Hyperspectral Prediction Models of Chlorophyll Content in Paulownia Leaves under Drought Stress.

This study explored the quantitative inversion of the chlorophyll content in Paulownia seedling leaves under drought stress and analyzed the factors influencing the chlorophyll content from multiple perspectives to obtain the optimal model. Paulownia seedlings were selected as the experimental materials for the potted water control experiments. Four drought stress treatments were set up to obtain four types of Paulownia seedlings: one pair of top leaves (T1), two pairs of leaves (T2), three pairs of leaves (T3), and four pairs of leaves (T4). In total, 23 spectral transformations were selected, and the following four methods were adopted to construct the prediction model, select the best spectral preprocessing method, and explore the influence of water bands: partial least squares modeling with all spectral bands (all-band partial least squares, AB-PLS), principal component analysis partial least squares (PCA-PLS), correlation analysis partial least squares (CA-PLS), correlation analysis (water band) partial least squares, ([CA(W)-PLS]), and vegetation index modeling. Based on the prediction accuracy and the uniformity of different leaf positions, the optimal model was systematically explored. The results of the analysis of spectral reflectance showed significant differences at different leaf positions. The sensitive bands of chlorophyll were located near 550 nm, whereas the sensitive bands of water were located near 1440 and 1920 nm. The results of the vegetation index models indicate that the multiple-index models outperformed the single-index models. Accuracy decreased as the number of indicators decreased. We found that different model construction methods matched different optimal spectral preprocessing methods. First derivative spectra (R') was the best preprocessing method for the AB-PLS, PCA-PLS, and CA-PLS models, whereas the inverse log spectra (log(1/R)) was the best preprocessing method for the CA(W)-PLS model. Among the 14 indices, the green normalized difference vegetation index (GNDVI) was most correlated with the chlorophyll content sensitivity indices, and the water index (WI) was most correlated with the water sensitive indices. At the same time, the water band affected the cross validation accuracy. When characteristic bands were used for modeling, the cross validation accuracy was significantly increased. In contrast, when vegetation indices were used for modeling, the accuracy of the cross validation increased slightly but its predictive ability was reduced; thus, these changes could be ignored. We found that leaf position also affected the prediction accuracy, with the first pair of top leaves exhibiting the worst predictive ability. This was a bottleneck that limited predictive capability. Finally, we found that the CA(W)-PLS model was optimal. The model was based on 23 spectral transformations, four PLS construction methods, water bands, and different leaf positions to ensure systematicity, stability, and applicability.

The effect of platelet-rich fibrin on the biological properties of urothelial cells.

Urethral reconstruction presents a challenging issue in urology, primarily due to the limited availability of alternative materials for repair. The advancement of bioengineering technology has brought new hope to researchers, with a focus on the selection of appropriate biological scaffolds and seed cells. In order to find an ideal alternative material, we used platelet-rich fibrin as the bioscaffold and urothelial cells as the seed cells, meanwhile, we intended to investigate the effect of platelet-rich fibrin on the biological properties of urothelial cells. We transformed and characterised induced pluripotent stem cells into urothelial cells and prepared platelet-rich fibrin. Platelet-rich fibrin was cultured in a complex with urothelial cells to observe the effect of platelet-rich fibrin on the proliferation and migration ability of urothelial cells. The results showed that the induced pluripotent stem cells were successfully transformed into urothelial cells, platelet-rich fibrin was regularly arranged in cords, with platelets and other structures distributed between them, and the proliferation and migration of urothelial cells were significantly increased. These results suggested that platelet-rich fibrin is biocompatible with urothelial cells and it promotes the proliferation and migration of urothelial cells, which lays a good foundation for its use as an alternative material for urethral repair.

Effect of radiation after surgery on the prognosis of children with Wilms tumor.

