Search

Fructokinase (FRK) is the main fructose phosphorylase and plays an important role in catalyzing the irreversible reaction of free fructose phosphorylation. In order to study the regulatory effect of different forms and concentrations of nitrogen on PtFRK genes in Populus trichocarpa, seven genes encoding the hypothetical FRK proteins were identified in Populus trichocarpa genome by bioinformatics method. Phylogenetic analysis revealed that PtFRK family genes can be divided into two subgroups: SI (PtFRK 1, 3, 4, 6) and SII (PtFRK 2, 5, 7). The tissue-specific expression data obtained from PopGenIE indicate that PtFRK2, 3, 4 and 5 are expressed highly in the stem. Quantitative real-time RT-PCR illustrate that PtFRK1-7 showed different expression patterns in different tissues under different concentrations and morphological nitrogen application. Under high nitrate treatment, the expression levels of PtFRK1, 2, 3 and 6 in stem increased significantly, while under low nitrate treatment, only the expression of PtFRK1, 4 in the upper stem and the expression of PtFRK3, 5 in the lower stem increased significantly. In contrast, ammonium tends to inhibit the expression of PtFRKs in lower stems, the expression levels of PtFRK2, 3, 4 and 5 are significantly reduced under ammonium treatment. However, high ammonium had significant effects on PtFRK6 in the apical bud and upper leaves, which were 6 and 8 times of the control, respectively. These results laid the foundation for the study of the PtFRK gene family of poplar and provided a theoretical basis for the molecular mechanism of nitrogen regulating cell wall development.

Lignin is essential for the characteristics and quality of timber. Nitrogen has significant effects on lignin contents in plants. Nitrogen has been found to affect wood quality in plantations and lignin content in plants. Caffeoyl-CoA 3-O-methyltransferase (CCoAOMT) is an important methyltransferase in lignin biosynthesis. However, the classification of woody plant CCoAOMT gene family members and the regulation mechanism of nitrogen are not clear. Bioinformatics methods were used to predict the members, classification, and transcriptional distribution of the CCoAOMT gene family in Populus trichocarpa. The results showed that there were five PtCCoAOMTs identified, and they could be divided into three sub-groups according to their structural and phylogenetic features. The results of tissue expression specificity analysis showed that: PtCCoAOMT1 was highly expressed in roots and internodes; PtCCoAOMT2 was highly expressed in roots, nodes, and internodes, PtCCoAOMT3 was highly expressed in stems; PtCCoAOMT4 was highly expressed in young leaves, and, PtCCoAOMT5 was highly expressed in roots. Different forms and concentrations of nitrogen had varying effects on the expression patterns of genes in different plant tissue types. The results of real-time PCR showed that the expression levels of PtCCoAOMT1 and PtCCoAOMT2 in stems increased significantly under different forms of nitrogen. PtCCoAOMT3 and PtCCoAOMT4 were induced by nitrate nitrogen in upper stems and lower leaves, respectively. PtCCoAOMT4 and PtCCoAOMT5 were induced by different concentrations of nitrate nitrogen in lower stems and roots, respectively. These results could provide valuable information for revealing the differences between functions and expression patterns of the various CCoAOMT gene family members under different forms and concentrations of exogenous nitrogen in poplar.

Background Radial Polydactyly Type IV-D deformity is difficult to treat because of the most complex bone and soft tissue anomalies. Resection and reconstruction for one of the two thumbs was an option for treatment. Objective The study was to present our method of resection and reconstruction with a new incision for radial polydactyly Type IV-D and evaluate the clinical efficacy comprehensively using Rotterdam assessment system in a large sample. Methods 206 cases of type IV-D thumb duplication underwent resection and reconstruction surgical treatment between 2010 and 2019. Two equal triangle flap incisions were designed around the radial thumb. The radial thumb was resected and the ulnar thumb was reconstructed in aspects of bone, tendons, ligaments and abductor pollicis brevis. The clinical results were evaluated using Rotterdam assessment system. Results The mean follow–up period was 2.2 years (SD 1.5). The mean age of the patients was 9 months (SD 1.8) at the time of operation. The mean ranges of active IP and MP joint flexion and extension were 110° and 26°. The mean angulations for IP and MP joint instabilities were 3° and 11°, relatively. Angulation for palmar abduction was 58°. The mean appearance domain score was 8.9. The average parental satisfaction score was 2.5 and the average patient-reported pain score was 2.1. The mean functional domain score for all patients was 6.6. The average appearance domain score was 8.9. The mean patient-reported domain score was 4.5. The mean Rotterdam outcome score was 20.0, equivalent to 67% of the full score. The postoperative score of patients over two years old was significantly lower than that of patients under two years old. Conclusion Resection and reconstruction method with two equal triangle flap incisions was a recommended treatment for radial polydactyly Type IV-D. Level of evidence IV

