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Premixed hydrogen-air explosion experiments were carried out in a 1000 mm × 50 mm × 10 mm half-open narrow channel, concerning with the influences of equivalence ratio and ignition position on explosion behaviors. Experimental phenomena were different from explosion in large space. The results indicated that when ignited at the closed end of the channel, three overpressure peaks appeared, caused by the rupture of the film, Helmholtz Oscillation, and the flame-acoustic interaction, respectively. As the equivalence ratio of the hydrogen-air mixtures varied from 0.6 to 1.6, the peak overpressure first increased and then decreased. The maximum peak overpressure occurred at ϕ = 1.2. The hydrogen flame would develop into the plane tulip structure without the influence of the end wall. With the ignition position moved to the open end, overpressure wave and flame oscillated significantly. Compared with other ignition positions, the minimum value of

Decline in mitochondrial function underlies aging and age-related diseases, but the role of mitochondrial DNA (mtDNA) mutations in these processes remains elusive. To investigate patterns of mtDNA mutations, it is particularly important to quantify mtDNA mutations and their associated pathogenic effects at the single-cell level. However, existing single-cell mtDNA sequencing approaches remain inefficient due to high cost and low mtDNA on-target rates. In this study, we developed a cost-effective mtDNA targeted-sequencing protocol called single-cell sequencing by targeted amplification of multiplex probes (scSTAMP) and experimentally validated its reliability. We then applied our method to assess single-cell mtDNA mutations in 768 B lymphocytes and 768 monocytes from a 76-y-old female. Across 632 B lymphocyte and 617 monocytes with medium mtDNA coverage over >100×, our results indicated that over 50% of cells carried at least one mtDNA mutation with variant allele frequencies (VAFs) over 20%, and that cells carried an average of 0.658 and 0.712 such mutation for B lymphocytes and monocytes, respectively. Surprisingly, more than 20% of the observed mutations had VAFs of over 90% in either cell population. In addition, over 60% of the mutations were in protein-coding genes, of which over 70% were nonsynonymous, and more than 50% of the nonsynonymous mutations were predicted to be highly pathogenic. Interestingly, about 80% of the observed mutations were singletons in the respective cell populations. Our results revealed mtDNA mutations with functional significance might be prevalent at advanced age, calling further investigation on age-related mtDNA mutation dynamics at the single-cell level.

Brassinosteroids (BRs) are widely used class of natural steroidal plant hormones. BRs take part in the regulation of growth and development of plants, maintaining BRs homeostasis, and allowing adaptation to environmental changes through the life cycle. They also play an important role in abiotic stress responses such as drought, salinity, high temperature, low temperature and heavy metal stresses. Through the signal transduction pathway, BRs interact with a variety of transcription factors via a series of phosphorylation cascades to regulate the expression of BR target genes. Thus, they regulate the various growth and development processes of plants. BRs crosstalk with different hormones to regulate plant physiology and development. This review primarily introduces the signaling pathways of BRs, their role in regulating plant growth and development, abiotic stresses, and their interaction with other plant hormones at the transcriptional and post-transcriptional levels. Our review of this topic will provide a complete reference for the study and utilization of BRs in the future.

Cytokinins are a class of phytohormone that participate in the regulation of the plant growth, development, and stress response. In this review, the potential regulating mechanism during plant growth and stress response are discussed. Cytokinins are a class of phytohormone that participate in the regulation of plant growth, physiological activities, and yield. Cytokinins also play a key role in response to abiotic stresses, such as drought, salt and high or low temperature. Through the signal transduction pathway, cytokinins interact with various transcription factors via a series of phosphorylation cascades to regulate cytokinin-target gene expression. In this review, we systematically summarize the biosynthesis and metabolism of cytokinins, cytokinin signaling, and associated gene regulation, and highlight the function of cytokinins during plant development and resistance to abiotic stress. We also focus on the importance of crosstalk between cytokinins and other classes of phytohormones, including auxin, ethylene, strigolactone, and gibberellin. Our aim is to provide a comprehensive overview of recent findings on the mechanisms by which cytokinins act as central regulators of plant development and stress reactions, and highlight topics for future research.