BACKGROUND: To explore the association between radiation after surgery and the 5-year overall survival (OS) and 5-year cancer-specific survival (CSS) in patients with Wilms tumor. METHODS: In this cohort study, 1564 participants were identified from the Surveillance, Epidemiology, and End Results (SEER) database. The univariate and multivariable COX proportional risk model as well as competitive risk model were used to explore the covariates associated with 5-year OS and 5-year CSS of patients with Wilms tumor and the correlation between radiation after surgery and 5-year OS or 5-year CSS of patients with Wilms tumor, respectively. The Kaplan-Meier curves of participants were plotted. RESULTS: The median follow-up was 126.00 (84.00, 178.00) months. Patients receiving surgery had higher 5-year survival probability than those not receiving surgery, while participants receiving radiation after surgery showed poor 5-year survival than those not. After adjusting for covariates including age and SEER stage, increased risk of 5-year overall mortality in patients with Wilms tumor [hazard ratio (HR) = 1.62, 95% confidence interval (CI): 1.10-2.41). After the adjustment for confounding factors including age, SEER stage and ethnicity, increased risk of 5-year cancer-specific mortality of patients with Wilms tumor was observed in those receiving radiation after surgery (HR = 1.77, 95%CI: 1.13-2.79). CONCLUSION: Radiation after surgery was associated with poor prognosis of patients with Wilms tumor, which indicated that the clinicians should assess whether the patient was suitable for using radiation after surgery.

Identification and Analysis of PPO Gene Family Members in Paulownia fortunei.

Polyphenol oxidase (PPO) is a common metalloproteinase in plants with important roles in plant responses to abiotic and biotic stresses. There is evidence that PPOs contribute to stress responses in Paulownia fortunei. In this study, PPO gene family members in P. fortunei were comprehensively identified and characterized using bioinformatics methods as well as analyses of phylogenetic relationships, gene and protein structure, codon usage bias, and gene expression in response to stress. The genome contained 10 PPO gene family members encoding 406-593 amino acids, with a G/C bias. Most were localized in chloroplasts. The motif structure was conserved among family members, and α-helices and random coils were the dominant elements in the secondary structure. The promoters contained many cis-acting elements, such as auxin, gibberellin, salicylic acid, abscisic acid, and photoresponsive elements. The formation of genes in this family was linked to evolutionary events, such as fragment replication. Real-time quantitative PCR results showed that PfPPO7, PfPPO10, PfPPO1, PfPPO2, PfPPO3, PfPPO4, PfPPO5, and PfPPO8 may be key genes in drought stress resistance. PfPPO1, PfPPO3, PfPPO4, and PfPPO10 were resistant stress-sensitive genes. These results provide a reliable basis for fully understanding the potential functions of these genes and the selection of resistance breeding.

Assessment of testicular volume in neonates in the tropical province of China.

BACKGROUND: Testicular volume in neonates is a potential indicator of testicular development during the fetal period, particularly the masculinization programming window. Reliable measurements of testicular volume provide an opportunity for early detection of testicular abnormalities. This study aimed to assess the testicular volume in neonates and evaluate its relationship with gestational week and birth weight in Hainan Province, China. METHODS: Data on 458 neonates who underwent ultrasonography examinations at our institution from 2018 to 2022 were collected. The neonates were categorized by gestational week, birth weight, and presence of cryptorchidism. We evaluated the testicular volume among different groups and its relationship to gestational week and birth weight. RESULTS: There was no significant difference between the right and left testicular volume in neonates without cryptorchidism. However, a significant difference was observed between normal birth weight and low birth weight neonates in terms of testicular volume. Similarly, there was a significant difference between premature and full-term neonates in testicular volume. Bilateral testicular volume showed positive and significant correlations with gestational week and birth weight. Additionally, a significant difference was noted in testicular volume between the affected side in neonates with cryptorchidism and the same side in normal birth weight full-term neonates. CONCLUSIONS: We established the normal range of testicular volume for neonates in Hainan Province and demonstrated that testicular volume is positively correlated with both birth weight and gestational week. Cryptorchidism also affects testicular volume during the neonatal period, likely due to reduced androgenic exposure in utero, particularly during the masculinization programming window. The findings of this study have significant implications for assessing testis development during fetal development.

Effect of icariin on the transformation efficiency of induced pluripotent stem cells into sperm cells in vitro.

