Construction of a Chinese traditional instrumental music dataset: A validated set of naturalistic affective music excerpts.

Music is omnipresent among human cultures and moves us both physically and emotionally. The perception of emotions in music is influenced by both psychophysical and cultural factors. Chinese traditional instrumental music differs significantly from Western music in cultural origin and music elements. However, previous studies on music emotion perception are based almost exclusively on Western music. Therefore, the construction of a dataset of Chinese traditional instrumental music is important for exploring the perception of music emotions in the context of Chinese culture. The present dataset included 273 10-second naturalistic music excerpts. We provided rating data for each excerpt on ten variables: familiarity, dimensional emotions (valence and arousal), and discrete emotions (anger, gentleness, happiness, peacefulness, sadness, solemnness, and transcendence). The excerpts were rated by a total of 168 participants on a seven-point Likert scale for the ten variables. Three labels for the excerpts were obtained: familiarity, discrete emotion, and cluster. Our dataset demonstrates good reliability, and we believe it could contribute to cross-cultural studies on emotional responses to music.

Insights into ZmWAKL in maize kernel development: genome-wide investigation and GA-mediated transcription.

BACKGROUND: The functional roles of the Wall Associated Kinase (WAK) and Wall Associated Kinase Like (WAKL) families in cellular expansion and developmental processes have been well-established. However, the molecular regulation of these kinases in maize development is limited due to the absence of comprehensive genome-wide studies. RESULTS: Through an in-depth analysis, we identified 58 maize WAKL genes, and classified them into three distinct phylogenetic clusters. Moreover, structural prediction analysis showed functional conservation among WAKLs across maize. Promoter analysis uncovered the existence of cis-acting elements associated with the transcriptional regulation of ZmWAKL genes by Gibberellic acid (GA). To further elucidate the role of WAKL genes in maize kernels, we focused on three highly expressed genes, viz ZmWAKL38, ZmWAKL42 and ZmWAKL52. Co-expression analyses revealed that their expression patterns exhibited a remarkable correlation with GA-responsive transcription factors (TF) TF5, TF6, and TF8, which displayed preferential expression in kernels. RT-qPCR analysis validated the upregulation of ZmWAKL38, ZmWAKL42, ZmWAKL52, TF5, TF6, and TF8 following GA treatment. Additionally, ZmWAKL52 showed significant increase of transcription in the present of TF8, with ZmWAKL52 localizing in both the plasma membrane and cell wall. TF5 positively regulated ZmWAKL38, while TF6 positively regulated ZmWAKL42. CONCLUSIONS: Collectively, these findings provide novel insights into the characterization and regulatory mechanisms of specific ZmWAKL genes involved in maize kernel development, offering prospects for their utilization in maize breeding programs.

The human lncRNA GOMAFU suppresses neuronal interferon response pathways affected in neuropsychiatric diseases.

Long noncoding RNAs (lncRNAs) play multifaceted roles in regulating brain gene networks. LncRNA abnormalities are thought to underlie the complex etiology of numerous neuropsychiatric disorders. One example is the human lncRNA gene GOMAFU, which is found dysregulated in schizophrenia (SCZ) postmortem brains and harbors genetic variants that contribute to the risk of SCZ. However, transcriptome-wide biological pathways regulated by GOMAFU have not been determined. How GOMAFU dysregulation contributes to SCZ pathogenesis remains elusive. Here we report that GOMAFU is a novel suppressor of human neuronal interferon (IFN) response pathways that are hyperactive in the postmortem SCZ brains. We analyzed recently released transcriptomic profiling datasets in clinically relevant brain areas derived from multiple SCZ cohorts and found brain region-specific dysregulation of GOMAFU. Using CRISPR-Cas9 to delete the GOMAFU promoter in a human neural progenitor cell model, we identified transcriptomic alterations caused by GOMAFU deficiency in pathways commonly affected in postmortem brains of SCZ and autism spectrum disorder (ASD), with the most striking effects on upregulation of numerous genes underlying IFN signaling. In addition, expression levels of GOMAFU target genes in the IFN pathway are differentially affected in SCZ brain regions and negatively associated with GOMAFU alterations. Furthermore, acute exposure to IFN-γ causes a rapid decline of GOMAFU and activation of a subclass of GOMAFU targets in stress and immune response pathways that are affected in SCZ brains, which form a highly interactive molecular network. Together, our studies unveiled the first evidence of lncRNA-governed neuronal response pathways to IFN challenge and suggest that GOMAFU dysregulation may mediate environmental risks and contribute to etiological neuroinflammatory responses by brain neurons of neuropsychiatric diseases.

