LncRNA DANA1 promotes drought tolerance and histone deacetylation of drought responsive genes in Arabidopsis.

Although many long noncoding RNAs have been discovered in plants, little is known about their biological function and mode of action. Here we show that the drought-induced long intergenic noncoding RNA DANA1 interacts with the L1p/L10e family member protein DANA1-INTERACTING PROTEIN 1 (DIP1) in the cell nucleus of Arabidopsis, and both DANA1 and DIP1 promote plant drought resistance. DANA1 and DIP1 increase histone deacetylase HDA9 binding to the CYP707A1 and CYP707A2 loci. DIP1 further interacts with PWWP3, a member of the PEAT complex that associates with HDA9 and has histone deacetylase activity. Mutation of DANA1 enhances CYP707A1 and CYP707A2 acetylation and expression resulting in impaired drought tolerance, in agreement with dip1 and pwwp3 mutant phenotypes. Our results demonstrate that DANA1 is a positive regulator of drought response and that DANA1 works jointly with the novel chromatin-related factor DIP1 on epigenetic reprogramming of the plant transcriptome during the response to drought.

RNA splicing modulates the postharvest physiological deterioration of cassava storage root.

Rapid postharvest physiological deterioration (PPD) of cassava (Manihot esculenta Crantz) storage roots is a major constraint that limits the potential of this plant as a food and industrial crop. Extensive studies have been performed to explore the regulatory mechanisms underlying the PPD processes in cassava to understand their molecular and physiological responses. However, the exceptional functional versatility of alternative splicing (AS) remains to be explored during the PPD process in cassava. Here, we identified several aberrantly spliced genes during the early PPD stage. An in-depth analysis of AS revealed that the abscisic acid (ABA) biosynthesis pathway might serve as an additional molecular layer in attenuating the onset of PPD. Exogenous ABA application alleviated PPD symptoms through maintaining ROS generation and scavenging. Interestingly, the intron retention transcript of MeABA1 (ABA DEFICIENT 1) was highly correlated with PPD symptoms in cassava storage roots. RNA yeast three-hybrid and RNA immunoprecipitation assays showed that the serine/arginine-rich protein MeSCL33 (SC35-like splicing factor 33) binds to the precursor mRNA of MeABA1. Importantly, overexpressing MeSCL33 in cassava conferred improved PPD resistance by manipulating the AS and expression levels of MeABA1 and then modulating the endogenous ABA levels in cassava storage roots. Our results uncovered the pivotal role of the ABA biosynthesis pathway and RNA splicing in regulating cassava PPD resistance and proposed the essential roles of MeSCL33 for conferring PPD resistance, broadening our understanding of SR proteins in cassava development and stress responses.

PSEUDO-RESPONSE REGULATOR 3b and transcription factor ABF3 modulate abscisic acid-dependent drought stress response in soybean.

The circadian system plays a pivotal role in facilitating the ability of crop plants to respond and adapt to fluctuations in their immediate environment effectively. Despite the increasing comprehension of PSEUDO-RESPONSE REGULATORs (PRRs) and their involvement in the regulation of diverse biological processes, including circadian rhythms, photoperiodic control of flowering, and responses to abiotic stress, the transcriptional networks associated with these factors in soybean (Glycine max (L.) Merr.) remain incompletely characterized. In this study, we provide empirical evidence highlighting the significance of GmPRR3b as a crucial mediator in regulating the circadian clock, drought stress response, and abscisic acid (ABA) signaling pathway in soybeans. A comprehensive analysis of DNA affinity purification sequencing and transcriptome data identified 795 putative target genes directly regulated by GmPRR3b. Among them, a total of 570 exhibited a significant correlation with the response to drought, and eight genes were involved in both the biosynthesis and signaling pathways of ABA. Notably, GmPRR3b played a pivotal role in the negative regulation of the drought response in soybeans by suppressing the expression of abscisic acid responsive element-binding factor 3 (GmABF3). Additionally, the overexpression of GmABF3 exhibited an increased ability to tolerate drought conditions, and it also restored the hypersensitive phenotype of the GmPRR3b overexpressor. Consistently, studies on the manipulation of GmPRR3b gene expression and genome editing in plants revealed contrasting reactions to drought stress. The findings of our study collectively provide compelling evidence that emphasizes the significant contribution of the GmPRR3b-GmABF3 module in enhancing drought tolerance in soybean plants. Moreover, the transcriptional network of GmPRR3b provides valuable insights into the intricate interactions between this gene and the fundamental biological processes associated with plant adaptation to diverse environmental conditions.

