Blocking miR528 function promotes tillering and regrowth in switchgrass.

MiRNAs have been reported to be the key regulators involving a wide range of biological processes in diverse plant species, but their functions in switchgrass, an important biofuel and forage crop, are largely unknown. Here, we reported the novel function of miR528, which has expanded to four copies in switchgrass, in controlling biomass trait of tillering number and regrowth rate after mowing. Blocking miR528 activity by expressing short tandem target mimic (STTM) increased tiller number and regrowth rate after mowing. The quadruple pvmir528 mutant lines derived from genome editing also showed such improved traits. Degradome and RNA-seq analysis, combined with in situ hybridization assay revealed that up-regulation of two miR528 targets coding for Cu/Zn-SOD enzymes, might be responsible for the improved traits of tillering and regrowth in pvmir528 mutant. Additionally, natural variations in the miR528-SOD interaction exist in C3 and C4 monocot species, implying the distinct regulatory strength of the miR528-SOD module during monocot evolution. Overall, our data illuminated a novel role of miR528 in controlling biomass traits and provided a new target for genetic manipulation-mediated crop improvement.

Design, Synthesis, and Bioactivities of Novel Tryptophan Derivatives Containing 2,5-Diketopiperazine and Acyl Hydrazine Moieties.

Based on the scaffolds widely used in drug design, a series of novel tryptophan derivatives containing 2,5-diketopiperazine and acyl hydrazine moieties have been designed, synthesized, characterized, and evaluated for their biological activities. The bioassay results showed that the target compounds possessed moderate to good antiviral activities against tobacco mosaic virus (TMV), among which compounds 4, 9, 14, 19, and 24 showed higher inactivation, curative, and protection activities in vivo than that of ribavirin (39 ± 1, 37 ± 1, 39 ± 1 at 500 mg/L) and comparable to that of ningnanmycin (58 ± 1, 55 ± 1, 57 ± 1% at 500 mg/L). Thus, these compounds are a promising candidate for anti-TMV development. Most of these compounds showed broad-spectrum fungicidal activities against 13 kinds of phytopathogenic fungi and selective fungicidal activities against Alternaria solani, Phytophthora capsica, and Sclerotinia sclerotiorum. Additionally, some of these compounds exhibited larvicidal activities against Tetranychus cinnabarinus, Plutella xylostella, Culex pipiens pallens, Mythimna separata, Helicoverpa armigera, and Pyrausta nubilalis.

Design, Synthesis, and Bioactivity Study of Novel Tryptophan Derivatives Containing Azepine and Acylhydrazone Moieties.

Based on the scaffolds widely used in drug design, a series of novel tryptophan derivatives containing azepine and acylhydrazone moieties have been designed, synthesized, characterized, and evaluated for their biological activities. The bioassay results showed that the target compounds possessed moderate to good antiviral activities against the tobacco mosaic virus (TMV), among which compounds 5c, 6a, 6h, 6t, 6v, and 6y exhibited higher inactivation, curative, and protection activities in vivo than that of ribavirin (40 ± 1, 37 ± 1, 39 ± 2% at 500 mg/L). Especially, 6y showed comparable activities to that of ningnanmycin (57 ± 2, 55 ± 3, 58 ± 1% at 500 mg/L). Meanwhile, we were pleased to find that almost all these derivatives showed good larvicidal activities against Plutella xylostella. Meanwhile, these derivatives also showed a broad spectrum of fungicidal activities.

Personalized decision support system for tailoring IgA nephropathy treatment strategies.

BACKGROUND: The ongoing debate surrounding the use of immunosuppressive treatments for IgA nephropathy (IgAN) underscores the demand for personalized and effective strategies. METHODS: Analyzed data from 807 IgAN patients over 5+ years using three methods: Random Forest with molecular biomarkers, network biomarkers with graph engineering, and an auto-encoder model. All models were trained using identical demographic, clinical, and pathological data, employing an 80-20 split for training and testing purposes. RESULTS: In the comprehensive assessment of IgAN prognosis, the Random Forest model, employing molecular biomarkers, demonstrated strong performance metrics (AUC = 0.83, sensitivity = 0.51, specificity = 0.96). However, traditional graph feature engineering on patient-specific networks outperformed these results with an AUC of 0.90, sensitivity of 0.64, and specificity of 0.94. The Auto-encoder model showed the best accuracy (AUC = 0.91, sensitivity = 0.46, specificity = 0.96). The findings highlighted the superior predictive capabilities of network biomarkers over molecular biomarkers for adverse renal outcome prediction in IgAN. Consequently, we integrated Auto-encoder-derived Network Biomarkers with Random Forest Models to enhance prognostic precision in diverse IgAN treatment scenarios. The prediction for the prognosis of patients receiving supportive care, glucocorticoid therapy, and immunosuppressant treatment yielded AUC values of 0.95, 0.96, and 1, respectively, indicating high specificity. Drawing from these insights, we pioneered the development of an innovative decision support model for IgAN treatment. This model demonstrated the ability to make medical decisions comparable to those by experienced nephrologists, enabling the customization of personalized disease management strategies. CONCLUSION: Our system accurately predicted IgAN prognosis and evaluated various treatment efficacies, aiding physicians in devising optimal therapeutic strategies for patients.

