Development and validation of an assessment index for quantifying cognitive task load in pilots under simulated flight conditions using heart rate variability and principal component analysis.

To investigate whether high cognitive task load (CTL) for aircraft pilots can be identified by analysing heart-rate variability, electrocardiograms were recorded while cadet pilots (n = 68) performed the plane tracking, anti-gravity pedalling, and reaction tasks during simulated flight missions. Data for standard electrocardiogram parameters were extracted from the R-R-interval series. In the research phase, low frequency power (LF), high frequency power (HF), normalised HF, and LF/HF differed significantly between high and low CTL conditions (p < .05 for all). A principal component analysis identified three components contributing 90.62% of cumulative heart-rate variance. These principal components were incorporated into a composite index. Validation in a separate group of cadet pilots (n = 139) under similar conditions showed that the index value significantly increased with increasing CTL (p < .05). The heart-rate variability index can be used to objectively identify high CTL flight conditions.Practitioner summary: We used principal component analysis of electrocardiogram data to construct a composite index for identifying high cognitive task load in pilots during simulated flight. We validated the index in a separate group of pilots under similar conditions. The index can be used to improve cadet training and flight safety.Abbreviations: ANOVA: a one-way analysis of variance; AP: anti-gravity pedaling task; CTL: cognitive task load; ECG: electrocardiograms; HR: heart rate; HRV: heart-rate variability; HRVI: heart-rate variability index; PT: plane-tracking task; RMSSD: root-mean square of differences between consecutive R-R intervals; RT: reaction task; SDNN: standard deviation of R-R intervals; HF: high frequency power; HFnu: normalized HF; LF: low frequency power; LFnu: normalized LF; PCA: principal component analysis.

Identification of watermelon H3K4 and H3K27 genes and their expression profiles during watermelon fruit development.

BACKGROUND: The ClaH3K4s and ClaH3K27s gene families are subfamilies of the SET family, each with a highly conserved SET structure domain and a PHD structural domain. Both participate in histone protein methylation, which affects the chromosome structure and gene expression, and is essential for fruit growth and development. METHODS AND RESULTS: In order to demonstrate the structure and expression characteristics of ClaH3K4s and ClaH3K27s in watermelon, members of the watermelon H3K4 and H3K27 gene families were identified, and their chromosomal localization, gene structure, and protein structural domains were analyzed. The phylogeny and covariance of the gene families with other species were subsequently determined, and the expression profiles were obtained by performing RNA-Seq and qRT-PCR. The watermelon genome had five H3K4 genes with 3207-8043 bp nucleotide sequence lengths and four H3K27 genes with a 1107-5499 bp nucleotide sequence. Synteny analysis revealed the close relationship between watermelon and cucumber, with the majority of members displaying a one-to-one covariance. Approximately half of the 'Hua-Jing 13 watermelon' ClaH3K4s and ClaH3K27s genes were expressed more in the late fruit development stages, while the changes were minimal for the remaining half. H3K4-2 expression was observed to be slightly greater on day 21 compared to other periods. Moreover, ClaH3K27-1 and ClaH3K27-2 were hardly expressed throughout the developing period, and ClaH3K27-4 exhibited the highest expression. CONCLUSION: These results serve as a basis for further functional characterization of the H3K4 and H3K27 genes in the fruit development of watermelon.

Comparative microbiome analysis reveals the variation in microbial communities between 'Kyoho' grape and its bud mutant variety.