Identification of GmPT proteins and investigation of their expressions in response to abiotic stress in soybean.

MAIN CONCLUSION: Investigation the expression patterns of GmPT genes in response to various abiotic stresses and overexpression of GmPT11 in soybean hairy roots and Arabidopsis exhibited hypersensitivity to salt stress. Soybean is considered to be one of the significant oil crops globally, as it offers a diverse range of essential nutrients that contribute to human health. Salt stress seriously affects the yield of soybean through negative impacts on the growth, nodulation, reproduction, and other agronomy traits. The phosphate transporters 1(PHT1) subfamily, which is a part of the PHTs family in plants, is primarily found in the cell membrane and responsible for the uptake and transport of phosphorus. However, the role of GmPT (GmPT1-GmPT14) genes in response to salt stress has not been comprehensively studied. Here, we conducted a systematic analysis to ascertain the distribution and genomic duplications of GmPT genes, as well as their expression patterns in response to various abiotic stresses. Promoter analysis of GmPT genes revealed that six stress-related cis-elements were enriched in these genes. The overexpression of GmPT11 in soybean hairy roots and Arabidopsis exhibited hypersensitivity to salt stress, while no significant change was observed under low phosphate treatment, suggesting a crucial role in the response to salt stress. These findings provide novel insights into enhancing plant tolerance to salt stress.

A novel natural variation in the promoter of GmCHX1 regulates conditional gene expression to improve salt tolerance in soybean.

Identification and characterization of soybean germplasm and gene(s)/allele(s) for salt tolerance is an effective way to develop improved varieties for saline soils. Previous studies identified GmCHX1 (Glyma03g32900) as a major salt tolerance gene in soybean, and two main functional variations were found in the promoter region (148/150 bp insertion) and the third exon with a retrotransposon insertion (3.78 kb). In the current study, we identified four salt-tolerant soybean lines, including PI 483460B (Glycine soja), carrying the previously identified salt-sensitive variations at GmCHX1, suggesting new gene(s) or new functional allele(s) of GmCHX1 in these soybean lines. Subsequently, we conducted quantitative trait locus (QTL) mapping in a recombinant-inbred line population (Williams 82 (salt-sensitive) × PI 483460B) to identify the new salt tolerance loci/alleles. A new locus, qSalt_Gm18, was mapped on chromosome 18 associated with leaf scorch score. Another major QTL, qSalt_Gm03, was identified to be associated with chlorophyll content ratio and leaf scorch score in the same chromosomal region of GmCHX1 on chromosome 3. Novel variations in a STRE (stress response element) cis-element in the promoter region of GmCHX1 were found to regulate the salt-inducible expression of the gene in these four newly identified salt-tolerant lines including PI 483460B. This new allele of GmCHX1 with salt-inducible expression pattern provides an energy cost efficient (conditional gene expression) strategy to protect soybean yield in saline soils without yield penalty under non-stress conditions. Our results suggest that there might be no other major salt tolerance locus similar to GmCHX1 in soybean germplasm, and further improvement of salt tolerance in soybean may rely on gene-editing techniques instead of looking for natural variations.

Wide-Band Unambiguous Quantum Sensing via Geodesic Evolution.

We present a quantum sensing technique that utilizes a sequence of π pulses to cyclically drive the qubit dynamics along a geodesic path of adiabatic evolution. This approach effectively suppresses the effects of both decoherence noise and control errors while simultaneously removing unwanted resonance terms, such as higher harmonics and spurious responses commonly encountered in dynamical decoupling control. As a result, our technique offers robust, wide-band, unambiguous, and high-resolution quantum sensing capabilities for signal detection and individual addressing of quantum systems, including spins. To demonstrate its versatility, we showcase successful applications of our method in both low-frequency and high-frequency sensing scenarios. The significance of this quantum sensing technique extends to the detection of complex signals and the control of intricate quantum environments. By enhancing detection accuracy and enabling precise manipulation of quantum systems, our method holds considerable promise for a variety of practical applications.