Recent advances in combining photo- and N-heterocyclic carbene catalysis.

N-Heterocyclic carbenes (NHCs) are unique Lewis basic catalysts that mediate various organic transformations by means of polarity reversal. Although the scope of research on two-electron reactions mediated by NHC catalysts has been expanding, the types of these reactions are limited by the inability of NHCs to engage sp3-electrophiles. However, the revival of photocatalysis has accelerated the development of free-radical chemistry, and combining photoredox catalysis and NHC catalysis to achieve NHC-mediated radical reactions under mild conditions could overcome the above-mentioned limitation. This review summarizes recent advances in combining photoredox and NHC catalysis, focusing on elucidation and exploration of mechanisms, with the aim of identifying challenges and opportunities to develop more types of catalytic models.

Direct allylic acylation via cross-coupling involving cooperative N­heterocyclic carbene, hydrogen atom transfer, and photoredox catalysis.

Herein, we report a mild, operationally simple, multicatalytic method for the synthesis of ß,γ-unsaturated ketones via allylic acylation of alkenes. Specifically, the method combines N­heterocyclic carbene catalysis, hydrogen atom transfer catalysis, and photoredox catalysis for cross-coupling reactions between a wide range of feedstock carboxylic acids and readily available olefins to afford structurally diverse ß,γ-unsaturated ketones without olefin transposition. The method could be used to install acyl groups on highly functionalized natural-product-derived compounds with no need for substrate pre-activation, and C-H functionalization proceed with excellent site selectivity. To demonstrate the potential applications of the method, we convert a representative coupling product into various useful olefin synthons.

Design, Synthesis, and Bioactivity of Aldisine Derivatives Containing Oxime and Hydrazine Moieties Based on Hydrogen Bonds.

Marine natural products have attracted more and more attention in drug research and development due to their unique structure, diverse biological activities, and novel mode of action. Using antiviral alkaloid aldisine as the lead compound and drawing on the hydrogen bond effect widely used in drug design, derivatives containing oxime and hydrazone moieties were designed and synthesized by introducing functional groups with hydrogen-bond receptors or donors into molecules. The configuration of derivatives was systematically studied through nuclear Overhauser effect (NOE) spectroscopy and single crystal analysis. The antiviral activity test result showed that most derivatives had antiviral activity against tobacco mosaic virus (TMV), and some compounds had better activity than the commercial antiviral drug ribavirin, especially compounds 2 and 24, which had comparable activity to the most effective commercial antiviral drug ningnanmycin. Preliminary mode of action studies showed that compound 2 could affect the assembly of rod-shaped TMVs by promoting the aggregation and fragmentation of TMV coat proteins. Molecular docking experiments demonstrated that the introduction of oxime and hydrazone moieties could indeed increase the hydrogen bond between molecules and target proteins. In addition, we conducted fungicidal and larvicidal activities study of these derivatives. Most of these derivatives had good larvicidal activities against Mythimna separata and Plutella xylostella and showed broad-spectrum fungicidal activities.

The long non-coding RNA DANA2 positively regulates drought tolerance by recruiting ERF84 to promote JMJ29-mediated histone demethylation.