Reversing neural circuit and behavior deficit in mice exposed to maternal inflammation by Zika virus.

Zika virus (ZIKV) infection during pregnancy is linked to various developmental brain disorders. Infants who are asymptomatic at birth might have postnatal neurocognitive complications. However, animal models recapitulating these neurocognitive phenotypes are lacking, and the circuit mechanism underlying behavioral abnormalities is unknown. Here, we show that ZIKV infection during mouse pregnancy induces maternal immune activation (MIA) and leads to autistic-like behaviors including repetitive self-grooming and impaired social memory in offspring. In the medial prefrontal cortex (mPFC), ZIKV-affected offspring mice exhibit excitation and inhibition imbalance and increased cortical activity. This could be explained by dysregulation of inhibitory neurons and synapses, and elevated neural activity input from mPFC-projecting ventral hippocampus (vHIP) neurons. We find structure alterations in the synaptic connections and pattern of vHIP innervation of mPFC neurons, leading to hyperconnectivity of the vHIP-mPFC pathway. Decreasing the activity of mPFC-projecting vHIP neurons with a chemogenetic strategy rescues social memory deficits in ZIKV offspring mice. Our studies reveal a hyperconnectivity of vHIP to mPFC projection driving social memory deficits in mice exposed to maternal inflammation by ZIKV.

Epi-Brassinolide Regulates ZmC4 NADP-ME Expression through the Transcription Factors ZmbHLH157 and ZmNF-YC2.

Maize is a main food and feed crop with great production potential and high economic benefits. Improving its photosynthesis efficiency is crucial for increasing yield. Maize photosynthesis occurs mainly through the C4 pathway, and NADP-ME (NADP-malic enzyme) is a key enzyme in the photosynthetic carbon assimilation pathway of C4 plants. ZmC4-NADP-ME catalyzes the release of CO2 from oxaloacetate into the Calvin cycle in the maize bundle sheath. Brassinosteroid (BL) can improve photosynthesis; however, its molecular mechanism of action remains unclear. In this study, transcriptome sequencing of maize seedlings treated with epi-brassinolide (EBL) showed that differentially expressed genes (DEGs) were significantly enriched in photosynthetic antenna proteins, porphyrin and chlorophyll metabolism, and photosynthesis pathways. The DEGs of C4-NADP-ME and pyruvate phosphate dikinase in the C4 pathway were significantly enriched in EBL treatment. Co-expression analysis showed that the transcription level of ZmNF-YC2 and ZmbHLH157 transcription factors was increased under EBL treatment and moderately positively correlated with ZmC4-NADP-ME. Transient overexpression of protoplasts revealed that ZmNF-YC2 and ZmbHLH157 activate C4-NADP-ME promoters. Further experiments showed ZmNF-YC2 and ZmbHLH157 transcription factor binding sites on the -1616 bp and -1118 bp ZmC4 NADP-ME promoter. ZmNF-YC2 and ZmbHLH157 were screened as candidate transcription factors mediating brassinosteroid hormone regulation of the ZmC4 NADP-ME gene. The results provide a theoretical basis for improving maize yield using BR hormones.

Coordinated regulation of starch synthesis in maize endosperm by microRNAs and DNA methylation.