N6-methyladenosine (m6A) is the most common type of eukaryotic mRNA modification. It plays an important role in regulating plant growth and development and stress resistance. m6A modification influences nearly all aspects of RNA metabolism and functionality and has great potential for improving crop quality. However, changing m6A modification levels as a whole may have unpredictable effects, making it impossible to accurately predict the effect of specific m6A modifications on RNA. In this opinion article, the main challenges and possible solutions for exploring m6A modification functions in plant systems are discussed. An m6A editing platform that uses new high-throughput methods to identify m6A modification at single-base resolution, and genome editing for selective editing of specific m6A sites for crop improvement is proposed.

Maize (Zea mays) is an important food and forage crop, as well as an industrial raw material, that plays important roles in agriculture and national economies. Drought stress has negative effects on seed germination and seedling growth, and it decreases crop production. In this study, we selected two maize inbred lines with different drought-tolerance levels: drought-tolerant 287M and drought-sensitive 753F. The physiological results showed that drought stress resulted in a large accumulation of reactive oxygen species (ROS) in maize root cells. However, in 287M, the activity levels of the ROS scavenging enzymes superoxide dismutase and ascorbate peroxidase also increased, resulting in a higher ROS scavenging ability than 753F. We used Illumina RNA sequencing to obtain the gene expression profiles of the two maize inbred lines at the seedling stage in response to drought stress. The transcriptome data were analyzed to reveal the mechanisms underlying the drought tolerance of 287M at the gene regulatory level. The differences in drought tolerance between 287M and 753F may be associated with different ROS scavenging capabilities, signal interaction networks, and some transcription factors. Our results will aid in understanding the molecular mechanisms involved in plant responses to drought stress.

Sweet sorghum has strong stress resistance and is considered a promising energy crop. In the present study, the effects of salt on the membrane lipid metabolism of two sweet sorghum inbred lines (salt-tolerant M-81E and salt-sensitive Roma) were analyzed. After treatment with 150 mM NaCl, higher levels of fresh weight and chlorophyll fluorescence, as well as lower levels of malondialdehyde (MDA) were found in salt-tolerant M-81E. Concomitantly, 702 and 1339 differentially expression genes (DEGs) in M-81E and Roma were identified in response to salt stress. We determined that most DEGs were related to glycerophospholipid metabolism, glycerolipid metabolism, and other membrane lipid metabolisms. Under NaCl treatment, the expression of the membrane-associated phospholipase A1 was down-regulated at the transcriptional level, along with an increased content of phosphatidylcholine (PC) in both cultivars. The inhibition of triacylglycerol (TAG) mobilization in M-81E delayed salt-induced leaf senescence. Furthermore, enhanced levels of glycerol-3-phosphate acyltransferase (GPAT) expression contributed to improved salt resistance in M-81E. The results of this study demonstrate membrane the role of lipid regulation in mediating salt-defensive responses in sweet sorghum and expand our understanding of the relationship between changes in membrane lipid content and salt resistance.

SbWRKY55 functions as a key component of the ABA-mediated signaling pathway; transgenic sorghum regulates plant responses to saline environments and will help save arable land and ensure food security. Salt tolerance in plants is triggered by various environmental stress factors and endogenous hormonal signals. Numerous studies have shown that WRKY transcription factors are involved in regulating plant salt tolerance. However, the underlying mechanism for WRKY transcription factors regulated salt stress response and signal transduction pathways remains largely unknown. In this study, the SbWRKY55 transcription factor was found to be the key component for reduced levels of salt and abscisic acid in SbWRKY55 overexpression significantly reduced salt tolerance in sorghum and Arabidopsis. Mutation of the homologous gene AtWRKY55 in A. thaliana significantly enhanced salt tolerance, and SbWRKY55 supplementation in the mutants restored salt tolerance. In the transgenic sorghum with SbWRKY55 overexpression, the expression levels of genes involved in the abscisic acid (ABA) pathway were altered, and the endogenous ABA content decreased. Yeast one-hybrid assays and dual-luciferase reporter assay showed that SbWRKY55 binds directly to the promoter of SbBGLU22 and inhibits its expression level. In addition, both in vivo and in vitro biochemical analyses showed that SbWRKY55 interacts with the FYVE zinc finger protein SbFYVE1, blocking the ABA signaling pathway. This could be an important feedback regulatory pathway to balance the SbWRKY55-mediated salt stress response. In summary, the results of this study provide convincing evidence that SbWRKY55 functions as a key component in the ABA-mediated signaling pathway, highlighting the dual role of SbWRKY55 in ABA signaling. This study also showed that SbWRKY55 could negatively regulate salt tolerance in sorghum.

