TPS Genes Research Articles

Identification of genes involved in oleoresin biosynthesis in Pinus massoniana through the combination of SMRT and Illumina sequencing

Oleoresin, a terpene with important economic and industrial value, is produced via the secondary metabolism of plants in the genus Pinus. Owing to its adaptability and high economic and ecological value, Pinus massoniana (Masson pine) is widely planted in southern China, and this species is also the main species for oleoresin tapping in the world. However, the differences in the expression of genes related to terpene biosynthesis in needles and xylem tissues at the transcriptional level at different time points during oleoresin tapping are still unclear. By combining SMRT and Illumina sequencing, we revealed the key genes involved in terpene biosynthesis in needles and xylem tissues. A total of 32.07 Gb of polymerase reads and 562.60 Gb of Illumina clean reads were obtained in this study. After annotating them in seven databases, we identified 68 genes involved in terpene biosynthesis, and most of them were highly expressed in needles, implying that needles are the biosynthetic sites of oleoresin. Moreover, we found that the TPS genes of gymnosperms more likely to be ‘DDXYD’, compared to the ‘DDXXD’ motif in angiosperms. The genes involved in the MEP pathway are highly expressed in the needles, implying the different efficiency of use of the MEP and MVA pathways in Masson pine. Furthermore, by performing controlled experiments, we found that PmPMK2, PmHDR1, PmTPS09, PmTPS11, PmTPS16, and PmTPS19 genes may play a critical role in oleoresin biosynthesis. This study provide new insights into terpene and oleoresin biosynthesis.

Genome‐wide characterization of the terpene synthase gene family in Ricinus communis and its transcriptional regulation under heat stress

AbstractTerpene synthase (TPS) genes are responsible for producing highly specialized metabolites that assist in the plant's response to biotic and abiotic stresses, ecological signaling, and the regulation of homeostasis. Ricinus communis L. is an important oilseed crop that can grow in harsh environments and still display good yield. Thus, we aimed at characterizing the TPS gene family in R. communis and its transcriptional regulation under heat stress. For that, bioinformatics and transcriptomics were used to characterize the R. communis TPS (RcTPS) family and to pinpoint potential candidate genes for further genomics studies focused on stress‐related agronomic problems. The R. communis genome possesses 46 TPS genes that were characterized by extensive bioinformatics, including phylogenetic analysis, subcellular localization, exon and intron distribution, and transcriptional regulatory regions. All 46 genes contained C‐ and N‐terminal Pfam domains (PF01397 and PF03936) characteristics of the TPS enzymes. These genes also showed the conserved motifs DDXXD, DXDD, NSE/DTE, and RRX8W. The TPS sequences were aligned with several model plant species, and the presence of the canonical motif DDXXD amongst them indicates that TPS genes were highly conserved during plant evolution. Transcriptomics indicated that 37 RcTPS genes are readily responsive to high‐temperature stress because they showed higher expression levels in seedlings growing at 35 °C compared with those growing at 20 and 25 °C. Altogether, TPS genes are potential candidates for genome editing techniques to develop abiotic stress‐tolerant crops.

Mechanism of HIF1-α-mediated regulation of Tribolium castaneum metabolism under high CO2 concentration elucidated

HIF1-α is an inducer that plays an important role in the regulation of hypoxia stress in insects in the way of regulating the corresponding enzyme activity which depends on the oxygen concentration through the hydroxylation of proline residues. In this study, we silenced HIF1-α expression in the model insect Tribolium castaneum under a hypoxic environment to explore its role in regulating metabolism in T. castaneum. We found that ATP and NAD + contents decreased significantly after HIF1-α interference at normoxic conditions, while activity of the soluble trehalase increased. The expression of TRE1-2, TRE1-3, TRE2, and TPS genes in the trehalose metabolism pathway were highly enhanced which are compared with normoxic conditions. Meanwhile, the expression of InR2 was significantly up-regulated, both of which play an important role in metabolism. We speculate that the enhancement of the insulin metabolic pathway may lead to enhanced glycolysis. We propose that the HIF1-α gene effectively regulates metabolism for T. castaneum to adapt to high CO2 concentrations in the environment. Our results provide a solid theoretical basis for controlling stored-grain pests incidence using high CO2 treatment.