OBJECTIVE: To investigate the effect of icariin on the transformation efficiency of germ cell-like cells from mouse induced pluripotent stem cells into sperm cells in vitro. METHODS: Firstly, mouse induced pluripotent stem cells were induced and cultured to transform into germ cell-like cells, and the primordial germ cell-like cells were identified by Western blot and RT-PCR. Then, different concentrations of icariin (0.1µg/mL, 1µg/mL, 10µg/mL and 100µg/mL) were added into the culture medium, and the obtained primitive germ cell-like cells were cultured, Western blot and RT-PCR were used to identify the obtained sperm cells, the transformation efficiency was compared. RESULTS: The primordium germ cell-like cells obtained from mouse induced pluripotent stem cells in vitro specially expressed Oct-4 protein, C-kit protein, Mvh mRNA, Fragilis mRNA and Stella mRNA. The sperm cells were specially expressed VASA, SCP3 and γH2AX proteins. RT-PCR showed that the sperm cells were specially expressed Ddx4, Tp2 and Prm1 mRNA. Compared with the control group, the expression level of VASA protein (1.744±0.283, 2.882±0.373, 6.489±0.460), SCP3 protein (2.250±0.306, 7.058±0.521, 8.654±0.804), γH2AX protein (4.304±0.433, 5.713±0.339, 9.268±0.545), Ddx4 mRNA (1.374±0.145, 2.846±0.194, 4.021±0.154), Tp2 mRNA (1.358±0.130, 3.623±0.326, 5.811±0.390) and Prm1 mRNA (1.326±0.162, 3.487±0.237, 4.666±0.307) in 0.1µg/mL, 1µg/mL, 10µg/mL icariin experimental groups were all lower than that of VASA protein (10.560±0.413), SCP3 protein (13.804±0.642), γH2AX protein (11.874±0.464), Ddx4 mRNA (6.4005±0.361), Tp2 mRNA (7.314±0.256) and Prm1 mRNA (7.334±0.390) in 100µg/mL icariin experimental group. CONCLUSIONS: Icariin can promote the transformation of mouse induced pluripotent stem cells into sperm cells in vitro, and it is concentration-dependent manner in a certain concentration range.

The stability of transcription factor PfSPL1 participates in the response to phytoplasma stress in Paulownia fortunei.

The current understanding of the pathogenesis of phytoplasma is still very limited and challenging. Here, ceRNA regulatory network and degradome sequencing identified a PfmiR156f-PfSPL regulatory module in Paulownia fortunei infected by phytoplasma, and RLM-5'RACE and dual luciferase analyses verified the relationship. The PfmiR156 cleavage site was located at 1104 nt and 1177 nt of PfSPL1 and PfSPL10, respectively. MG132 and epoxomicin, two 26S proteasome inhibitors, significantly increased the accumulation of PfSPL1. PfSPL1 was also the attack target of phytoplasma effectors (Pawb 3/9/16/37/51) after the phytoplasma invaded Paulownia. Moreover, molecular docking implied that the effectors may interact with the conserved SBP domain of the target protein PfSPL1. Basically, these results indicated that the stability of PfSPL1 was regulated by PfmiR156 cleavage activity and/or the 26S proteasome pathway at the post-translation level. The PfSPL1, which is a transcription factor, was also the one of the targets of multiple effectors attacking Paulownia. This study provides a good scope to understand the paulownia phytoplasma infecting mechanism.

Comprehensive analyses of the SPL transcription factor family in Paulownia fortunei and their responses to biotic and abiotic stresses.

To study the molecular characteristics, phylogenetic evolution, and gene functions of the SQUAMOSA-PROMOTER BINDING PROTEIN-LIKE (SPL) genes in Paulownia fortunei, a whole genome sequence analysis was carried out, and a total of 23 PfSPL genes were identified. Tandem duplication and fragment replication were the main patterns of gene expansion in the PfSPL family. Phylogenetic analysis showed that the 23 identified PfSPLs formed seven subgroups, and the structures of the proteins in the same subgroup were similar. Functional analysis indicated that PfSPL11 may regulate flowering, PfSPL5 was involved in gibberellin signaling, PfSPL1/4/23 regulated branching, and PfSPL9/16/18 were related to pathogen resistance. Yeast one hybrid technology confirmed that PfSPL4 and PfSP23 can bind to the promoter of PfTCPa. The transcriptome analysis indicated that PfSPL10 was sensitive to both drought and salt stress. Ten PfSPLs that responded to phytoplasma infection were identified. Molecular docking showed that PfSPL10 and PfSPL 4/5/9/10/11/13 formed active pockets in the conserved SBP domain that could bind methyl methane sulfonate (MMS) and rifampicin (Rif) through stable hydrogen bonds, respectively. This study provides a basis for further studies on the functions of the PfSPL transcription factor family, and for genetic improvement and breeding of trees resistant to PaWB disease.

