable mine site rehabilitation. However, root-driven mineral weathering and secondary mineral formation remain poorly understood in tailings, despite being prerequisites for aggregate formation and pedogenesis. The present study aimed at characterizing the direct role of plant roots in tailing mineral weathering and secondary mineral formation in a compartmented cultivation system. It was found that root activities accelerated the weathering of biotite-like minerals via Fe(II) oxidation coupled with Fe(III) and Si dissolution. Numerous nanosized Fe–Si short-range-ordered (SRO) minerals and vermiculite were neoformed in the tailings after root interactions, as revealed by various microspectroscopic analyses. The Fe–Si-SRO minerals may have resulted from co-precipitation of dissolved Fe(III) and Si on mineral surfaces under alkaline and circumneutral pH conditions. Among the three plant species, Sorghum spp. (Gramineae plant) root developed most extensively in the tailings, possibly leading to more efficient mineral weathering and secondary mineral formation than Atriplex amnicola (halophyte plant) and Acacia chisholmii (leguminous plant). Overall, the study has elucidated the rhizosphere effects on tailing mineral (biotite dominant) weathering and secondary Fe–Si mineral formation, justifying pioneer plant roles in eco-engineering Fe ore tailings into soil.

Glioblastoma is the most common malignant tumor of the brain. Despite advances in treatment, the prognosis for the condition has remained poor. Glioblastoma is often associated with peritumoral brain edema (PTBE), which can result in increased intracranial pressure and devastating neurological sequelae if left untreated. Surgery is the main treatment for glioblastoma, however current international surgical guidelines do not specify whether glioblastoma-induced PTBE tissue should be resected. In this study, we analyzed treatment outcomes of PTBE using surgical resection. We performed a retrospective analysis of 255 cases of glioblastoma between 2014 and 2016, and found that a significant proportion of patients had a degree of PTBE. We found that surgical resection led to reduction in midline shift that had resulted from edema, however, postoperative complications and KPS scores were not significantly different in the two conditions. We also observed a delay in glioblastoma recurrence in patients undergoing PTBE tissue resection vs patients without resection of PTBE tissue. Interestingly, there was an abnormal expression of tumor associated genes in PTBE, which has not been previously been found. Taken together, this study indicates that glioblastoma-induced PTBE should be investigated further particularly as the tumor microenvironment is a known therapeutic target and therefore interactions between the microenvironment and PTBE should be explored. This study also highlights the importance of resection of PTBE tissue to not only reduce the mechanical obstruction associated with edema but also to delay recurrence of glioblastoma.

Eco-engineering Fe ore tailings into technosols (i.e., soil-like growth substrates) has been advocated to be a promising technology for sustainable rehabilitation of tailings with native plant communities 1-3. Arbuscular mycorrhizal (AM) symbiosis has been found to be able to colonize tailing technosol eco-engineered through exogenous plant biomass input, and contributed to aggregate development and organic matter stabilization in the tailings4. However, the AM performance and their eco-functionality usually varies depending on water conditions and tailing technosols developed from different plant biomass residue (PBR) input, which has yet been addressed in previous studies. Therefore, the present study aimed to investigate the role of AM symbiosis in aggregate development and association of organic carbon (C) and nitrogen (N) with mineral phase of aggregates in the developing technosols eco-engineered from Fe ore tailings, in relation to low water supply and plant biomass residues of contrasting nutrient quality (e.g., C:N ratios). The results showed that AM symbiosis did not influence aggregate development, but stimulated organic carbon and nitrogen stabilization in tailings-technosol. In particular, AM symbiosis enriched organic C (rather than N) sequestration in minerals of tailings-technosol amended with Lucerne hay containing high N and low C:N ratio. Comparatively, AM symbiosis seemed to have enriched significantly N (rather than organic C) in aggregate minerals in tailings-technosols amended with Sugarcane mulch (with low N and high C:N ratio). This increased N sequestration may have resulted from N-rich AM fungal exudates or fungal biomass. AM symbiosis enhanced organic matter sequestration through enhancing associations between carboxyl-rich organics and key Fe-rich phyllosilicates and/or Fe(oxy)hydroxides. Drought stress limited AM symbiosis role in organic C and N sequestration in the tailing-technosol. In summary, the study indicated that plant biomass of different C:N ratio could influence AM role in organic matter stabilization in Fe ore tailings-technosol, and further studies are required to unravel implications of different organic C and N sequestration in aggregate minerals of tailings-technosols, in relation to long-term pedological development and sustainability of soil functions.Wu, S.; Liu, Y.; Bougoure, J. J.; Southam, G.; Chan, T. S.; Lu, Y. R.; Haw, S. C.; Nguyen, T. A. H.; You, F.; Huang, L., Organic Matter Amendment and Plant Colonization Drive Mineral Weathering, Organic Carbon Sequestration, and Water-Stable Aggregation in Magnetite Fe Ore Tailings. Environ Sci Technol 2019, 53, (23), 13720-13731. Huang, L.; Baumgartl, T.; Zhou, L.; Mulligan, R. In The new paradigm for phytostabilising mine wastes–ecologically engineered pedogenesis and functional root zones, Life-of-Mine Conference, 2014; 2014; pp 16-18. Huang, L.; Baumgartl, T.; Mulligan, D., Is rhizosphere remediation sufficient for sustainable revegetation of mine tailings? Ann Bot 2012, 110, (2), 223-38. Li, Z.; Wu, S.; Liu, Y.; Yi, Q.; You, F.; Ma, Y.; Thomsen, L.; Chan, T.-S.; Lu, Y.-R.; Hall, M.; Saha, N.; Huang, Y.; Huang, L., Arbuscular mycorrhizal symbiosis enhances water stable aggregate formation and organic matter stabilization in Fe ore tailings. Geoderma 2022, 406.

