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Sugarcane has recently attracted increasing attention for its potential as a source of sugar and bioethanol, so increasing its yield is essential to ensure the sugar security and bioenergy production. Intergeneric hybridization is a highly efficient method to produce new genetic variants of crop plants, particularly those species with high ploidy such as sugarcane (Saccharum spp.). Tripidium arundinaceum exhibits many desirable agronomic traits, and has been widely studied to produce hybrids with improved stress tolerance and other characteristics in sugarcane breeding. However, the genetic relationship between T. arundinaceum and Saccharum species, and the individual T. arundinaceum chromosomal compositions in sugarcane hybrids are still elusive. Here we used whole-genome single-nucleotide polymorphisms (SNPs) to ascertain the phylogenetic relationships between these species and found that T. arundinaceum is more closely related to Saccharum than Sorghum, in contrast to the previous narrow genetic analyses using chloroplast DNA. Additionally, oligonucleotide (oligo)-based chromosome-specific painting derived from Saccharum officinarum was able to distinctly identify the chromosomes of T. arundinaceum. We developed the oligo-genomic in situ hybridization (GISH) system for the first time, to unveil the novel chromosome translocations and the transmission of individual T. arundinaceum chromosomes in sugarcane progeny. Notably, we discovered that the chromosomal transmission of T. arundinaceum exhibited several different inheritance modes, including n, 2n, and over 2n in the BC1 progenies. Such inheritance patterns may have resulted from first division restitution (FDR) or FDR+nondisjunction of a chromosome with the sister chromatids in the second meiosis division/second division restitution (FDR+NSC/SDR) model during meiosis. These results will be of substantial benefit for the further selection of T. arundinaceum chromosomes for sugarcane genetic improvement.

MicroRNAs (miRNAs) play an essential regulatory role in plant-virus interaction. However, few studies have focused on the roles of miRNAs and their targets after sugarcane mosaic virus (SCMV) infection in sugarcane. To address this issue, we conducted small RNA (sRNA) and degradome sequencing on two contrasting sugarcanes (SCMV-resistant ‘Fuoguo1’ [FG1] and susceptible ‘Badila’) infected by SCMV at five time points. A total of 1,578 miRNAs were profiled from 30 sRNA libraries, comprising 660 known miRNAs and 380 novel miRNAs. Differential expression analysis of miRNAs revealed that most were highly expressed during the SCMV exponential phase in Badila at 18 h postinfection, with expression profiles positively correlated with virus replication dynamics as observed through clustering. Analysis of degradome data indicated a higher number of differential miRNA targets in Badila compared to FG1 at 18 h postinfection. Gene ontology (GO) enrichment analysis significantly enriched the stimulus-response pathway, suggesting negative regulatory roles to SCMV resistance. Specifically, miR160 upregulated expression patterns and validated in Badila through quantitative real-time PCR (qRT-PCR) in the early stages of SCMV multiplication. Our research provides new insights into the dynamic response of plant miRNA and virus replication and contributes valuable information on the intricate interplay between miRNAs and SCMV infection dynamics. [Graphic: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Abstract Background Guangxi is the leading sugarcane-producing area in China. Due to the Panama disease outbreak in banana gardens, sugarcane and banana rotation was recommended. A field experiment with the newly released sugarcane cultivar Zhongzhe 1 (ZZ1) was conducted to understand the role of the sugarcane–banana rotation system in shaping the rhizosphere microbiota. Fields in the region possess characteristics of red laterite soil. Results Using Illumina HiSeq sequencing to analyze soil samples’ 16S rRNA V3-V4 region, the preceding banana rotation field had relatively greater bacterial diversity than the monoculture sugarcane field. Proteobacteria, Chloroflexi, Actinobacteria, and Acidobacteria were the dominant phyla, with distinct taxa enriched in each environment. However, the preceding sugarcane monoculture field enriched functional groups related to nitrogen fixation and cellulolysis. Network analysis highlighted contrasting network structures between sugarcane and banana rhizospheres, suggesting differential stability and susceptibility to environmental influences. Furthermore, correlations between soil properties and bacterial alpha-diversity underscored the influence of preceding crops on rhizosphere microbial communities. Conclusion This research enhances our understanding of crop rotation effects on soil microbial ecology and provides insights into optimizing agricultural practices for enhanced soil health and crop productivity. Future studies should explore the underlying mechanisms driving these interactions and evaluate the long-term impacts of crop rotation on soil microbial dynamics. Graphical abstract

Abstract Leaf scald, caused by Xanthomonas albilineans, is a severe disease affecting sugarcane worldwide. One of the most practical ways to control it is by developing resistant sugarcane cultivars. It is essential to identify genes associated with the response to leaf scald. A panel of 170 sugarcane genotypes was evaluated for resistance to leaf scald in field conditions for 2 years, followed by a 1-year greenhouse experiment. The phenotypic evaluation data showed a wide continuous distribution, with heritability values ranging from 0.58 to 0.84. Thirteen single nucleotide polymorphisms (SNPs) were identified, significantly associated with leaf scald resistance. Among these, eight were stable across multiple environments and association models. The candidate genes identified and validated based on RNA-seq and qRT-PCR included two genes that encode NB-ARC leucine-rich repeat (LRR)-containing domain disease-resistance protein. These findings provide a basis for developing marker-assisted selection strategies in sugarcane breeding programs.

Isoorientin (Iso) is a natural flavonoid present in the human diet, known for its anti-inflammatory, antioxidant, and antiviral properties. The purpose of this research was to illustrate the anti-inflammatory potential of Iso in ulcerative colitis (UC) mice and elucidate potential mechanisms. The mice model of UC was induced by cyclic intervention with Dextran Sulfate Sodium (DSS). We evaluated the efficacy of Iso in the treatment of UC, detected the expression of proteins related to the Galectin-3/NLRP3/IL-1β signaling pathway, and assessed the intestinal mucosa barrier function of colon tissue. Our findings demonstrated that Iso could improve colon length, the index of colonic weight, pathological damage to the colon, and serum cytokine secretion of UC mice. Most importantly, Iso could competitively bind Galectin-3, inhibit the interaction of Galectin-3 with NLRP3 and the expression of Galectin-3, NLRP3, ASC, caspase-1, IL-1β, and IL-18, increase the expression of MUC2, Occludin, and ZO-1. In summary, Iso had a therapeutic effect on UC mice, and its mechanism may be to inhibit the inflammatory response and improve the intestinal mucosa barrier by binding Galectin-3 and inhibiting the Galectin-3/NLRP3/IL-1β signaling pathway.

Abstract Background Saccharum spontaneum L. is a closely related species of sugarcane and has become an important genetic component of modern sugarcane cultivars. Stem development is one of the important factors for affecting the yield, while the molecular mechanism of stem development remains poorly understanding in S. spontaneum. Phenylalanine ammonia-lyase (PAL) is a vital component of both primary and secondary metabolism, contributing significantly to plant growth, development and stress defense. However, the current knowledge about PAL genes in S. spontaneum is still limited. Thus, identification and characterization of the PAL genes by transcriptome analysis will provide a theoretical basis for further investigation of the function of PAL gene in sugarcane. Results In this study, 42 of PAL genes were identified, including 26 SsPAL genes from S. spontaneum, 8 ShPAL genes from sugarcane cultivar R570, and 8 SbPAL genes from sorghum. Phylogenetic analysis showed that SsPAL genes were divided into three groups, potentially influenced by long-term natural selection. Notably, 20 SsPAL genes were existed on chromosomes 4 and 5, indicating that they are highly conserved in S. spontaneum. This conservation is likely a result of the prevalence of whole-genome replications within this gene family. The upstream sequence of PAL genes were found to contain conserved cis-acting elements such as G-box and SP1, GT1-motif and CAT-box, which collectively regulate the growth and development of S. spontaneum. Furthermore, quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis showed that SsPAL genes of stem had a significantly upregulated than that of leaves, suggesting that they may promote the stem growth and development, particularly in the + 6 stem (The sixth cane stalk from the top to down) during the growth stage. Conclusions The results of this study revealed the molecular characteristics of SsPAL genes and indicated that they may play a vital role in stem growth and development of S. spontaneum. Altogether, our findings will promote the understanding of the molecular mechanism of S. spontaneum stem development, and also contribute to the sugarcane genetic improving.

Abstract Sugarcane is a vital crop with significant economic and industrial value. However, the cultivated sugarcane’s ultra-complex genome still needs to be resolved due to its high ploidy and extensive recombination between the two subgenomes. Here, we generate a chromosomal-scale, haplotype-resolved genome assembly for a hybrid sugarcane cultivar ZZ1. This assembly contains 10.4 Gb genomic sequences and 68,509 annotated genes with defined alleles in two sub-genomes distributed in 99 original and 15 recombined chromosomes. RNA-seq data analysis shows that sugar accumulation-associated gene families have been primarily expanded from the ZZSO subgenome. However, genes responding to pokkah boeng disease susceptibility have been derived dominantly from the ZZSS subgenome. The region harboring the possible smut resistance genes has expanded significantly. Among them, the expansion of WAK and FLS2 families is proposed to have occurred during the breeding of ZZ1. Our findings provide insights into the complex genome of hybrid sugarcane cultivars and pave the way for future genomics and molecular breeding studies in sugarcane.