Starch synthesis is an essential feature of crop filling, but knowledge of the molecular mechanisms regulating the expression of starch synthesis genes (SSGs) is currently limited to transcription factors (TFs). Here, we obtained transcriptome, small RNAome, and DNA methylome data from maize (Zea mays) endosperms during multiple developmental stages and established a regulatory network atlas of starch synthesis. Transcriptome analysis showed a sharp transition at 9-10 days after pollination, when genes involved in starch and sucrose metabolism are upregulated and starch accumulates rapidly. Expression pattern analysis established a comprehensive network between SSGs and TFs. During maize endosperm development, the miRNAs with preferential repression of the expression of TFs, particularly the TFs regulating SSG expression, were extensively downregulated. Specifically, ZmMYB138 and ZmMYB115 affected the transcriptional activities of Du1/Wx and Ae1/Bt2 genes at their respective promoter regions. Remarkably, the two TFs were negatively regulated by the copious expression of Zma-miR159k-3p at the post-transcriptional level. This suggests that miRNAs are important regulators of starch synthesis. Moreover, with the exclusion of the TFs, the expression of both SSGs and miRNAs was globally regulated by DNA methylation. Altogether, the present results (i) establish the regulatory functions of miRNAs and DNA methylation in starch synthesis and (ii) indicate that DNA methylation functions as a master switch.

Leaf trait association in relation to herbivore defense, drought resistance, and economics in a tropical invasive plant.

PREMISE: Exploring how functional traits vary and covary is important to understand plant responses to environmental change. However, we have limited understanding of the ways multiple functional traits vary and covary within invasive species. METHODS: We measured 12 leaf traits of an invasive plant Chromolaena odorata, associated with plant or leaf economics, herbivore defense, and drought resistance on 10 introduced populations from Asia and 12 native populations from South and Central America, selected across a broad range of climatic conditions, and grown in a common garden. RESULTS: Species' range and climatic conditions influenced leaf traits, but trait variation across climate space differed between the introduced and native ranges. Traits that confer defense against herbivores and drought resistance were associated with economic strategy, but the patterns differed by range. Plants from introduced populations that were at the fast-return end of the spectrum (high photosynthetic capacity) had high physical defense traits (high trichome density), whereas plants from native populations that were at the fast-return end of the spectrum had high drought escape traits (early leaf senescence and high percentage of withered shoots). CONCLUSIONS: Our results indicate that invasive plants can rapidly adapt to novel environmental conditions. Chromolaena odorata showed multiple different functional trait covariation patterns and clines in the native and introduced ranges. Our results emphasize that interaction between multiple traits or functions should be considered when investigating the adaptive evolution of invasive plants.

The Schiff Base Probe With J-aggregation Induced Emission for Selective Detection of Cu2.

Here, three Schiff bases 3a-c, differing by the substitutions (-H, -Cl, and -N(CH3)2) on the phenyl ring, have been designed and synthesized via the reaction of ortho-aminophenol with benzaldehyde, 2,4-dichlorobenzaldehyde and para-dimethylamine benzaldehyde in 1:1 molar ratio with favourable yields of 89-92%, respectively. Their structural characterizations were studied by FT-IR, NMR, MALDI-MS and elemental analysis. The fluorescence behaviours of compounds 3a and 3b exhibited a severe aggregation caused quenching (ACQ) effect in EtOH/water system. On the contrary, compound 3c had an obvious J-aggregation induced emission (AIE) feature in EtOH/water mixture (v/v = 1:1), and exhibited excellent sensitivity and anti-interference towards Cu2+ with the limit of detection (LOD) of 1.35 × 10-8 M. Job's plot analysis and MS spectroscopic study revealed the 2:1 complexation of probe 3c and Cu2+. In addition, probe 3c was successfully applied to the determination of Cu2+ in real aqueous samples.

Development and External Validation of a Model for Predicting Sufficient Filter Lifespan in Anticoagulation-Free Continuous Renal Replacement Therapy Patients.

