Transcriptome and metabolome analysis reveals mechanism of light intensity modulating iridoid biosynthesis in Gentiana macrophylla Pall.

Light intensity is a key factor affecting the synthesis of secondary metabolites in plants. However, the response mechanisms of metabolites and genes in Gentiana macrophylla under different light intensities have not been determined. In the present study, G. macrophylla seedlings were treated with LED light intensities of 15 µmol/m2/s (low light, LL), 90 µmol/m2/s (medium light, ML), and 200 µmol/m2/s (high light, HL), and leaves were collected on the 5th day for further investigation. A total of 2162 metabolites were detected, in which, the most abundant metabolites were identified as flavonoids, carbohydrates, terpenoids and amino acids. A total of 3313 and 613 differentially expressed genes (DEGs) were identified in the LL and HL groups compared with the ML group, respectively, mainly enriched in KEGG pathways such as carotenoid biosynthesis, carbon metabolism, glycolysis/gluconeogenesis, amino acids biosynthesis, plant MAPK pathway and plant hormone signaling. Besides, the transcription factors of GmMYB5 and GmbHLH20 were determined to be significantly correlated with loganic acid biosynthesis; the expression of photosystem-related enzyme genes was altered under different light intensities, regulating the expression of enzyme genes involved in the carotenoid, chlorophyll, glycolysis and amino acids pathway, then affecting their metabolic biosynthesis. As a result, low light inhibited photosynthesis, delayed glycolysis, thus, increased certain amino acids and decreased loganic acid production, while high light got an opposite trend. Our research contributed significantly to understand the molecular mechanism of light intensity in controlling metabolic accumulation in G. macrophylla.

Five Pairs of Enantiomer as Rearrangement Products from Secoiridoids in Gentiana macrophylla Pall.

Five racemates (1-5) were isolated from Gentiana macrophylla, in which 2-5 were successfully separated into four pairs of enantiomers (2a and 2b, 3a and 3b, 4a and 4b, and 5a and 5b), whereas the resolution of 1 failed due to the hemiacetal functionality at the stereogenic center. Using electronic circular dichrosim calculation, the relationship of the molecular rotation direction and the carbon R/S chirality was revealed, and each pair of enantiomer was identified as (-)-(S)-gentianmacrol B (2a) and (+)-(R)-gentianmacrol B (2b), (-)-(S)-8-methoxy-gentianol (3a) and (+)-(R)-8-methoxy-gentianol (3b), (+)-(S)-8-methyl-gentianadine (4a) and (-)-(R)-8-methyl-gentianadine (4b), and (-)-(S)-gentianol (5a) and (+)-(R)-gentianol (5b). Besides, these compounds could be divided into two series, 1-2 containing the benzene ring moiety and 3-5 containing the pyridine ring moiety. Considering that their molecular skeleton could not be generated from the classical biosynthesis pathway in plants, the plausible biosynthesis pathways of 1-5 were deduced to be transformed from secoiridoids in G. macrophylla. Due to the significant difference in the pharmacological effect for the optical factor, our research provided new diverse molecules for further optical activity studies in drug research.

Genomic characterization of WRKY transcription factors related to secoiridoid biosynthesis in Gentiana macrophylla.