Tens of thousands of long non-coding RNAs have been uncovered in plants, but few of them have been comprehensively studied for their biological function and molecular mechanism of their mode of action. Here, we show that the Arabidopsis long non-coding RNA DANA2 interacts with an AP2/ERF transcription factor ERF84 in the cell nucleus and then affects the transcription of JMJ29 that encodes a Jumonji C domain-containing histone H3K9 demethylase. Both RNA sequencing (RNA-seq) and genetic analyses demonstrate that DANA2 positively regulates drought stress responses through JMJ29. JMJ29 positively regulates the expression of ERF15 and GOLS2 by modulation of H3K9me2 demethylation. Accordingly, mutation of JMJ29 causes decreased ERF15 and GOLS2 expression, resulting in impaired drought tolerance, in agreement with drought-sensitive phenotypes of dana2 and erf84 mutants. Taken together, these results demonstrate that DANA2 is a positive regulator of drought response and works jointly with the transcriptional activator ERF84 to modulate JMJ29 expression in plant response to drought.

Discovery of Aldisine and Its Derivatives as Novel Antiviral, Larvicidal, and Antiphytopathogenic-Fungus Agents.

Based on the widespread use of hydrogen bonds in drug design, a series of aldisine derivatives containing oxime, oxime ether, and hydrazone moieties were designed and synthesized, and their antiviral, larvicidal, and fungicidal activities were evaluated for the first time. The bioassay results showed that most of these derivatives were active against tobacco mosaic virus (TMV). Hydrazone derivative 12 showed in vivo inactivation, curative, and protection activities of 52 ± 4, 49 ± 1, and 52 ± 3% at 500 mg/L, which are comparable to that of the commercial antiviral drug ningnanmycin (57 ± 3, 56 ± 2, and 59 ± 1%, respectively) at the same dose. The antiviral mechanism study showed that compound 12 could cause 20S CP (coating protein) disk fusion and disintegration, thus affecting the assembly of virus particles. The result of molecular docking indicated that there were obvious hydrogen bonds between compound 12 and TMV CP. Most derivatives were active against larvae of lepidopteran pests, such as Mythimna separata, Pyrausta nubilalis, and Plutella xylostella. Some compounds also exhibited larvicidal activities against Culex pipiens; among them compounds 9 and 13 exhibited larvicidal activities of 0.81 and 1.54 mg/L (LC50), respectively. Moreover, most of the derivatives showed broad-spectrum fungicidal activities against 14 kinds of phytopathogenic fungi at 50 mg/L.

Regulation of AhFRO1, an Fe(III)-chelate reductase of peanut, during iron deficiency stress and intercropping with maize.

Iron deficiency-induced chlorosis in peanut during anthesis was alleviated when peanut was intercropped with maize in field and pot experiments. Iron acquisition of graminaceous plants is characterized by the synthesis and secretion of the iron-chelating phytosiderophores. Compared to the roots of monocropped maize, the roots of maize intercropped with peanut always secreted higher amounts of phytosiderophores during peanut anthesis. For non-graminaceous plants, reduction of ferric to ferrous iron on the root surface is the rate-limiting step for mobilizing iron from soil. The full-length cDNA, AhFRO1, which is encoding an Fe(III)-chelate reductase, was isolated from peanut. AhFRO1 expression in yeast conferred Fe(III)-chelate reductase activity to the cells. Consistent with its function in iron uptake, AhFRO1 was determined to be a membrane protein by transient expression analysis. AhFRO1 mRNA accumulated under iron deficiency conditions. During pre-anthesis, the Fe(III)-chelate reductase activity and the transcript levels of AhFRO1 were similar in monocropped and intercropped peanut. When the iron deficiency-induced chlorosis developed in the monocropped peanuts, both the Fe(III)-chelate reductase activity of peanut and the transcript levels of AhFRO1 were higher in intercropped than in monocropped peanuts, which is consistent with the secretion of phytosiderophores by maize roots. We conclude that AhFRO1 in peanut and phytosiderophores from maize co-operate to improve the iron nutrition of peanut when intercropped with maize.

Fine-Tuning of MiR528 Accumulation Modulates Flowering Time in Rice.

In plants, microRNA (miRNA) functions in the post-transcriptional repression of target mRNAs have been well explored. However, the mechanisms regulating the accumulation of miRNAs remain poorly understood. Here, we report that distinct mechanisms regulate accumulation of a monocot-specific miRNA, rice (Oryza sativa) miR528. At the transcriptional level, miR528 accumulated to higher levels in older plants than in young seedlings and exhibited aging-modulated gradual accumulation and diurnal rhythms in leaves; at the post-transcriptional level, aging also modulated miR528 levels by enhancing pri-miR528 alternative splicing. We found that miR528 promotes rice flowering under long-day conditions by targeting RED AND FAR-RED INSENSITIVE 2 (OsRFI2). Moreover, natural variations in the MIR528 promoter region caused differences in miR528 expression among rice varieties, which are correlated with their different binding affinities with the transcription factor OsSPL9 that activates the expression of miR528. Taken together, our findings reveal rice plants have evolved sophisticated modes fine-tuning miR528 levels and provide insight into the mechanisms that regulate MIRNA expression in plants.