BACKGROUND: Anticoagulation-free continuous renal replacement therapy (CRRT) was recommended by the current clinical guideline for patients with increased bleeding risk and contraindications of citrate. Nevertheless, anticoagulation-free CRRT yielded heterogeneous filter lifespan. Furthermore, the specific cutoff values for traditional coagulation parameters to predict sufficient filter lifespan of anticoagulation-free CRRT have not yet been determined. The purpose of our present study was to develop and validate a model for predicting sufficient filter lifespan in anticoagulation-free CRRT patients. METHODS: Patients who underwent anticoagulation-free CRRT in our center between June 2013 and June 2019 were retrospectively included. The primary outcome was sufficient filter lifespan (≥24 h). Thirty-seven predictors were included for modeling based on their clinical significance and previous reports. The final model was developed by using multivariable logistic regression analysis and was validated in a separate external cohort. RESULTS: The development cohort included 170 patients. Sufficient filter lifespan was observed in 80 patients. Thirteen variables were independent predictors for sufficient filter lifespan by logistic regression: body temperature, mean arterial pressure, activated partial thromboplastin time, direct bilirubin, alkaline phosphatase, blood urea nitrogen, vasopressor use, body mass index, white blood cell, platelet count, D-dimer, uric acid, and pH. The area under the curve (AUC) of the stepwise model and internal validation model was 0.82 (95% confidence interval [CI] [0.76-0.88]) and 0.8 (95% CI [0.74-0.87]), respectively. The positive predictive value and the negative predictive value of the stepwise model were 0.77 and 0.79, respectively. The validation cohort included 44 eligible patients and the AUC of the external validation model was 0.82 (95% CI [0.69-0.96]). CONCLUSIONS: The use of a prediction model instead of an assessment based only on coagulation parameters could facilitate the identification of the patients with filter lifespan of ≥24 h when they accepted anticoagulation-free CRRT.

Comparative Study of Starch Phosphorylase Genes and Encoded Proteins in Various Monocots and Dicots with Emphasis on Maize.

Starch phosphorylase (PHO) is a multimeric enzyme with two distinct isoforms: plastidial starch phosphorylase (PHO1) and cytosolic starch phosphorylase (PHO2). PHO1 specifically resides in the plastid, while PHO2 is found in the cytosol. Both play a critical role in the synthesis and degradation of starch. This study aimed to report the detailed structure, function, and evolution of genes encoding PHO1 and PHO2 and their protein ligand-binding sites in eight monocots and four dicots. "True" orthologs of PHO1 and PHO2 of Oryza sativa were identified, and the structure of the enzyme at the protein level was studied. The genes controlling PHO2 were found to be more conserved than those controlling PHO1; the variations were mainly due to the variable sequence and length of introns. Cis-regulatory elements in the promoter region of both genes were identified, and the expression pattern was analyzed. The real-time quantitative polymerase chain reaction indicated that PHO2 was expressed in all tissues with a uniform pattern of transcripts, and the expression pattern of PHO1 indicates that it probably contributes to the starch biosynthesis during seed development in Zea mays. Under abscisic acid (ABA) treatment, PHO1 was found to be downregulated in Arabidopsis and Hordeum vulgare. However, we found that ABA could up-regulate the expression of both PHO1 and PHO2 within 12 h in Zea mays. In all monocots and dicots, the 3D structures were highly similar, and the ligand-binding sites were common yet fluctuating in the position of aa residues.

Genome-wide identification of ZmSnRK2 genes and functional analysis of ZmSnRK2.10 in ABA signaling pathway in maize (Zea mays L).

