Extranodal natural killer/T-cell lymphoma with hepatosplenic involvement: a retrospective study of a consecutive 14-year case series.

Extranodal natural killer/T-cell lymphoma (ENKTL) with hepatosplenic involvement is rare, accounting for approximately 0.2% of ENKTL cases. The clinicopathologic features of ENKTL with hepatosplenic involvement are still poorly understood. Seven cases of ENKTL with hepatosplenic involvement were investigated retrospectively by clinical features, pathology, immunophenotype, genotype, Epstein-Barr virus (EBV) status, and survival analysis. The median age was 36 years; three patients (3/7) had a history of primary nasal ENKTL. Six cases (6/7) presented liver or spleen structures that were replaced by neoplasms, and the neoplastic cells displayed diffuse infiltration; one case (1/7) displayed neoplastic cells scattered in hepatic sinuses and portal areas. The cellular morphology and immunohistochemical features were similar to those of ENKTL involving other sites. Follow-up data were available in five of the seven patients. All five patients received first-line chemotherapy based on L-asparaginase. Three patients died, and two were still alive by the last follow-up. The median overall survival (OS) was 21 months. ENKTL with hepatosplenic involvement is rare, regardless of whether it is initial or secondary. There are two histopathologic patterns of ENKTL with hepatosplenic involvement, and L-asparaginase-based chemotherapy combined with AHSCT might yield good efficacy. Morphological features of ENKTL in the spleen and liver A The architecture of the spleen was affected, and dense infiltration of the neoplastic cells was observed in the left part; B Focal infiltration of the neoplastic cells was located in the red pulp; C Dense infiltration of the neoplastic cells in the liver, accompanied by fatty change of hepatocytes and congestion; D More neoplastic cells accumulated in sinusoidal region.

Proteome-wide and lysine crotonylation profiling reveals the importance of crotonylation in chrysanthemum (Dendranthema grandiforum) under low-temperature.

BACKGROUND: Low-temperature severely affects the growth and development of chrysanthemum which is one kind of ornamental plant well-known and widely used in the world. Lysine crotonylation is a recently identified post-translational modification (PTM) with multiple cellular functions. However, lysine crotonylation under low-temperature stress has not been studied. RESULTS: Proteome-wide and lysine crotonylation of chrysanthemum at low-temperature was analyzed using TMT (Tandem Mass Tag) labeling, sensitive immuno-precipitation, and high-resolution LC-MS/MS. The results showed that 2017 crotonylation sites were identified in 1199 proteins. Treatment at 4 °C for 24 h and - 4 °C for 4 h resulted in 393 upregulated proteins and 500 downregulated proteins (1.2-fold threshold and P < 0.05). Analysis of biological information showed that lysine crotonylation was involved in photosynthesis, ribosomes, and antioxidant systems. The crotonylated proteins and motifs in chrysanthemum were compared with other plants to obtain orthologous proteins and conserved motifs. To further understand how lysine crotonylation at K136 affected APX (ascorbate peroxidase), we performed a site-directed mutation at K136 in APX. Site-directed crotonylation showed that lysine decrotonylation at K136 reduced APX activity, and lysine complete crotonylation at K136 increased APX activity. CONCLUSION: In summary, our study comparatively analyzed proteome-wide and crotonylation in chrysanthemum under low-temperature stress and provided insights into the mechanisms of crotonylation in positively regulated APX activity to reduce the oxidative damage caused by low-temperature stress. These data provided an important basis for studying crotonylation to regulate antioxidant enzyme activity in response to low-temperature stress and a new research ideas for chilling-tolerance and freezing-tolerance chrysanthemum molecular breeding.

Transcriptomic analysis of Verbena bonariensis roots in response to cadmium stress.