The molecular mechanism of the maintenance and differentiation of plant stem cells is an eternal theme in studies on plant growth and development. Recent advances in single-cell RNA sequencing (scRNA-seq) methods have completely changed the understanding of cell heterogeneity and cell function, allowing research precision to identify the differentiation trajectory of stem cells maintained and differentiated at the cellular level. This review aimed to mainly discuss the novel insights provided by scRNA-seq for the maintenance and initiation of plant stem cells, cell differentiation, cell response to environmental changes, and improvement strategies for scRNA-seq. In addition, it highlighted additional perspectives beyond scRNA-seq, such as spatial transcriptomes, epigenomes, and single-cell multiomics, for a renewed understanding of stem cell maintenance and cell differentiation, thus providing potential targets and theoretical foundations for crop improvement.

Introduction: bHLH family proteins play an important role in plant stress response. However, the molecular mechanism regulating salt response of bHLH is largely unknown.Materials and Methods: Here, we investigated the function and regulating mechanism of the sweet sorghum SbbHLH85 during salt stress. Results: Results show that SbbHLH85, different from its homologs in other species, is a new atypical bHLH transcription factor and is a key gene for root development in sweet sorghum. Knockout of SbbHLH85 in sorghum by CRISPR-Cas9 results in the inhibition of root development. Overexpression of SbbHLH85 resulted in significantly increased number and length of root hairs by participating in ABA and auxin signaling pathways, which can increase the absorption of Na+. While SbbHLH85 plays a negative regulatory role in salt tolerance of sorghum. Through screening yeast two-hybrid library, we identified a potential interaction partner of SbbHLH85 that is phosphate transporter chaperone PHF1, which modulates the distribution of phosphate. Both yeast two-hybrid and BiFC experiments confirmed interaction between SbbHLH85 and PHF1. Discussion: Based on these results, we suggest that the increase of Na+ content and the decrease of Pi content result in the salt sensitivity of transgenic sorghum.

bHLH family proteins play an important role in plant stress response. However, the molecular mechanism regulating the salt response of bHLH is largely unknown. This study aimed to investigate the function and regulating mechanism of the sweet sorghum SbbHLH85 during salt stress. The results showed that SbbHLH85 was different from its homologs in other species. Also, it was a new atypical bHLH transcription factor and a key gene for root development in sweet sorghum. The overexpression of SbbHLH85 resulted in significantly increased number and length of root hairs via ABA and auxin signaling pathways, increasing the absorption of Na+. Thus, SbbHLH85 plays a negative regulatory role in the salt tolerance of sorghum. We identified a potential interaction partner of SbbHLH85, which was phosphate transporter chaperone PHF1 and modulated the distribution of phosphate, through screening a yeast two-hybrid library. Both yeast two-hybrid and BiFC experiments confirmed the interaction between SbbHLH85 and PHF1. The overexpression of SbbHLH85 led to a decrease in the expression of PHF1 as well as the content of Pi. Based on these results, we suggested that the increase in the Na+ content and the decrease in the Pi content resulted in the salt sensitivity of transgenic sorghum.

The N6-methyladenosine (m6A) modification is the most common internal post-transcriptional modification, with important regulatory effects on RNA export, splicing, stability, and translation. Studies on the m6A modifications in plants have focused on Arabidopsis thaliana growth and development. However, A. thaliana is a salt-sensitive and model plant species. Thus, studies aimed at characterizing the role of the m6A modification in the salt stress responses of highly salt-tolerant crop species are needed. Sweet sorghum is cultivated as an energy and forage crop, which is highly suitable for growth on saline-alkaline land. Exploring the m6A modification in sweet sorghum may be important for elucidating the salt-resistance mechanism of crops. In this study, we mapped the m6A modifications in two sorghum genotypes (salt-tolerant M-81E and salt-sensitive Roma) that differ regarding salt tolerance. The m6A modification in sweet sorghum under salt stress was drastically altered, especially in Roma, where the m6A modification on mRNAs of some salt-resistant related transcripts increased, resulting in enhanced mRNA stability, which in turn was involved in the regulation of salt tolerance in sweet sorghum. Although m6A modifications are important for regulating sweet sorghum salt tolerance, the regulatory activity is limited by the initial m6A modification level. Additionally, in M-81E and Roma, the differences in the m6A modifications were much greater than the differences in gene expression levels and are more sensitive. Our study suggests that the number and extent of m6A modifications on the transcripts of salt-resistance genes may be important factors for determining and assessing the salt tolerance of crops.