BACKGROUND: Phytohormone abscisic acid (ABA) is involved in the regulation of a wide range of biological processes. In Arabidopsis, it has been well-known that SnRK2s are the central components of the ABA signaling pathway that control the balance between plant growth and stress response, but the functions of ZmSnRK2 in maize are rarely reported. Therefore, the study of ZmSnRK2 is of great importance to understand the ABA signaling pathways in maize. RESULTS: In this study, 14 ZmSnRK2 genes were identified in the latest version of maize genome database. Phylogenetic analysis revealed that ZmSnRK2s are divided into three subclasses based on their diversity of C-terminal domains. The exon-intron structures, phylogenetic, synteny and collinearity analysis indicated that SnRK2s, especially the subclass III of SnRK2, are evolutionally conserved in maize, rice and Arabidopsis. Subcellular localization showed that ZmSnRK2 proteins are localized in the nucleus and cytoplasm. The RNA-Seq datasets and qRT-PCR analysis showed that ZmSnRK2 genes exhibit spatial and temporal expression patterns during the growth and development of different maize tissues, and the transcript levels of some ZmSnRK2 genes in kernel are significantly induced by ABA and sucrose treatment. In addition, we found that ZmSnRK2.10, which belongs to subclass III, is highly expressed in kernel and activated by ABA. Overexpression of ZmSnRK2.10 partially rescued the ABA-insensitive phenotype of snrk2.2/2.3 double and snrk2.2/2.3/2.6 triple mutants and led to delaying plant flowering in Arabidopsis. CONCLUSION: The SnRK2 gene family exhibits a high evolutionary conservation and has expanded with whole-genome duplication events in plants. The ZmSnRK2s expanded in maize with whole-genome and segmental duplication, not tandem duplication. The expression pattern analysis of ZmSnRK2s in maize offers important information to study their functions. Study of the functions of ZmSnRK.10 in Arabidopsis suggests that the ABA-dependent members of SnRK2s are evolutionarily conserved in plants. Our study elucidated the structure and evolution of SnRK2 genes in plants and provided a basis for the functional study of ZmSnRK2s protein in maize.

Identification of quantitative trait loci for kernel-related traits and the heterosis for these traits in maize (Zea mays L.).

Heterosis has been extensively applied for many traits during maize breeding, but there has been relatively little attention paid to the heterosis for kernel size. In this study, we evaluated a population of 301 recombinant inbred lines derived from a cross between 08-641 and YE478, as well as 298 hybrids from an immortalized F2 (IF2) population to detect quantitative trait loci (QTLs) for six kernel-related traits and the mid-parent heterosis (MPH) for these traits. A total of 100 QTLs, six pairs of loci with epistatic interactions, and five significant QTL × environment interactions were identified in both mapping populations. Seven QTLs accounted for over 10% of the phenotypic variation. Only four QTLs affected both the trait means and the MPH, suggesting the genetic mechanisms for kernel-related traits and the heterosis for kernel size are not completely independent. Moreover, more than half of the QTLs for each trait in the IF2 population exhibited dominance, implying that dominance is more important than other genetic effects for the heterosis for kernel-related traits. Additionally, 20 QTL clusters comprising 46 QTLs were detected across ten chromosomes. Specific chromosomal regions (bins 2.03, 6.04-6.05, and 9.01-9.02) exhibited pleiotropy and congruency across diverse heterotic patterns in previous studies. These results may provide additional insights into the genetic basis for the MPH for kernel-related traits.

Regional citrate anticoagulation vs no-anticoagulation for CRRT in hyperlactatemia patients with increased bleeding risk: A retrospective cohort study.

There are controversial opinions on the use of regional citrate anticoagulation (RCA) continuous renal replacement therapy (CRRT) in hyperlactatemia patients with increased bleeding risk. Patients with hyperlactatemia and increased bleeding risk who accepted RCA or no-anticoagulation CRRT in our center were retrospectively included. Eighty patients who underwent RCA-CRRT and 47 patients received no-anticoagulation CRRT were included. Filter lifespan was significantly longer in the RCA group than the no-anticoagulation group (44.5 hours [2-89] vs 24.5 hours [1.5-70], P < .001). The adjusted results demonstrated that patients in the no-anticoagulant group had significantly higher risk of filter failure (HR = 4.765, 95% CI 2.703-8.4, P < .001). Bleeding episodes occurred in 19 (24.1%) and 22 (46.8%) patients in the RCA and no-anticoagulation group, respectively (P = .012). The overall citrate accumulation (CA) rate was 5% in the RCA group. Patient mortality was associated with the comorbidity of hypertension, increased serum lactate level, and increased SOFA score. After matching, the filter lifespan was significantly longer in the RCA group than the no-anticoagulation group. With careful monitoring and timely adjustment, RCA most likely was safe and effective for CRRT in hyperlactatemia patients with increased bleeding risk.

Regional Citrate Anticoagulation versus No-Anticoagulation for Continuous Venovenous Hemofiltration in Acute Severe Hypernatremia Patients with Increased Bleeding Risk: A Retrospective Cohort Study.