Abstract Background Sugarcane (Saccharum spp.) is the core crop for sugar and bioethanol production over the world. A major problem in sugarcane production is stalk lodging due to weak mechanical strength. Rind penetrometer resistance (RPR) and breaking force are two kinds of regular parameters for mechanical strength characterization. However, due to the lack of efficient methods for determining RPR and breaking force in sugarcane, genetic approaches for improving these traits are generally limited. This study was designed to use near-infrared spectroscopy (NIRS) calibration assay to accurately assess mechanical strength on a high-throughput basis for the first time. Results Based on well-established laboratory measurements of sugarcane stalk internodes collected in the years 2019 and 2020, considerable variations in RPR and breaking force were observed in the stalk internodes. Following a standard NIRS calibration process, two online models were obtained with a high coefficient of determination (R 2 ) and the ratio of prediction to deviation (RPD) values during calibration, internal cross-validation, and external validation. Remarkably, the equation for RPR exhibited R 2 and RPD values as high as 0.997 and 17.70, as well as showing relatively low root mean square error values at 0.44 N mm−2 during global modeling, demonstrating excellent predictive performance. Conclusions This study delivered a successful attempt for rapid and precise prediction of rind penetrometer resistance and breaking force in sugarcane stalk by NIRS assay. These established models can be used to improve phenotyping jobs for sugarcane germplasm on a large scale.

Sugarcane smut, caused by the fungus Sporisorium scitamineum (Sydow), significantly affects sugarcane crops worldwide. Infected plants develop whip-like structures known as sori. Significant variations in these whip lengths are commonly observed, but the physiological and molecular differences causing these morphological differences remain poorly documented. To address this, we employed conventional microbe isolation, metagenomic, and metabolomic techniques to investigate smut-infected sugarcane stems and whips of varying lengths. Metagenomics analysis revealed a diverse fungal community in the sugarcane whips, with Sporisorium and Fusarium genera notably present (>1%) in long whips. Isolation techniques confirmed these findings. Ultra-performance liquid chromatography analysis (UHPLC-MS/MS) showed high levels of gibberellin hormones (GA3, GA1, GA4, GA8, and GA7) in long whips, with GA4 and GA7 found exclusively in long whips and stems. Among the prominent genera present within long whips, Fusarium was solely positively correlated with these gibberellin (GA) hormones, with the exception of GA8, which was positively correlated with Sporisorium. KEGG enrichment analysis linked these hormones to pathways like diterpenoid biosynthesis and plant hormone signal transduction. These findings suggest that Fusarium may influence GA production leading to whip elongation. Our study reveals fungal dynamics and gibberellin responses in sugarcane smut whips. Future research will explore the related molecular gibberellin synthesis mechanisms.

ABSTRACTSugarcane is a critical sugar and bioenergy crop in China. However, numerous factors, including root rot disease, hamper its yield. Root rot disease is a severe agricultural issue, reducing yield and threatening sustainable crop production. The current study aimed to explore the fungal community structure, identify and characterize the primary pathogen for sugarcane root rot in Guangzhou, China. Eighty-nine samples of sugarcane root, stalk, rhizosphere soil, and irrigation water were collected from five sites in Guangzhou, China. Subsequently, 276 fungal strains were isolated to identify the primary pathogens. The five most common genera identified were Penicillium, Fusarium, Gongronella, Trichoderma, and Cladosporium. Fusarium was more prevalent in the infected soil samples than in healthy ones. Pathogenic assays of the strains revealed that the strain GX4-46 caused 80% of the disease. The strain was confirmed as Fusarium commune through phylogenetic and genome sequence analysis. Rhizosphere soil samples from different regional crops were collected to better understand the fungal community structure and the primary pathogen. We observed a significant presence of Fusarium in irrigation water, indicating that the root rot disease could originate from the irrigation water and then spread as a soil-borne disease. This research is pioneering and one of the most comprehensive investigations on the occurrence and prevalence of sugarcane root rot disease. This study will serve as a reference for expanding the sugarcane industry and a foundation for further exploration and control of root rot.IMPORTANCESugarcane, a significant economic crop, faces challenges due to root rot pathogens that accumulate each year in plants and soil through ratoon planting. This disrupts soil microbial balance and greatly impedes sugarcane industry growth. Symptoms range from wilting and yellowing leaves to stunted growth and reduced seedling tillers. The rhizosphere microbiota plays an important role in plant development and soil health. Little is known about root rot fungal community structure, especially in sugarcane. Here, we focused on exploring the main causative pathogen of root rot in the area alongside a detailed survey of the rhizosphere soil of different severity sugarcane cultivars and rotation crops of the region. To validate the findings, we also investigated the irrigation water of the area. Our study revealed Fusarium commune as the causative pathogen of root rot in the area, primarily originating from water and later as soil-borne. Using Trichoderma can control the disease effectively.

The Augmented Transformer U-Net (AugTransU-Net) is proposed to address limitations in existing transformer-related U-Net models for brain tumor segmentation. While previous models effectively capture long-range dependencies and global context, these works ignore the hierarchy to a certain degree and need more feature diversity as depth increases. The proposed AugTransU-Net integrates two advanced transformer modules into different positions within a U-shaped architecture to overcome these issues. The fundamental innovation lies in constructing improved augmentation transformer modules that incorporate Augmented Shortcuts into standard transformer blocks. These augmented modules are strategically placed at the bottleneck of the segmentation network, forming multi-head self-attention blocks and circulant projections, aiming to maintain feature diversity and enhance feature interaction and diversity. Furthermore, paired attention modules operate from low to high layers throughout the network, establishing long-range relationships in both spatial and channel dimensions. This allows each layer to comprehend the overall brain tumor structure and capture semantic information at critical locations. Experimental results demonstrate the effectiveness and competitiveness of AugTransU-Net in comparison to representative works. The model achieves Dice values of 89.7%/89.8%, 78.2%/78.6%, and 80.4%/81.9% for whole tumor (WT), enhancing tumor (ET) and tumor core (TC) segmentation on the BraTS2019-2020 validation datasets, respectively. The code for AugTransU-Net will be made publicly available at https://github.com/MuqinZ/AugTransUnet.

ABSTRACT Fusarium sacchari is one of the primary pathogens causing pokkah boeng disease in sugarcane in China. Common fungal extracellular membrane (CFEM) domain-containing proteins only exist in fungi and play a significant role in the interaction of pathogens and plants. However, the CFEM proteins in F. sacchari were not identified and functionally resolved. Of the 20 FsCFEM proteins identified from the genome of F. sacchari, 16 FsCFEM genes were cloned, while 4 FsCFEM proteins (Fs06761, Fs08184, Fs10706, and Fs13617) were identified as effector proteins that could suppress the programmed cell death triggered by BCL2-associated X protein in Nicotiana benthamiana. Subcellular localization analysis revealed that these four effectors could enter plant cells and are mainly located in the cell membrane and nucleus. By the yeast YTK12 secretion system, the signal peptides of four CFEM proteins were functionally verified. The expression levels of these four effector proteins were significantly increased in the F. sacchari-infected sugarcane plants. Through fungal gene knockout, three genes (Fs06761, Fs08184, and Fs13617) were found to be important pathogenic factors for pathogens. Our results support that the FsCFEM effector proteins were virulence effectors and might be involved in regulating plant immunity. IMPORTANCE Common fungal extracellular membrane (CFEM) domain-containing protein has long been considered an essential effector, playing a crucial role in the interaction of pathogens and plant. Strategies aimed at understanding the pathogenicity mechanism of F. sacchari are eagerly anticipated to ultimately end the spread of pokkah boeng disease. Twenty FsCFEM proteins in the genome of F. sacchari have been identified, and four FsCFEM effector proteins have been found to suppress BCL2-associated X protein-triggered programmed cell death in N. benthamiana. These four effector proteins have the ability to enter plant cells and inhibit plant immunity. Furthermore, the expression of these four FsCFEM effector proteins significantly increases during the infection stage, with the three of them playing an essential role in achieving full virulence. These study findings provide a direction toward further exploration of the immune response in sugarcane. By applying these discoveries, we can potentially control the spread of disease through techniques such as host-induced gene silencing.

A homeobox transcription factor is a conserved transcription factor, ubiquitous in eukaryotes, that regulates the tissue formation of structure, cell differentiation, proliferation, and cancer. This study identified the homeobox transcription factor family and its distribution in Phoma sorghina var. saccharum at the whole genome level. It elucidated the gene structures and evolutionary characteristics of this family. Additionally, knockout experiments were carried out and the preliminary function of these transcription factors was studied. Through bioinformatics approaches, nine homeobox transcription factors (PsHOX1–PsHOX9) were identified in P. sorghina var. saccharum, and these contained HOX-conserved domains and helix–turn–helix secondary structures. Nine homeobox gene deletion mutants were obtained using the homologous recombinant gene knockout technique. Protoplast transformation was mediated by polyethylene glycol (PEG) and the transformants were identified using PCR. The knockouts of PsHOX1, PsHOX2, PsHOX3, PsHOX4, PsHOX6, PsHOX8, and PsHOX9 genes resulted in a smaller growth diameter in P. sorghina var. saccharum. In contrast, the knockouts of the PsHOX3, PsHOX6, and PsHOX9 genes inhibited the formation of conidia and led to a significant decrease in the pathogenicity. This study’s results will provide insights for understanding the growth and development of P. sorghina var. saccharum. The pathogenic mechanism of the affected sugarcane will provide an essential theoretical basis for preventing and controlling sugarcane twisted leaf disease.