BACKGROUND: Cadmium (Cd) is a serious heavy metal (HM) soil pollutant. To alleviate or even eliminate HM pollution in soil, environmental-friendly methods are applied. One is that special plants are cultivated to absorb the HM in the contaminated soil. As an excellent economical plant with ornamental value and sound adaptability, V. bonariensis could be adapted to this very situation. In our study, the Cd tolerance in V. bonariensis was analyzed as well as an overall analysis of transcriptome. RESULTS: In this study, the tolerance of V. bonariensis to Cd stress was investigated in four aspects: germination, development, physiological changes, and molecular alterations. The results showed that as a non-hyperaccumulator, V. bonariensis did possess the Cd tolerance and the capability to concentration Cd. Under Cd stress, all 237, 866 transcripts and 191, 370 unigenes were constructed in the transcriptome data of V. bonariensis roots. The enrichment analysis of gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway revealed that differentially expressed genes (DEGs) under Cd stress were predominately related to cell structure, reactive oxygen species (ROS) scavenging system, chelating reaction and secondary metabolites, transpiration and photosynthesis. DEGs encoding lignin synthesis, chalcone synthase (CHS) and anthocyanidin synthase (ANS) were prominent in V. bonariensis under Cd stress. The expression patterns of 10 DEGs, validated by quantitative real-time polymerase chain reaction (qRT-PCR), were in highly accordance with the RNA-Sequence (RNA-Seq) results. The novel strategies brought by our study was not only benefit for further studies on the tolerance of Cd and functional genomics in V. bonariensis, but also for the improvement molecular breeding and phytoremediation.

Transcriptome analysis of chrysanthemum (Dendranthema grandiflorum) in response to low temperature stress.

BACKGROUND: Chrysanthemum is one kind of ornamental plant well-known and widely used in the world. However, its quality and production were severely affected by low temperature conditions in winter and early spring periods. Therefore, we used the RNA-Seq platform to perform a de novo transcriptome assembly to analyze chrysanthemum (Dendranthema grandiflorum) transcription response to low temperature. RESULTS: Using Illumina sequencing technology, a total of 86,444,237 high-quality clean reads and 93,837 unigenes were generated from four libraries: T01, controls; T02, 4 °C cold acclimation (CA) for 24 h; T03, - 4 °C freezing treatments for 4 h with prior CA; and T04, - 4 °C freezing treatments for 4 h without prior CA. In total, 7583 differentially expressed genes (DEGs) of 36,462 annotated unigenes were identified. We performed GO and KEGG pathway enrichment analyses, and excavated a group of important cold-responsive genes related to low temperature sensing and signal transduction, membrane lipid stability, reactive oxygen species (ROS) scavenging and osmoregulation. These genes encode many key proteins in plant biological processes, such as protein kinases, transcription factors, fatty acid desaturase, lipid-transfer proteins, antifreeze proteins, antioxidase and soluble sugars synthetases. We also verified expression levels of 10 DEGs using quantitative real-time polymerase chain reaction (qRT-PCR). In addition, we performed the determination of physiological indicators of chrysanthemum treated at low temperature, and the results were basically consistent with molecular sequencing results. CONCLUSION: In summary, our study presents a genome-wide transcript profile of Dendranthema grandiflorum var. jinba and provides insights into the molecular mechanisms of D. grandiflorum in response to low temperature. These data contributes to our deeper relevant researches on cold tolerance and further exploring new candidate genes for chilling-tolerance and freezing-tolerance chrysanthemum molecular breeding.

Chrysanthemum DgWRKY2 Gene Enhances Tolerance to Salt Stress in Transgenic Chrysanthemum.