Identification of the domestication gene GmCYP82C4 underlying the major quantitative trait locus for the seed weight in soybean.

KEY MESSAGE: A major quantitative trait locus (QTL) for the hundred-seed weight (HSW) was identified and confirmed in the two distinct soybean populations, and the target gene GmCYP82C4 underlying this locus was identified that significantly associated with soybean seed weight, and it was selected during the soybean domestication and improvement process. Soybean is a major oil crop for human beings and the seed weight is a crucial goal of soybean breeding. However, only a limited number of target genes underlying the quantitative trait loci (QTLs) controlling seed weight in soybean are known so far. In the present study, six loci associated with hundred-seed weight (HSW) were detected in the first population of 573 soybean breeding lines by genome-wide association study (GWAS), and 64 gene models were predicted in these candidate QTL regions. The QTL qHSW_1 exhibits continuous association signals on chromosome four and was also validated by region association study (RAS) in the second soybean population (409 accessions) with wild, landrace, and cultivar soybean accessions. There were seven genes in qHSW_1 candidate region by linkage disequilibrium (LD) block analysis, and only Glyma.04G035500 (GmCYP82C4) showed specifically higher expression in flowers, pods, and seeds, indicating its crucial role in the soybean seed development. Significant differences in HSW trait were detected when the association panels are genotyped by single-nucleotide polymorphisms (SNPs) in putative GmCYP82C4 promoter region. Eight haplotypes were generated by six SNPs in GmCYP82C4 in the second soybean population, and two superior haplotypes (Hap2 and Hap4) of GmCYP82C4 were detected with average HSW of 18.27 g and 18.38 g, respectively. The genetic diversity of GmCYP82C4 was analyzed in the second soybean population, and GmCYP82C4 was most likely selected during the soybean domestication and improvement process, leading to the highest proportion of Hap2 of GmCYP82C4 both in landrace and cultivar subpopulations. The QTLs and GmCYP82C4 identified in this study provide novel genetic resources for soybean seed weight trait, and the GmCYP82C4 could be used for soybean molecular breeding to develop desirable seed weight in the future.

Green Synthesis of Polyurethane Sponge-Grafted Calcium Alginate with Carbon Ink Aerogel with High Water Vapor Harvesting Capacity for Solar-Driven All-Weather Atmospheric Water Harvesting.

Atmospheric water harvesting (AWH) technology is a new strategy for alleviating freshwater scarcity. Adsorbent materials with high hygroscopicity and high photothermal conversion efficiency are the key to AWH technology. Hence, in this study, a simple and large-scale preparation for a hygroscopic compound of polyurethane (PU) sponge-grafted calcium alginate (CA) with carbon ink (SCAC) was developed. The PU sponge in the SCAC aerogel acts as a substrate, CA as a moisture adsorber, and carbon ink as a light adsorber. The SCAC aerogel exhibits excellent water absorption of 0.555-1.40 g·g-1 within a wide range of relative humidity (40-80%) at 25 °C. The SCAC aerogel could release adsorbed water driven by solar energy, and more than 92.17% of the adsorbed water could be rapidly released over a wide solar intensity range of 1.0-2.0 sun. In an outdoor experiment, 57.517 g of SCAC was able to collect 32.8 g of clean water in 6 h, and the water quality meets the drinking water standards set by the World Health Organization. This study suggests a new approach to design promising AWH materials and infers the potential practical application of SCAC aerogel-based adsorbents.

Low prevalence of mcr-1 in Escherichia coli from food-producing animals and food products in China.