Small nucleolar RNAs (snoRNAs) are noncoding RNAs (ncRNAs) that guide chemical modifications of structural RNAs, which are essential for ribosome assembly and function in eukaryotes. Although numerous snoRNAs have been identified in plants by high-throughput sequencing, the biological functions of most of these snoRNAs remain unclear. Here, we identified box C/D SnoR28.1s as important regulators of plant growth and development by screening a CRISPR/Cas9-generated ncRNA deletion mutant library in Arabidopsis thaliana. Deletion of the SnoR28.1 locus, which contains a cluster of three genes producing SnoR28.1s, resulted in defects in root and shoot growth. SnoR28.1s guide 2′-O-ribose methylation of 25S rRNA at G2396. SnoR28.1s facilitate proper and efficient pre-rRNA processing, as the SnoR28.1 deletion mutants also showed impaired ribosome assembly and function, which may account for the growth defects. SnoR28 contains a 7-bp antisense box, which is required for 2′-O-ribose methylation of 25S rRNA at G2396, and an 8-bp extra box that is complementary to a nearby rRNA methylation site and is partially responsible for methylation of G2396. Both of these motifs are required for proper and efficient pre-rRNA processing. Finally, we show that SnoR28.1s genetically interact with HIDDEN TREASURE2 and NUCLEOLIN1. Our results advance our understanding of the roles of snoRNAs in Arabidopsis.

The acidophilic sulfur oxidizing bacterium (SOB), Acidithiobacillus ferrooxidans, has been found to stimulate elemental sulfur (S

Biochar modification by metal/metal oxide is promising for improving its adsorption capability for contaminants, especially the anions. However, conventional chemical modifications are complicated and costly. In this study, novel Fe/Fe oxide loaded biochars (RMBCs) were synthesized from a one-step co-pyrolysis of red mud (RM) and shaddock peel (SP), and their potential application for removing anionic azo dye (acid orange 7, AO7) from the aqueous environment was evaluated. Fe from red mud was successfully loaded onto biochars pyrolyzed at 300-800 °C, which presented from oxidation form (Fe

Subarachnoid hemorrhage (SAH) is a form of stroke associated with high mortality and morbidity. Despite advances in treatment for SAH, the prognosis remains poor. We have previously demonstrated that glycine, a non-essential amino acid is involved in neuroprotection following intracerebral hemorrhage via the Phosphatase and tensin homolog (PTEN)/protein kinase B (AKT) signaling pathway. However, whether it has a role in inducing neuroprotection in SAH is not known. The present study was designed to investigate the role of glycine in SAH. In this study, we show that glycine can reduce brain edema and protect neurons in SAH via a novel pathway. Following a hemorrhagic episode, there is evidence of downregulation of S473 phosphorylation of AKT (p-AKT), and this can be reversed with glycine treatment. We also found that administration of glycine can reduce neuronal cell death in SAH by activating the AKT pathway. Glycine was shown to upregulate miRNA-26b, which led to PTEN downregulation followed by AKT activation, resulting in inhibition of neuronal death. Inhibition of miRNA-26b, PTEN or AKT activation suppressed the neuroprotective effects of glycine. Glycine treatment also suppressed SAH-induced M1 microglial polarization and thereby inflammation. Taken together, we conclude that glycine has neuroprotective effects in SAH and is mediated by the miRNA-26b/PTEN/AKT signaling pathway, which may be a therapeutic target for treatment of SAH injury.

Hardpans are massively indurated layers formed at the top layer of sulfidic tailings dams, which develop cementation structures and result in heavy metal immobilization. However, the micro-structural and complex forms of the cementing materials are not fully understood, as well as the mechanisms by which Zn and Pb are stabilized in the hardpans. The present study deployed synchrotron-based X-ray fluorescence microscopy (XFM) to have characterized the cementing structures, examined the distribution of Fe, Zn and Pb, and obtained laterally-resolved speciation of Zn within the hardpans using fluorescence X-ray absorption near-edge structure (XANES) imaging. The XFM analyses revealed that the Fe-rich cement layers consisted of Fe (oxyhydr)oxides coupled with amorphous Si materials, immobilizing Zn and Pb. Through laterally-resolved XANES imaging analyses, Zn-ferrihydrite-like precipitates were predicted to account for >76% of the total Zn within the Fe-rich cement layers. In contrast, outside of the cement layers, 9–63% of the Zn was estimated as labile ZnSO4.7H2O, with the remainder in the form of Zn-sulfide. These findings demonstrated that the Fe-rich cement layers were critical in immobilizing Zn and Pb within hardpans via mineral passivation and encapsulation, as the basis for long-term geochemical stability in the hardpan layer of sulfidic mine tailings.