Microbes are an important part of the vineyard ecosystem, which significantly influence the quality of grapes. Previously, we identified a bud mutant variety (named 'Fengzao') from 'Kyoho' grapes. The variation of microbial communities in grape and its bud mutant variety has not been studied yet. So, in this study, with the samples of both 'Fengzao' and 'Kyoho', we conducted high-throughput microbiome sequencing and investigated their microbial communities in different tissues. Obvious differences were observed in the microbial communities between 'Fengzao' and 'Kyoho'. The fruit and the stem are the tissues with relatively higher abundance of microbes, while the leaves contained less microbes. The fruit and the stem of 'Kyoho' and the stem of 'Fengzao' had relatively higher species diversity based on the alpha diversity analysis. Proteobacteria, Enterobacteriaceae and Rhodobacteraceae had significantly high abundance in 'Fengzao'. Firmicutes and Pseudomonas were highly abundant in the stems of 'Kyoho', and family of Spirochaetaceae, Anaplasmataceae, Chlorobiaceae, and Sphingomonadaceae, and genera of Spirochaeta, Sphingomonas, Chlorobaculum and Wolbachia were abundant in the fruits of 'Kyoho'. These identified microbes are main components of the microbial communities, and could be important regulators of grapevine growth and development. This study revealed the differences in the microbial compositions between 'Kyoho' and its bud mutant, and these identified microbes will be significant resources for the future researches on the quality regulation and disease control of grapevines.

Genome-wide characterization of long terminal repeat retrotransposons provides insights into trait evolution of four cucurbit species.

Cucurbits are a diverse plant family that includes economically important crops, such as cucumber, watermelon, melon, and pumpkin. Knowledge of the roles that long terminal repeat retrotransposons (LTR-RTs) have played in diversification of cucurbit species is limited; to add to understanding of the roles of LTR-RTs, we assessed their distributions in four cucurbit species. We identified 381, 578, 1086, and 623 intact LTR-RTs in cucumber (Cucumis sativus L. var. sativus cv. Chinese Long), watermelon (Citrullus lanatus subsp. vulgaris cv. 97103), melon (Cucumis melo cv. DHL92), and Cucurbita (Cucurbita moschata var. Rifu), respectively. Among these LTR-RTs, the Ale clade of the Copia superfamily was the most abundant in all the four cucurbit species. Insertion time and copy number analysis revealed that an LTR-RT burst occurred approximately 2 million years ago in cucumber, watermelon, melon, and Cucurbita, and may have contributed to their genome size variation. Phylogenetic and nucleotide polymorphism analyses suggested that most LTR-RTs were formed after species diversification. Analysis of gene insertions by LTR-RTs revealed that the most frequent insertions were of Ale and Tekay and that genes related to dietary fiber synthesis were the most commonly affected by LTR-RTs in Cucurbita. These results increase our understanding of LTR-RTs and their roles in genome evolution and trait characterization in cucurbits.

Proteome-Wide Identification of Non-histone Lysine Methylation during Grape Berry Ripening.

To gain a comprehensive understanding of non-histone methylation during berry ripening in grape (Vitis vinifera L.), the methylation of non-histone lysine residues was studied using a 4D label-free quantitative proteomics approach. In total, 822 methylation sites in 416 methylated proteins were identified, with xxExxx_K_xxxxxx as the conserved motif. Functional annotation of non-histone proteins with methylated lysine residues indicated that these proteins were mostly associated with "ripening and senescence", "energy metabolism", "oxidation-reduction process", and "stimulus response". Most of the genes encoding proteins subjected to methylation during grape berry ripening showed a significant increase in expression during maturation at least at one developmental stage. The correlation of methylated proteins with QTLs, SNPs, and selective regions associated with fruit quality and development was also investigated. This study reports the first proteomic analysis of non-histone lysine methylation in grape berry and indicates that non-histone methylation plays an important role in grape berry ripening.

Plant transcriptional memory and associated mechanism of abiotic stress tolerance.

Plants face various adverse environmental conditions, particularly with the ongoing changes in global climate, which drastically affect the growth, development and productivity of crops. To cope with these stresses, plants have evolved complex mechanisms, and one of the crucial ways is to develop transcriptional memories from stress exposure. This induced learning enables plants to better and more strongly restart the response and adaptation mechanism to stress when similar or dissimilar stresses reoccur. Understanding the molecular mechanism behind plant transcriptional memory of stress can provide a theoretical basis for breeding stress-tolerant crops with resilience to future climates. Here we review the recent research progress on the transcriptional memory of plants under various stresses and the applications of underlying mechanisms for sustainable agricultural production. We propose that a thorough understanding of plant transcriptional memory is crucial for both agronomic management and resistant breeding, and thus may help to improve agricultural yield and quality under changing climatic conditions.