Chemotherapy Combined With Surgery in a Case With Metanephric Adenoma.

Background: Metanephric adenoma is an extremely rare renal neoplasm, especially in pediatrics. Chemotherapy combined with surgery in metanephric adenoma has not been reported. Methods: We describe a case of metanephric adenoma in a child less than 2 years old, which were treated by chemotherapy combined with surgery. Results: Nephron sparing surgery was performed after regular chemotherapy, and the pathological result was metanephric adenoma. Conclusion: Pediatric metanephric adenoma is extremely rare; the clinical manifestations and imaging examinations lack specificity. Nephron sparing surgery is recommended as the preferred treatment for metanephric adenoma. Long-term follow-up and more in-depth molecular genetic research are still needed to determine the benign or malignant of metanephric adenoma and whether chemotherapy drugs have an effect on it.

Comparative study of testicular volume in children with unilateral cryptorchidism of different ages in the tropical province of China.

OBJECTIVE: To assess the testicular volume in children with unilateral cryptorchidism of different ages in Hainan Province, China. METHODS: The study included 424 children (ranging in age from 0 month to 4 years) with unilateral cryptorchidism or normal who were treated from 2017 to 2021 at our institution. They were divided into different groups according to age. We evaluated the correlation of testicular volume between the children with cryptorchidism and the normal children among different groups. RESULTS: There was a significant difference in testicular volume between the affected side and the healthy side. There was no difference in testicular volume between the left side and the right side of each control group. There were significant differences between the affected side of cryptorchid groups and the same side of the control groups. There were no significant differences between the healthy side of cryptorchid groups and the same side of the control groups. There were no significant differences between the affected side of left cryptorchid groups and right cryptorchid groups. There were no significant differences between the healthy side of left cryptorchid groups and right cryptorchid groups. There were significant differences in testicular volume among different age groups of the control group, while there were no differences in the cryptorchid groups. CONCLUSIONS: The development of testicular volume in children with unilateral inguinal cryptorchidism is affected in earlier age, and there was no compensatory testicular adaptation in the healthy testis.

Gene Co-Expression Analysis Reveals Transcriptome Divergence between Wild and Cultivated Sugarcane under Drought Stress.

Drought is the main abiotic stress that constrains sugarcane growth and production. To understand the molecular mechanisms that govern drought stress, we performed a comprehensive comparative analysis of physiological changes and transcriptome dynamics related to drought stress of highly drought-resistant (ROC22, cultivated genotype) and weakly drought-resistant (Badila, wild genotype) sugarcane, in a time-course experiment (0 h, 4 h, 8 h, 16 h and 32 h). Physiological examination reviewed that ROC22, which shows superior drought tolerance relative to Badila, has high performance photosynthesis and better anti-oxidation defenses under drought conditions. The time series dataset enabled the identification of important hubs and connections of gene expression networks. We identified 36,956 differentially expressed genes (DEGs) in response to drought stress. Of these, 15,871 DEGs were shared by the two genotypes, and 16,662 and 4423 DEGs were unique to ROC22 and Badila, respectively. Abscisic acid (ABA)-activated signaling pathway, response to water deprivation, response to salt stress and photosynthesis-related processes showed significant enrichment in the two genotypes under drought stress. At 4 h of drought stress, ROC22 had earlier stress signal transduction and specific up-regulation of the processes response to ABA, L-proline biosynthesis and MAPK signaling pathway-plant than Badila. WGCNA analysis used to compile a gene regulatory network for ROC22 and Badila leaves exposed to drought stress revealed important candidate genes, including several classical transcription factors: NAC87, JAMYB, bHLH84, NAC21/22, HOX24 and MYB102, which are related to some antioxidants and trehalose, and other genes. These results provide new insights and resources for future research and cultivation of drought-tolerant sugarcane varieties.