The complete mitochondrial DNA (mtDNA) of Japanese Spanish mackerel (Scomberomorus niphonius) was cloned and sequenced. The total length of the mitochondrial genome is 16,646 bp with an accession number KY228987. Thirty-seven genes are identified in total, including 13 protein-coding genes, 22 transfer RNA (tRNA) genes, 2 ribosomal RNA (rRNA) genes and a putative D-loop region. Among these genes, 9 are encoded on the light strand, while others are encoded on the heavy strand. The overall base composition of mitogenome is 28.39% for A, 16.14% for G, 26.52% for T, 28.96% for C, respectively, with a slight higher A + T content (54.91%). The phylogeny analysis based on 18 COI amino acid sequences suggested that S. niphonius and the other two species from Scomberomorus (Scombridae) formed a cluster apart from the one comprising other genus from Scombridae. The complete mitogenome may shed light on the future study of genetic mechanism of Scomberomorus niphonius.

The N

N6-methyladenosine (m6A) is the most common type of eukaryotic mRNA modification and has been found in many organisms, including mammals, and plants. It has important regulatory effects on RNA splicing, export, stability, and translation. The abundance of m6A on RNA depends on the dynamic regulation between methyltransferase ("writer") and demethylase ("eraser"), and m6A binding protein ("reader") exerts more specific regulatory function by binding m6A modification sites on RNA. Progress in research has revealed important functions of m6A modification in plants. In this review, we systematically summarize the latest advances in research on the composition and mechanism of action of the m6A system in plants. We emphasize the function of m6A modification on RNA fate, plant development, and stress resistance. Finally, we discuss the outstanding questions and opportunities exist for future research on m6A modification in plant.

Sweet sorghum is an annual C4 crop with a high salt tolerance. However, little is known about the molecular mechanisms of salt exclusion in roots of sweet sorghum. In this study, the physiological parameters and transcript profiles of two inbred lines of sweet sorghum roots (salt-tolerant M-81E and salt-sensitive Roma) were analyzed in the presence of 0 or 150 mM NaCl in order to elucidate the molecular mechanisms of salt exclusion. We found that the Na+ concentrations in both shoots and roots of M-81E were lower than that of Roma. Moreover, we identified 2085 and 3172 differentially expressed genes between control plants and those subjected to salt stress in M-81E and Roma strains, respectively. The differentially expressed genes involved in pathways related to salt exclusion such as formation of root casparian bands and suberin lamellae, membrane-bound ion translocating proteins. Many of these genes underwent greater change in M-81E compared to Roma. These results revealed that the better ability of salt exclusion in M-81E may be caused by the combination of physical barrier effect of root apoplastic barriers and the transportation of Na+ out of the xylem by HKT1;5. Moreover, some genes encoding transcription factors were also differentially expressed, which may be involved in the regulation of genes related to salt exclusion. This RNA-seq dataset provide comprehensive insights into the transcriptomic landscape to reveal molecular mechanisms of salt exclusion in roots of sweet sorghum.

LncRNAs can act as competitive endogenous RNAs (ceRNAs) to competitively bind miRNAs, thereby indirectly regulating the transcription levels of other RNA transcripts to confer resistance to plants. But how specific ceRNAs respond to salt stress in sweet sorghum is still unclear. In this study, 126 and 133 differentially expressed lncRNAs were identified in salt-tolerant sweet sorghum (M-81E) and a salt-sensitive line (Roma) by high-throughput RNA-seq, respectively. And five new lncRNAs were identified in M-81E and Roma after salt stress treatment, lncRNA13472, lncRNA11310, lncRNA2846, lncRNA26929 and lncRNA14798 acted as ceRNAs to regulate the expression of target genes related to salt resistance by binding the five miRNAs sbi-MIR169b-p3, sbi-MIR5567-p3-2ss16CT17TC, sbi-MIR5567-p5-2, sbi-MIR5567-p5-2ss17CT18TC and PC-3p-270284-34, respectively. The target genes mainly included proton pump proteins, transport proteinsantioxidants, signal transduction proteins and transcription factors. However M-81E had more complex ceRNAs network than in Roma, which might be related with its different salt tolerance. In summary, this study identified a new ceRNA network within the transcriptome and revealed the effect of lncRNAs in the salt stress response.