The plant hormone auxin acts as a signaling molecule to regulate numerous developmental processes throughout all stages of plant growth. Understanding how auxin regulates various physiological and developmental processes has been a hot topic and an intriguing field. Recent studies have unveiled more molecular details into how diverse auxin responses function in every aspect of plant growth and development. In this review, we systematically summarized and classified the molecular mechanisms of diverse auxin responses, and comprehensively elaborated the characteristics and multilevel regulation mechanisms of the canonical transcriptional auxin response. On this basis, we described the characteristics and differences between different auxin responses. We also presented some auxin response genes that have been genetically modified in plant species and how their changes impact various traits of interest. Finally, we summarized some important aspects and unsolved questions of auxin responses that need to be focused on or addressed in future research. This review will help to gain an overall understanding of and some insights into the diverse molecular mechanisms of auxin responses in plant growth and development that are instrumental in harnessing genetic resources in molecular breeding of extant plant species.

Plant Pectin acetylesterase (PAE) belongs to family CE13 of carbohydrate esterases in the CAZy database. The ability of PAE to regulate the degree of acetylation of pectin, an important polysaccharide in the cell wall, affects the structure of plant cell wall. In this study, ten PtPAE genes were identified and characterized in Populus trichocarpa genome using bioinformatics methods, and the physiochemical properties such as molecular weight, isoelectric points, and hydrophilicity, as well as the secondary and tertiary structure of the protein were predicted. According to phylogenetic analysis, ten PtPAEs can be divided into three evolutionary clades, each of which had similar gene structure and motifs. Tissue-specific expression profiles indicated that the PtPAEs had different expression patterns. Real-time quantitative PCR (RT-qPCR) analysis showed that transcription level of PtPAEs was regulated by different CO2 and nitrogen concentrations. These results provide important information for the study of the phylogenetic relationship and function of PtPAEs in Populus trichocarpa.

Pectin is one of the most important components of the plant cell wall. Galacturonosyltransferase-like (GATL) is an important enzyme involved in forming pectin in Arabidopsis thaliana. In this study, 12 PtGATL genes were identified and characterized based on the Populus trichocarpa genome using bioinformatics methods. The results showed that the PtGATLs contained four typical motifs, including DXD, LPPF, GLG, and HXXGXXKPW. According to phylogenetic analysis, PtGATLs were divided into six groups. Chromosome distribution and genome synteny analysis showed that there were 11 segmental-duplicated gene pairs with repeated fragments on chromosomes 2, 5, 7, 8, 10, and 14. Tissue-specific expression profiles indicated that these PtGATLs had different expression patterns. The transcription level of PtGATLs was regulated by different carbon dioxide and nitrogen concentrations. In conclusion, the identification and analysis of PtGATL genes in poplar provide important information on the gene function. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-022-03129-y.

Plant Pectin acetylesterase (PAE) belongs to family CE13 of carbohydrate esterases in the CAZy database. The ability of PAE to regulate the degree of acetylation of pectin, an important polysaccharide in the cell wall, affects the structure of plant cell wall. In this study, ten PtPAE genes were identified and characterized in Populus trichocarpa genome using bioinformatics methods, and the physiochemical properties such as molecular weight, isoelectric points, and hydrophilicity, as well as the secondary and tertiary structure of the protein were predicted. According to phylogenetic analysis, ten PtPAEs can be divided into three evolutionary clades, each of which had similar gene structure and motifs. Tissue-specific expression profiles indicated that the PtPAEs had different expression patterns. Real-time quantitative PCR (RT-qPCR) analysis showed that transcription level of PtPAEs was regulated by different CO(2) and nitrogen concentrations. These results provide important information for the study of the phylogenetic relationship and function of PtPAEs in Populus trichocarpa. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-021-02918-1.