Gentiana macrophylla is one of Chinese herbal medicines in which 4 kinds of iridoids or secoiridoids, such as loganic acid, sweroside, swertiamarin, and gentiopicroside, are identified as the dominant medicinal secondary metabolites. WRKY, as a large family of transcription factors (TFs), plays an important role in the synthesis of secondary metabolites in plants. Therefore, WRKY genes involved in the biosynthesis of secoiridoids in G. macrophylla were systematically studied. First, a comprehensive genome-wide analysis was performed, and 42 GmWRKY genes were identified, which were unevenly distributed in 12 chromosomes. Accordingly, gene structure, collinearity, sequence alignment, phylogenetic, conserved motif and promoter analyses were performed, and the GmWRKY proteins were divided into three subfamilies based on phylogenetic and multiple sequence alignment analyses. Moreover, the enzyme-encoding genes of the secoiridoid biosynthesis pathway and their promoters were then analysed, and the contents of the four secoiridoids were determined in different tissues. Accordingly, correlation analysis was performed using Pearson's correlation coefficient to construct WRKY gene-enzyme-encoding genes and WRKY gene-metabolite networks. Meanwhile, G. macrophylla seedlings were treated with methyl jasmonate (MeJA) to detect the dynamic change trend of GmWRKYs, biosynthetic genes, and medicinal ingredient accumulation. Thus, a total of 12 GmWRKYs were identified to be involved in the biosynthesis of secoiridoids, of which 8 (GmWRKY1, 6, 12, 17, 33, 34, 38 and 39) were found to regulate the synthesis of gentiopicroside, and 4 (GmWRKY7, 14, 26 and 41) were found to regulate the synthesis of loganic acid. Taken together, this study systematically identified WRKY transcription factors related to the biosynthesis of secoiridoids in G. macrophylla, which could be used as a cue for further investigation of WRKY gene functions in secondary metabolite accumulation.

Comparison of Intergrowth-21st and Fenton growth standards to evaluate and predict the postnatal growth in eastern Chinese preterm infants.

Objectives: The aim of this article was to compare the differences between Intergrowth-21st (IG-21) and Fenton growth standards in the classification of intrauterine and extrauterine growth restriction (EUGR) in eastern Chinese preterm infants, and detect which one can better relate to neonatal diseases and predict the physical growth outcomes at 3-5 years old. Methods: Premature infants admitted to a tertiary pediatric hospital in Shanghai, China, from 2016 to 2018 were enrolled. Prenatal information, neonatal diseases during hospitalization, and anthropometric data (weight, height, and head circumference) at birth and at discharge were collected and analyzed. Physical growth outcomes (short stature, thinness, and overweight) were examined by telephone investigations in 2021 at age 3-5 years. Results: The medium gestational age and birth weight of the included 1,065 preterm newborns were 33.6 weeks and 1,900 g, respectively. The IG-21 curves diagnosed more newborns with small for gestational age (SGA) (19% vs. 14.7%) and fewer newborns with longitudinal EUGR on height (25.5% vs. 27.9%) and head circumference (17.9% vs. 24.7%) compared to Fenton curves. Concordances between Fenton and IG-21 standards were substantial or almost perfect in the classification of SGA and longitudinal EUGR, but minor in cross-sectional EUGR. EUGR identified by Fenton curves was better related to neonatal diseases than IG-21 curves. There were no statistical significances in the prediction of short stature, thinness, and overweight at 3-5 years old between the two charts. Conclusions: IG-21 growth standards are not superior to Fenton in assessing preterm growth and development in the eastern Chinese population.

Incidence of malnutrition and changes in phosphocalcic metabolism in perioperative liver transplantation patients -a retrospective study in a tertiary children's hospital in China.

BACKGROUND: The primary aim of the study was to assess the nutritional status of pediatric liver transplant outpatients in nutrition clinic, particularly the nutritional status of their bones.  METHODS: One hundred thirty-eight pediatric liver transplant outpatients, who had visited the nutrition clinic in Shanghai Children's Medical Center between January 2017 and December 2019, were recruited. The bone mineral density (BMD) z-scores were determined by dual energy X-ray absorptiometry (DXA). Nutritional assessment was performed, and their corresponding height-for-age z-scores (HAZs)/weight-for-age z-scores (WAZs)/BMI-for-age z-scores (BMIZs) were obtained. RESULTS: A total of 138 patients came to our nutrition outpatient clinic, including 68 boys (49.3%) and 70 girls (50.7%). The median age was 0.87y (0.68y, 1.71y). Among these patients, 44 (31.9%) had acute malnutrition with WAZ/BMIZ value -1.14 (-2.38, -0.18), 55 (38.4%) had chronic malnutrition with HAZ value -1.51 (-2.39, -0.38), and 96 (69.6%) had a BMD lower than normal. The BMD z-score was significantly correlated with the WAZ/BMIZ value (Spearman's correlation coefficient = 0.334, p < 0.001). A total of 37 infants re-visited the nutrition clinic for a follow-up after (147 ± 127) days. The WAZ/BMIZ value of the re-visiting patients and the BMD z-score of the re-visiting patients were significantly improved compared to those of the first-visit patients (p = 0.004 and p = 0.001 respectively). CONCLUSIONS: There were different rates of malnutrition before and after liver transplantation. At the same time, BMD Z-score and serum vitamin D level of patients decreased. There was a significant correlation between BMD z-scores and WAZ/BMIZ values. Proper and professional nutrition guidance significantly improved the WAZ/BMIZ-values and BMD Z-score of liver transplantation patients.