Modern sugarcane cultivars (Saccharum spp., 2n = 100~120) are complex polyploids primarily derived from interspecific hybridization between S. officinarum and S. spontaneum. Nobilization is the theory of utilizing wild germplasm in sugarcane breeding, and is the foundation for utilizing S. spontaneum for stress resistance. However, the exact chromosomal transmission remains elusive due to a lack of chromosome-specific markers. Here, we applied chromosome-specific oligonucleotide (oligo)-based probes for identifying chromosomes 1-10 of the F1 hybrids between S. officinarum and S. spontaneum. Then, S. spontaneum-specific repetitive DNA probes were used to distinguish S. spontaneum in these hybrids. This oligo- fluorescence in situ hybridization (FISH) system proved to be an efficient tool for revealing individual chromosomal inheritance during nobilization. We discovered the complete doubling of S. officinarum-derived chromosomes in most F1 hybrids. Notably, we also found defective S. officinarum-derived chromosome doubling in the F1 hybrid Yacheng75-4191, which exhibited 1.5n transmission for all nonhomologous chromosomes. Altogether, these results highlight the presence of variable chromosome transmission in nobilization between S. officinarum and S. spontaneum, including 1.5n + n and 2n + n. These findings provide robust chromosome markers for in-depth studies into the molecular mechanism underlying chromosome doubling during the nobilization, as well as tracing chromosomal inheritance for sugarcane breeding.

Abstract Background The realization of the “microbiota–gut–brain” axis plays a critical role in neuropsychiatric disorders, particularly depression, is advancing rapidly. Matrine is a natural bioactive compound, which has been found to possess potential antidepressant effect. However, the underlying mechanisms of regulation of the “microbiota–gut–brain” axis in the treatment of depression by oral matrine remain elusive. Methods Its antidepressant effects were initially evaluated by behavioral tests and relative levels of monoamine neurotransmitters, and matrine has been observed to attenuate the depression-like behavior and increase neurotransmitter content in CUMS-induced mice. Subsequently, studies from the “gut” to “brain” were conducted, including detection of the composition of gut microbiota by 16S rRNA sequencing; the metabolomics detection of gut metabolites and the analysis of differential metabolic pathways; the assessment of relative levels of diamine oxidase, lipopolysaccharide, pro-inflammatory cytokines, and brain-derived neurotrophic factor (BDNF) by ELISA kits or immunofluorescence. Results Matrine could regulate the disturbance of gut microbiota and metabolites, restore intestinal permeability, and reduce intestinal inflammation, thereby reducing the levels of pro-inflammatory cytokines in peripheral blood circulation and brain regions, and ultimately increase the levels of BDNF in brain. Conclusion Matrine may ameliorate CUMS-induced depression in mice by modulating the “microbiota–gut–brain” axis.

Abstract Background Xanthomonas is a genus of gram-negative bacterium containing more than 35 species. Among these pathogenic species, Xanthomonas albilineans (Xal) is of global interest, responsible for leaf scald disease in sugarcane. Another notable Xanthomonas species is Xanthomonas sachari (Xsa), a sugarcane-associated agent of chlorotic streak disease. Result The virulence of 24 Xanthomonas strains was evaluated by disease index (DI) and Area Under Disease Progress Curve (AUDPC) in the susceptible inoculated plants (GT 46) and clustered into three groups of five highly potent, seven mild virulent, and twelve weak virulent strains. The highly potent strain (X. albilineans, Xal JG43) and its weak virulent related strain (X. sacchari, Xsa DD13) were sequenced, assembled, and annotated in the circular genomes. The genomic size of JG43 was smaller than that of DD13. Both strains (JG43 and DD13) lacked a Type III secretory system (T3SS) and T6SS. However, JG43 possessed Salmonella pathogenicity island-1 (SPI-1). More pathogen-host interaction (PHI) genes and virulent factors in 17 genomic islands (GIs) were detected in JG43, among which six were related to pathogenicity. Albicidin and a two-component system associated with virulence were also detected in JG43. Furthermore, 23 Xanthomonas strains were sequenced and classified into three categories based on Single Nucleotide Polymorphism (SNP) mutation loci and pathogenicity, using JG43 as a reference genome. Transitions were dominant SNP mutations, while structural variation (SV) is frequent intrachromosomal rearrangement (ITX). Two essential genes (rpfC/rpfG) of the two-component system and another gene related to SNP were mutated to understand their virulence effect. The mutation of rpfG resulted in a decrease in pathogenicity. Conclusion These findings revealed virulence of 24 Xanthomonas strains and variations by 23 Xanthomonas strains. We sequenced, assembled, and annotated the circular genomes of Xal JG43 and Xsa DD13, identifying diversity detected by pathogenic factors and systems. Furthermore, complete genomic sequences and sequenced data will provide a theoretical basis for identifying pathogenic factors responsible for sugarcane leaf scald disease.

Accurate and dependable weed detection technology is a prerequisite for weed control robots to do autonomous weeding. Due to the complexity of the farmland environment and the resemblance between crops and weeds, detecting weeds in the field under natural settings is a difficult task. Existing deep learning-based weed detection approaches often suffer from issues such as monotonous detection scene, lack of picture samples and location information for detected items, low detection accuracy, etc. as compared to conventional weed detection methods. To address these issues, WeedNet-R, a vision-based network for weed identification and localization in sugar beet fields, is proposed. WeedNet-R adds numerous context modules to RetinaNet’s neck in order to combine context information from many feature maps and so expand the effective receptive fields of the entire network. During model training, meantime, a learning rate adjustment method combining an untuned exponential warmup schedule and cosine annealing technique is implemented. As a result, the suggested method for weed detection is more accurate without requiring a considerable increase in model parameters. The WeedNet-R was trained and assessed using the OD-SugarBeets dataset, which is enhanced by manually adding the bounding box labels based on the publicly available agricultural dataset, i.e. SugarBeet2016. Compared to the original RetinaNet, the mAP of the proposed WeedNet-R increased in the weed detection job in sugar beet fields by 4.65% to 92.30%. WeedNet-R’s average precision for weed and sugar beet is 85.70% and 98.89%, respectively. WeedNet-R outperforms other sophisticated object detection algorithms in terms of detection accuracy while matching other single-stage detectors in terms of detection speed.

Sugarcane is a major industrial crop around the world. Lodging due to weak mechanical strength is one of the main problems leading to huge yield losses in sugarcane. However, due to the lack of high efficiency phenotyping methods for stalk mechanical strength characterization, genetic approaches for lodging-resistant improvement are severely restricted. This study attempted to apply near-infrared spectroscopy high-throughput assays for the first time to estimate the crushing strength of sugarcane stalks. A total of 335 sugarcane samples with huge variation in stalk crushing strength were collected for online NIRS modeling. A comprehensive analysis demonstrated that the calibration and validation sets were comparable. By applying a modified partial least squares method, we obtained high-performance equations that had large coefficients of determination (R2 > 0.80) and high ratio performance deviations (RPD > 2.4). Particularly, when the calibration and external validation sets combined for an integrative modeling, we obtained the final equation with a coefficient of determination (R2) and ratio performance deviation (RPD) above 0.9 and 3.0, respectively, demonstrating excellent prediction capacity. Additionally, the obtained model was applied for characterization of stalk crushing strength in large-scale sugarcane germplasm. In a three-year study, the genetic characteristics of stalk crushing strength were found to remain stable, and the optimal sugarcane genotypes were screened out consistently. In conclusion, this study offers a feasible option for a high-throughput analysis of sugarcane mechanical strength, which can be used for the breeding of lodging resistant sugarcane and beyond.

Sugarcane is one of the critical commercial crops and principal sources of ethanol and sugar worldwide. Unfavorable conditions and poor seed setting rates hinder variety development in sugarcane. Countries like Pakistan directly import fuzz (true seed) and other propagation material from the USA, China, Brazil, etc. In this study, we imported fuzz from China, developed 29 genotypes germinating in the glasshouse, and evaluated at field conditions along with two local checks (CPF-251 and HSF-240). Morphophysiological data were recorded, including plant height (PH), cane length (CL), internodal length (IL), tiller number (TN), brix percentage (B), cane diameter (CD), chlorophyll a (Chl. a), chlorophyll b (Chl. b), and total chlorophyll (T. Chl). Results showed highly significant (p < 0.001) differences among the sugarcane accessions for all the studied traits. High broad-sense heritability (81.89% to 99.91%) was recorded for all the studied parameters. Genetic Advance (GA) ranges from 4.6% to 65.32%. The highest GA was observed for PH (65.32%), followed by CL (63.28%). Chlorophyll leaching assay was also performed at different time points (0, 50, 100, 150, and 200 min). All the genotypes showed the same leaching trend at all times, and better performing genotypes showed less leaching compared to poor performing, indicating the high amount of cutin and wax on the leaf surface. Correlation analysis showed that PH, CL, IL, and TN had significant associations. Principal components analysis (PCA) further confirms these results. Based on PCA and correlation results, PH, CL, IL, and TN can be utilized as a selection criterion for sugarcane improvement. Genotypes such as NS-4a, NS-5, NS-6, NS-8, NS-9, and NS-15 are recommended for future breeding programs related to sugarcane variety development.