PURPOSE: This study was aimed at evaluating the efficacy and safety of regional citrate anticoagulation (RCA) versus no-anticoagulation continuous venovenous hemofiltration (CVVH) in acute severe hypernatremia patients with increased bleeding risk. MATERIALS AND METHODS: Acute severe hypernatremia patients with high bleeding risk who underwent CVVH in our center between January 2011 and October 2017 were considered as candidates. Patients who were <18 years old, with hypovolemic hypernatremia, and had systemic anticoagulation were excluded. The included patients were divided into RCA and no-anticoagulation groups according to their anticoagulation strategy during CVVH and matched by age, sequential organ failure assessment scores, and vasopressor dependency. RESULTS: Of the 64 included patients, no-anticoagulation and RCA were employed for CVVH in 23 and 41 patients, respectively. The serum sodium reduction rate (RRSeNa) was not significantly different between the no-anticoagulation and RCA groups (p = 0.729). Compared to no-anticoagulation, RCA significantly prolonged the circuit survival time (15 h [4.1-23.9] vs. 51 h [21.3-80.7], p = 0.001). The incidence of filter failure was 65.2% (15/23) in the no-anticoagulation group and 2.4% (1/41) in the RCA group (p < 0.001), respectively. In the matched cohort, the RRSeNas were not different between the 2 groups (p = 0.569), and the filter lifespan was significantly longer in the RCA group as well (p < 0.001). CONCLUSION: RCA might be safe and effective for acute severe hypernatremia patients who underwent CVVH treatment. Further prospective, randomized, control trials are warranted to obtain robust evidences.

Regional citrate anticoagulation versus low molecular weight heparin anticoagulation for continuous venovenous hemofiltration in patients with severe hypercalcemia: a retrospective cohort study.

PURPOSE: We conducted a retrospective study to evaluate the efficacy and safety of regional citrate anticoagulation (RCA) versus those of low molecular weight heparin (LMWH) anticoagulation for CVVH in severe hypercalcemia patients. METHODS: Between January 2014 and May 2019, 33 severe hypercalcemia patients underwent CVVH. Patients were divided into the RCA and LMWH groups. Calcium-free replacement solution was used. Serum total calcium reduction rate (RRSeCa), filter lifespan, bleeding, totCa/ionCa ratio, citrate accumulation, and catheter occlusion were evaluated as outcomes. RESULTS: RCA and LMWH were employed for CVVH in 14 and 43 filters, respectively. RRSeCa was not significantly different between the LMWH and RCA groups (p = .320), but RCA-CVVH was more effective in reducing ionized calcium at half of the time points (p < .05). RCA significantly prolonged the median filter lifespan (>72 h vs. 24.0 h [IQR, 15.0-26.0], p = .012). The incidence of filter failure was 55.8% (24/43) in the LMWH group and 21.4% (3/14) in the RCA group (p = .033). The adjusted results demonstrated that RCA could significantly reduce the risk of filter failure (p = .043, 95% CI 0.059-0.957, HR = 0.238). No citrate accumulation or bleeding episodes were observed in the RCA-CVVH group. Seven bleeding episodes (7/43, 16.3%) occurred in the LMWH-CVVH group. CONCLUSIONS: In patients with severe hypercalcemia who underwent CVVH, RCA more effectively decreased calcium levels and had a superior filter lifespan and no obvious adverse events compared with LMWH. Further prospective, randomized, controlled studies are warranted to obtain robust evidence.

Systematic identification and validation of the reference genes from 60 RNA-Seq libraries in the scallop Mizuhopecten yessoensis.