Extrauterine growth restriction in preterm infants: Postnatal growth pattern and physical development outcomes at age 3-6 years.

Objectives: To investigate the postnatal growth trajectories of preterm infants and evaluate the association between extrauterine growth restriction (EUGR) at discharge and adverse physical growth outcomes at age 3-6 years. Methods: Premature infants admitted to Shanghai Children's Medical Center within 24 h after birth from 1 January 2016 to 31 December 2018 were enrolled. Neonatal complications, nutrition support, and anthropometric data were collected and analyzed to diagnose EUGR on different definitions at discharge. The weight and the height of each subject were collected by telephone investigation from 1 September 2021 to 31 November 2021 to access the incidences of overweight/obesity, short stature, and thinness at age 3-6 years. Results: A total of 527 preterm infants were included in the final sample. The overall mean weight and height Z-scores were -0.37 ± 0.97 SD and -0.29 ± 1.18 SD at birth, and increased to -0.03 ± 1.11 SD and 0.13 ± 1.2 SD at follow-up, respectively. The logistic regression analysis indicated longitudinal EUGR on head circumference as the risk factor of overweight or obesity, cross-sectional EUGR on height as the risk factor of short stature, and delayed EN as the risk factor of thinness. Conclusion: The growth trajectories of the preterm newborns tended toward the normal direction. Longitudinal EUGR on the head circumference and cross-sectional EUGR on height at discharge were associated with adverse physical growth outcomes at age 3-6 years.

Assessment of nutritional status in paediatric outpatients using bioelectrical impedance analysis and anthropometric z-scores.

AIM: To investigate paediatric outpatients' nutritional status using bioelectrical impedance analysis and anthropometric z-scores. METHODS: A retrospective data analysis of tertiary paediatric hospital outpatients from 2017 to 2019 was conducted. Patients were categorised into three groups (non-illness, illness and simple obesity) according to clinical diagnoses. The nutritional status was evaluated using anthropometric and bioelectrical impedance analysis. In addition, body composition measurements of patients in three subgroups of the illness group and age- and gender-matched healthy controls were compared. RESULTS: A total of 2015 paediatric outpatients were enrolled. According to body mass index z-scores, undernutrition prevalence among participants was 14.0% (non-illness group, 21.3%; illness group, 11.4%). Body composition measurements indicated that 41.6% of participants had a low fat-free mass index, and the proportions of participants with a low fat-free mass index in the non-illness, illness and simple obesity groups were 48.4, 47.0 and 10.7%, respectively. Compared with healthy controls, the haematology and oncology subgroup had a significantly lower fat-free mass index and fat mass index; the nephrology and rheumatology subgroup had significantly lower height-for-age z-scores but higher fat mass index; and the gastroenterology subgroups had lower fat mass index, fat-free mass index and body mass index z-scores. CONCLUSIONS: The results suggested the low fat-free mass index prevalence was greater than the low body mass index z-score prevalence among paediatric outpatients, and body composition parameters varied across different illnesses. Body composition analysis is recommended in nutrition clinics for accurate paediatric outpatient nutritional assessment, thereby providing timely individualised nutritional interventions.

Arg-type dihydroflavonol 4-reductase genes from the fern Dryopteris erythrosora play important roles in the biosynthesis of anthocyanins.