Creation of a watermelon haploid inducer line via ClDMP3-mediated single fertilization of the central cell.

The use of doubled haploids is one of the most efficient breeding methods in modern agriculture. Irradiation of pollen grains has been shown to induce haploids in cucurbit crops, possibly because it causes preferential fertilization of the central cell over the egg cell. Disruption of the DMP gene is known to induce single fertilization of the central cell, which can lead to the formation of haploids. In the present study, a detailed method of creating a watermelon haploid inducer line via ClDMP3 mutation is described. The cldmp3 mutant induced haploids in multiple watermelon genotypes at rates of up to 1.12%. These haploids were confirmed via fluorescent markers, flow cytometry, molecular markers, and immuno-staining. The haploid inducer created by this method has the potential to greatly advance watermelon breeding in the future.

Genome-wide association study of 23 flowering phenology traits and 4 floral agronomic traits in tree peony (Paeonia section Moutan DC.) reveals five genes known to regulate flowering time.

Tree peony is a unique traditional flower in China, with large, fragrant, and colorful flowers. However, a relatively short and concentrated flowering period limits the applications and production of tree peony. A genome-wide association study (GWAS) was conducted to accelerate molecular breeding for the improvement of flowering phenology traits and ornamental phenotypes in tree peony. A diverse panel of 451 tree peony accessions was phenotyped for 23 flowering phenology traits and 4 floral agronomic traits over 3 years. Genotyping by sequencing (GBS) was used to obtain a large number of genome-wide single-nucleotide polymorphisms (SNPs) (107 050) for the panel genotypes, and 1047 candidate genes were identified by association mapping. Eighty-two related genes were observed during at least 2 years for flowering, and seven SNPs repeatedly identified for multiple flowering phenology traits over multiple years were highly significantly associated with five genes known to regulate flowering time. We validated the temporal expression profiles of these candidate genes and highlighted their possible roles in the regulation of flower bud differentiation and flowering time in tree peony. This study shows that GWAS based on GBS can be used to identify the genetic determinants of complex traits in tree peony. The results expand our understanding of flowering time control in perennial woody plants. Identification of markers closely related to these flowering phenology traits can be used in tree peony breeding programs for important agronomic traits.

Dissection of the Pearl of Csaba pedigree identifies key genomic segments related to early ripening in grape.

Pearl of Csaba (PC) is a valuable backbone parent for early-ripening grapevine (Vitis vinifera) breeding, from which many excellent early ripening varieties have been bred. However, the genetic basis of the stable inheritance of its early ripening trait remains largely unknown. Here, the pedigree, consisting of 40 varieties derived from PC, was re-sequenced for an average depth of ∼30×. Combined with the resequencing data of 24 other late-ripening varieties, 5,795,881 high-quality single nucleotide polymorphisms (SNPs) were identified following a strict filtering pipeline. The population genetic analysis showed that these varieties could be distinguished clearly, and the pedigree was characterized by lower nucleotide diversity and stronger linkage disequilibrium than the non-pedigree varieties. The conserved haplotypes (CHs) transmitted in the pedigree were obtained via identity-by-descent analysis. Subsequently, the key genomic segments were identified based on the combination analysis of haplotypes, selective signatures, known ripening-related quantitative trait loci (QTLs), and transcriptomic data. The results demonstrated that varieties with a superior haplotype, H1, significantly (one-way ANOVA, P < 0.001) exhibited early grapevine berry development. Further analyses indicated that H1 encompassed VIT_16s0039g00720 encoding a folate/biopterin transporter protein (VvFBT) with a missense mutation. VvFBT was specifically and highly expressed during grapevine berry development, particularly at veraison. Exogenous folate treatment advanced the veraison of "Kyoho". This work uncovered core haplotypes and genomic segments related to the early ripening trait of PC and provided an important reference for the molecular breeding of early-ripening grapevine varieties.

A simple and efficient protocol for transient transformation of sliced grape berries.