Ratooning in sugarcane often leads to soil problems such as degradation, acidification, and soil-borne diseases that negatively impact agriculture output and sustainability. Understanding the alteration in bacterial communities, activities, and their diversity connected to the plant and soil under consecutive ratooning still needs to be clarified. To address this gap, multidisciplinary approaches such as Illumina sequencing and measurement of soil nutrients and enzymes were used in this study to analyze soil samples in a field with three consecutive ratooning sugarcane crops. The results revealed a decline in crop yield and significant changes (P < 0.05) in soil nutrients and bacterial diversity. Ratooning resulted in an acidic environment that potentially affected soil nutrients and enzyme activity responsible for the cycling of carbon, nitrogen, and phosphorous. Non-metric dimensional scaling (NMDS) confirmed the effect of ratooning on soil attributes. Moreover, a positive correlation between soil physiochemical properties and soil enzymes was observed. Alpha diversity indices indicated greater bacterial diversity in ratooning sugarcane. Bacterial diversity varied throughout the ratooning crop, and significant (P < 0.05) changes in the relative abundance of specific phyla were observed. For example, the relative abundance of Proteobacteria was decreased, and Acidobacteria was increased. Furthermore, the relative abundance of bacterial phyla was strongly correlated with soil attributes (enzymes and nutrients). Additionally, ratooning results in the depletion or enrichment of important agriculture microbial genera such as Sphingomonas, Burkholderia, and Acidothermus (P < 0.05), respectively. In conclusion, ratooning led to soil acidification, decreased fertility, and altered microbial structure and activity. Thus, restraining soil acidity by means of liming or biofertilizers to maintain soil nutrients, enzymatic activities, and microbial structure could benefit plants and soil to help create a long-term eco-friendly sugarcane cropping system.

Farmers must accurately and promptly identify sugarcane leaf diseases with identical symptoms. RGB images have a beneficial function in disease identification. Nevertheless, complex backgrounds and identical symptoms can significantly reduce the recognition accuracy and robustness. To overcome these challenges, the SLViT hybrid network is presented, in which the transformer encoder is converted to a flexible plug-in (LViT) that is subsequently integrated into several locations of a lightweight CNN architecture (SHDC). SLViT is initially trained on the publicly available disease dataset Plant Village before being moved to the self-created sugarcane leaf disease dataset SLD10k, which consists of seven classes and 10,309 images. The ablation experiments demonstrate that all the adjustments to SLViT have contributed positively to its overall performance. SLViT outperforms six SOTA models and three custom-designed leaf-disease recognition models on Plant Village in terms of speed (1,832 FPS), weight (2 MB), consumption (50 M), and precision (98.84 %). SLViT also outperformed MobileNetV3_small on the SLD10k dataset with an accuracy bonus of 1.87 % and a size reduction of 66.3 %. The experiment also reveals that SLViT has absorbed the advantages of both the lightweight CNN and the noise-resistant transformer. This study demonstrates the applicability of SLViT for sugarcane leaf diagnosis in the field.

ABSTRACT Fusarium sacchari is one of the primary pathogens causing Pokkah Boeng disease (PBD) in sugarcane in China. Pectate lyases (PL), which play a critical role in pectin degradation and fungal virulence, have been extensively studied in major bacterial and fungal pathogens of a wide range of plant species. However, only a few PLs have been functionally investigated. In this study, we analyzed the function of the pectate lyase gene, FsPL, from F. sacchari. FsPL is a key virulence factor of F. sacchari and can induce plant cell death. FsPL also triggers the pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) response in Nicotiana benthamiana, as reflected by increases in reactive oxygen species (ROS) production, electrolyte leakage, and callose accumulation, as well as the upregulation of defense response genes. In addition, our study also found that the signal peptide of FsPL was necessary for induced cell death and PTI responses. Virus-induced gene silencing showed that FsPL-induced cell death in Nicotiana benthamiana was mediated by leucine-rich repeat (LRR) receptor-like kinases BAK1 and SOBIR1. Thus, FsPL may not only be a critical virulence factor for F. sacchari but may also induce plant defense responses. These findings provide new insights into the functions of pectate lyase in host-pathogen interactions. IMPORTANCE Pokkah Boeng disease (PBD) is one of the main diseases affecting sugarcane in China, seriously damaging sugarcane production and economic development. Therefore, it is important to clarify the pathogenic mechanisms of this disease and to provide a theoretical basis for the breeding of PBD-resistant sugarcane strains. The present study aimed to analyze the function of FsPL, a recently identified pectate lyase gene from F. sacchari. FsPL is a key virulence factor of F. sacchari that induces plant cell death. Our results provide new insights into the function of pectate lyase in host-pathogen interactions.

Sugarcane is a globally significant crop for sugar and energy production, and developing high light-efficiency sugarcane varieties is crucial for enhancing yield and quality. However, limited research is available on the screening of sugarcane germplasm with high photosynthetic efficiency, especially with different leaf positions. The present study, conducted in Guangxi, China, aimed to analyze the photosynthetic characteristics of 258 sugarcane varieties at different leaf positions over three consecutive years in field experiments. The results showed significant differences in photosynthetic characteristics among genotypes, years, and leaf positions. Heritability estimates for various photosynthetic parameters ranged from 0.76 to 0.88. Principal component analysis revealed that the first three principal components accounted for over 99% of the cumulative variance. The first component represented photosynthetic efficiency and light utilization, the second focused on electron transfer and reaction center status, and the third was associated with chlorophyll content. Cluster and discriminant analysis classified sugarcane genotypes into three categories: high photosynthetic efficiency (HPE) with 86 genotypes, medium photosynthetic efficiency (MPE) with 60 genotypes, and low photosynthetic efficiency (LPE) with 112 genotypes. Multi-year trials confirmed that HPE sugarcane genotypes had higher single-stem weight and sucrose content. This study provides valuable insights into the photosynthetic physiological characteristics of different sugarcane varieties, which can contribute to further research regarding high yields and sugar breeding.

IntroductionReceptor-like cytoplastic kinases (RLCKs) are known in many plants to be involved in various processes of plant growth and development and regulate plant immunity to pathogen infection. Environmental stimuli such as pathogen infection and drought restrict the crop yield and interfere with plant growth. However, the function of RLCKs in sugarcane remains unclear.Methods and resultsIn this study, a member of the RLCK VII subfamily, ScRIPK, was identified in sugarcane based on sequence similarity to the rice and Arabidopsis RLCKs. ScRIPK was localized to the plasma membrane, as predicted, and the expression of ScRIPK was responsive to polyethylene glycol treatment and Fusarium sacchari infection. Overexpression of ScRIPK in Arabidopsis enhanced drought tolerance and disease susceptibility of seedlings. Moreover, the crystal structure of the ScRIPK kinase domain (ScRIPK KD) and the mutant proteins (ScRIPK-KD K124R and ScRIPK-KD S253A|T254A) were characterized in order to determine the activation mechanism. We also identified ScRIN4 as the interacting protein of ScRIPK.DiscussionOur work identified a RLCK in sugarcane, providing a potential target for sugarcane responses to disease infection and drought, and a structural basis for kinase activation mechanisms.

Abstract Background Ratooning in sugarcane is a crucial strategy for ensuring the long-term sustainability of the sugarcane industry. Knowledge gap relating to the interaction between rhizosphere microbiome and ratooning crop, particularly the impact of different sugarcane cultivars on the rhizosphere microbiome in consecutive ratooning, requires additional research. The response of two different sugarcane cultivars, viz ZZ-1 and ZZ-13, were evaluated in consecutive ratooning towards the rhizosphere microbial community and cane morphological characters. Results Significant changes in the rhizosphere microbiome were observed in the second ratooning over the years. Several important genera were observed in high abundance during the second ratooning, including Burkholderia, Sphingomonas, Bradyzhizobium, and Acidothermus. Cultivar ZZ-13 caused more alterations in the rhizosphere microbiome than ZZ-1, resulting in a more favorable rhizosphere environment for sugarcane growth. The genotypes also varied in terms of nutrients and enzyme activity over the years. There were significant differences between the genotypes and year for number of stalks and yield was significant for genotypes, years and genotype × year. Conclusion This finding will help to understand thorough interactions between rhizosphere microorganisms and ratoon sugarcane and lay the foundation for promoting and maximizing yield as far as possible. In the future, this work can serve as guidance in sugarcane husbandry, mainly in Guangxi, China.