BACKGROUND: mcr-1-positive Escherichia coli has emerged as a significant threat to human health, veterinary health, and food safety in recent years. After the prohibition of colistin as a feed additive in animal husbandry in China, a noticeable reduction in both colistin resistance and the prevalence of mcr-1 was observed in E. coli from animals and humans. OBJECTIVES: To assess the prevalence of the colistin resistance gene mcr-1 and characterize its genetic context in E. coli strains derived from fecal and meat samples from food-producing animals in China. METHODS: A total of 1,353 fecal samples and 836 food samples were collected between 2019 and 2020 in China. E. coli isolates were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and their susceptibility to colistin were determined using the broth microdilution method. The colistin-resistant E. coli isolates were screened for the presence of mcr by PCR analysis and sequencing. The minimal inhibitory concentrations (MICs) of 15 antimicrobial agents against the mcr-1-positive strains were further tested using the agar dilution method, conjugation assays were performed, and whole genome sequencing was performed using Illumina HiSeq. RESULTS: In total, 1,403 E. coli strains were isolated. Thirteen isolates from chicken meat (n = 7), chickens (n = 3), and pigs (n = 3) were resistant to colistin with MIC values of 4 to 16 mg/L, and carried mcr-1. All mcr-1-positive strains, except for isolate AH20PE105, contained multiple resistance genes and exhibited multidrug-resistant phenotypes. They belonged to 10 sequence types (STs), including a novel ST (ST14521). mcr-1 was located on IncI2 (n = 9), IncX4 (n = 2), and IncHI2 (n = 2) plasmids, which were highly similar to other mcr-1-carrying plasmids sharing the same incompatibility type. Seven mcr-1-carrying plasmids could be successfully conjugally transferred to E. coli C600. CONCLUSIONS: While the low prevalence of mcr-1 (0.93%) identified in this study may not immediately seem alarming, the very emergence of this gene merits attention given its implications for colistin resistance and public health. Hence, ongoing surveillance of mcr-1 in E. coli remains crucial.

Both arthroscopic one-step Broström-Gould and Lasso-loop stitch techniques achieved favourable clinical outcomes for chronic lateral ankle instability.

PURPOSE: Both the arthroscopic Broström-Gould and Lasso-loop stitch techniques are commonly used to treat chronic lateral ankle instability (CLAI). The purpose of this study is to introduce an arthroscopic one-step outside-in Broström-Gould (AOBG) technique and compare the mid-term outcomes of the AOBG technique and Lasso-loop stitch technique. METHODS: All CLAI patients who underwent arthroscopic lateral ankle stabilization surgery in our department from 2018 to 2019 were retrospectively enrolled. The patients were divided into two groups according to the surgical methods employed: the AOBG technique (Group A) and the Lasso-loop technique (Group B). The visual analogue scale pain score, American Orthopaedic Foot and Ankle Society ankle hindfoot score, Tegner activity score and Karlsson-Peterson score were evaluated preoperatively and during the follow-up from June to December 2022. The surgical duration, return to sports, sprain recurrence and surgical complications were also recorded and compared. RESULTS: A total of 74 patients (Group A, n = 42; Group B, n = 32) were included in this study with a mean follow-up of 39 months. No statistically significant differences were observed in demographic parameters or follow-up time between the two groups. Postoperative clinical scores indicated a significant improvement (all with p < 0.001) with no significant difference between the two groups (not significant [n.s.]). There was no significant difference in the surgical duration (46.1 vs. 49.7 min, n.s.), return to sports (92.9% vs. 93.8%, n.s.), or sprain recurrence (4.8% vs. 6.3%, n.s.). Only two cases in Group A reported knot irritation (4.8% vs. 0, n.s.), and one case in Group A experienced local skin numbness (0 vs. 3.1%, n.s.), with no significant difference. CONCLUSION: Both the AOBG and Lasso-loop stitch techniques yielded comparable favourable mid-term outcomes and return to sports with a low rate of surgical complications. Both procedures could be feasible strategies for CLAI patients. LEVEL OF EVIDENCE: Level III.

Palladium-Catalyzed Deuteration of Arylketone Oxime Ethers.