WRKY transcription factors (TFs) play a vital part in coping with different stresses. In this study, DgWRKY2 was isolated from Dendranthema grandiflorum. The gene encodes a 325 amino acid protein, belonging to the group II WRKY family, and contains one typical WRKY domain (WRKYGQK) and a zinc finger motif (C-X4-5-C-X22-23-H-X1-H). Overexpression of DgWRKY2 in chrysanthemum enhanced tolerance to high-salt stress compared to the wild type (WT). In addition, the activities of antioxidant enzymes (superoxide dismutase (SOD), peroxidase (POD), catalase (CAT)), proline content, soluble sugar content, soluble protein content, and chlorophyll content of transgenic chrysanthemum, as well as the survival rate of the transgenic lines, were on average higher than that of the WT. On the contrary, hydrogen peroxide (H2O2), superoxide anion (O2-), and malondialdehyde (MDA) accumulation decreased compared to WT. Expression of the stress-related genes DgCAT, DgAPX, DgZnSOD, DgP5CS, DgDREB1A, and DgDREB2A was increased in the DgWRKY2 transgenic chrysanthemum compared with their expression in the WT. In conclusion, our results indicate that DgWRKY2 confers salt tolerance to transgenic chrysanthemum by enhancing antioxidant and osmotic adjustment. Therefore, this study suggests that DgWRKY2 could be used as a reserve gene for salt-tolerant plant breeding.

Whole-Transcriptome Sequence Analysis of Verbena bonariensis in Response to Drought Stress.

Drought is an important abiotic factor that threatens the growth and development of plants. Verbena bonariensis is a widely used landscape plant with a very high ornamental value. We found that Verbena has drought tolerance in production practice, so in order to delve into its mechanism of drought resistance and screen out its drought-resistance genes, we used the RNA-Seq platform to perform a de novo transcriptome assembly to analyze Verbena transcription response to drought stress. By high-throughput sequencing with Illumina Hiseq Xten, a total of 44.59 Gb clean data was obtained from T01 (control group) and T02 (drought experiment group). After assembly, 111,313 unigenes were obtained, and 53,757 of them were annotated by compared databases. In this study, 4829 differentially expressed genes were obtained, of which 4165 were annotated. We performed GO (Gene Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway enrichment analyses, and explored a lot of differently expressed genes related to plant energy production, hormone synthesis, cell signal transduction, and metabolism to understand the stress response of Verbena in drought stress. In addition, we also found that a series of TFs related to drought-resistance of Verbena and provide excellent genetic resources for improving the drought tolerance of crops.

Overexpression of a chrysanthemum transcription factor gene DgNAC1 improves the salinity tolerance in chrysanthemum.

KEY MESSAGE: DgNAC1, a transcription factor of chrysanthemum, was functionally verified to confer salt stress responses by regulating stress-responsive genes. NAC transcription factors play effective roles in resistance to different abiotic stresses, and overexpressions of NAC TFs in Arabidopsis have been proved to be conducive in improving salinity tolerance. However, functions of NAC genes in chrysanthemum continue to be poorly understood. Here, we performed physiology and molecular experiments to evaluate roles of DgNAC1 in chrysanthemum salt stress responses. In this study, DgNAC1-overexpressed chrysanthemum was obviously more resistant to salt over the WT (wild type). Specifically, the transgenic chrysanthemum showed a higher survival rate and lower EC (electrolyte conductivity) than WT under salt stress. The transgenic chrysanthemum also showed fewer accumulations of MDA (malondialdehyde) and reactive oxygen species (H2O2 and O2-), greater activities of SOD (superoxide dismutase), POD (peroxidase) and CAT (catalase), as well as more proline content than WT under salt stress. Furthermore, stress-responsive genes in transgenic chrysanthemum were greater up-regulated than in WT under salinity stress. Thus, all results revealed that DgNAC1 worked as a positive regulator in responses to salt stress and it may be an essential gene for molecular breeding of salt-tolerant plants.

[Superficial Esophageal Carcinoma and Esophageal Intraepithelial Neoplasia: a Pathological Study of 130 Cases].