IntroductionPlant-specific Class III peroxidases (PRXs) play a crucial role in lignification, cell elongation, seed germination, and biotic and abiotic stresses.MethodsThe class III peroxidase gene family in sugarcane were identified by bioinformatics methods and realtime fluorescence quantitative PCR.ResultsEighty-two PRX proteins were characterized with a conserved PRX domain as members of the class III PRX gene family in R570 STP. The ShPRX family genes were divided into six groups by the phylogenetic analysis of sugarcane, Saccharum spontaneum, sorghum, rice, and Arabidopsis thaliana. The analysis of promoter cis-acting elements revealed that most ShPRX family genes contained cis-acting regulatory elements involved in ABA, MeJA, light responsiveness, anaerobic induction, and drought inducibility. An evolutionary analysis indicated that ShPRXs was formed after Poaceae and Bromeliaceae diverged, and tandem duplication events played a critical role in the expansion of ShPRX genes of sugarcane. Purifying selection maintained the function of ShPRX proteins. SsPRX genes were differentially expressed in stems and leaves at different growth stages in S. spontaneum. However, ShPRX genes were differentially expressed in the SCMV-inoculated sugarcane plants. A qRT-PCR analysis showed that SCMV, Cd, and salt could specifically induce the expression of PRX genes of sugarcane.DiscussionThese results help elucidate the structure, evolution, and functions of the class III PRX gene family in sugarcane and provide ideas for the phytoremediation of Cd-contaminated soil and breeding new sugarcane varieties resistant to sugarcane mosaic disease, salt, and Cd stresses.

Abstract Background Plant microbiomes and soil are bridged by rhizobacteria, maintaining and improving plant health and growth in different aspects. This study was conducted in the field station of the Guangxi University, Fusui, China. We investigated soil nutrients, root morphology and rhizosphere bacterial composition, and community structures in 18 sugarcane genotypes concerning sugar content under the same environmental condition. Results Most of the rhizosphere microbiomes of these genotypes exhibited similar bacterial compositions. However, the evaluated genotypes harbored a significant effect and difference in the abundance of operational taxonomic units and bacterial composition in the rhizosphere compartments. Alpha diversity analysis on the rhizosphere microbiome showed a significant difference in the bacterial diversity (Shannon index, p

ABSTRACT Huanglongbing (HLB; greening disease), caused by Candidatus Liberibacter asiaticus (CLas), is the most damaging citrus disease worldwide. The disease has spread throughout the citrus-producing regions of Guangxi, Guangdong, Fujian, and others in China. A total of 1,788 HLB-like symptomatic or asymptomatic samples were collected from the Guangxi and Fujian provinces of China to decipher the genetic diversity of CLas and its correlation with geographic region and host plant. The disease was the most severe in orange and the least in pomelo. CLas bacteria associated with the specific geographical and citrus variety infected more than 50% of the HLB-like symptomatic samples. We identified 6,286 minor variations by comparing 35 published CLas genomes and observed a highly heterogeneous variation distribution across the genome, including four highly diverse nonprophages and three prophage segments. Four hypervariable genomic regions (HGRs) were identified to determine the genetic diversity among the CLas isolates collected from Guangxi and Fujian, China. A phylogenetic tree constructed from four HGRs showed that 100 CLas strains could be separated into four distinct clades. Ten new strains with high variations of prophage regions were identified in the mandarin and tangerine grown in new plantation areas of Guangxi. Characterizing these HGR variations in the CLas bacteria may provide insight into their evolution and adaptation to host plants and insects. IMPORTANCE The hypervariable genomic regions derived from 35 published CLas genomes were used to decipher the genetic diversity of CLas strains and identify 10 new strains with high variations in prophage regions. Characterizing these variations in the CLas bacteria might provide insight into their evolution and adaptation to host plants and insects in China.

Sugarcane is one of the most crucial sugar crops globally that supplies the main raw material for sugar and ethanol production, but drought stress causes a severe decline in sugarcane yield worldwide. Enhancing sugarcane drought resistance and reducing yield and quality losses is an ongoing challenge in sugarcane genetic improvement. Here, we introduced a Tripidium arundinaceum dehydration-responsive element-binding transcription factor (TaDREB2B) behind the drought-responsible RD29A promoter into a commercial sugarcane cultivar FN95-1702 and subsequently conducted a series of drought tolerance experiments and investigation of agronomic and quality traits. Physiological analysis indicated that Prd29A: TaDREB2B transgenic sugarcane significantly confers drought tolerance in both the greenhouses and the field by enhancing water retention capacity and reducing membrane damage without compromising growth. These transgenic plants exhibit obvious improvements in yield performance and various physiological traits under the limited-irrigation condition in the field, such as increasing 41.9% yield and 44.4% the number of ratooning sugarcane seedlings. Moreover, Prd29A: TaDREB2B transgenic plants do not penalize major quality traits, including sucrose content, gravity purity, Brix, etc. Collectively, our results demonstrated that the Prd29A-TaDREB2B promoter-transgene combination will be a useful biotechnological tool for the increase of drought tolerance and the minimum of yield losses in sugarcane.

Naringenin (Nar) is a natural flavonoid extracted from citrus fruits with abundant pharmacological properties against cardiac diseases, but existing studies are unsystematic and scattered. The present research systematically investigates the mechanism of action of Nar in the treatment of myocardial ischemia (MI). Network pharmacology was used to analyze the relevant targets of Nar against MI as well as the biological mechanisms. The protective effect of Nar was initially assessed in H9c2 cells induced by CoCl2. In acutely isolated rat cardiomyocytes, Nar was further explored for effects on L-type Ca2+ currents, cell contractility and Ca2+ transients by using patch-clamp technique and Ion Optix system. Network pharmacology analysis indicated that Nar improved apoptosis, mitochondrial energy metabolism, inflammation and oxidative stress. Experimental validation demonstrated that Nar decreased ROS and MDA levels and increased antioxidant activity (e.g., GSH-PX, SOD, and CAT), mitochondrial membrane potential, ATP and Ca2+-ATPase contents. Nar also markedly reduced inflammatory factor levels, apoptosis, and intracellular Ca2+ concentrations in H9c2 cells. Based on the experimental results, it is speculated that Ca2+ signals play an essential role in the process of Nar against MI. Thus, we further confirmed that Nar significantly inhibited the L-type Ca2+ currents, contractility and Ca2+ transients in acutely isolated cardiomyocytes. The inhibition of Ca2+ overload by Nar may be a novel cardioprotective mechanism. The present study may serve as a basis for future clinical research, and Nar as a Ca2+ channel inhibitor may provide new perspectives for the treatment of myocardial ischemic diseases.

Nitrogen availability might play an essential role in plant diseases by enhancing fungal cell growth and influencing the expression of genes required for successful pathogenesis. Nitrogen availability could modulate secondary metabolic pathways as evidenced by the significant differential expression of several core genes involved in mycotoxin biosynthesis and genes encoding polyketide synthase/nonribosomal peptide synthetases, cytochrome P450 and carbohydrate-active enzymes in Fusarium sacchari, grown on different nitrogen sources. A combined analysis was carried out on the transcript and metabolite profiles of regulatory metabolic processes and the virulence of Fusarium sacchari grown on various nitrogen sources. The nitrogen regulation of the gibberellin gene cluster included the metabolic flux and multiple steps of gibberellin synthesis. UHPLC-MS/MS-based metabolome analysis revealed the coordination of these related transcripts and the accumulation of gibberellin metabolites. This integrated analysis allowed us to uncover additional information for a more comprehensive understanding of biological events relevant to fungal secondary metabolic regulation in response to nitrogen availability.

Abstract Background Sugarcane (Saccharum) is the most critical sugar crop worldwide. As one of the most enriched transcription factor families in plants, MYB genes display a great potential to contribute to sugarcane improvement by trait modification. We have identified the sugarcane MYB gene family at a whole-genome level through systematic evolution analyses and expression profiling. R2R3-MYB is a large subfamily involved in many plant-specific processes. Results A total of 202 R2R3-MYB genes (356 alleles) were identified in the polyploid Saccharum spontaneum genomic sequence and classified into 15 subgroups by phylogenetic analysis. The sugarcane MYB family had more members by a comparative analysis in sorghum and significant advantages among most plants, especially grasses. Collinearity analysis revealed that 70% of the SsR2R3-MYB genes had experienced duplication events, logically suggesting the contributors to the MYB gene family expansion. Functional characterization was performed to identify 56 SsR2R3-MYB genes involved in various plant bioprocesses with expression profiling analysis on 60 RNA-seq databases. We identified 22 MYB genes specifically expressed in the stem, of which RT-qPCR validated MYB43, MYB53, MYB65, MYB78, and MYB99. Allelic expression dominance analysis implied the differential expression of alleles might be responsible for the high expression of MYB in the stem. MYB169, MYB181, MYB192 were identified as candidate C4 photosynthetic regulators by C4 expression pattern and robust circadian oscillations. Furthermore, stress expression analysis showed that MYB36, MYB48, MYB54, MYB61 actively responded to drought treatment; 19 and 10 MYB genes were involved in response to the sugarcane pokkah boeng and mosaic disease, respectively. Conclusions This is the first report on genome-wide analysis of the MYB gene family in sugarcane. SsMYBs probably played an essential role in stem development and the adaptation of various stress conditions. The results will provide detailed insights and rich resources to understand the functional diversity of MYB transcription factors and facilitate the breeding of essential traits in sugarcane.