Plant UDP-glucose 6-dehydrogenase (UGDH) is an important enzyme for the formation of hemicellulose and pectin. Previous studies on UGDH have primarily focused on the biosynthesis of cell wall polysaccharides, while few studies have focused on their regulation by exogenous nitrogen. In the present study, four genes encoding PtUGDH proteins were analyzed by bioinformatics methods. And, the expression profiles of PtUGDH genes under different nitrogen treatments were evaluated with qRT-PCR. The results showed that PtUGDHs have conserved NAD coenzyme binding motif GAGYVGG and the catalytic motif GFGGSCFQKDIL. According to the phylogenetic analysis, PtUGDHs were divided into two subgroups. PtUGDH3 and PtUGDH4 were closely related to AtUGDH1 (important for normal development of Arabidopsis cell wall structure). Chromosomal distribution and genome synteny analysis revealed four segmental-duplicated gene pairs on chr4, 8, 10 and 17. Tissue-specific data from PlantGenIE showed that PtUGDH3 and PtUGDH4 were highly expressed in stems. The qRT-PCR detection showed that the expression of PtUGDH3 in the lower stem and PtUGDH2 of upper leaves were significantly increased induced by low ammonium or nitrate condition. This comprehensive analysis of the UGDH family in poplar provides new insights into their regulation by nitrogen, and would increase our understanding of the roles of UGDHs in hemicellulose and pectin biosynthesis in the cell wall and during poplar development.

Fructokinase (FRK) is the main fructose phosphorylase and plays an important role in catalyzing the irreversible reaction of free fructose phosphorylation. In order to study the regulatory effect of different forms and concentrations of nitrogen on PtFRK genes in Populus trichocarpa, seven genes encoding the hypothetical FRK proteins were identified in Populus trichocarpa genome by bioinformatics method. Phylogenetic analysis revealed that PtFRK family genes can be divided into two subgroups: SI (PtFRK 1, 3, 4, 6) and SII (PtFRK 2, 5, 7). The tissue-specific expression data obtained from PopGenIE indicate that PtFRK2, 3, 4 and 5 are expressed highly in the stem. Quantitative real-time RT-PCR illustrate that PtFRK1-7 showed different expression patterns in different tissues under different concentrations and morphological nitrogen application. Under high nitrate treatment, the expression levels of PtFRK1, 2, 3 and 6 in stem increased significantly, while under low nitrate treatment, only the expression of PtFRK1, 4 in the upper stem and the expression of PtFRK3, 5 in the lower stem increased significantly. In contrast, ammonium tends to inhibit the expression of PtFRKs in lower stems, the expression levels of PtFRK2, 3, 4 and 5 are significantly reduced under ammonium treatment. However, high ammonium had significant effects on PtFRK6 in the apical bud and upper leaves, which were 6 and 8 times of the control, respectively. These results laid the foundation for the study of the PtFRK gene family of poplar and provided a theoretical basis for the molecular mechanism of nitrogen regulating cell wall development. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12298-021-01055-6.

Plant UDP-glucose 6-dehydrogenase (UGDH) is an important enzyme for the formation of hemicellulose and pectin. Previous studies on UGDH have primarily focused on the biosynthesis of cell wall polysaccharides, while few studies have focused on their regulation by exogenous nitrogen. In the present study, four genes encoding PtUGDH proteins were analyzed by bioinformatics methods. And, the expression profiles of PtUGDH genes under different nitrogen treatments were evaluated with qRT-PCR. The results showed that PtUGDHs have conserved NAD coenzyme binding motif GAGYVGG and the catalytic motif GFGGSCFQKDIL. According to the phylogenetic analysis, PtUGDHs were divided into two subgroups. PtUGDH3 and PtUGDH4 were closely related to AtUGDH1 (important for normal development of Arabidopsis cell wall structure). Chromosomal distribution and genome synteny analysis revealed four segmental-duplicated gene pairs on chr4, 8, 10 and 17. Tissue-specific data from PlantGenIE showed that PtUGDH3 and PtUGDH4 were highly expressed in stems. The qRT-PCR detection showed that the expression of PtUGDH3 in the lower stem and PtUGDH2 of upper leaves were significantly increased induced by low ammonium or nitrate condition. This comprehensive analysis of the UGDH family in poplar provides new insights into their regulation by nitrogen, and would increase our understanding of the roles of UGDHs in hemicellulose and pectin biosynthesis in the cell wall and during poplar development. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-021-02697-9.