Conformational Changes in Three-Dimensional Chromatin Structure in Paulownia fortunei After Phytoplasma Infection.

Higher-order chromatin structures play important roles in regulating multiple biological processes such as growth and development as well as biotic and abiotic stress response. However, little is known about three-dimensional chromatin structures in Paulownia or about whole-genome chromatin conformational changes that occur in response to Paulownia witches' broom (PaWB) disease. We used high-throughput chromosome conformation capture (Hi-C) to obtain genome-wide profiles of chromatin conformation in both healthy and phytoplasma-infected Paulownia fortunei genome. The heat map results indicated that the strongest interactions between chromosomes were in the telomeres. We confirmed that the main structural characteristics of A/B compartments, topologically associated domains, and chromatin loops were prominent in the Paulownia genome and were clearly altered in phytoplasma-infected plants. By combining chromatin immunoprecipitation sequencing, Hi-C signals, and RNA sequencing data, we inferred that the chromatin structure changed and the modification levels of three histones (H3K4me3/K9ac/K36me3) increased in phytoplasma-infected P. fortunei, which was associated with changes of transcriptional activity. We concluded that for epigenetic modifications, transcriptional activity might function in combination to shape chromatin packing in healthy and phytoplasm-infected Paulownia. Finally, 11 genes (e.g., RPN6, Sec61 subunit-α) that were commonly located at specific topologically associated domain boundaries, A/B compartment switching and specific loops, and had been associated with histone marks were identified and considered as closely related to PaWB stress. Our results provide new insights into the nexus between gene regulation and chromatin conformational alterations in nonmodel plants upon phytopathogen infection and plant disease resistance.

Genomic insights into the fast growth of paulownias and the formation of Paulownia witches' broom.

Paulownias are among the fastest growing trees in the world, but they often suffer tremendous loss of wood production due to infection by Paulownia witches' broom (PaWB) phytoplasmas. In this study, we have sequenced and assembled a high-quality nuclear genome of Paulownia fortunei, a commonly cultivated paulownia species. The assembled genome of P. fortunei is 511.6 Mb in size, with 93.2% of its sequences anchored to 20 pseudo-chromosomes, and it contains 31 985 protein-coding genes. Phylogenomic analyses show that the family Paulowniaceae is sister to a clade composed of Phrymaceae and Orobanchaceae. Higher photosynthetic efficiency is achieved by integrating C3 photosynthesis and the crassulacean acid metabolism pathway, which may contribute to the extremely fast growth habit of paulownia trees. Comparative transcriptome analyses reveal modules related to cambial growth and development, photosynthesis, and defense responses. Additional genome sequencing of PaWB phytoplasma, combined with functional analyses, indicates that the effector PaWB-SAP54 interacts directly with Paulownia PfSPLa, which in turn causes the degradation of PfSPLa by the ubiquitin-mediated pathway and leads to the formation of witches' broom. Taken together, these results provide significant insights into the biology of paulownias and the regulatory mechanism for the formation of PaWB.

Whole-genome landscape of H3K4me3, H3K36me3 and H3K9ac and their association with gene expression during Paulownia witches' broom disease infection and recovery processes.

Histone methylation and acetylation participate in the modulation of gene expression. Here, chromatin immunoprecipitation sequencing (ChIP-Seq) was used to determine genome-wide patterns of three histone modifications, H3K4me3, H3K36me3, and H3K9ac (associated with actively expressed genes) and their associations with gene expression in Paulownia fortunei following phytoplasma infection and recovery from Paulownia witches' broom (PaWB) disease after methyl methane sulfonate treatment. The three histone marks were preferentially deposited in genic regions, especially downstream of transcription start sites, and were highly concurrent with gene expression. Genes with all three histone marks exhibited the highest expression levels. Based on the comparison scheme, we detected 365, 2244, and 752 PaWB-associated genes with H3K4me3, H3K36me3, and H3K9ac marks, separately. KEGG pathway analysis showed that these genes were involved in plant-pathogen interaction, plant hormone signal transduction, and starch and sucrose metabolism. A small proportion of differentially modified genes showed changes in expression in response to phytoplasma infection, including genes involved in calcium ion signal transduction, abscisic acid signal transduction, and ethylene biosynthesis. This comprehensive analysis of genome-wide histone modifications and gene expression in Paulownia following phytoplasma infection provides new insights into the epigenetic responses to phytoplasma infection and will be useful for further studies on epigenetic regulation mechanisms in plants under biotic stress.