Genome-wide identification of the trehalose-6-phosphate synthase gene family in sweet orange (Citrus sinensis) and expression analysis in response to phytohormones and abiotic stresses.

BackgroundTrehalose-6-phosphate synthase (TPS) is an essential enzyme for synthesizing trehalose and is a significant regulator of plant development and stress response. Sweet orange (Citrus sinensis) is an economically important fruit tree crop and a common transgenic material. At present, little information is available about the TPS gene family in sweet orange.MethodsThe TPS gene family were identified from sweet orange genome by bioinformatics analysis. Additionally, the expression of CisTPS genes was analyzed under phytohormones and abiotic stresses by quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR).ResultsHere, eight TPS genes were identified and were found to be randomly distributed in five sweet orange chromosomes. TPS and trehalose-6-phosphate phosphatase (TPP) domains were observed in all CisTPS proteins. The phylogenetic tree showed that CisTPS genes were divided into two subfamilies, and genes in each subfamily had conserved intron structures and motif compositions. The cis-acting elements of CisTPS genes suggested their roles in phytohormone and stress responses. All CisTPS genes were ubiquitously expressed in roots, leaves, and stems, and six members were highly expressed in roots. Expression profiles showed that CisTPS genes exhibited tissue specificity and were differentially expressed in response to phytohormones and abiotic stresses. This study lays a foundation for revealing the functions of the TPS gene family in trehalose regulation in sweet orange, and provides a valuable reference for this gene family in other plants.

Changes in the Physiological Adaptation and Regulation Ability in Harmonia axyridis under Chlorpyrifos and Imidacloprid Stress

As the dominant natural enemy of aphids, Harmonia axyridis plays a crucial role in integrated pest control (IPM) in agro-ecosystems. In order to study the physiological adaptation and regulation ability of Harmonia axyridis to insecticides under chemical pesticide stress, ladybirds were treated with organophosphorus chlorpyrifos (chlorpyrifos) and new nicotine imidacloprid (imidacloprid) to explore the physiological adaptability of ladybirds under chemical pesticide stress by activating trehalose metabolism. The results showed that the imidacloprid affect the larvae develop to pupate, resulted in the H. axyridis died and significantly increased the food consumption of Harmonia axyridis, while the chlorpyrifos prolong the development period of pupae significantly and decreased significantly the food intake of H. axyridis fed with aphids treated with chlorpyrifos. It was further found that Chlorpyrifos could inhibit the activity of the trehalase, while the trehalase activity increased under imidacloprid stress, but both insecticides could decrease the trehalose content. The TRE and TPS genes of Harmonia axyridis under chlorpyrifos and imidacloprid stress were upregulated or downregulated. These relevant results can provide a strong reference for the rational use of chemical pesticides or biological pesticides to control pests in the future.

Trehalose-6-phosphate synthase influences polysaccharide synthesis and cell wall components in Ganoderma lucidum.

Trehalose-6-phosphate synthase (TPS) is a key enzyme that participates in trehalose metabolism, which can synthesize trehalose in a two-step pathway with trehalose phosphatase, but its role in fungi is rarely studied, especially in large basidiomycetes. In this study, the tps gene of Ganoderma lucidum was cloned and named as gltps. And gltps-silenced strains were constructed by RNA interference. In this study, it is found that the extracellular polysaccharidecontent increased 1.6-2-fold, but there was no significant change on intracellular polysaccharidecontent in gltps-silenced strains compared with the wild-type (WT) strain. Furthermore, the cell wall compositions of the gltps-silenced strains were also altered, which showed that the chitin and β-1,3-glucan contents were significantly decreased. Compared with WT, the concentration of chitin decreased by 20%-50% and that of β-1, 3-glucan decreased by 15%-30%. The study found that the cells of gltps-silenced strains were more sensitive to cell wall stress, which might be due to changes in the compounds and structure of the cell wall. These results showed that gltps had an important effect on carbohydrate metabolism of G. lucidum cells.