A range of AgI modified Bi24O31Br10 heterojunction microsheets were produced by a hydrothermal subsequent deposition-precipitation method for highly efficient photocatalytic removal of Hg0 under fluorescent light irradiation. Diverse characterization techniques such as XRD, BET, SEM, TEM, UV − vis DRS, XPS, PL, and ESR were implemented to investigate the properties of the as-fabricated materials. The experimental parameters such as AgI content, sample dosage, pH value of solution, reaction temperature, FSL illumination, inorganic anions, SO2 and NO were employed to evaluate the activity of the materials. It was found that the AgI material was successfully deposited on the surface of Bi24O31Br10 microsheets. In comparison, the dramatic enhancement photocatalytic performance of AgI-Bi24O31Br10 could be assigned to synergies of Bi24O31Br10 and AgI under fluorescent light irradiation, including effective electron-hole separations and generation of photocatalytic active substances at the interfaces of the two semiconductors. AgI loading, inorganic carbonate ion contents and SO2 gas all had significant influence on the removal of Hg0. The 2% AgI-Bi24O31Br10 sample was testified to exhibit an extraordinary enhanced photocatalytic activity. On the basis of the results of ESR detection and radical trapping experiments, reactive substances O2− and h+ were significant players in the photocatalytic reaction.

Over 160 RNA modifications have been identified, including N7-methylguanine (m7G), N6-methyladenosine (m6A), and 5-methylcytosine (m5C). These modifications play key roles in regulating the fate of RNA. In eukaryotes, m6A is the most abundant mRNA modification, accounting for over 80% of all RNA methylation modifications. Highly dynamic m6A modification may exert important effects on organismal reproduction and development. Significant advances in understanding the mechanism of m6A modification have been made using immunoprecipitation, chemical labeling, and site-directed mutagenesis, combined with next-generation sequencing. Single-molecule real-time and nanopore direct RNA sequencing (DRS) approaches provide additional ways to study RNA modifications at the cellular level. In this review, we explore the technical history of identifying m6A RNA modifications, emphasizing technological advances in detecting m6A modification. In particular, we discuss the challenge of generating accurate dynamic single-base resolution m6A maps and also strategies for improving detection specificity. Finally, we outline a roadmap for future research in this area, focusing on the application of RNA epigenetic modification, represented by m6A modification.

Additional file 3. Comparison of our NRS with four published studies.

CCCH-type zinc-finger proteins constitute a large family playing key roles during plant development and growth. In the present study, we investigated the involvement of the CCCH-type zinc finger protein of AtZFP1 (At2g25900) in flowering and salt stress response in Arabidopsis. Compared with the wild type (WT), bolting and flowering were delayed in AtZFP1-overexpressing plants. Real-time PCR analysis of floral regulating genes in overexpressing Arabidopsis revealed that enhanced expression of FLC decreased the expressions of FT and SOC1. The Fv/Fm of overexpressing Arabidopsis lines was unchanged under salt stress. In contrast, ΦPSII activity and PSI oxidoreduction decreased in WT, overexpressing and mutant strains under salt stress conditions, with the smallest reduction in these parameters observed in the overexpressing strains. These results suggest that the CCCH zinc-finger protein AtZFP1 primarily controls flowering time by changing the expression of flowering genes under long-day conditions. The overexpression of this protein delayed flowering and increased the content and double-bond index of unsaturated fatty acids. Elevation of unsaturated fatty acid content might play important role in protecting the photosynthetic apparatus and maintaining the membrane function at salt stress by alleviating PSII and PSI photoinhibition.