Genome-wide DNA methylation analysis of paulownia with phytoplasma infection.

DNA methylation, an important epigenetic modification, regulates a wide range of biological processes. Previous MSAP results showed that the occurrence of PaWB related to changes of DNA methylation level; however, the relationship between DNA methylation and gene expression remains obscure in paulownia. Therefore, in the present study, we applied WGBS and RNA-seq techniques to investigate the DNA methylation and gene expression changes between healthy Paulownia fortunei seedlings and the phytoplasma-infected ones. A map of methylated cytosines at the single base pair resolution of paulownia was constructed. Compared to the healthy seedlings, the DNA methylation level increased after phytoplasma infection, and the change of mCHH was the main methylation pattern. DMR analysis showed that 422,662 DMRs in the genome were identified, in which, 27,871 DMR-associated genes were differentially expressed. Finally, 436 genes with significant differences in their methylation levels and mRNA expression profiles were identified through integrated analysis of the DNA methylomic and transcriptomic. KEGG pathway analysis revealed that these genes are mainly involved in plant hormone signal transduction, carbon metabolism, and starch and sucrose metabolism pathways. Two of DMR-associated genes were verified by BS- PCR. Finally, we selected TRP 1 and R2R3-MYB protein were closely related to the occurrence of PaWB. Our findings provide valuable insight into the mechanism of PaWB at the epigenetic level.

A comparison of the transcriptomes between diploid and autotetraploid Paulownia fortunei under salt stress.

Paulownia is a tree species grown in many countries. Our previous study reveals that tetraploid Paulownia fortunei is more tolerant to salt stress than its corresponding diploid tree. To investigate the molecular mechanisms of salt stress tolerance in P. fortunei, the transcriptomes of normal and salt-stressed diploid and tetraploid were investigated. After assembling the clean reads, we obtained 130,842 unigenes. The unigenes were aligned against six public databases (Nr, Nt, Swiss-Prot, COG, KEGG, GO) to discover homologs and assign functional annotations. We retrieved 7983 and 15,503 differentially expressed unigenes (DEUs) between the normal and the salt-stressed diploid and tetraploid P. fortunei, respectively. We identified dozens of important DEUs including 3 related to photosynthesis, 10 related to plant growth and development and 11 related to osmolytes. Some of these DEUs were upregulated in tetraploid compared to diploid and others were upregulated under salt stress. Quantitative reverse transcriptase polymerase chain reaction verified the expression patterns of 15 unigenes. Our results provided insights into the molecular aspects why tetraploid is stronger and more energetic than diploid under saline environment. This study provides useful information for further studies on the molecular mechanisms of salt tolerance in other tree plants.

[Distribution Characteristics and Health Risk Assessment of Heavy Metals in a Soil-Rice System in an E-waste Dismantling Area].

This study selected Guiyu Town, Guangdong Province as the research area, the content of 15 kinds of metals (As, Be, Cd, Co, Cr, Cu, Hg, Li, Mn, Ni, Sb, Sn, Pb, V, and Zn) in the soil was determined, and the content of heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn in the rice of this research area was identified. Multivariate statistical analysis and a human health risk assessment model were used to investigate the distribution characteristics and health risk of heavy metals in a soil-rice system. The results showed that Hg, Sb, and Sn in the surface soil surrounding the electronic waste dismantling area have obvious accumulation effect. The average content of Cd and Hg exceeds the Ⅱ standard limit of the "Environmental Quality Standard for Soil" (GB 156182-1995), and that Guiyu Town is more seriously polluted than Chendian Town and Simapu Town. The multivariate statistical analysis showed that Cu, Sb, Ni, Zn, Sn, Pb, and Hg originated from the surrounding electronic waste dismantling activities, Cd and Be originated from other man-made sources of pollution, and V, Li, Cr, Co, As, and Mn originated from natural sources. Heavy metal evaluation concentration in the soil-rice system by heavy metal migration accumulated in rice are in compliance with national food hygiene standards, and the enrichment ability is Cd > Zn > Cu > Ni > As > Cr > Hg > Pb. Soil heavy metal health risk assessment results showed that children are more susceptible to heavy metal pollution, and handling-oral ingestion is the main way of soil exposure risk. The non-carcinogenic risk and carcinogenic risk of heavy metals in the soil of each town are acceptable. The health risk in Guiyu Town through ingestion of rice is mainly from the elements that include As, Cr, Cu, and Ni.