OBJECTIVE: To identify the pathological features of superficial esophageal carcinoma and esophageal intraepithelial neoplasia resected through endoscopic submucosal dissection (ESD). METHODS: The clinical and pathologic profiles of 130 cases were reviewed, including gross type, histology type, infiltration depth, infiltrative growth pattern, presence of tumor budding, lymphatic and vascular invasion, and margin status. RESULTS: The patients had a median age of 62 years old. The predominant gross type was mixed type (78/130, 60.0%), followed by Type 0-II (49/130, 37.7%). The longest diameter of lesionshad a median of 13.8 mm. Morphologically, there were 3 cases (2.3%) of undetermined dysplasia, 25 cases (19.2%) of low grade intraepithelial neoplasia, 56 cases (43.1%) of high grade of intraepithelial neoplasia, and 46 cases (35.4%) of invasive carcinoma. No correlation was found between histological type and gross type. Intramucosal and submucosal invasive carcinoma accounted for 87.0% (40/46) and 13.0% (6/46) of the cases, respectively; sm1 and sm2 accounted for 4.3% (2/46) and 8.7% (4/46) of the cases, respectively. Infiltrative growth pattern was identified as infiltrative growth pattern (INF) a (23/46, 50.0%), INFbeta (17/46, 37.0%) and INFc (6/46, 13.0%). Tumor budding was found in 3 cases and lymphatic and vascular invasion was found in 2 cases. Margin was positive in 30 cases (23.1%). Invasive carcinomahad a higher margin positive rate (24/46, 52.1%) than low grade intraepithelial neoplasia (1/25, 4.0%) and high grade intraepithelial neoplasia (5/56, 89%) (P<0.001). No association between margin positivity and invasive pattern was found (P=0.208). Fifteen cases (11.5%) recurred, with invasive carcinoma being more likely to recur (17.4%, 8/46) than low grade intraepithelial neoplasia (8.0%, 2/25) and high grade intraepithelial neoplasia (8.9%, 5/56) (P<0.05). No association between margin positivity and recurrence rate was found (P= 0.590). CONCLUSION: The superficial esophageal carcinoma and esophageal intraepithelial neoplasia resected by ESD are predominantly mixed type under endoscope, with histological features of high grade intraepithelial neoplasia and invasive carcinoma. Invasive carcinomas are more likely to recur and present with a positive margin.

Biphasic effects of ethanol consumption on N,N-dimethylformamide-induced liver injury in mice.

N,N-Dimethylformamide (DMF) is a well-documented occupational hazardous material, which can induce occupational liver injury. The current study was designed to investigate whether ethanol consumption can affect DMF-induced hepatotoxicity and the potential underlying mechanisms involved. We found that a single dose of ethanol (1.25, 2.5, or 5 g/kg bw by gavage) significantly repressed the increase in serum alanine transaminase (ALT) and aspartate transaminase (AST) activities and alleviated the liver histopathological changes in mice challenged with 3 g/kg DMF. In contrast, long-term moderate drinking (2.5 g/kg bw) significantly aggravated the repeated DMF (0.7 g/kg bw) exposure-induced increase in the serum ALT and AST activities. Mechanistically, acute ethanol consumption suppressed DMF-induced activation of the NLR family pyrin domain-containing protein 3 (NLRP3) inflammasome, while long-term moderate ethanol consumption promoted hepatocyte apoptosis in the mouse liver. Notably, cytochrome P4502E1 (CYP2E1) protein level and activity in mouse livers were not significantly affected by ethanol per se in the two models. These results confirm that regular drinking can increase the risk of DMF-induced hepatotoxicity, and suggest that DMF-handling workers should avoid consuming ethanol to reduce the risk of DMF-indued liver injury.

Evaluating Fluorinated-Aniline Units with Functionalized Spiro[Fluorene-9,9'-Xanthene] as Hole-Transporting Materials in Perovskite Solar Cells and Light-Emitting Diodes.