Dihydroflavonol 4-reductase (DFR), a key enzyme involved in the biosynthesis of anthocyanins, has been cloned from various species. However, little research has been conducted on this enzyme in ferns, which occupy a unique evolutionary position. In this study, we isolated two novel DFR genes from the fern Dryopteris erythrosora. In vitro enzymatic analysis revealed that DeDFR1 and DeDFR2 enzymes can catalyze dihydrokaempferol and dihydroquercetin but cannot catalyze dihydromyricetin. Amino acid sequence analysis showed that DeDFR1 and DeDFR2 have an arginine at the same substrate-specificity-determining site as that in the ferns Salvinia cucullata and Azolla filiculoides. Thus, we speculate that the Arg-type DFR is a new DFR functional type. To further verify the substrate preferences of the Arg-type DFR, an amino acid substitution assay was conducted. When N133 was mutated to R133, Arabidopsis DFR protein completely lost its catalytic activity for dihydromyricetin, as observed for DeDFR1 and DeDFR2. Additionally, heterologous expression of DeDFR2 in the Arabidopsis tt3-1 mutant resulted in increasing anthocyanin accumulation. In summary, DeDFR1 and DeDFR2 are considered to be a new type of DFR with unique structures and functions. The discovery of the Arg-type DFR provides new insights into the anthocyanin biosynthesis pathway in ferns.

Adding nutrients to the biocontrol strain JK-SH007 promotes biofilm formation and improves resistance to stress.

Burkholderia pyrrocinia JK-SH007 is an important biocontrol strain for the prevention and treatment of poplar canker disease. Its powerful biocontrol function is inseparable from its successful colonization of poplar trees. Bacterial biofilms can ensure the long-term colonization of a host. To explore the mechanism of action of biofilms in the biocontrol process, we manipulated various exogenous factors to explore the morphology of the JK-SH007 biofilm in vitro. The addition of glycerol and MgSO4 to TSB medium stimulated biofilm production, increased the resistance of JK-SH007 to disease, enhanced the survival of JK-SH007 in nutrient-poor environments and maintained the antagonistic ability of JK-SH007 against the poplar canker pathogen. Therefore, we constructed and optimized a biofilm-forming system to produce a large number of stable JK-SH007 biofilms. The optimized system showed that the optimal incubation time for JK-SH007 biofilm formation was 14 h, the optimal temperature of the static culture was 25 °C, and the optimal pH was 5. The optimal medium for biofilm formation was TSB medium, 1% glycerol and 50 mM MgSO4. RT-qPCR experiments showed that an increase in the expression of the suhB gene promoted JK-SH007 biofilm formation, while an increase in the expression level of the ropN gene inhibited JK-SH007 biofilm formation. The possible mechanism by which JK-SH007 was inhibited by biofilm formation under natural culture was revealed. These results indicate the importance of adding nutrients to JK-SH007 biocides produced on a commercial scale. This is the first report of JK-SH007 producing a long-lasting biofilm that guarantees antagonism.

Indole-3-Acetic Acid in Burkholderia pyrrocinia JK-SH007: Enzymatic Identification of the Indole-3-Acetamide Synthesis Pathway.

Burkholderia pyrrocinia JK-SH007 is a plant growth-promoting bacteria (PGPB), that can promote the growth of poplar and other trees, and, production of the plant hormone indole-3-acetic acid (IAA) is one of the reasons for this effect. Therefore, the aims of this study were to evaluate the effect of the external environment on the synthesis of IAA by B. pyrrocinia JK-SH007 and to perform a functional analysis of its IAA synthesis pathway. In this study, IAA and its synthetic intermediates indole-3-acetamide (IAM), indole-3-pyruvic acid (IPyA), tryptamine (TAM), and indole-3-acetonitrile (IAN) were detected in B. pyrrocinia JK-SH007 fermentation broth by high-performance liquid chromatography and tandem mass spectrometry (HPLC-MS/MS), and these indolic compounds were also found in the cell-free extraction of B. pyrrocinia JK-SH007, but the genomic analysis of B. pyrrocinia JK-SH007 indicated that IAA biosynthesis was mainly through the IAM and TAM pathways. The effects of L-tryptophan (L-Trp), temperature and pH on the synthesis of IAA were investigated, and the results showed that L-Trp exerted a significant effect on IAA synthesis and that 37°C and pH 7 were the optimal conditions IAA production by B. pyrrocinia JK-SH007. In addition, the protein expression of tryptophan 2-monooxygenase and indoleacetamide hydrolase, which are the key enzymes of the indole acetamide-mediated IAA synthesis pathway, was analyzed, and their activity was verified by substrate feeding experiments. The results revealed the existence of an IAA synthesis pathway mediated by IAM and indicated that this pathway plays a role in B. pyrrocinia JK-SH007. This study lays the foundation for further exploration of the specific pathway and mechanism of IAA synthesis in B. pyrrocinia JK-SH007.