Sugarcane pokkah boeng disease (PBD) is emerging as a prevalent foliar disease in China. This airborne disease is caused by the Fusarium species complex. To investigate the diversity and evolution of Fusarium spp., we performed whole-genome sequencing of Fusarium andiyazi YN28 using a combination of Oxford Nanopore and Illumina technology. The F. andiyazi YN28 genome was sequenced, assembled, and annotated. A high-quality genome was assembled into 24 contigs with an N50 of 2.80 Mb. The genome assembly generated a total size of 44.1 Mb with a GC content of 47.64%. In total, 15,508 genes were predicted, including 794 genes related to the carbohydrate-active enzymes, 397 noncoding RNA, 155 genes associated with transporter classification, 4,550 genes linked to pathogen–host interactions, and 269 genes involved in effector proteins. Collectively, our results will provide insight into the host–pathogen interactions and will facilitate the breeding of new varieties of sugarcane resistant to PBD.[Graphic: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Abstract Background Sugarcane is an essential crop for sugar and ethanol production. Immediate processing of sugarcane is necessary after harvested because of rapid sucrose losses and deterioration of stalks. This study was conducted to fill the knowledge gap regarding the exploration of fungal communities in harvested deteriorating sugarcane. Experiments were performed on simulating production at 30 °C and 40 °C after 0, 12, and 60 h of sugarcane harvesting and powder-processing. Results Both pH and sucrose content declined significantly within 12 h. Fungal taxa were unraveled using ITS amplicon sequencing. With the increasing temperature, the diversity of the fungal community decreased over time. The fungal community structure significantly changed within 12 h of bagasse storage. Before stored, the dominant genus (species) in bagasse was Wickerhamomyces (W. anomalus). Following storage, Kazachstania (K. humilis) and Saccharomyces (S. cerevisiae) gradually grew, becoming abundant fungi at 30 °C and 40 °C. The bagasse at different temperatures had a similar pattern after storage for the same intervals, indicating that the temperature was the primary cause for the variation of core features. Moreover, most of the top fungal genera were significantly correlated with environmental factors (pH and sucrose of sugarcane, storage time, and temperature). In addition, the impact of dominant fungal species isolated from the deteriorating sugarcane on sucrose content and pH in the stored sugarcane juice was verified. Conclusions The study highlighted the importance of timeliness to refine sugar as soon as possible after harvesting the sugarcane. The lessons learned from this research are vital for sugarcane growers and the sugar industry for minimizing post-harvest losses.

Abstract Background Sugarcane (Saccharum officinarum L.) is an economically important crop with stalks as the harvest organs. Improvement in stalk quality is deemed a promising strategy for enhancing sugarcane production. However, the lack of efficient approaches for systematic evaluation of sugarcane germplasm largely limits improvements in stalk quality. This study is designed to develop a systematic near-infrared spectroscopy (NIRS) assay for high-throughput phenotyping of sugarcane stalk quality, thereby providing a feasible solution for precise evaluation of sugarcane germplasm. Results A total of 628 sugarcane accessions harvested at different growth stages before and after maturity were employed to take a high-throughput assay to determine sugarcane stalk quality. Based on high-performance anion chromatography (HPAEC-PAD), large variations in sugarcane stalk quality were detected in terms of biomass composition and the corresponding fundamental ratios. Online and offline NIRS modeling strategies were applied for multiple purpose calibration with partial least square (PLS) regression analysis. Consequently, 25 equations were generated with excellent determination coefficients (R 2 ) and ratio performance deviation (RPD) values. Notably, for some observations, RPD values as high as 6.3 were observed, which indicated their exceptional performance and predictive capability. Conclusions This study provides a feasible method for consistent and high-throughput assessment of stalk quality in terms of moisture, soluble sugar, insoluble residue and the corresponding fundamental ratios. The proposed method permits large-scale screening of optimal sugarcane germplasm for sugarcane stalk quality breeding and beyond.

Abstract Background The dehydration-responsive element-binding proteins (DREBs) are important transcription factors that interact with a DRE/CRT (C-repeat) sequence and involve in response to multiple abiotic stresses in plants. Modern sugarcane are hybrids from the cross between Saccharum spontaneum and Saccharum officinarum, and the high sugar content is considered to the attribution of S. officinaurm, while the stress tolerance is attributed to S. spontaneum. To understand the molecular and evolutionary characterization and gene functions of the DREBs in sugarcane, based on the recent availability of the whole genome information, the present study performed a genome-wide in silico analysis of DREB genes and transcriptome analysis in the polyploidy S. spontaneum. Results Twelve DREB1 genes and six DREB2 genes were identified in S. spontaneum genome and all proteins contained a conserved AP2/ERF domain. Eleven SsDREB1 allele genes were assumed to be originated from tandem duplications, and two of them may be derived after the split of S. spontaneum and the proximal diploid species sorghum, suggesting tandem duplication contributed to the expansion of DREB1-type genes in sugarcane. Phylogenetic analysis revealed that one DREB2 gene was lost during the evolution of sugarcane. Expression profiling showed different SsDREB genes with variable expression levels in the different tissues, indicating seven SsDREB genes were likely involved in the development and photosynthesis of S. spontaneum. Furthermore, SsDREB1F, SsDREB1L, SsDREB2D, and SsDREB2F were up-regulated under drought and cold condition, suggesting that these four genes may be involved in both dehydration and cold response in sugarcane. Conclusions These findings demonstrated the important role of DREBs not only in the stress response, but also in the development and photosynthesis of S. spontaneum.

Abstract Background Sugarcane is one of the most crucial energy crops that produces high yields of sugar and lignocellulose. The cellulose crystallinity index (CrI) and lignin are the two kinds of key cell wall features that account for lignocellulose saccharification. Therefore, high-throughput screening of sugarcane germplasm with excellent cell wall features is considered a promising strategy to enhance bagasse digestibility. Recently, there has been research to explore near-infrared spectroscopy (NIRS) assays for the characterization of the corresponding wall features. However, due to the technical barriers of the offline strategy, it is difficult to apply for high-throughput real-time analyses. This study was therefore initiated to develop a high-throughput online NIRS assay to rapidly detect cellulose crystallinity, lignin content, and their related proportions in sugarcane, aiming to provide an efficient and feasible method for sugarcane cell wall feature evaluation. Results A total of 838 different sugarcane genotypes were collected at different growth stages during 2018 and 2019. A continuous variation distribution of the near-infrared spectrum was observed among these collections. Due to the very large diversity of CrI and lignin contents detected in the collected sugarcane samples, seven high-quality calibration models were developed through online NIRS calibration. All of the generated equations displayed coefficient of determination (R 2) values greater than 0.8 and high ratio performance deviation (RPD) values of over 2.0 in calibration, internal cross-validation, and external validation. Remarkably, the equations for CrI and total lignin content exhibited RPD values as high as 2.56 and 2.55, respectively, indicating their excellent prediction capacity. An offline NIRS assay was also performed. Comparable calibration was observed between the offline and online NIRS analyses, suggesting that both strategies would be applicable to estimate cell wall characteristics. Nevertheless, as online NIRS assays offer tremendous advantages for large-scale real-time screening applications, it could be implied that they are a better option for high-throughput cell wall feature prediction. Conclusions This study, as an initial attempt, explored an online NIRS assay for the high-throughput assessment of key cell wall features in terms of CrI, lignin content, and their proportion in sugarcane. Consistent and precise calibration results were obtained with NIRS modeling, insinuating this strategy as a reliable approach for the large-scale screening of promising sugarcane germplasm for cell wall structure improvement and beyond.

Abstract Background In recent years, sugarcane has attracted increasing attention as an energy crop. Wild resources are widely used to improve the narrow genetic base of sugarcane. However, the infertility of F1 hybrids between Saccharum officinarum (S. officinarum) and Erianthus arundinaceus (E. arundinaceus) has hindered sugarcane breeding efforts. To discover the cause of this infertility, we studied the hybridization process from a cytological perspective. Results We examined the meiotic process of pollen mother cells (PMCs) in three F1 hybrids between S. officinarum and E. arundinaceus. Cytological analysis showed that the male parents, Hainan 92–77 and Hainan 92–105, had normal meiosis. However, the meiosis process in F1 hybrids showed various abnormal phenomena, including lagging chromosomes, micronuclei, uneven segregation, chromosome bridges, and inability to form cell plates. Genomic in situ hybridization (GISH) showed unequal chromatin distribution during cell division. Interestingly, 96.70% of lagging chromosomes were from E. arundinaceus. Furthermore, fluorescence in situ hybridization (FISH) was performed using 45S rDNA and 5S rDNA as probes. Either 45S rDNA or 5S rDNA sites were lost during abnormal meiosis, and results of unequal chromosomal separation were also clearly observed in tetrads. Conclusions Using cytogenetic analysis, a large number of meiotic abnormalities were observed in F1. GISH further confirmed that 96.70% of the lagging chromosomes were from E. arundinaceus. Chromosome loss was found by further investigation of repeat sequences. Our findings provide insight into sugarcane chromosome inheritance to aid innovation and utilization in sugarcane germplasm resources.