In the field of perovskite optoelectronics, developing hole-transporting materials (HTMs) on the spiro[fluorene-9,9'-xanthene] (SFX) platform is one of the current research focuses. The SFX inherits the merits of spirobifluorene in terms of the configuration and property, but it is more easily derivatized and regulated by virtue of its binary structure. In this work, we design and synthesize four isomeric SFX-based HTMs, namely m-SFX-mF, p-SFX-mF, m-SFX-oF, and p-SFX-oF, through varying the positions of fluorination on the peripheral aniline units and their substitutions on the SFX core, and the optoelectronic performance of the resulting HTMs is evaluated in both perovskite solar cells (PSCs) and light-emitting diodes (PeLEDs) by the vacuum thermal evaporating hole-transporting layers (HTLs). The HTM p-SFX-oF exhibits an improved power conversion efficiency of 15.21% in an inverted PSC using CH3NH3PbI3 as an absorber, benefiting from the deep HOMO level and good HTL/perovskite interface contact. Meanwhile, the HTM m-SFX-mF provides a maximum external quantum efficiency of 3.15% in CsPb(Br/Cl)3-based PeLEDs, which is attributed to its perched HOMO level and shrunken band-gap for facilitating charge carrier injection and then exciton combination. Through elucidating the synergistic position effect of fluorination on aniline units and their substitutions on the SFX core, this work lays the foundation for developing low-cost and efficient HTMs in the future.

Overexpression of a novel chrysanthemum Cys2/His2-type zinc finger protein gene DgZFP3 confers drought tolerance in tobacco.

A drought stress-responsive Cys2/His2-type zinc finger protein gene DgZFP3 was previously isolated (Liu et al., Afr J Biotechnol 11:7781-7788, 2012b) from chrysanthemum. To assess roles of DgZFP3 in plant drought stress responses, we performed gain-of-function experiment. The DgZFP3-overexpression tobacco plants showed significant drought tolerance over the wild type (WT). The transgenic lines exhibited less accumulation of H2O2 under drought stress, more accumulation of proline and greater activities of peroxidase (POD) and superoxide dismutase than the WT under both control conditions and drought stress. In addition, there was greater up-regulation of the ROS-related enzyme genes (NtSOD and NtPOD) and stress-related genes (NtLEA5 and NtDREB) in transgenic lines under normal or drought conditons. Thus DgZFP3 probably plays a positive regulatory role in drought stress response and has the potential to be utilized in transgenic breeding to improve drought stress tolerance in plants.

Fluorinated poly(p-triphenyl piperidine) anion exchange membranes with robust dimensional stability for fuel cells.

Anion exchange membrane fuel cells (AEMFCs), which are more economical than proton exchange membrane fuel cells (PEMFCs), stand out in the context of the rapid development of renewable energy. Superacid-catalyzed ether-free aromatic polymers have recently received a lot of attention due to their exceptional performance, but their development has been hampered by the trade-off between the dimensional stability and ionic conductivity of anion exchange membranes (AEMs). Here, we introduced fluoroketones containing different numbers of fluorinated groups (x = 0, 3 and 6) in the main chain of p-terphenyl piperidine because of the favorable hydrophobic properties of fluorinated groups. The results show that fluorinated AEMs can enhance OH- conductivity by building more aggregated hydrophilic channels while ensuring dimensional stability. The PTF6-QAPTP AEM with more fluorinated groups has the most excellent performance at 80 °C with an OH- conductivity of 142.7 mS cm-1 and a swelling ratio (SR) of only 4.55 %. Additionally, it exhibits good alkali durability, with the OH- conductivity and quaternary ammonium (QA) cation retaining at 93.45% and 92.6%, respectively, after immersion in a 2 M NaOH solution at 80 °C for 1200 h. In addition, the power density of the PTF6-QAPTP based single cell reaches 849 mW cm-2 when the current density is 1600 mA cm-2. The PTF6-QAPTP based cell has a voltage retention of 88% after 80 h of stability testing at a constant current density of 300 mA cm-2 at 80 °C.

Highly conductive branched poly(aryl piperidinium) anion exchange membranes with robust chemical stability.