Proteomic analysis of gametophytic sex expression in the fern Ceratopteris thalictroides.

Ceratopteris thalictroides, a model fern, has two kinds of gametophytes with different sex expression: male and hermaphrodite. Hermaphroditic gametophytes have one or several archegonia beneath the growing point and a few antheridia at the base or margin. Male gametophytes show a spoon-like shape with much longer than the width and produce many antheridia at the margin and surface. The results of chlorophyll fluorescence detection showed that the photochemical efficiency of hermaphrodites was higher than that of males. By using two-dimensional electrophoresis and mass spectrometry, the differentially abundant proteins in hermaphroditic and male gametophytes were identified. A total of 1136 ± 55 protein spots were detected in Coomassie-stained gels of proteins from hermaphroditic gametophytes, and 1130 ± 65 spots were detected in gels of proteins from male gametophytes. After annotation, 33 spots representing differentially abundant proteins were identified. Among these, proteins involved in photosynthesis and chaperone proteins were over-represented in hermaphrodites, whereas several proteins involved in metabolism were increased in male gametophytes in order to maintain their development under relatively nutritionally deficient conditions. Furthermore, the differentially abundant cytoskeletal proteins detected in this study, such as centrin and actin, may be involved in the formation of sexual organs and are directly related to sex expression. These differentially abundant proteins are important for maintaining the development of gametophytes of different sexes in C. thalictroides.

Agronomic Management and Rice Varieties Controlling Cd Bioaccumulation in Rice.

Selection of rice varieties and application of amendments are effective measures to ensure food safety. Here we report that in the non-Cd area, the grain quality of all rice varieties met the Chinese National Grain Safety Standards (CNGSS). In the high-Cd area, rice varieties showed significant different bioaccumulation of Cd with lower rice yields than those in non-Cd area with the average decrease of 31.1%. There was a negative correlation between grain Cd content and yields. A total of 19 rice varieties were selected as low Cd accumulating rice varieties and their Cd content met CNGSS in the low-Cd area. Six of them met CNGSS in the high-Cd area. The application of amendments significantly reduced Cd content in rice grains by 1.0-84.7% with an average of 52.6% and 13 of varieties met CNGSS. The amendments reduced available Cd content in soils by 1.1-75.8% but had no significant effects on rice yields. Therefore, the current study implied that proper agronomic management with selection of rice varieties and soil amendments was essential in controlling Cd accumulation in rice grains.

The effect of postnatal manganese exposure on the NMDA receptor signaling pathway in rat hippocampus.

Overexposure to manganese (Mn) is associated with neurological disorders in children. Evidence indicated that N-methyl-d-aspartate (NMDA) receptor signaling pathway was critical for neurobehavioral function. However, whether NMDA receptor signaling pathway contributes to Mn-induced neurotoxicity remains unknown. In this study, newborn Sprague-Dawley rats were randomly assigned to four groups exposed to 0, 10, 20, and 30 mg/kg of Mn2+ by intraperitoneal injection (n = 10/group: five males and five females). After 3 weeks of Mn exposure, messenger RNA (mRNA) and protein expression of NMDA receptor subunits (NR1, NR2A, and NR2B), cAMP-response element binding protein (CREB), and brain-derived neurotrophic factor (BDNF) in hippocampus were measured by real-time quantitative RT-PCR and Western blot. In Mn-exposed rats, decreased mRNA and protein expression of NR1, NR2A, and NR2B, CREB, and BDNF was observed. The results imply that downregulated NMDA receptor signaling pathway may be of vital importance in the neuropathological process of Mn-induced neurotoxicity.