Grape is an economically important crop but recalcitrant to Agrobacterium-mediated genetic transformation and in vitro regeneration. Here, we have developed a protocol for transient transformation of grapes by investigating the effects of explant pre-culture and duration of vacuum infiltration on transformation efficiency. Using sliced grape berries of "Shine-Muscat" (Vitis labrusca × Vitis vinifera) between the end of fruit expansion phase and the mature stage as explants, we firstly compared the effect of pre-culture explants into a susceptible state (incubation on Murashige and Skoog (MS) agar plate in the dark at 25 ± 1 °C for 48 h) with no pre-culture and then tested different vacuum infiltration times on transformation efficiency using ß-glucuronidase (GUS) reporter system. Pre-culture increased the susceptibility of explants to the agrobacteria infection and increased transient transformation efficiency as assessed by histochemical GUS activity, with intense blue coloration compared with the faint staining observed in the non-susceptible explants. Using a Circulating Water Vacuum Pump system to facilitate agrobacteria entry into berry cells, we tested vacuum durations of 5, 10, and 15 min and observed that transformation efficiency increased with vacuum duration of infiltration. These results were confirmed by relative gene expression of GUS transgene as assessed by RT-qPCR and GUS activity assay. To further confirm the usefulness of our protocol, we transiently transformed grape berries with the hydrogen peroxide sensor gene VvHPCA3, and this was confirmed by gene expression analysis as well as increased sensitivity of the explants to hydrogen peroxide treatment. Overall, this study has resulted in a simple but efficient transient transformation protocol for grape berries and would be a valuable tool for the rapid testing of gene function and the study of key regulatory networks in this important crop.

Fragmentation Dynamics of a Carbon Dioxide Dication Produced by Ion Impact.

The response of carbon dioxide to radiolysis is crucial for understanding the atmospheric chemistry of planets. Here, we present a combined experimental and theoretical investigation of the three-body fragmentation dynamics of CO22+ to C+ + O+ + O initiated by 1 keV/u Ar2+ impact. Taking advantage of the kinematic complete measurement employing a reaction microscope, three dissociation mechanisms are distinguished, and their branching ratios are determined. The concerted fragmentation with two C-O bonds breaking simultaneously is dominant, while the sequential pathway with CO+ as the intermediate also makes a significant contribution. Also, a novel isomerization pathway with transitory formation of O2+ is identified. The identified mechanisms can contribute to O+ and O escaping from the Martian atmosphere, since the kinetic energies of most of the fragments are observed to be higher than the escape energy of oxygen.

Dormancy-release, germination and seedling growth of Paeonia ostii 'Fengdan' seeds under measures of physical and chemical treatment and sowing.

Paeonia ostii 'Fengdan', a woody oleaginous plant native from China, is considered an oil crop with economic potential. However, a low germination rate was still a restriction for Paeonia ostii 'Fengdan' production. The present research evaluated the germination, rooting and physiological characteristics of seedlings of Paeonia ostii 'Fengdan' in response to different physical treatments and the application of exogenous chemicals. Results indicated that seeds stored in sand at room temperature, and soaked in water for 3 days prior to planting, had a beneficial effect on hypocotyl dormancy-breaking. The rate of rooting and root growth of Paeonia ostii 'Fengdan' were significantly improved with 5 cm sowing depth in 15-20℃ soils. Compared with other sowing depths, the rooting percentage was significantly increased by 1.19% (2.5 cm), 0.98% (7.5 cm) and 1.47% (10 cm), respectively. Epicotyl dormancy was relieved when taproot length reached 50 mm. Soaking seeds in 0.76 mmol/L 5-aminolevulinic acid for 48 hours had the greatest beneficial effect on seed germination and seedling growth, the germination percentage was significantly increased by 4.25% (24 h) and 5.08% (72 h) compared with other treatments. While seed soaked in 10 mmol/L sodium nitroprusside for 48 hours also exhibited enhanced seedling growth, and the germination percentage was significantly increased by 4.36% (24 h) and 7.40% (72 h). Those results benefited seed germination and seedling growth of Paeonia ostii 'Fengdan' which could suggest the promotion of its industrial values and productive potentials. The mechanism of seed breaking dormancy and germination of Paeonia ostii 'Fengdan' needs further study.

Genome-wide identification and expression analysis of JmjC domain-containing genes in grape under MTA treatment.