Poly(aryl piperidinium) (PAP) anion exchange membranes (AEMs) furnish an important avenue for the commercialization of anion exchange membrane fuel cells (AEMFCs), but their ionic conductivity and alkali resistance still need to be improved. Here, we report the synthesis of PAP AEMs with a branched structure by the acid-catalyzed reaction and compare them with the main-chain AEMs. The experimental results show that the branched AEMs have higher OH- conductivity and alkaline resistance than the poly(terphenyl piperidine) (PTPQ1) AEM. The alkaline stability and OH- conductivity of the AEMs were further improved by a flexible multi-cation crosslinker. The results show that the branched poly(p-terphenyl triphenylmethane 1-methyl piperidine) membrane crosslinked by multi-cation (PTTPQ4-40) shows an excellent OH- conductivity (155.3 mS cm-1) at 80 °C. The OH- conductivity of the PTTPQ4-40 membrane was maintained at 92.1% after soaking in 2 M NaOH for 1080 h at 80 °C. In addition, the peak power density (PPD) of the crosslinked PTTPQ4-40 membrane can reach 656.7 mW cm-2. Compared to the PTPQ1 AEM, the PPD of the crosslinked PTTPQ4-40 AEM is increased by 38.6% in H2-O2. All of the results confirm that the PTTPQ4-40 AEM has excellent fuel cell application prospects.

Transcriptome analysis during axillary bud growth in chrysanthemum (chrysanthemum×morifolium).

The chrysanthemum DgLsL gene, homologous with tomato Ls, is one of the earliest expressed genes controlling axillary meristem initiation. In this study, the wild-type chrysanthemum (CW) and DgLsL-overexpressed line 15 (C15) were used to investigate the regulatory mechanism of axillary bud development in chrysanthemum. Transcriptome sequencing was carried out to detect the differentially expressed genes of the axillary buds 0 h, 24 h and 48 h after decapitation. The phenotypic results showed that the number of axillary buds of C15 was significantly higher than CW. A total of 9,224 DEGs were identified in C15-0 vs. CW-0, 10,622 DEGs in C15-24 vs. CW-24, and 8,929 DEGs in C15-48 vs. CW-48.GO and KEGG pathway enrichment analyses showed that the genes of the flavonoid, phenylpropanoids and plant hormone pathways appeared to be differentially expressed, indicating their important roles in axillary bud germination. DgLsL reduces GA content in axillary buds by promoting GA2ox expression.These results confirmed previous studies on axillary bud germination and growth, and revealed the important roles of genes involved in plant hormone biosynthesis and signal transduction, aiding in the study of the gene patterns involved in axillary bud germination and growth.

Effects of the crown ether cavity on the performance of anion exchange membranes.

Anion exchange membrane fuel cells (AEMFCs) have emerged as a promising alternative to proton exchange membrane fuel cells (PEMFCs) due to their adaptability to low-cost stack components and non-noble-metals catalysts. However, the poor alkaline resistance and low OH- conductivity of anion exchange membranes (AEMs) have impeded the large-scale implementation of AEMFCs. Herein, the preparation of a new type of AEMs with crown ether macrocycles in their main chains via a one-pot superacid catalyzed reaction was reported. The study aimed to examine the influence of crown ether cavity size on the phase separation structure, ionic conductivity and alkali resistance of anion exchange membranes. Attributed to the self-assembly of crown ethers, the poly (crown ether) (PCE) AEMs with dibenzo-18-crown-6-ether (QAPCE-18-6) exhibit an obvious phase separated structure and a maximum OH- conductivity of 122.5 mS cm-1 at 80 °C (ionic exchange capacity is 1.51 meq g-1). QAPCE-18-6 shows a good alkali resistance with the OH- conductivity retention of 94.5% albeit being treated in a harsh alkali condition. Moreover, the hydrogen/oxygen single cell equipped with QAPCE-18-6 can achieve a peak power density (PPD) of 574 mW cm-2 at a current density of 1.39 A cm-2.