BACKGROUND: Reverse transcription quantitative PCR (RT-qPCR) is widely used for gene expression analysis in various organisms. Its accuracy largely relies on the stability of reference genes, making reference gene selection a vital step in RT-qPCR experiments. However, previous studies in mollusks only focused on the reference genes widely used in vertebrates. RESULTS: In this study, we conducted the transcriptome-wide identification of reference genes in the bivalve mollusk Mizuhopecten yessoensis based on 60 transcriptomes covering early development, adult tissues and gonadal development. A total of 964, 1210 and 2097 candidate reference genes were identified, respectively, resulting in a core set of 568 genes. Functional enrichment analysis showed that these genes are significantly overrepresented in Gene Ontology (GO) terms or Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways related to ribosomes, energy production, etc. Six genes (RS23, EF1A, NDUS4, SELR1, EIF3F, and OLA1) were selected from the candidate genes for RT-qPCR validation, together with 6 commonly used reference genes (ACT, CYTC, HEL, EF1B, GAPDH and RPL16). Stability analyses using geNorm, NormFinder and the comparative delta-Ct method revealed that the new candidate reference genes are more stable than the traditionally used genes, and ACT and CYTC are not recommended under either of the three circumstances. There was a significant correlation between the Ct of RT-qPCR and the log2(TPM) of RNA-Seq data (Ct = - 0.94 log2(TPM) + 29.67, R2 = 0.73), making it easy to estimate the Ct values from transcriptome data prior to RT-qPCR experiments. CONCLUSION: Our study represents the first transcriptome-wide identification of reference genes for early development, adult tissues, and gonadal development in the Yesso scallop and will benefit gene expression studies in other bivalve mollusks.

Genetic dissection of yield-related traits and mid-parent heterosis for those traits in maize (Zea mays L.).

BACKGROUND: Utilization of heterosis in maize could be critical in maize breeding for boosting grain yield. However, the genetic architecture of heterosis is not fully understood. To dissect the genetic basis of yield-related traits and heterosis in maize, 301 recombinant inbred lines derived from 08 to 641 × YE478 and 298 hybrids from the immortalized F2 (IF2) population were used to map quantitative trait loci (QTLs) for nine yield-related traits and mid-parent heterosis. RESULTS: We observed 156 QTLs, 28 pairs of loci with epistatic interaction, and 10 significant QTL × environment interactions in the inbred and hybrid mapping populations. The high heterosis in F1 and IF2 populations for kernel weight per ear (KWPE), ear weight per ear (EWPE), and kernel number per row (KNPR) matched the high percentages of QTLs (over 50%) for those traits exhibiting overdominance, whereas a notable predominance of loci with dominance effects (more than 70%) was observed for traits that show low heterosis such as cob weight per ear (CWPE), rate of kernel production (RKP), ear length (EL), ear diameter (ED), cob diameter, and row number (RN). The environmentally stable QTL qRKP3-2 was identified across two mapping populations, while qKWPE9, affecting the trait mean and the mid-parent heterosis (MPH) level, explained over 18% of phenotypic variations. Nine QTLs, qEWPE9-1, qEWPE10-1, qCWPE6, qEL8, qED2-2, qRN10-1, qKWPE9, qKWPE10-1, and qRKP4-3, accounted for over 10% of phenotypic variation. In addition, QTL mapping identified 95 QTLs that were gathered together and integrated into 33 QTL clusters on 10 chromosomes. CONCLUSIONS: The results revealed that (1) the inheritance of yield-related traits and MPH in the heterotic pattern improved Reid (PA) × Tem-tropic I (PB) is trait-dependent; (2) a large proportion of loci showed dominance effects, whereas overdominance also contributed to MPH for KNPR, EWPE, and KWPE; (3) marker-assisted selection for markers at genomic regions 1.09-1.11, 2.04, 3.08-3.09, and 10.04-10.05 contributed to hybrid performance per se and heterosis and were repeatedly reported in previous studies using different heterotic patterns is recommended.

Maize brachytic2 (br2) suppresses the elongation of lower internodes for excessive auxin accumulation in the intercalary meristem region.