Reversible glycosylation polypeptide (RGP) is a type of plant-specific protein, primarily involved in the biosynthesis of cell wall polysaccharides, which in turn changes the shape of the cell walls and affects the wood properties of plants. Poplar is a major industrial timber species, and the RGP gene has not been studied. This study uses bioinformatics methods to predict physical and chemical characters such as molecular weight, isoelectric point, and hydrophilicity; and fluorescent quantitative method to determine the effect of different forms of nitrogen on the transcription level of the gene family. The results showed that there are six RGP homologous genes in the Populus trichocarpa genome, which were distributed on the six chromosomes of P. trichocarpa. The family members have a simple gene structure and contain four exons and introns. Phylogenetic tree analysis showed that RGP genes all belong to Class I in P. trichocarpa. Tissue-specific expression analysis showed that PtRGP1 and PtRGP2 were highly expressed in the stems, PtRGP4 and PtRGP5 were highly expressed in the upper leaves, PtRGR3 and PtRGR6 were expressed in stems and internodes, but the relative expression is not high. Quantitative real-time RT-PCR (qRT-PCR) analyses revealed that PtRGP3 and 6 were up-regulated in the upper stem in response to the low ammonium and high nitrate treatments. The influence of nitrogen on the expression of PtRGP3 and 6 genes may affect the formation of the plant secondary cell wall. This study lays a foundation for further study on the function of RGP genes in P. trichocarpa.

Plant litter will influence the bioavailability of heavy metals in sediments of wetlands used to treat acid mine drainage. To investigate the effect of plant litter on sediments in wetlands and define the comprehensive and continuous role of plant litter, different mass ratios (0%, 5%, 20%) of litter were added into the sediments to study the influence of litter decomposition on the overlying water and sediments. The changes in pH, EC, Eh, Fe, and Mn of the overlying water and the organic matter in the sediments and the forms of Fe and Mn after 1, 7, 14, 21, and 28 days of litter decomposition were studied. The results indicated that litter decomposition increased the pH, EC, and reduced Eh of the overlying water. Litter decomposition promoted the release of Fe and Mn from the sediments into the overlying water and with the continuous decomposition of litter, the concentration of Fe and Mn in the overlying water declined. Litter decomposition increased the content of the organic matter in the sediment, and the forms of Fe and Mn indicated that litter decomposition could significantly affect the transformation of the forms of Fe and Mn. Reducible Fe was the main form in the sediments. Litter decomposition promoted the transformation of reducible Fe, the main form found in the sediments, into exchangeable and oxidizable Fe, but had no effect on residual form. Exchangeable Mn was the main form in the sediments, and litter decomposition accelerated the transformation of reducible Mn, most commonly found in the sediments, into oxidizable Mn and had little influence on the exchangeable and residual forms.