Histone demethylases containing the JmjC domain play an extremely important role in maintaining the homeostasis of histone methylation and are closely related to plant growth and development. Currently, the JmjC domain-containing proteins have been reported in many species; however, they have not been systematically studied in grapes. In this paper, 21 VviJMJ gene family members were identified from the whole grape genome, and the VviJMJ genes were classified into five subfamilies: KDM3, KDM4, KDM5, JMJD6, and JMJ-only based on the phylogenetic relationship and structural features of Arabidopsis and grape. After that, the conserved sites of VviJMJ genes were revealed by protein sequence analysis. In addition, chromosomal localization and gene structure analysis revealed the heterogeneous distribution of VviJMJ genes on grape chromosomes and the structural features of VviJMJ genes, respectively. Analysis of promoter cis-acting elements demonstrated numerous hormone, light, and stress response elements in the promoter region of the VviJMJ genes. Subsequently, the grape fruit was treated with MTA (an H3K4 methylation inhibitor), which significantly resulted in the early ripening of grape fruits. The qRT-PCR analysis showed that VviJMJ genes (except VviJMJ13c) had different expression patterns during grape fruit development. The expression of VviJMJ genes in the treatment group was significantly higher than that in the control group. The results indicate that VviJMJ genes are closely related to grape fruit ripening.

Large-scale discovery of non-conventional peptides in grape (Vitis vinifera L.) through peptidogenomics.

Non-conventional peptides (NCPs), which are peptides derived from previously unannotated coding sequences, play important biological roles in plants. In this study, we used peptidogenomic methods that integrated mass spectrometry (MS) peptidomics and a six-frame translation database to extensively identify NCPs in grape. In total, 188 and 2021 non-redundant peptides from the Arabidopsis thaliana and Vitis vinifera L. protein database at Ensembl/URGI and an individualized peptidogenomic database were identified. Unlike conventional peptides, these NCPs derived mainly from intergenic, intronic, upstream ORF, 5'UTR, 3'UTR, and downstream ORF regions. These results show that unannotated regions are translated more broadly than we thought. We also found that most NCPs were derived from regions related to phenotypic variations, LTR retrotransposons, and domestication selection, indicating that the NCPs have an important function in complex biological processes. We also found that the NCPs were developmentally specific and had transient and specific functions in grape berry development. In summary, our study is the first to extensively identify NCPs in grape. It demonstrated that there was a large amount of translation in the genome. These results lay a foundation for studying the functions of NCPs and also provide a reference for the discovery of new functional genes in grape.

Identification of differentially expressed miRNAs and their target genes in response to brassinolide treatment on flowering of tree peony (Paeonia ostii).

Tree peony is a famous flower plant in China, but the short and concentrated flowering period limits its ornamental value and economic value. Brassinolide (BR) plays an important role in plant growth and development including flowering. There have been a large number of reports on the molecular aspects of the flowering process, but the genetic mechanism that was responsible for miRNA-guided regulation of tree peony is almost unclear. In this study, the leaves of tree peony cultivar, 'Feng Dan', were sprayed with different concentrations of BR, and the obvious bloom delay was found at the treatment with BR 50 µg/L. The small RNA sequencing and transcriptome sequencing were performed on the petals of tree peony under an untreated control (CK) and the treatment with BR 50 µg/L during four consecutive flowering development stages. A total of 22 known miRNAs belonging to 12 families were identified and 84 novel miRNAs were predicted. Combined with transcriptome data, a total of 376 target genes were predicted for the 18 differentially expressed known miRNAs and 177 target genes were predicted for the 23 differentially expressed novel miRNAs. Additionally, the potential miRNAs and their target genes were identified, including miR156b targeting SPL, miR172a_4 targeting AP2 and four novel miRNAs targeting SPA1, and revealed that they might affect the flowering time in tree peony. Collectively, these results would provide a theoretical basis for further analysis of miRNA-guided regulation on flowering period in tree peony.

Effectiveness and Practicality of eKTANG as a Digital Treatment for Diabetes and Relevant Influence Factors.