BACKGROUND: Short internodes contribute to plant dwarfism, which is exceedingly beneficial for crop production. However, the underlying mechanisms of internode elongation are complicated and have been not fully understood. RESULTS: Here, we report a maize dwarf mutant, dwarf2014 (d2014), which displays shortened lower internodes. Map-based cloning revealed that the d2014 gene is a novel br2 allele with a splicing variation, resulting in a higher expression of BR2-T02 instead of normal BR2-T01. Then, we found that the internode elongation in d2014/br2 exhibited a pattern of inhibition-normality-inhibition (transient for the ear-internode), correspondingly, at the 6-leaf, 12-leaf and 14-leaf stages. Indeed, BR2 encodes a P-glycoprotein1 (PGP1) protein that functions in auxin efflux, and our in situ hybridization assay showed that BR2 was mainly expressed in vascular bundles of the node and internode. Furthermore, significantly higher auxin concentration was detected in the stem apex of d2014 at the 6-leaf stage and strictly in the node region for the ear-internode at the 14-leaf stage. In such context, we propose that BR2/PGP1 transports auxin from node to internode through the vascular bundles, and excessive auxin accumulation in the node (immediately next to the intercalary meristem) region suppresses internode elongation of d2014. CONCLUSIONS: These findings suggest that low auxin levels mediated by BR2/PGP1 in the intercalary meristem region are crucial for internode elongation.

The miR164-dependent regulatory pathway in developing maize seed.

MicroRNA164 (miR164) plays a key role in leaf and flower development, lateral root initiation, and stress responses. However, little is known about the regulatory roles of miR164 during seed development, particularly in maize. The aim of this study was to discover the developmental function of miR164 in maize seed. Small RNA sequencing (sRNA-seq) was performed at two key stages. The results indicated that miR164 was down-regulated during maize seed development. In addition, degradome library sequencing and transient expression assays identified the target genes for miR164. Two microRNA (miRNA) pairs, miR164-NAM, ATAF, and CUC32 (NAC32) and miR164-NAC40, were isolated. The developmental function of miR164 was determined by analyzing the differentially expressed genes (DEGs) between the wild-type and miR164 transgenic lines using RNA sequencing (RNA-seq) and by screening the DEGs related to NAC32 and NAC40 via co-expression and transient expression analysis. These results identified two beta-expansin genes, EXPB14 and EXPB15, which were located downstream of the NAC32 and NAC40 genes. This study revealed, for the first time, a miR164-dependent regulatory pathway, miR164-NAC32/NAC40-EXPB14/EXPB15, which participates in maize seed expansion. These findings highlight the significance of miR164 in maize seed development, and can be used to explore the role of miRNA in seed development.

Loss of p53 Sensitizes Cells to Palmitic Acid-Induced Apoptosis by Reactive Oxygen Species Accumulation.

Palmitic acid, the most common saturated free fatty acid, can lead to lipotoxicity and apoptosis when overloaded in non-fat cells. Palmitic acid accumulation can induce pancreatic ß-cell dysfunction and cardiac myocyte apoptosis. Under various cellular stresses, the activation of p53 signaling can lead to cell cycle arrest, DNA repair, senescence, or apoptosis, depending on the severity/type of stress. Nonetheless, the precise role of p53 in lipotoxicity induced by palmitic acid is not clear. Here, our results show that palmitic acid induces p53 activation in a dose- and time-dependent manner. Furthermore, loss of p53 makes cells sensitive to palmitic acid-induced apoptosis. These results were demonstrated in human colon carcinoma cells (HCT116) and primary mouse embryo fibroblasts (MEF) through analysis of DNA fragmentation, flow cytometry, colony formation, and Western blots. In the HCT116 p53-/- cell line, palmitic acid induced greater reactive oxygen species formation compared to the p53+/+ cell line. The reactive oxygen species (ROS) scavengers N-acetyl cysteine (NAC) and reduced glutathione (GSH) partially attenuated apoptosis in the HCT116 p53-/- cell line but had no obvious effect on the p53+/+ cell line. Furthermore, p53 induced the expression of its downstream target genes, p21 and Sesn2, in response to ROS induced by palmitic acid. Loss of p21 also leads to more palmitic acid-induced cell apoptosis in the HCT116 cell line compared with HCT116 p53+/+ and HCT116 p53-/-. In a mouse model of obesity, glucose tolerance test assays showed higher glucose levels in p53-/- mice that received a high fat diet compared to wild type mice that received the same diet. There were no obvious differences between p53-/- and p53+/+ mice that received a regular diet. We conclude that p53 may provide some protection against palmitic acid- induced apoptosis in cells by targeting its downstream genes in response to this stress.