Background and Objective: Arsenic trioxide (As2O3) induced cardiotoxicity to limit the clinical applications of the effective anticancer agent. 6-Gingerol (6G) is the main active ingredient of ginger, a food with many health benefits. The present study aims to investigate the potential pharmacological mechanisms of 6G on As2O3-induced myocardial injury.Methods and Results: Fifty KunMing mice were divided into five groups (n = 10) receiving: 1) physiological saline; 2) 6G (20 mg/kg) alone; 3) As2O3 (5 mg/kg); 4) 6G (10 mg/kg) and As2O3 (5 mg/kg); 5) 6G (20 mg/kg) and As2O3 (5 mg/kg). 6G was given orally and As2O3 was given intraperitoneally once per day for seven consecutive days. Biochemical, histopathological, transmission electron microscopy, ELISA, and western blotting analyses were then performed. Based on the resultant data, As2O3 was found to induce cardiotoxicity in mice. 6G significantly ameliorated As2O3-induced heart injury, histopathological changes, oxidative stress, myocardial mitochondrial damage, inflammation, and cardiomyocyte apoptosis, while reversed As2O3-induced inhibition of the AMPK/SIRT1/PGC-1α pathway.Conclusion: Our experimental results reveal that 6G effectively counteracts As2O3-induced cardiotoxicity including oxidative stress, inflammation and apoptosis, which might be attributed to its activation action on AMPK/SIRT1/PGC-1α signaling pathway.

Minimizing the use of chemical fertilizers and investigating an appropriate ecofriendly level of nitrogen fertilizer is the key to sustainable agriculture. Sugarcane is the main cash crop of China, especially in the Guangxi region. Information regarding the effect of different nitrogen levels on sugarcane rhizosphere microbiota is still limited. In this study, we evaluated the effect of four different levels of nitrogen fertilizers on rhizosphere bacterial composition using high throughput sequencing, along with soil physiochemical properties, sugarcane agronomic and yield performance. The four treatment combinations were CK (no fertilizers), L (Low, 100 kg ha–1), M (Medium, 150 kg ha–1), and H (High, 200 kg ha–1). The results showed that M nitrogen application significantly altered the rhizosphere bacterial community, soil properties, and sugarcane yield. The richness and evenness of the bacterial community were higher in M treatment than CK. In M treatment important bacterial phyla Acidobacteria and Proteobacteria increased by 47 and 71%, respectively; and at genus level, Acidothermus and Bradyrhizobium increased by 77.2 and 30.3%, respectively, compared to CK. Principal component analysis (PCA) and cluster analysis further confirmed the level of differences among the treatments. The PCA analysis explained 80% of the total variation among the treatments. Spearmen correlation heatmap showed that environmental factors such as pH, AP (available phosphorous), AK (available potassium), and SCAT (soil catalase) were the key factors impacting sugarcane rhizosphere microbiome composition. The H and L nitrogen application alter the bacterial community and sugarcane performance but the M nitrogen application appears to be ecofriendly, productive, and an appropriate nitrogen application rate that could be further used in the Guangxi region.

Abstract Background APETALA2/ETHYLENE RESPONSIVE FACTOR (AP2/ERF) transcription factors play essential roles in plant growth, development, metabolism, and responses to biotic and abiotic stresses. However, few studies concerning AP2/ERF genes in sugarcane which are the most critical sugar and energy crops worldwide. Results A total of 218 AP2/ERF genes were identified in the Saccharum spontaneum genome. Phylogenetic analysis showed that these genes could be divided into four groups, including 43 AP2s, 160 ERFs and Dehydration-responsive element-binding (DREB) factors, 11 ABI3/VPs (RAV), and four Soloist genes. These genes were unevenly distributed on 32 chromosomes. The structural analysis of SsAP2/ERF genes showed that 91 SsAP2/ERFs lacked introns. Sugarcane and sorghum had a collinear relationship between 168 SsAP2/ERF genes and sorghum AP2/ERF genes that reflected their similarity. Multiple cis-regulatory elements (CREs) present in the SsAP2/ERF promoter were related to abiotic stresses, suggesting that SsAP2/ERF activity could contribute to sugarcane adaptation to environmental changes. The tissue-specific analysis showed spatiotemporal expression of SsAP2/ERF in the stems and leaves of sugarcane at different development stages. In ten sugarcane samples, 39 SsAP2/ERFs were not expressed, whereas 58 SsAP2/ERFs were expressed in all samples. Quantitative PCR experiments showed that SsERF52 expression was up-regulated under salt stress, but suppressed under dehydration stress. SsSoloist4 had the most considerable upregulation in response to treatment with the exogenous hormones ABA and GA. Within 3 h of ABA or PEG6000 treatment, SsSoloist4 expression was up-regulated, indicating that this gene could play a role in the responses to ABA and GA-associated dehydration stress. Analysis of AP2/ERF gene expression patterns under different treatments indicated that SsAP2/ERF genes played an essential role in dehydration and salt stress responses of S. spontaneum. Conclusions In this study, a total of 218 members of the AP2 / ERF superfamily were identified in sugarcane, and their genetic structure, evolution characteristics, and expression patterns were studied and analyzed. The results of this study provide a foundation for future analyses to elucidate the importance of AP2/ERF transcription factors in the function and molecular breeding of sugarcane.

Abstract Background Sucrose phosphate synthase (SPS) genes play vital roles in sucrose production across various plant species. Modern sugarcane cultivar is derived from the hybridization between the high sugar content species Saccharum officinarum and the high stress tolerance species Saccharum spontaneum, generating one of the most complex genomes among all crops. The genomics of sugarcane SPS remains under-studied despite its profound impact on sugar yield. Results In the present study, 8 and 6 gene sequences for SPS were identified from the BAC libraries of S. officinarum and S. spontaneum, respectively. Phylogenetic analysis showed that SPSD was newly evolved in the lineage of Poaceae species with recently duplicated genes emerging from the SPSA clade. Molecular evolution analysis based on Ka/Ks ratios suggested that polyploidy reduced the selection pressure of SPS genes in Saccharum species. To explore the potential gene functions, the SPS expression patterns were analyzed based on RNA-seq and proteome dataset, and the sugar content was detected using metabolomics analysis. All the SPS members presented the trend of increasing expression in the sink-source transition along the developmental gradient of leaves, suggesting that the SPSs are involved in the photosynthesis in both Saccharum species as their function in dicots. Moreover, SPSs showed the higher expression in S. spontaneum and presented expressional preference between stem (SPSA) and leaf (SPSB) tissue, speculating they might be involved in the differentia of carbohydrate metabolism in these two Saccharum species, which required further verification from experiments. Conclusions SPSA and SPSB genes presented relatively high expression and differential expression patterns between the two Saccharum species, indicating these two SPSs are important in the formation of regulatory networks and sucrose traits in the two Saccharum species. SPSB was suggested to be a major contributor to the sugar accumulation because it presented the highest expressional level and its expression positively correlated with sugar content. The recently duplicated SPSD2 presented divergent expression levels between the two Saccharum species and the relative protein content levels were highest in stem, supporting the neofunctionalization of the SPSD subfamily in Saccharum.

Abstract Background The association of rs28362491 polymorphism in NF-κB1 gene and coronary artery disease (CAD) risk was reported in several studies with inconsistent outcomes. This study aimed to comprehensively collect and synthesize the existing evidence to appraise whether rs28362491 was correlated to CAD susceptibility. Methods Databases of Web of Science, EMBASE, PubMed, Wanfang, and CNKI were retrieved from inception to August 1, 2019 without any restriction on language. The strengths of association between rs28362491 polymorphism and CAD were presented as odds ratios (ORs) and 95% confidence intervals (CIs). Results Thirteen case-control studies with 17 individual cohorts containing 9378 cases and 10,738 controls were incorporated into this meta-analysis. The findings indicated that rs28362491 polymorphism was significantly correlated to CAD risk in five genetic models: D vs. I, OR = 1.16, 95%CI 1.11–1.21, P

The commercial application of genetically modified plants has been seriously impeded by public concern surrounding the potential risks posed by such plants to the ecosystem and human health. Previously, we have developed a ‘pollen- and seed-specific Gene Deletor’ system that automatically excised all transgenes from the pollen and seeds of greenhouse-grown transgenic Nicotiana tabacum. In this study, we conducted seven field experiments over three consecutive years to evaluate the stability of transgene excision under field conditions. Our results showed that transgenes were stably excised from transgenic Nicotiana tabacum under field conditions with 100% efficiency. The stability of transgene excision was confirmed based on PCR, as well as the GUS staining patterns of various organs (roots, leaves, petiole, stem, flower, fruit, and seeds) from transgenic N. tabacum. In six transgenic lines (D4, D10, D31, D56, and D43), the transgenes were stably deleted in the T0 and T1 generations. Thus, the ‘Gene Deletor’ system is an efficient and reliable method to reduce pollen- and seed-mediated unintentional gene flow. This system might help to alleviate the food safety concerns associated with transgenic crops.