Orchard grass coverage has been widely adopted to increase fruit yield by improving soil fertility. However, the impact of the environment on the changes in soil organic carbon (SOC) stocks consecutive to orchard grass coverage remain poorly quantified at a large scale. The present study aimed to examine the responses of SOC stocks to grass coverage at a soil depth of 0-30 cm in orchards compared to clean tillage. A total of 342 observations across China from 139 peer-reviewed publications were subjected to meta-analysis. Aggregated boosted tree analysis was performed, evaluating the determinants of SOC stocks, such as plant traits (e.g., fruit tree type, grass type, orchard age, and grass age), edaphic variables (e.g., initial SOC and nitrogen concentration, soil pH, and soil clay content), climatic factors (e.g., mean annual precipitation (MAP) and mean annual temperature (MAT)), and management practices (e.g., grass source, grass growing mode, fertilization, grass mowing, placement of mowed residues, and irrigation). On average, orchard grass coverage significantly enhanced SOC stocks by 21.47% (percentage change) compared to clean tillage. Biotic and abiotic factors influenced this increase in SOC stocks following grass coverage in orchards to different extents. Grass age and soil clay content were the main determinants driving the variation in the SOC stocks following grass coverage in orchards. Thus, we propose an efficient way to optimize C sequestration in grass covered orchards, regarding plant traits, climatic factors, edaphic variables, and management practices. Longer than 12 months of surface grass coverage with cultivated grass species in mature deciduous fruit orchards (≥5 years) efficiently increased SOC stocks. This is particularly the case for acidic (pH 6.5) soils with low C content (SOM 15 g kg

Lignin is essential for the characteristics and quality of timber. Nitrogen has significant effects on lignin contents in plants. Nitrogen has been found to affect wood quality in plantations and lignin content in plants. Caffeoyl-CoA 3-O-methyltransferase (CCoAOMT) is an important methyltransferase in lignin biosynthesis. However, the classification of woody plant CCoAOMT gene family members and the regulation mechanism of nitrogen are not clear. Bioinformatics methods were used to predict the members, classification, and transcriptional distribution of the CCoAOMT gene family in Populus trichocarpa. The results showed that there were five PtCCoAOMTs identified, and they could be divided into three sub-groups according to their structural and phylogenetic features. The results of tissue expression specificity analysis showed that: PtCCoAOMT1 was highly expressed in roots and internodes; PtCCoAOMT2 was highly expressed in roots, nodes, and internodes, PtCCoAOMT3 was highly expressed in stems; PtCCoAOMT4 was highly expressed in young leaves, and, PtCCoAOMT5 was highly expressed in roots. Different forms and concentrations of nitrogen had varying effects on the expression patterns of genes in different plant tissue types. The results of real-time PCR showed that the expression levels of PtCCoAOMT1 and PtCCoAOMT2 in stems increased significantly under different forms of nitrogen. PtCCoAOMT3 and PtCCoAOMT4 were induced by nitrate nitrogen in upper stems and lower leaves, respectively. PtCCoAOMT4 and PtCCoAOMT5 were induced by different concentrations of nitrate nitrogen in lower stems and roots, respectively. These results could provide valuable information for revealing the differences between functions and expression patterns of the various CCoAOMT gene family members under different forms and concentrations of exogenous nitrogen in poplar.

Asparagine synthetase (AS), a key enzyme in plant nitrogen metabolism, plays an important role in plant nitrogen assimilation and distribution. Asparagine (Asn), the product of asparagine synthetase, is one of the main compounds responsible for organic nitrogen transport and storage in plants. In this study, we performed complementation experiments using an Asn-deficient Escherichia coli strain to demonstrate that three putative asparagine synthetase family members in poplar (Populus simonii &times, P. nigra) function in Asn synthesis. Quantitative real-time PCR revealed that the three members had high expression levels in different tissues of poplar and were regulated by exogenous nitrogen. PnAS1 and PnAS2 were also affected by diurnal rhythm. Long-term dark treatment resulted in a significant increase in PnAS1 and PnAS3 expression levels. Under long-term light conditions, however, PnAS2 expression decreased significantly in the intermediate region of leaves. Exogenous application of ammonium nitrogen, glutamine, and a glutamine synthetase inhibitor revealed that PnAS3 was more sensitive to exogenous glutamine, while PnAS1 and PnAS2 were more susceptible to exogenous ammonium nitrogen. Our results suggest that the various members of the PnAS gene family have distinct roles in different tissues and are regulated in different ways.