Advances in Biosynthesis and Pharmacological Effects of Cinnamomum camphora (L.) Presl Essential Oil

Cinnamomum camphora (L.) Presl essential oil (CCEO) is a volatile oil with aroma and is extracted from various tissues of Cinnamomumcamphora. It is traditionally used as a spice, preservative, as an anti-inflammatory and for sterilization. Terpenoids are the main active components in CCEO. Based on currently available research, considerable effort is still needed to study the biosynthesis and regulation of terpenoids in CCEO. In this review, the research progress related to terpenoid biosynthesis and bioactivity in CCEO in recent years is summarized, with the data compiled and presented mainly from online resources such as PubMed, Scopus and CNKI in China up to May 2022. The research advances related to key enzymes in the terpenoid biosynthesis pathway are mainly discussed. Previous studies have isolated some genes encoding key enzymes involved in terpenoid biosynthesis; however, among these genes, only a few TPS genes have been verified to catalyze the production of terpenoid synthases at the protein level. Most genes encoding key enzymes have been cloned and isolated, but no transgenic experiments have been carried out to verify gene function. In-depth study of the biosynthesis of terpenoids in CCEO may contribute to a better understanding of the differential accumulation of terpenoids in different types of C. camphora and provide reference for improving terpenoid content in CCEO.

Secondary Metabolism Gene Diversity and Cocultivation toward Isolation and Identification of Potent Bioactive Compounds Producing Bacterial Strains from Thailand's Natural Resources.

Thailand was proposed to be rich unexplored source of microorganisms, especially bacterial strains. There should be bacteria with high secondary metabolite production potential in the natural resources that are still unidentified. Moreover, they might not produce secondary metabolites in standard laboratory culture condition after isolation, in which coculture condition would help us pursuing the bacteria to produce bioactive metabolites. Here, we aimed to identify new bacterial strains with high secondary metabolite production potential from Thailand's natural resources. To achieve the goal, we performed bacteria isolation, phylogenetic analysis, degenerate PCR of secondary metabolism genes, cocultivation, antibacterial analysis, and HPLC chemical profiling. We isolated distinct 40 bacterial strains, which have over 98% 16S rRNA sequence similarity with known species. There were 22, 31, and 29 strains giving positive PCR amplification of NRPS, PKS, and TPS genes, respectively. Among them, Bacillus licheniformis RSUCC0101 had the highest number of PCR products, 26. In standard single culture condition, crude extracts prepared from Bacillus safensis RSUCC0021 and Bacillus amyloliquefaciens RSUCC0282 could inhibit the growth of Staphylococcus aureus ATCC25923. Furthermore, the cocultivation and HPLC analyses showed that the extracts prepared from 3 pairs of culture between Staphylococcus sp. RSUCC0020, Micrococcus luteus RSUCC0053, Staphylococcus sp. RSUCC0087, and Staphylococcus pasteuri RSUCC0090 could inhibit the growth of Staphylococcus aureus ATCC25923 and produced distinct chemical profiles from their single culture condition. Our study led to the isolation and identification of several promising bacterial strains for production of secondary metabolites that might be useful in biomedical applications.

A Chromosome-Level Genome of the Camphor Tree and the Underlying Genetic and Climatic Factors for Its Top-Geoherbalism.

Camphor tree [Cinnamomum camphora (L.) J. Presl], a species in the magnoliid family Lauraceae, is known for its rich volatile oils and is used as a medical cardiotonic and as a scent in many perfumed hygiene products. Here, we present a high-quality chromosome-scale genome of C. camphora with a scaffold N50 of 64.34 Mb and an assembled genome size of 755.41 Mb. Phylogenetic inference revealed that the magnoliids are a sister group to the clade of eudicots and monocots. Comparative genomic analyses identified two rounds of ancient whole-genome duplication (WGD). Tandem duplicated genes exhibited a higher evolutionary rate, a more recent evolutionary history and a more clustered distribution on chromosomes, contributing to the production of secondary metabolites, especially monoterpenes and sesquiterpenes, which are the principal essential oil components. Three-dimensional analyses of the volatile metabolites, gene expression and climate data of samples with the same genotype grown in different locations showed that low temperature and low precipitation during the cold season modulate the expression of genes in the terpenoid biosynthesis pathways, especially TPS genes, which facilitates the accumulation of volatile compounds. Our study lays a theoretical foundation for policy-making regarding the agroforestry applications of camphor tree.