Long non-coding RNA (lncRNA) is a non-coding RNA greater than 200 nucleotides in length. LncRNAs can regulate gene expression at transcription and post-transcription, epigenetic level, and plays an important role in a wide range of biological processes such as genomic imprinting, chromatin remodeling, transcriptional activation, transcriptional interference and cell cycle. It becomes the current hot topics in the study of molecular biology and genetics. Emerging evidence proposed that lncRNAs play important roles in response to both abiotic and biotic stress. In this review, we discuss the role of lncRNAs in drought resistance, salt resistance, disease resistance, and immunity of plants, providing strong evidence for exploring the important role of lncRNAs in plant resistance, in order to explore new ideas and new targets for prevention and control.

Sweet sorghum is a C4 crop that shows high salt tolerance and high yield. NADP-malate dehydrogenase (NADP-ME) is a crucial enzyme of the C4 pathway. The regulatory mechanism of NADP-ME remains unclear. In this study, we isolated SbNADP-ME from sweet sorghum. The open reading frame of SbNADP-ME is 1911 bp and 637 amino acid residues. Quantitative real-time PCR analysis showed that SbNADP-ME transcription in sweet sorghum was enhanced by salt stress. The SbNADP-ME transcript level was highest under exposure to 150 mM NaCl. Arabidopsis overexpressing SbNADP-ME showed increased germination rate and root length under NaCl treatments. At the seedling stage, physiological photosynthesis parameters, chlorophyll content, PSII photochemical efficiency, and PSI oxidoreductive activity in the wild type decreased more severely than in the overexpression lines but less than in T-DNA insertion mutants under salt stress. Overexpression of SbNADP-ME in Arabidopsis may also increase osmotic adjustment and scavenging activi...

High-pressure water jet technology is an emerging type of welding joint strengthening process in recent years, which has unique advantages such as non-polluting, high efficiency, and can strengthen some complicated welds that in dead end position such as fillet welds. However, there is no supporting water jet strengthening nozzle domestically, so this paper uses the computational fluid dynamics method to simulate the internal and external flow fields of the nozzle, which is the most commonly used four conical convergence nozzles with different structure of the current water jet technology, making the flow field velocity distribution of the four nozzles and the impact pressure on the target surface compared and analysed. The results show that the impact pressure and axial speed of the conical short-line nozzle are slightly smaller than that of the conical (13°) nozzle, but conical short-line nozzle’s jet collection property and stability are superior to the other types of nozzles. Therefore, the conical short-line nozzle should be selected when the high-pressure water jet technology is utilized for welding joint reinforcement.

Genetic variants of mitochondrial DNA (mtDNA) were implicated to be associated with male infertility. Our previous whole mitochondrial genome sequencing and association study has identified two susceptibility mtDNA variants for oligoasthenospermia in Han Chinese men. In this study, we tested promising associations in an extended validation using 670 idiopathic oligoasthenospermia cases and 793 healthy controls to identify additional risk variants. We found that the genetic variant of m.11696G>A showed significantly higher frequency in the case group than that in the control group (odds ratio (OR) 2.21, 95% CI 1.21-4.04) (P=7.90×10−3). To elucidate the exact role of the genetic variants in spermatogenesis, two main sperm parameters (sperm count and motility) were taken into account. We found that m.11696G>A was associated with low sperm motility, with the OR of 2.38 (95 % CI 1.27-4.46) (P =5.22×10−3). These results advance our understanding of the genetic susceptibility to oligoasthenospermia and more functional studies are needed to provide insights into its pathogenic mechanism.

Rhodopsins are photoreceptive proteins with seven-transmembrane alpha-helices and a covalently bound retinal. Based on their protein sequences, rhodopsins can be classified into microbial rhodopsins and metazoan rhodopsins. Because there is no clearly detectable sequence identity between these two groups, their evolutionary relationship was difficult to decide. Through ancestral state inference, we found that microbial rhodopsins and metazoan rhodopsins are divergently related in their seven-transmembrane domains. Our result proposes that they are homologous proteins and metazoan rhodopsins originated from microbial rhodopsins. Structure alignment shows that microbial rhodopsins and metazoan rhodopsins share a remarkable structural homology while the position of retinal-binding lysine is different between them. It suggests that the function of photoreception was once lost during the evolution of rhodopsin genes. This result explains why there is no clearly detectable sequence similarity between the two rhodopsin groups: after losing the photoreception function, rhodopsin gene was freed from the functional constraint and the process of divergence could quickly change its original sequence beyond recognition.