Afforestation made great contributions to ecological benefits across China. Robinia pseudoacacia is widely used in the Grain-for-Green Program. The responses of soil organic carbon (SOC) and soil total nitrogen (STN) to afforestation with R. pseudoacacia on cropland depend on plantation attributes, climatic factors, topographic features, and edaphic variables, thus making a synthesis of these studies necessary for understanding the magnitude and direction of SOC and STN to afforestation and the associated regulating factors. A meta-analysis was employed by compiling data of 1202 paired observations from 94 peer-reviewed publications to depict potential mechanisms of change in SOC and STN stocks following afforestation with R. pseudoacacia on cropland. Afforestation with R. pseudoacacia on cropland, on average, significantly and positively increased SOC and STN stocks. The changes in SOC and STN stocks increased with plantation age and altitude, but decreased with mean annual temperature, slope gradients, soil depth, soil clay content, initial SOC content and initial STN content. Greater accumulation rates of SOC and STN stocks after afforestation were detected in middle canopy density (0.6–0.8) and middle mean annual precipitation (450–550 mm). Among four kinds of biotic and abiotic factors, plantation attributes made greatest contributes to the variance in the response size of SOC and STN stocks. In particular, plantation age was the most essential variable on the response size of SOC and STN stocks. These results indicated that SOC and STN stocks following afforestation with R. pseudoacacia on cropland could be enhanced through plantation management practices.

INTRODUCTION The aim of this study was to determine the value of Doppler sonography for evaluation of ulnar neuropathy at the elbow (UNE). METHODS A total of 102 patients with a clinical suspicion of UNE and 50 healthy controls were examined by Doppler and gray-scale sonography. RESULTS Intraneural vascularization was found in 31 (46.3%) of 67 patients with confirmed UNE and in 3 (6.0%) of 50 healthy controls. Combining gray-scale sonography measurement of nerve size and the presence of intraneural vascularization increased sensitivity by 3%, but decreased the specificity. Patients with intraneural vascularization had more severe disease than those without intraneural vascularization (P < 0.05). The variables obtained by Doppler sonography were associated with the severity of UNE (P < 0.05). CONCLUSIONS Doppler sonography is not helpful for diagnosing UNE but can be used to assess the severity of UNE. Muscle Nerve 54: 258-263, 2016.

To identify palmar cutaneous branches of median nerve and ulnar nerve (PCBMN and PCBUN) and try to find a safe path at wrist and forearm in the decompression procedure of carpal tunnel syndrome. Ten formalin-fixed and five fresh-frozen cadaveric forearms were included in the study. The cross point of longitude of middle finger and distal wrist crease was defined as 0 point. Distal wrist crease (DWC) and 0 point were chosen as references for measurements. Several points on the pathway of PCBMN and PCBUN were measured. The average distance between the origin of the PCBMN and PCBUN to the DWC was 4.95 ± 0.88 cm, 10.12 ± 1.50 cm, separately. The average distance between DWC and the point where PCBMN and PCBUN separated from their trunk was found to be 2.09 ± 0.31 cm, 2.90 ± 0.50 cm, separately. The distances between PCBMN, PCBUN and 0 point at DWC level was found to be 0.61 ± 0.12 cm, 0.47 ± 0.31 cm, separately. The diameters of two cutaneous branches were 0.10 ± 0.02 cm, 0.11 ± 0.04 cm, separately. The general longitudinal palmar incision could avoid injuries to recurrent branch of median nerve and distal branches of palmar cutaneous nerve can be avoided macroscopically. The area about 5 mm ulnar and 6 mm radial to 0 point at wrist level was a relatively safe area.

The aim of this study was to determine the value of Doppler sonography for evaluation of ulnar neuropathy at the elbow (UNE).A total of 102 patients with a clinical suspicion of UNE and 50 healthy controls were examined by Doppler and gray-scale sonography.Intraneural vascularization was found in 31 (46.3%) of 67 patients with confirmed UNE and in 3 (6.0%) of 50 healthy controls. Combining gray-scale sonography measurement of nerve size and the presence of intraneural vascularization increased sensitivity by 3%, but decreased the specificity. Patients with intraneural vascularization had more severe disease than those without intraneural vascularization (P0.05). The variables obtained by Doppler sonography were associated with the severity of UNE (P0.05).Doppler sonography is not helpful for diagnosing UNE but can be used to assess the severity of UNE. Muscle Nerve 54: 258-263, 2016.