Genomic Analysis Based on Chromosome-Level Genome Assembly Reveals an Expansion of Terpene Biosynthesis of Azadirachta indica.

Azadirachta indica (neem), an evergreen tree of the Meliaceae family, is a source of the potent biopesticide azadirachtin. The lack of a chromosome-level assembly impedes an in-depth understanding of its genome architecture and the comparative genomic analysis of A. indica. Here, a high-quality genome assembly of A. indica was constructed using a combination of data from Illumina, PacBio, and Hi-C technology, which is the first chromosome-scale genome assembly of A. indica. Based on the length of our assembly, the genome size of A. indica is estimated to be 281 Mb anchored to 14 chromosomes (contig N50 = 6 Mb and scaffold N50 = 19 Mb). The genome assembly contained 115 Mb repetitive elements and 25,767 protein-coding genes. Evolutional analysis revealed that A. indica didn’t experience any whole-genome duplication (WGD) event after the core eudicot γ event, but some genes and genome segment might likely experienced recent duplications. The secondary metabolite clusters, TPS genes, and CYP genes were also identified. Comparative genomic analysis revealed that most of the A. indica-specific TPS genes and CYP genes were located on the terpene-related clusters on chromosome 13. It is suggested that chromosome 13 may play an important role in the specific terpene biosynthesis of A. indica. The gene duplication events may be responsible for the terpene biosynthesis expansion in A. indica. The genomic dataset and genomic analysis created for A. indica will shed light on terpene biosynthesis in A. indica and facilitate comparative genomic research of the family Meliaceae.

Chromosome-Scale Assembly of the Dendrobium nobile Genome Provides Insights Into the Molecular Mechanism of the Biosynthesis of the Medicinal Active Ingredient of Dendrobium.

Orchids constitute approximately 10% of flowering plant species. However, only about 10 orchid genomes have been published. Metabolites are the main way through which orchids respond to their environment. Dendrobium nobile, belonging to Dendrobium, the second largest genus in Orchidaceae, has high ornamental, medicinal, and ecological value. D. nobile is the source of many popular horticultural varieties. Among the Dendrobium species, D. nobile has the highest amount of dendrobine, which is regarded as one of the criteria for evaluating medicinal quality. Due to lack of data and analysis at the genomic level, the biosynthesis pathways of dendrobine and other related medicinal ingredients in D. nobile are unknown. In this paper, we report a chromosome-scale reference genome of D. nobile to facilitate the investigation of its genomic characteristics for comparison with other Dendrobium species. The assembled genome size of D. nobile was 1.19 Gb. Of the sequences, 99.45% were anchored to 19 chromosomes. Furthermore, we identified differences in gene number and gene expression patterns compared with two other Dendrobium species by integrating whole-genome sequencing and transcriptomic analysis [e.g., genes in the polysaccharide biosynthesis pathway and upstream of the alkaloid (dendrobine) biosynthesis pathway]. Differences in the TPS and CYP450 gene families were also found among orchid species. All the above differences might contribute to the species-specific medicinal ingredient biosynthesis pathways. The metabolic pathway-related analysis will provide further insight into orchid responses to the environment. Additionally, the reference genome will provide important insights for further molecular elucidation of the medicinal active ingredients of Dendrobium and enhance the understanding of orchid evolution.

Integrated application of Iso-seq and RNA-seq provides insights into unsynchronized growth in red swamp crayfish (Procambarus clarkii)

Red swamp crayfish is one of the most important freshwater shrimps with high economic value in China. The crayfish shows obvious sexual dimorphism in growth and secondary sex characteristics, however, the mechanisms underlying the growth of muscle tissue in the crayfish still remain unclear. Both high-throughput RNA-Seq and Iso-seq strategies were applied to reveal the molecular basis of the growth difference between fast-growing and slow-growing crayfish. After splicing and assembling, 63,350 genes with an average length of 2151 bp and N50 of 2568 bp were obtained. A total of 122 growth-related differentially expressed genes (DEGs) were identified, of which 87 genes were significantly up-regulated and 35 were down-regulated. Using quantitative PCR it was confirmed that the expressions of tps, inpp5l, flna, flnc, tpnc3 and other genes was higher in the fast-growing individuals. Subsequently, 144 genes differentially expressed between males and females were identified. 130 of them, 84 up-regulated and 46 down-regulated, were identified in the fast-growing group, while only 14 genes, 3 up-regulated and 11 down-regulated, were identified in the slow-growing group. The KEGG pathway enrichment analysis indicated that the identified DEGs were mainly involved in metabolic pathways, including arachidonic acid metabolism, glutathione metabolism, alanine, aspartate and glutamate metabolism. This study provides a basis for understanding the molecular mechanism of the sexual growth dimorphism and its application for future genetic breeding in red swamp crayfish.