We report herein the development of palladium-catalyzed deacylative deuteration of arylketone oxime ethers. This protocol features excellent functional group tolerance, heterocyclic compatibility, and high deuterium incorporation levels. Regioselective deuteration of some biologically important drugs and natural products are showcased via Friedel-Crafts acylation and subsequent deacylative deuteration. Vicinal meta-C-H bond functionalization (including fluorination, arylation, and alkylation) and para-C-H bond deuteration of electro-rich arenes are realized by using the ketone as both directing group and leaving group, which is distinct from aryl halide in conventional dehalogenative deuteration.

Formation of photonic band gaps by direct destructive interference.

We study a photonic band gap (PBG) material consisting of multiple waveguides. The multiconnected waveguides provide different paths for direct wave interference within the material. Using coaxial cables as waveguides, we are able to tune the PBG of the material. Using direct destructive interference between different paths of the waveguides, we experimentally observe a kind of PBG which is quite different from the traditional PBG that is caused by scattering in dielectrics with inhomogeneous refractive indices. Particularly, this newly observed PBG has an extremely strong wave attenuation, making electromagnetic (EM) waves in the PBG cannot even pass through one unit cell under certain conditions. We also systematically investigate the transmission of EM waves in our PBG materials and discuss the mechanism of band gap formation. Our results provide a new insight to develop new band gap materials for photons and phonons.

miR-132 Regulates PTSD-like Behaviors in Rats Following Single-Prolonged Stress Through Fragile X-Related Protein 1.

Fragile X-related protein 1 (FXR1) is a member of the fragile X family of RNA-binding proteins, which regulates a number of neurological and neuropsychiatric disorders such as fragile X syndrome, and is expected as a novel therapeutic target for some psychiatric diseases. However, it is unknown how FXR1 changes and functions in post-traumatic stress disorder (PTSD), a common mental disorder related to trauma and stressor. In this study, we characterized the expression pattern of FXR1 in the pathophysiological process of PTSD and further investigated the possible mechanism underlying these changes by finding an upstream regulator, namely miRNA-132 (miR-132). Furthermore, we verified whether miR-132 silence had an effect on the PTSD-like behaviors of single prolonged stress (SPS) rats through open field test, forced swimming test, and water maze test. At last, we examined the expression levels of PSD95 and synapsin I in the hippocampus, which was one of the key brain regions associated with PTSD. We showed that the levels of FXR1 and fragile X mental retardation protein (FMRP), an autosomal homolog of FXR1, were decreased in the hippocampus of PTSD rats, but the levels of PSD95 and synapsin I were increased, which could be reversed by downregulation of miR-132. The results revealed that miR-132 could modulate PTSD-like behaviors in rats following SPS through regulating FXR1 and FMRP.

Continuous focus on COVID-19 epidemic: Changes in China's clinical guidance.

BACKGROUNDS: The epidemic of coronavirus disease 2019 (COVID-19) is spreading across the world. As the first country who suffered from the outbreak, China has been taking strict and effective measures to contain the epidemic and treat the disease under the instruction of updating guidance. AIMS: To compare the changes and updates in China's clinical guidance for COVID-19. METHODS: We explored China's experience in dealing with the epidemic by longitudinal comparison of China's clinical guidance for COVID-19. RESULTS: As of March 4, there are 7 editions of the guidance. With the increasing understanding of COVID-19, changes have been made in aetiology, epidemiology, pathology, clinical features, diagnostic criteria, clinical classification, and treatment. CONCLUSIONS: We have made a summary of the changes and updates in China's clinical guidance for COVID-19, which mirrors the deepening understanding of the disease over the course of fighting it, hoping to help clinicians worldwide.

[Analysis of spectrum-activity relationship among antioxidant parts of Lycii Fructus using three different chemometrics methods].