Transcriptional Regulation of miR528 by OsSPL9 Orchestrates Antiviral Response in Rice.

Many microRNAs (miRNAs) are critical regulators of plant antiviral defense. However, little is known about how these miRNAs respond to virus invasion at the transcriptional level. We previously show that defense against Rice stripe virus (RSV) invasion entailed a reduction of miR528 accumulation in rice, alleviating miR528-mediated degradation of L-Ascorbate Oxidase (AO) mRNA and bolstering the antiviral activity of AO. Here we show that the miR528-AO defense module is regulated by the transcription factor SPL9. SPL9 displayed high-affinity binding to specific motifs within the promoter region of miR528 and activated the expression of miR528 gene in vivo. Loss-of-function mutations in SPL9 caused a significant reduction in miR528 accumulation but a substantial increase of AO mRNA, resulting in enhanced plant resistance to RSV. Conversely, transgenic overexpression of SPL9 stimulated the expression of miR528 gene, hence lowering the level of AO mRNA and compromising rice defense against RSV. Importantly, gain in RSV susceptibility did not occur when SPL9 was overexpressed in mir528 loss-of-function mutants, or in transgenic rice expressing a miR528-resistant AO. Taken together, the finding of SPL9-mediated transcriptional activation of miR528 expression adds a new regulatory layer to the miR528-AO antiviral defense pathway.

Identification of crucial genes associated with rat traumatic spinal cord injury.

The aim of the present study was to investigate the key genes associated with traumatic spinal cord injuries (TSCI). The dataset GSE52763 was downloaded from the Gene Expression Omnibus, for which lumbar spinal cord samples were obtained from rats at 1 and 3 weeks following contusive spinal cord injury and 1 week subsequent to a sham laminectomy, and used to identify differentially expressed genes (DEGs). Functional enrichment analysis, co­expression analysis and transcription factor (TF) identification were performed for DEGs common to the 1 and 3 week injury samples. In total, 234 upregulated and 51 downregulated DEGs were common to the 1 and 3 week injury samples. The upregulated DEGs were significantly enriched in Gene Ontology terms concerning immunity (e.g. Itgal and Ccl2) and certain pathways, including natural killer cell mediated cytotoxicity [e.g. Ras­related C3 botulinum toxin substrate 2 (Rac2) and TYRO protein tyrosine kinase binding protein (Tyrobp)]. The downregulated DEGs were highly enriched in female gonad development [e.g. progesterone receptor (Pgr)], and the steroid biosynthesis pathway. A total of 139 genes had co­expression associations and the majority of them were upregulated genes. The upregulated co­expressed genes were predominantly enriched in biological regulation, including TGFB induced factor homeobox 1 (Tgif1) and Rac2. The downregulated co­expressed genes were enriched in anatomical structure development (e.g. Dnm3). A total of 92 co­expressed genes composed the protein­protein interaction network. Additionally, 9 TFs (e.g. Pgr and Tgif1) were identified from the DEGs. It was hypothesized that the genes including Tgif1, Rac2, Tyrobp, and Pgr may be closely associated with TSCI.

ROS accumulation and antiviral defence control by microRNA528 in rice.

MicroRNAs (miRNAs) are key regulators of plant-pathogen interactions. Modulating miRNA function has emerged as a new strategy to produce virus resistance traits1-5. However, the miRNAs involved in antiviral defence and the underlying mechanisms remain largely elusive. We previously demonstrated that sequestration by Argonaute (AGO) proteins plays an important role in regulating miRNA function in antiviral defence pathways6. Here we reveal that cleavage-defective AGO18 complexes sequester microRNA528 (miR528) upon viral infection. We show that miR528 negatively regulates viral resistance in rice by cleaving L-ascorbate oxidase (AO) messenger RNA, thereby reducing AO-mediated accumulation of reactive oxygen species. Upon viral infection, miR528 becomes preferentially associated with AGO18, leading to elevated AO activity, higher basal reactive oxygen species accumulation and enhanced antiviral defence. Our findings reveal a mechanism in which antiviral defence is boosted through suppression of an miRNA that negatively regulates viral resistance. This mechanism could be manipulated to engineer virus-resistant crop plants.