Terpene synthases in cucumber (Cucumis sativus) and their contribution to herbivore-induced volatile terpenoid emission.

Summary Terpenoids play important roles in flavour, pollinator attraction and defence of plants. In cucumber (Cucumis sativus) they are important components of the herbivore‐induced plant volatile blend that attracts natural enemies of herbivores.We annotated the cucumber TERPENE SYNTHASE gene (CsTPS) family and characterized their involvement in the response towards herbivores with different feeding guilds using a combined molecular and biochemical approach.Transcripts of multiple CsTPS genes were upregulated in leaves upon herbivory and the products generated by the expressed proteins match the terpenoids recorded in the volatile blend released by herbivore‐damaged leaves. Spatial and temporal analysis of the promoter activity of CsTPS genes showed that cell content‐feeding spider mites (Tetranychus urticae) and thrips (Frankliniella occidentalis) induced promoter activity of CsTPS9 and CsTPS19 within hours after initiation of infestation, while phloem‐feeding aphids (Myzus persicae) induced CsTPS2 promoter activity.Our findings offer detailed insights into the involvement of the TPS gene family in the dynamics and fine‐tuning of the emission of herbivore‐induced plant volatiles in cucumber, and open a new avenue to understand molecular mechanisms that affect plant–herbivore interactions.

New Insights into Stress-Induced β-Ocimene Biosynthesis in Tea (Camellia sinensis) Leaves during Oolong Tea Processing.

As the major contributors to the floral odors of tea products, terpenoid volatiles play critical roles in the defense response of plants to multiple stresses. Until now, only a few TPS genes in tea plants (Camellia sinensis) have been functionally validated. In this study, by comparative studies conducted at gene, protein, and metabolite levels during oolong tea processing, we isolated an ocimene synthase gene, CsOCS, which displays a low similarity to previously characterized tea ocimene synthases. Further prokaryotic expression and subcellular localization analysis showed that it is plastid-located and could produce (E)-β-ocimene and (Z)-β-ocimene using GPP as the substrate. The optimum temperature and pH of the enzyme were 30 °C and 7.5, respectively. Treatment with exogenous methyl jasmonate elevated the transcript level of CsOCS and enhanced the emission of ocimene from tea leaves. Collectively, CsOCS is implicated as a key enzyme for β-ocimene synthesis during oolong tea processing.

Chromosome-scale assembly of the Dendrobium chrysotoxum genome enhances the understanding of orchid evolution

As one of the largest families of angiosperms, the Orchidaceae family is diverse. Dendrobium represents the second largest genus of the Orchidaceae. However, an assembled high-quality genome of species in this genus is lacking. Here, we report a chromosome-scale reference genome of Dendrobium chrysotoxum, an important ornamental and medicinal orchid species. The assembled genome size of D. chrysotoxum was 1.37 Gb, with a contig N50 value of 1.54 Mb. Of the sequences, 95.75% were anchored to 19 pseudochromosomes. There were 30,044 genes predicted in the D. chrysotoxum genome. Two whole-genome polyploidization events occurred in D. chrysotoxum. In terms of the second event, whole-genome duplication (WGD) was also found to have occurred in other Orchidaceae members, which diverged mainly via gene loss immediately after the WGD event occurred; the first duplication was found to have occurred in most monocots (tau event). We identified sugar transporter (SWEET) gene family expansion, which might be related to the abundant medicinal compounds and fleshy stems of D. chrysotoxum. MADS-box genes were identified in D. chrysotoxum, as well as members of TPS and Hsp90 gene families, which are associated with resistance, which may contribute to the adaptive evolution of orchids. We also investigated the interplay among carotenoid, ABA, and ethylene biosynthesis in D. chrysotoxum to elucidate the regulatory mechanisms of the short flowering period of orchids with yellow flowers. The reference D. chrysotoxum genome will provide important insights for further research on medicinal active ingredients and breeding and enhances the understanding of orchid evolution.