[Seasonal Characteristics and Ecological Risk Assessment of Heavy Metals in PM10 Around Electroplating Plants].

PM10 samples were collected from 45 sites around the electroplating factories in five towns in Dongguan at different times during all four seasons in 2015. The contents of 12 heavy metals (HMs) from the PM10 samples were analyzed by ICP-MS. The seasonal and spatial distribution characteristics and the ecological risk were analyzed to provide a scientific foundation for the relevant department to make decisions regarding the environmental hazard, risk assessment and, pollution control. The results showed that PM10 concentrations in the towns were lower than national standard level-Ⅱ, and the air pollution was heavier in winter than summer. The HM concentrations were higher in autumn and winter, and As, Cd, and Cr concentrations were higher than national standard (GB3095-2012). The concentrations of HMs in Humen, Shatian, and Dalingshan were much higher. The results for the enrichment factor and the geoaccumulation index indicated that Cd, Sb, Hg, and Co were in the extreme degree of pollution category, Pb and Zn were in the slight to extreme degree of pollution category, and Ni, Cr, Mn, and V were described as uncontaminated. The average potential ecological risk assessment (RI) of the HMs from the PM10 samples was more than 600, which suggested an extremely serious ecological risk in the study area.

Identification and characterization of long noncoding RNA in Paulownia tomentosa treated with methyl methane sulfonate.

Paulownia is a tree native to China, with important ecological and economic value. Long noncoding RNAs (lncRNAs) are known to play important roles in eukaryotic gene regulation. However, no lncRNAs have been reported in Paulownia so far. We performed RNA sequencing of two Paulownia tomentosa lncRNA libraries constructed from the terminal buds of normal untreated seedlings and 60 mg L-1 MMS-treated seedlings, and obtained a total of 2531 putative lncRNAs. The average length of the lncRNA transcripts was much less than the average length of the mRNA transcripts in the P. tomentosa libraries. A few of the Paulownia lncRNAs were conserved among ten species tested. We identified seven lncRNAs as precursors of 13 known miRNAs, 15 lncRNAs may act as target mimics of 19 miRNAs, and 351 unique noncoding sequences belonging to 133 conserved lncRNA families. In addition, we identified 220 lncRNAs responsive to methyl methane sulfonate (MMS), including seven phytohormone-related lncRNAs and one lncRNAs involved in base excision repair. This is the first time that lncRNAs have been explored in Paulownia. The lncRNA data may also provide new insights into the MMS-response in P. tomentosa.

Genome-wide expression analysis of salt-stressed diploid and autotetraploid Paulownia tomentosa.

Paulownia tomentosa is a fast-growing tree species with multiple uses. It is grown worldwide, but is native to China, where it is widely cultivated in saline regions. We previously confirmed that autotetraploid P. tomentosa plants are more stress-tolerant than the diploid plants. However, the molecular mechanism underlying P. tomentosa salinity tolerance has not been fully characterized. Using the complete Paulownia fortunei genome as a reference, we applied next-generation RNA-sequencing technology to analyze the effects of salt stress on diploid and autotetraploid P. tomentosa plants. We generated 175 million clean reads and identified 15,873 differentially expressed genes (DEGs) from four P. tomentosa libraries (two diploid and two autotetraploid). Functional annotations of the differentially expressed genes using the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes databases revealed that plant hormone signal transduction and photosynthetic activities are vital for plant responses to high-salt conditions. We also identified several transcription factors, including members of the AP2/EREBP, bHLH, MYB, and NAC families. Quantitative real-time PCR analysis validated the expression patterns of eight differentially expressed genes. Our findings and the generated transcriptome data may help to accelerate the genetic improvement of cultivated P. tomentosa and other plant species for enhanced growth in saline soils.