The effects of preweaning manganese exposure on spatial learning ability and p-CaMKIIα level in the hippocampus.

BACKGROUND: The effects and mechanisms of preweaning Manganese (Mn) exposure on cognitive dysfunction remain unclear. OBJECTIVE: This study evaluated the effects of preweaning Mn exposure on spatial learning and memory as well as the protein expression of CaMKIIα and p-CaMKIIα. METHODS: We treated neonate rats with Mn(2+) doses of 0 (control group), 10, 20 and 30mg of Mn(2+) per kg body weight (Mn-exposed groups) over postnatal day (PND) 1-21 by intraperitoneal injection. The ability of spatial learning and memory was tested on PND 22 using the Morris water maze (MWM), while the protein expressions of CaMKIIα and p-CaMKIIα in the hippocampus were evaluated by Western blotting. The levels of Mn in the blood and hippocampus were measured by inductively coupled plasma-mass spectrometry (ICP-MS). RESULTS: The rats in Mn-exposed groups showed a significant delay in spatial learning ability on the third day of the MWM without dose-dependent differences, but there was no effect on the spatial memory ability. p-CaMKIIα, but not CaMKIIα protein expression significantly reduced in the Mn-exposed group. CONCLUSION: These findings suggested that the inhibition of p-CaMKIIα could be one of the mechanisms involved in the occurrence of Mn-induced cognitive impairments.

Selenium protects neonates against neurotoxicity from prenatal exposure to manganese.

Manganese (Mn) exposure can affect brain development. Whether Selenium (Se) can protect neonates against neurotoxicity from Mn exposure remains unclear. We investigated this issue in 933 mother-newborn pairs in Shanghai, China, from 2008 through 2009. Umbilical cord serum concentrations of Mn and Se were measured and Neonatal Behavioral Neurological Assessment (NBNA) tests were conducted. The scores <37 were defined as the low NBNA. The median concentrations of cord serum Mn and Se were 4.0 µg/L and 63.1 µg/L, respectively. After adjusting for potential confounders, the interaction between Se and Mn was observed. Cord blood Mn levels had different effects on NBNA scores stratified by different cord blood Se levels. With Se

Different levels of prenatal zinc and selenium had different effects on neonatal neurobehavioral development.

Either deficient or excessive of essential nutrients had adverse effects. Effects of different levels of prenatal zinc (Zn) and selenium (Se) on fetal neurobehavioral development remain unclear. To determine the effects of different cord serum levels of Zn and Se on neurobehavioral development in neonates and to explore possible threshold level of Zn and Se based on fetal neurodevelopment, we conducted this epidemiological research. In the multi-center study, we investigated these questions in 927 mother-newborn pairs in Shanghai, China, from 2008 through 2009. Umbilical cord serum concentrations of Zn and Se were measured and Neonatal Behavioral Neurological Assessment (NBNA) tests were conducted. The median cord serum Zn and Se concentrations were 794.3 µg/L and 63.1 µg/L, respectively. A nonlinear relationship was observed between cord serum Zn and NBNA after adjusting for potential confounders. NBNA score decreased with increasing Zn levels after 794.3 µg/L (adjusted ß=-3.0, 95% CI: -3.6 to -2.4, p<0.001). Additionally, an invert U-shape with a threshold Se of 100 µg/L was observed between cord serum Se and NBNA. The adjusted regression coefficient was 4.4 (95% CI: 3.6-5.2, p<0.001) for Se<100 µg/L while -3.6 (95% CI: -6.1 to -1.1, p<0.01) for Se≥100 µg/L. Of the 927 infants, 50% had a high level Zn (≥794.3 µg/L) and 8.6% had a high level Se (≥100 µg/L). High levels of both Zn and Se mainly had adverse effects on behavior and passive tone (p<0.001). Taken together, our study suggested that a threshold of cord blood Zn and Se was existed for fetal neurodevelopment and the prevalence of excessive Zn was high. Thus, the supplementation of Zn during pregnancy should be considered with caution in Shanghai, China.