Integrated Signals of Jasmonates, Sugars, Cytokinins and Auxin Influence the Initial Growth of the Second Buds of Chrysanthemum after Decapitation.

Simple SummaryWe sequenced the first third-generation transcriptome of chrysanthemum and analyzed the factors involved in the outgrowth of the second buds after decapitation. In addition to classic hormones (auxin, cytokinins, and strigolactone), jasmonates and sugars were also found to be involved in this process, which might be related to the initiation of dormant buds.Decapitation is common in horticulture for altering plant architecture. The decapitation of chrysanthemum plants breaks apical dominance and leads to more flowers on lateral branches, resulting in landscape flowers with good coverage. We performed both third- and second-generation transcriptome sequencing of the second buds of chrysanthemum. This third-generation transcriptome is the first sequenced third-generation transcriptome of chrysanthemum, revealing alternative splicing events, lncRNAs, and transcription factors. Aside from the classic hormones, the expression of jasmonate-related genes changed because of this process. Sugars also played an important role in this process, with upregulated expression of sucrose transport-related and TPS genes. We constructed a model of the initial growth of the second buds after decapitation. Auxin export and sugar influx activated the growth of these buds, while the JA-Ile caused by wounding inhibited the expression of CycD genes from 0 h to 6 h. After wound recovery, cytokinins accumulated in the second buds and might have induced ARR12 expression to upregulate CycD gene expression from 6 h to 48 h, together with sugars. Therefore, jasmonates, cytokinins, sugars, and auxin work together to determine the fate of the buds of plants with short internodes, such as chrysanthemum.

Chromosome-scale genome assembly provides insights into the evolution and flavor synthesis of passion fruit (Passiflora edulis Sims)

Passion fruit (Passiflora edulis Sims) is an economically valuable fruit that is cultivated in tropical and subtropical regions of the world. Here, we report an ~1341.7 Mb chromosome-scale genome assembly of passion fruit, with 98.91% (~1327.18 Mb) of the assembly assigned to nine pseudochromosomes. The genome includes 23,171 protein-coding genes, and most of the assembled sequences are repetitive sequences, with long-terminal repeats (LTRs) being the most abundant. Phylogenetic analysis revealed that passion fruit diverged after Brassicaceae and before Euphorbiaceae. Ks analysis showed that two whole-genome duplication events occurred in passion fruit at 65 MYA and 12 MYA, which may have contributed to its large genome size. An integrated analysis of genomic, transcriptomic, and metabolomic data showed that ‘alpha-linolenic acid metabolism’, ‘metabolic pathways’, and ‘secondary metabolic pathways’ were the main pathways involved in the synthesis of important volatile organic compounds (VOCs) in passion fruit, and this analysis identified some candidate genes, including GDP-fucose Transporter 1-like, Tetratricopeptide repeat protein 33, protein NETWORKED 4B isoform X1, and Golgin Subfamily A member 6-like protein 22. In addition, we identified 13 important gene families in fatty acid pathways and eight important gene families in terpene pathways. Gene family analysis showed that the ACX, ADH, ALDH, and HPL gene families, especially ACX13/14/15/20, ADH13/26/33, ALDH1/4/21, and HPL4/6, were the key genes for ester synthesis, while the TPS gene family, especially PeTPS2/3/4/24, was the key gene family for terpene synthesis. This work provides insights into genome evolution and flavor trait biology and offers valuable resources for the improved cultivation of passion fruit.

Analysis of Relative Scent Intensity, Volatile Compounds and Gene Expression in Freesia "Shiny Gold".