BACKGROUND: This work explored the effect of eKTANG, a new healthcare mode for diabetes patients, on diabetes management. METHODS: Allowing general utilization of medical service and health management based on Internet, eKTANG obtained the precise data like blood glucose and blood pressure examined by an intelligent glucometer, from which doctors and the nursing team will promptly analyze the data and return feedback to the patients. In our study, overall 204 patients receiving eKTANG management over 3 months in First Affiliated Hospital of Jinan University from May 2019 to Aug 2020 were enrolled as the research objects, with data collected from patient records. RESULTS: Through the biochemical test on relevant indexes of blood glucose, it was observed that FBG, PBG, HbA1c, TG, TC, LDL levels after management were lower than before whereas HDL expression after were lower than before. Contrasted with substandard group, standard group performed younger age, lower proportion of the married, decreased proportion of microvascular and macrovascular complications, longer course of disease, more frequent glucose monitoring, declined time of hyperglycemia and time of alarms, elevated time of euglycemia, increased proportion of diet control, more amount of exercise and higher compliance, as the number of patients choosing oral medicine in standard group was more than substandard group. The course of disease and time of hyperglycemia were risk factors of HbA1c standard reaching whereas frequency of glucose monitoring (≥1 time/week) and time of euglycemia were protective factors. CONCLUSION: eKTANG effectively improved diabetes management.

StWRKY13 promotes anthocyanin biosynthesis in potato (Solanum tuberosum) tubers.

Although the role of WRKY transcription factors (TFs) in colour formation has been reported in several species, their function in potato (Solanum tuberosum L.) anthocyanin biosynthesis remains unclear. In this study, the potato WRKY gene StWRKY13 was isolated and characterised. Expression analysis revealed a significantly higher StWRKY13 expression in chromatic tubers than in yellow ones. Transient activation assays showed that StWRKY13 could enhance the role of StAN2 in promoting anthocyanin biosynthesis in tobacco (Nicotiana tabacum L.). Over-expressing the StWRKY13 gene promoted anthocyanin biosynthesis in potato tubers. Further investigations indicated that StWRKY13 could interact with the StCHS, StF3H, StDFR, and StANS gene promoters and significantly enhance their activities. Our findings showed that StWRKY13 could promote anthocyanin biosynthesis by activating StCHS, StF3H, StDFR, and StANS transcription in potato tubers, thereby supporting the theoretical basis for anthocyanins formation in coloured potato tubers.

PtrMYB3, a R2R3-MYB Transcription Factor from Poncirus trifoliata, Negatively Regulates Salt Tolerance and Hydrogen Peroxide Scavenging.

MYB transcription factors are widely present in plants and play significant roles in abiotic stresses. However, most MYB genes have not been identified in plants and their functions in abiotic stresses are still unknown. In this study, one MYB gene, designated as PtrMYB3, was cloned from trifoliate orange (Poncirus trifoliata (L.) Raf.), and its function in salt tolerance was investigated. PtrMYB3 contains a conserved R2R3-MYB domain, which is the typical property of R2R3-MYB subfamily proteins. Expression profiling under abiotic stresses indicated that PtrMYB3 could be induced by salt, dehydration and cold stresses. PtrMYB3 was found to be localized to the nucleus and possessed transactivation activity. Overexpression of PtrMYB3 by genetic transformation in tobacco impaired its salt tolerance, whereas silencing of PtrMYB3 by VIGS (virus-induced gene silencing) in trifoliate orange conferred significantly enhanced salt tolerance, indicating that PtrMYB3 negatively regulates salt tolerance. Furthermore, a peroxidase gene (PtrPOD) was found to be greatly upregulated in PtrMYB3-silenced trifoliate orange, and a dual LUC (luciferase) assay confirmed that PtrMYB3 could suppress the expression of PtrPOD. The hydrogen peroxide (H2O2) accumulation in PtrMYB3 transgenic tobacco plants after salt stress was higher than the wild type (WT), further confirming that overexpression of PtrMYB3 inhibited PtrPOD-mediated H2O2 scavenging. Taken together, these results demonstrate that PtrMYB3 negatively regulates salt tolerance, at least in part, due to the excess accumulation of H2O2.