The expression level of Rosa Terminal Flower 1 (RTFL1) is related with recurrent flowering in roses.

We examined the relationship between the recurrent flowering character and the expression patterns of TERMINAL FLOWER 1 (TFL1) homologs in roses, using flower buds of Rosa multiflora, R. rugosa, R. chinensis, and six other rose species and nine rose cultivars. RTFL1 (Rosa TFL1) genes were amplified from rose genomic DNA using a combination of degenerate and gene-specific primers by thermal asymmetric interlaced-PCR and normal PCR, respectively. Their copy numbers in different species were determined by Southern blots. We used real-time PCR to analyze the expression patterns of RTFL1 genes at four developmental stages (pre-sprouting, young, mid-aged, and mature flower buds). Our results show that there are at least three RTFL1 homologs in roses; RTFL1a, RTFL1b, and RTFL1c. The sequences of the homologs were more similar among the same homolog in different species than among the different homologs in the same species. For RTFL1a, we detected two copies in R. multiflora, two copies in R. rugosa, and one copy in R. chinensis. For RTFL1c, we detected one copy in R. multiflora, two copies in R. rugosa, and three copies in R. chinensis. We detected only one copy of RTFL1b in R. chinensis. RTFL1c was expressed at high levels at all four flowering stages in R. multiflora and R. rugosa, which are non-recurrent flowering species, whereas it was barely detected in R. chinensis (a recurrent flowering species) at any stage. These results were further verified in six other non-recurrent flowering species and nine recurrent flowering cultivars. These results suggest that the recurrent flowering habit in roses results from lower expression of RTFL1c, which may be related to recurrent flowering character in roses.

The rapid appearance of homostyly in a cultivated distylous population of Primula forbesii.

Evolutionary breakdown from rigorous outbreeding to self-fertilization frequently occurs in angiosperms. Since the pollinators are not necessary, self-compatible populations often reduce investment in floral display characteristics and pollination reward. Primula forbesii is a biennial herb with distribution restricted to southwest China; it was initially a self-incompatible distylous species, but after 20 years of artificial domestication, homostyly appeared. This change in style provides an ideal material to explore the time required for plant mating systems to adapt to new environmental changes and test whether flower attraction has reduced following transitions to selfing. We did a survey in wild populations of P. forbesii where its seeds were originally collected 20 years ago and recorded the floral morph frequencies and morphologies. The floral morphologies, self-incompatibility, floral scent, and pollinator visitation between distyly and homostyly were compared in greenhouse. Floral morph frequencies of wild populations did not change, while the cultivated population was inclined to L-morph and produced homostyly. Evidence from stigma papillae and pollen size supports the hypothesis that the homostyly possibly originated from mutations of large effect genes in distylous linkage region. Transitions to self-compatible homostyly are accompanied by smaller corolla size, lower amounts of terpenoids, especially linalool and higher amounts of fatty acid derivatives. The main pollinators in the greenhouse were short-tongued Apis cerana. However, homostyly had reduced visiting frequency. The mating system of P. forbesii changed rapidly in just about 20 years of domestication, and our findings confirm the hypothesis that the transition to selfing is accompanied by decreased flower attraction.

Overexpression of a novel chrysanthemum NAC transcription factor gene enhances salt tolerance in tobacco.