Laccases play crucial roles in catalyzing lignin and flavonoid biosynthesis in plants, and are predominantly involved in lignin breakdown of bacteria and fungi. Lignin distributes in all parts of plant and is a key component in plant morphogenesis. The complex sugarcane genome limited the study of laccase genes, but our completed reference genome of tetraploid S. spontaneum AP85–441 makes it possible to study this gene family. We identified 29 laccase genes, and 10 genes with 4 alleles, 9 genes with 3 alleles, 5 genes with 2 alleles, 5 genes with 1 allele in sugarcane. Among them 4 genes have tandemly dupicated paralogs; and 12 genes have dispersely distributed paralogs. They distributed unevenly among 27 of 32 chromosomes, and 9 (31.03%) genes located in Chromosome 3. Phylogeny and conserved domain suggested sugarcane laccase genes had the highest similarity with sorghum, and laccase10 was the most conserved gene in monocots and dicotyledons. We found sugarcane laccase genes were regulated by light signal, phytohormones, abiotic stress and some tissue-specific transcription factors by predicted cis-elements in the promoters. Nine laccase genes had miR397 and miR528 target sites, which have been reported as post-transcriptionally regulated laccase genes. Four laccase genes had 4 new miRNA target sites, including stem specific miRNA. Analysis of RNA-seq data of different developmental stages of leaves and stems showed that 27 genes had expression of those tissues, and most of them mainly express in stems. Among them laccase 4 and laccase10 showed the highest expression level in mature stems, while laccase27 showed the highest expression in seedling leaves. Our results show the potential function of sugarcane laccase genes in catalyzing lignin biosynthesis, stress resistance, and morphogenesis. These findings and genomic resources will facilitate research on improving stress tolerance, lignin content, and biomass yield in sugarcane.

The formation of water-stable, hierarchical aggregate structure is one of the critical processes in eco-engineering iron (Fe) ore tailings into soil-like medium for sustainable rehabilitation of Fe ore mine site. Through systematically comparing physical structure and mineralogical differences between Fe ore tailings' aggregates and Fe-rich native soil aggregates at a magnetite-Fe ore mine, the present study captured the microstructure, mineralogy and organic matter composition of aggregates in aged (4 years old) tailings, in comparison with those in native soils. A suite of micro-spectroscopic methods have been employed to elucidate their physical, mineralogical and morphological characteristics, including synchrotron based Fe K edge X-ray absorption fine structure spectroscopy (XAFS), and backscattered electrons (BSE)-scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS). The results revealed significant differences in physical structure of aggregates in Fe ore tailings and natural soils rich in Fe, which was attributed to their different mineralogical and organic components and characteristics. Especially, it was found that the secondary Fe (oxy)hydroxides (i.e., goethite, ferrihydrite) and their interactions with Al/Si rich secondary phyllosilicates (or aluminosilicates) were required in the formation of amorphous Fe-Si-Al rich gels that acted as cementing agents for agglomerating Si-rich particles (e.g., quartz) in soil. In contrast, tailing aggregates (rich in more crystalline primary minerals such as magnetite and biotite) lacked these gels, resulting in poor stability. Comparatively, natural soil aggregates contained more recalcitrate organic carbon groups (e.g., aromatic, carboxyl and aliphatic C) than tailing aggregates, which would have also contributed to the improvement of aggregate stability through organo-mineral associations. This study has improved our understanding of key limiting geochemical factor(s) involved in the aggregation of Fe rich soils, which would provide the basis for formulating effective eco-engineering inputs to accelerate the development of soil-like structure in the Fe ore tailings for sustainable rehabilitation.

Arbuscular mycorrhizal (AM) fungi are ubiquitous soil fungi that form symbiotic associations with most terrestrial plants. The growth and functions of AM fungi depend on carbohydrates supplied by the plants, in return, the fungi assist the plants to acquire mineral nutrients (e.g., phosphorus) from soil. The AM symbiosis also improves plant survival in various unfavorable environments, such as metal (loid) contaminated soil. It has been well demonstrated that AM symbiosis improved plant adaptation to Cr contamination, which would have a great potential in phytoremediation and ecological restoration of Cr contaminated soils. In this paper, we have reviewed the role of AM fungi in alleviation of Cr phytotoxicity and associated factors influencing plant Cr tolerance. AM symbiosis improves plant Cr tolerance through its direct roles in Cr stabilization and transformation and indirect roles via AM symbiosis mediated nutrient acquisition and physiological regulation. Future research on physiological and molecular mechanisms underlying Cr behavior and detoxification in AM symbiosis, as well as potential use of AM fungi in ecological restoration and agriculture production in Cr contaminated soils were also proposed.