Sugarcane is a major crop for sugar production around the world. The complexity of the sugarcane genome creates challenges for the use of both conventional and molecular breeding methods to improve sugarcane at a genetic level. DNA sequencing is an important tool to assess how the genus Saccharum and the genera of the Saccharum complex are interrelated. Here, we identify the kinship of Nepal2013-6 (Saccharum spontaneum, x = 10) using a tetra-primer amplification refractory mutation system (ARMS) PCR. Based on rDNA-ITS sequence analysis, the accession Nepal2013-6 falls within a single cluster with S. spontaneum (Yunnan82-114 and SES208), which is consistent with the previous results. Moreover, fluorescence in situ hybridization (FISH) results indicate that the 5S rDNA spots are consistent with the chromosomal ploidy in the analytical Saccharum materials, whereas 35S rDNA has similar or fewer sites than the ploidy. Therefore, 5S rDNA FISH patterns would be more suitable than 35S rDNA for chromosomal ploidy analysis in S. spontaneum with varied basic chromosome number x = 8, 9, 10. Altogether, these results indicate that the rDNA sequences will be a useful marker for further rapidly identifying the relationship and ploidy of S. spontaneum in sugarcane breeding.

Liquiritigenin (LQ) has protective effects against various hepatotoxicities. However, its specific role on arsenic trioxide (ATO)-induced hepatotoxicity and the related biomolecular mechanisms remain unclear. The purpose of this study is to explore the protective actions of LQ on ATO-induced hepatotoxicity and its biomolecular mechanisms in mice. LQ was administered orally at 20 and 40 mg/kg per day for seven consecutive days with an intraperitoneal injection of ATO (5 mg/kg). Liver injury was induced by ATO and was alleviated by treatment with LQ as reflected by reduced histopathological damage of liver and decreased serum ALT, AST, and ALP levels. The generation of intracellular ROS induced by ATO was attenuated after LQ treatment. The levels of SOD, CAT, and GSH were elevated with LQ administration while MDA levels decreased. LQ mitigated elevated TNF-α and IL-6 levels as well as the hepatic mitochondrial damage caused by ATO. Moreover, LQ upregulated the expression of LC3-II and enhanced autophagy in the liver of ATO-induced mice. Further studies indicated that LQ significantly suppressed the expression of p-PI3K, p-AKT, and p-mTOR in ATO-induced mice. In conclusion, our findings show that LQ protects against ATO-induced hepatotoxicity due to its antioxidant and anti-inflammatory activities and enhancement of autophagy mediated by the PI3K/AKT/mTOR signaling pathway in mice.

Abstract Myocardial ischemia (MI) remains the leading cause of mortality worldwide. Therefore, it is urgent to seek the treatment to protect the heart. [8]‐Gingerol (8‐Gin), one of the most active ingredients in ginger, has antioxidant, cardiotonic, and cardiovascular protective properties. The present study elucidated the cardioprotection effects and underlying mechanisms of 8‐Gin in isoproterenol (ISO)‐induced MI. ISO (85 mg/kg/d) was subcutaneously injected for 2 consecutive days to induce acute MI model in rats. Electrocardiography, oxidative stress levels, calcium concentrations, and apoptosis degree were observed. The effects of 8‐Gin on L‐type Ca2+ current (ICa‐L), contraction, and Ca2+ transients were monitored in rat myocytes via patch‐clamp and IonOptix detection systems. 8‐Gin decreased J‐point elevation and heart rate and improved pathological heart damage. Moreover, 8‐Gin reduced the levels of CK, LDH, and MDA, ROS production, and calcium concentrations in myocardial tissue, while increased the activities of SOD, CAT, and GSH. In addition, 8‐Gin down‐regulated Caspase‐3 and Bax expressions, while up‐regulated Bcl‐2 expression. 8‐Gin produced a marked decrease in the expression of p38, JNK, and ERK1/2 proteins. 8‐Gin inhibited ICa‐L, cell contraction, and Ca2+ transients in isolated rat myocytes. The results indicate that 8‐Gin could exert anti‐myocardial ischemic effects, which may be associated with oxidative stress reduction, cardiomyocytes apoptosis inhibition through MAPK signaling pathway, and Ca2+ homeostasis regulation via ICa‐L modulation.

Sugarcane seedling emergence is important for sugar production. Manual counting is time-consuming and hardly practicable for large-scale field planting. Unmanned aerial vehicles (UAVs) with fast acquisition speed and wide coverage are becoming increasingly popular in precision agriculture. We provide a method based on improved Faster RCNN for automatically detecting and counting sugarcane seedlings using aerial photography. The Sugarcane-Detector (SGN-D) uses ResNet 50 for feature extraction to produce high-resolution feature expressions and provides an attention method (SN-block) to focus the network on learning seedling feature channels. FPN aggregates multi-level features to tackle multi-scale problems, while optimizing anchor boxes for sugarcane size and quantity. To evaluate the efficacy and viability of the proposed technology, 238 images of sugarcane seedlings were taken from the air with an unmanned aerial vehicle. Outcoming with an average accuracy of 93.67%, our proposed method outperforms other commonly used detection models, including the original Faster R-CNN, SSD, and YOLO. In order to eliminate the error caused by repeated counting, we further propose a seedlings de-duplication algorithm. The highest counting accuracy reached 96.83%, whilst the mean absolute error (MAE) reached 4.6 when intersection of union (IoU) was 0.15. In addition, a software system was developed for the automatic identification and counting of cane seedlings. This work can provide accurate seedling data, thus can support farmers making proper cultivation management decision.

Hesperetin (HSP) is a natural flavonoid that offers useful curative effects for cardiovascular diseases, but its effect on myocardial ischemia and its precise mechanism remains unclear. The aim of this study is to explore the potential cardioprotective mechanism of HSP on myocardial ischemia caused by isoproterenol (ISO). Adult male Kunming mice were randomly divided into five groups: control, ISO, low-dose HSP (L-HSP, 25 mg/kg/d), high-dose HSP (H-HSP, 50 mg/kg/d), and verapamil (VER) group. Treatment groups of mice received HSP or VER for seven days, and the groups other than the control group were injected with ISO (100 mg/kg/d) subcutaneously for two consecutive days to establish a model of myocardial ischemia. Electrocardiogram and heart-histology changes were used to assess changes in myocardial architecture. The activities and the content of oxidative stress markers and inflammatory cytokines were determined and assayed using kits respectively. The expressions of proteins associated with apoptosis and the Sirt1/Nrf2 pathway were evaluated by Western blotting. The results demonstrate that VER, L-HSP and H-HSP significantly reduced the J-point displacement, heart rate, cardiac pathomorphological changes, and the levels of creatine kinase, lactated dehydrogenase, malonaldehyde, interleukin-6, and tumor necrosis factor-α in serum while promoting the activation of superoxide dismutase, catalase, glutathione in serum in the ISO-treated animals. Furthermore, L-HSP and H-HSP also reversed the ISO-induced apoptosis and the changes in the Sirt1/Nrf2 signaling pathway, as evident from the levels of proteins Bax, Bcl-2, caspase-3, Sirt1, Nrf2, NQO-1, and HO-1. In conclusion, HSP plays a protective role in ISO-induced myocardial ischemia by modulating oxidative stress, inflammation, and apoptosis via Sirt1/Nrf2 pathway activation.

8-gingerol (8-Gin) is the series of phenolic substance that is extracted from ginger. Although many studies have revealed that 8-Gin has multiple pharmacological properties, the possible underlying mechanisms of 8-Gin against myocardial fibrosis (MF) remains unclear. The study examined the exact role and potential mechanisms of 8-Gin against isoproterenol (ISO)-induced MF. Male mice were intraperitoneally injected with 8-Gin (10 and 20 mg/kg/d) and concurrently subcutaneously injected with ISO (10 mg/kg/d) for 2 weeks. Electrocardiography, pathological heart morphology, myocardial enzymes, reactive oxygen species (ROS) generation, degree of apoptosis, and autophagy pathway-related proteins were measured. Our study observed 8-Gin significantly reduced J-point elevation and heart rate. Besides, 8-Gin caused a marked decrease in cardiac weight index and left ventricle weight index, serum levels of creatine kinase and lactate dehydrogenase (CK and LDH, respectively), ROS generation, and attenuated ISO-induced pathological heart damage. Moreover, treatment with 8-Gin resulted in a marked decrease in the levels of collagen types I and III and TGF-β in the heart tissue. Our results showed 8-Gin exposure significantly suppressed ISO-induced autophagosome formation. 8-Gin also could lead to down-regulation of the activities of matrix metalloproteinases-9 (MMP-9), Caspase-9, and Bax protein, up-regulation of the activity of Bcl-2 protein, and alleviation of cardiomyocyte apoptosis. Furthermore, 8-Gin produced an obvious increase in the expressions of the PI3K/Akt/mTOR signaling pathway-related proteins. Our data showed that 8-Gin exerted cardioprotective effects on ISO-induced MF, which possibly occurred in connection with inhibition of ROS generation, apoptosis, and autophagy via modulation of the PI3K/Akt/mTOR signaling pathway.