The plant-specific NAC (for NAM, ATAF1, 2 and CUC2) transcription factors (TFs) have been implicated in different cellular processes involved in stress responses such as cold, high salinity or drought as well as abscisic acid (ABA) signalling. However, the roles of the chrysanthemum NAC TF genes in plant stress responses are still unclear. A full-length cDNA designated DgNAC1, containing a highly conserved N-terminal DNA-binding NAC domain, has been isolated from chrysanthemum by RACE (rapid amplification of cDNA ends). It encodes a protein of 284 amino acids residues (=~32.9 kDa) and theoretical pI of 7.13. The transcript of DgNAC1 was enriched in roots and flowers than in stems and leaves of the adult chrysanthemum plants. The gene expression was strongly induced by ABA, NaCl, drought and cold treatment in the seedlings. Subcellular localization revealed that DgNAC1:GFP fusion protein was preferentially distributed to nucleus. To assess whether DgNAC1 is a practically useful target gene for improving the stress tolerance of chrysanthemum, we ectopically over-expressed the full-length DgNAC1 cDNA in tobacco and found that the 35S:DgNAC1 transgenic tobacco exhibited a markedly increased tolerance to salt. Despite this increased salt stress tolerance, the transgenic tobacco showed no detectable phenotype defects under normal growth conditions. These results proposed that DgNAC1 is appropriate for application in genetic engineering strategies aimed at improving salt stress tolerance in chrysanthemum.

Two-dimensional metal-organic framework-graphene oxide hybrid nanocomposite proton exchange membranes with enhanced proton conduction.

A novel two-dimensional (2D) zeolitic imidazolate framework-graphene oxide hybrid nanocomposite (ZIF-L@GO) is designed as an inorganic filler in sulfonated poly(ether ether ketone) (SPEEK). ZIF-L with unique leaf-like morphology is grown in-situ on the GO sheet in aqueous media at room temperature. The terminal imidazole linker in ZIF-L@GO and the -SO3H in SPEEK can form acid-base pairs in the membrane interface to produce low energy proton conduction highway. Benefiting from the unique structural advantage, the hybrid SP-ZIF-L@GO membranes displayed promoted physicochemical and electrochemical performances over the pure SPEEK. The SP-ZIF-L@GO-5 achieved a proton conductivity of 0.265 and 0.0364 S cm-1 at 70 °C-100% RH and 90 °C-40% RH, 1.76- and 6.24-fold higher than pure SPEEK, respectively. Meanwhile, a single cell based on SP-ZIF-L@GO-5 had an output power up to 652.82 mW cm-2 at 60 °C, 1.45 times higher than the pure SPEEK. In addition, the durability test was performed by holding open circuit voltage (OCV) for 24 h. The SP-ZIF-L@GO-5 provided better long-term stability than the pure SPEEK. These superior performance suggests a promising application in PEMFC.

External application of nitrogen alleviates toxicity of cadmium on poplars via starch and sucrose metabolism.

Phytoremediation technology can help achieve moderate cost and considerable effect with respect to the remediation of heavy metal (HM) pollution in soil and water. Many previous studies have suggested the role of nitrogen (N) in the alleviation of effects of HM on plants. Herein, we sought to determine the molecular mechanisms by which additional N supplementation mitigates cadmium (Cd) toxicity in poplars using a combination of physiological, transcriptomic and phosphoproteomic analyses. The application of N can alleviate the toxicity of Cd to Populus by reducing chlorophyll degradation, maintaining the stability of ions inside and outside the cell membrane and increasing the soluble sugar content. Plant samples from the control, Cd stress and Cd_N treatments were used for an integrated analysis of the transcriptome, as well as for phosphoproteomics analysis. Moreover, 1314 differentially expressed genes and 119 differentially expressed kinase genes were discovered. Application of additional N under Cd stress promoted the phosphorylation process. Furthermore, 51 significantly enriched phosphorylated protein sites and 23 differentially expressed kinases were identified using phosphoproteomic and proteomic analyses. Importantly, transcriptomic and phosphoproteomic analyses jointly determined that the application of N could activate corresponding gene expression [UDP-glucose-dehydrogenase (UGD), GAUT, PME, pectin lyase, UDP-glucose-pyrophosphorylase 2 (UGP2), sucrose phosphate synthase (SPS), SUS and SPP2] and protein phosphorylation (UGP2 and SPS) in the sugar and starch synthesis pathways, which promoted the synthesis of sucrose and soluble sugar and subsequently alleviated the damage caused by Cd.