The chemical components of Lycii Fructus were analyzed by liquid chromatography( LC) and mass spectrometry( MS for the establishment of spectrum-activity relationship,on the basis of which its antioxidant active ingredients were determined. In this experiment,Lycii Fructus was extracted with different solvents and then separated into 80 samples by macroporous adsorption resin and reversed-phase chromatography,respectively. The antioxidant components were enriched into 11 samples and their scavenging abilities against DPPH free radical and ferric ion reducing antioxidant power( FRAP) were significantly stronger than those before the treatment( P<0. 05). The spectrum-activity relationship regarding the antioxidant activity in vitro of Lycii Fructus was established by Pearson correlation analysis,orthogonal partial least squares( OPLS) and elastic net regression. Six chromatographic peaks greatly contributing to the antioxidant activity in vitro of Lycii Fructus were identified as rutin( P6),quercetin( P35),scopoletin( P14),N-cis-feruloyl-4-O-ß-D-glucopyranosyl-tyramine or N-( 4-O-ß-D-glucopyranosyl-trans-feruloyl)-tyramine( P8), ferulic acid( P13) and1,3,5-dihydroxy-2-isoprenyl-3-xanthone( P23). The active components associated with free radical scavenging were rutin and quercetin both belonging to flavonoids. The reduction of Fe3+was based on phenylpropanoids such as ferulic acid,scopoletin,xanthone and phenolic amides. These results indicated that the antioxidant activity of Lycii Fructus was ascribed to the synergistic action of different products through different ways. Besides,the data analysis model should be chosen carefully for the establishment of spectrum-activity relationship,thus ensuring the reliability of results.

Genome-Wide Identification of Cassava Serine/Arginine-Rich Proteins: Insights into Alternative Splicing of Pre-mRNAs and Response to Abiotic Stress.

Serine/arginine-rich (SR) proteins have an essential role in the splicing of pre-messenger RNA (pre-mRNA) in eukaryote. Pre-mRNA with introns can be alternatively spliced to generate multiple transcripts, thereby increasing adaptation to the external stress conditions in planta. However, pre-mRNA of SR proteins can also be alternatively spliced in different plant tissues and in response to diverse stress treatments, indicating that SR proteins might be involved in regulating plant development and adaptation to environmental changes. We identified and named 18 SR proteins in cassava and systematically studied their splicing and transcriptional changes under tissue-specific and abiotic stress conditions. Fifteen out of 18 SR genes showed alternative splicing in the tissues. 45 transcripts were found from 18 SR genes under normal conditions, whereas 55 transcripts were identified, and 21 transcripts were alternate spliced in some SR genes under salt stress, suggesting that SR proteins might participate in the plant adaptation to salt stress. We then found that overexpression of MeSR34 in Arabidopsis enhanced the tolerance to salt stress through maintaining reactive oxygen species homeostasis and increasing the expression of calcineurin B-like proteins (CBL)-CBL-interacting protein kinases and osmotic stress-related genes. Therefore, our findings highlight the critical role of cassava SR proteins as regulators of RNA splicing and salt tolerance in planta.

Effects of lycopene on vascular remodeling through the LXR-PI3K-AKT signaling pathway in APP/PS1 mice.

Alzheimer's disease (AD) is the commonest neurodegenerative disease and, in recent years, studies have increasingly shown that vascular lesions are involved in the pathology of AD onset and progression. Many vascular changes precede the pathological changes and clinical symptoms of AD, and vascular lesions and AD have many common risk factors. Understanding the relationship between vascular factors and the pathological process of AD may help us to identify novel prevention and treatment strategies as well as delay disease progress. Previous studies have shown that lycopene has neuroprotective, antioxidant, and anticancer effects; however, the specific molecular mechanism mediating these effects remains unknown. In the present study, we found: 1) lycopene improved learning and memory in an AD mouse model; 2) lycopene inhibited amyloid plaque aggregation and neuroinflammation; and 3) lycopene induced LXR expression and activated the LXR-PI3K-AKT signaling pathway. Our findings suggest that promotion of neurogenesis and improvement of the functions of the neurovascular unit could be a novel direction for the development of AD therapies.

EpCAM inhibits differentiation of human liver progenitor cells into hepatocytes in vitro by activating Notch1 signaling.