Scent is one of the most important economic traits in Freesia hybrida. “Shiny Gold”, a popular cultivar in South Korea, is widely cultivated for its scent. The relative scent intensity of “Shiny Gold” was approximately 16% higher in full-bloomed flower when compared to the yellow bud stage, while tissue-specifically, tepals showed higher intensity in electronic-nose (e-nose) analysis. E-nose analysis also showed that the scent intensity of “Shiny Gold” was higher and lower than “10C3-424” and “10C3-894”, respectively, and was similar to “Yvonne”. These results correlated to those of the olfactory tests. In total, 19 volatile compounds, including linalool, β-ocimene, D-limonene, trans-β-ionone were detected in gas chromatography–mass spectrometry analysis. Among these, linalool was the major volatile compound, accounting for 38.7% in “Shiny Gold”. Linalool synthase and TPS gene expression corresponded to the scent intensity of the four cultivars, with the lowest expression in the “10C3-424”. TPS 2, TPS 3, TPS 5, TPS 6 and TPS 8 were highly expressed in both bud and flower in “Shiny Gold”, while the expression of TPS 4 was lower, relative to other TPS genes in both the flowering stages. These results may aid in enhancing scent composition in Freesia cultivars using marker-assisted selection.

Genetic Variation in Neisseria meningitidis Does Not Influence Disease Severity in Meningococcal Meningitis.

Neisseria meningitidis causes sepsis and meningitis in humans. It has been suggested that pathogen genetic variation determines variance in disease severity. Here we report results of a genome-wide association study of 486 N. meningitidis genomes from meningococcal meningitis patients and their association with disease severity. Of 369 meningococcal meningitis patients for whom clinical data was available, 44 (12%) had unfavorable outcome and 24 (7%) died. To increase power, thrombocyte count was used as proxy marker for disease severity. Bacterial genetic variants were called as k-mers, SNPs, insertions and deletions and clusters of orthologous genes (COGs). Population-level meningococcal genetic variation did not explain variance in disease severity (unfavorable outcome or thrombocyte count) in this cohort (h2 = 0.0%; 95% confidence interval: 0.0–0.9). Genetic variants in the bacterial uppS gene represented the top signal associated with thrombocyte count (p-value = 9.96e-07) but this did not reach statistical significance. We did not find an association between previously published variants in lpxL1, fHbp, and tps genes and unfavorable outcome or thrombocyte count. A power analysis based on simulated phenotypes based on real genetic data from 880 N. meningitidis genomes showed that we would be able to detect a continuous phenotype with h2 > = 0.5 with the population size available in this study. This rules out a major contribution of pathogen genetic variation to disease severity in meningococcal meningitis, and shows that much larger sample sizes are required to find specific low-effect genetic variants modulating disease outcome in meningococcal meningitis.

The sequence characteristics and functions on regulating trehalose metabolism of two PTP genes in Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae)

Protein tyrosine phosphatase is a type of enzyme commonly found in eukaryotes that specifically hydrolyzes tyrosine phosphate bonds on protein substrates to remove phosphate, thereby regulating protein functions or even cell functions. In this study, we used the model insect Tribolium castaneum to study the sequence characteristics and functions on trehalose metabolism of two PTP proteins in T. castaneum. We found that TcPTP1X1 and TcPTPIVA1 contain 190 and 177 amino acids, respectively. The results of phylogenetic analysis showed that PTP1 and PTPIVA1 are less well conserved across insect lineages. Examining the tissue and developmental expression patterns revealed that TcPTP1X1 and TcPTPIVA1 are expressed in various tissues and stages of T. castaneum; they are highly expressed in the tarsus during the pupal and adult stages. Compared with the negative control dsGFP group, almost all trehalase and 6-trehalose phosphate synthase genes were significantly down-regulated at 48 h after injection with dsPTP1X1 or dsPTPIVA1, except TRE1-3. At 72 h, many of the TRE and TPS genes appeared to return to normal levels or were even significantly upregulated compared with the control group. Silencing of TcPTP1X1 or TcPTPIVA1 altered the distribution of trehalose, glucose and glycogen in T. castaneum. Moreover, suppression of TcPTP1X1 or TcPTPIVA1 expression resulted in reduced adenosine triphosphate (ATP) content. We suggest that knockdown of TcPTP1X1 or TcPTPIVA1 impairs trehalose and energy metabolism in T. castaneum, and they may be new targets for control of storage pests.