In both normal turnover of the hepatic tissue and acute hepatic injury, the liver predominantly activates terminally differentiated hepatocytes to proliferate and repair. However, in chronic and severe chronic injury, this capacity fails, and liver progenitor cells (LPCs) can give rise to hepatocytes to restore both hepatic architecture and liver metabolic function. Although the promotion of LPC-to-hepatocyte differentiation to acquire a considerable number of functional hepatocytes could serve as a potentially new therapeutic option for patients with end-stage liver disease, its development first requires the identification of the molecular mechanisms driving this process. Here, we found that the epithelial cell adhesion molecule (EpCAM), a progenitor cell marker, regulates the differentiation of LPCs into hepatocytes through Notch1 signaling pathway. Western blotting (WB) revealed a consistent expression pattern of EpCAM and Notch1 during LPC-to-hepatocyte differentiation in vitro. Additionally, overexpression of EpCAM blocked LPC-to-hepatocyte differentiation, which was in consistent with the repressive role of Notch signaling during hepatic differentiation. WB and immunofluorescence data also showed that the upregulation of EpCAM expression increased the generation of Notch intracellular domain (N1ICD), indicating the promotion of Notch1 activity. Our results established the EpCAM-Notch1 signaling axis as an inhibitory mechanism preventing LPC-to-hepatocyte differentiation in vitro.

Mutation of HPR1 encoding a component of the THO/TREX complex reduces STOP1 accumulation and aluminium resistance in Arabidopsis thaliana.

C2H2-type zinc finger transcription factor sensitive to proton rhizotoxicity 1 (STOP1) plays an essential role in aluminium (Al) resistance in Arabidopsis thaliana by controlling the expression of a set of Al-resistance genes, including the malate transporter-encoding gene A. thaliana aluminium activated malate transporter 1 (AtALMT1) that is critically required for Al resistance. STOP1 is suggested to be modulated by Al at post-transcriptional and/or post-translational levels. However, the underlying molecular mechanisms remain to be demonstrated. We carried out a forward genetic screen on an ethyl methanesulphonate mutagenized population, which contains the AtALMT1 promoter-driven luciferase reporter gene (pAtALMT1:LUC), and identified hyperrecombination protein 1 (HPR1), which encodes a subunit of the THO/TREX complex. We investigate the effect of hpr1 mutations on the expression of Al-resistance genes and Al resistance, and we also examined the regulatory role of HPR1 in nuclear messenger RNA (mRNA) and protein accumulation of STOP1 gene. Mutation of HPR1 reduces the expression of STOP1-regulated genes and the associated Al resistance. The hpr1 mutations increase STOP1 mRNA retention in the nucleus and consequently decrease STOP1 protein abundance. Mutation of regulation of AtALMT1 expression 1 (RAE1) that mediates STOP1 degradation in the hpr1 mutant background can partially rescue the deficient phenotypes of hpr1 mutants. Our results demonstrate that HPR1 modulates Al resistance partly through the regulation of nucleocytoplasmic STOP1 mRNA export.

Betulin isolated from Pyrola incarnata Fisch. inhibited lipopolysaccharide (LPS)-induced neuroinflammation with the guidance of computer-aided drug design.

This study aims to investigate active phytochemicals isolated from Pyrola incarnata Fisch. (P. incarnata) and their protection against neuroinflammation induced by LPS. Betulin, accompanied with other 9 compounds, were isolated from P. incarnata and elucidated by spectroscopic analysis (1H-, 13C NMR). ELISA kits and the measurement of NO production based on Griess reaction showed that betulin (5) (250 µg/mL) could suppress LPS-induced activation of microglial cell BV-2 better than others by inhibiting inflammatory cytokines (TNF-α, IL-6, IL-1ß) expression and NO production. With the guidance of computer-aided drug design and the analysis of biological experiment, we demonstrated betulin could reduce LPS-induced iNOS expression, prevent JNKs pathways, and down-regulate the phosphorylation levels of NF-κB/p65. In conclusion, betulin isolated from P. incarnata possessed outstanding anti-neuroinflammation potential, presumably related to iNOS expression, JNKs and NF-κB/p65 pathways. Therefore, Pyrola incarnata may be a valuable natural resource and betulin is a potential drug for the treatment of neurodegenerative disorders by inhibiting inflammatory mediators.