Ni─Co─O─S Derived Catalysts on Hierarchical N-doped Carbon Supports with Strong Interfacial Interactions for Improved Hybrid Water Splitting Performance.

Simultaneously improving electrochemical activity and stability is a long-term goal for water splitting. Herein, hierarchical N-doped carbon nanotubes on carbon nanowires derived from PPy are grown on carbon cloth, serving as a support for NiCo oxides/sulfides. The hierarchical electrodes annealed in N2 or H2/N2 display improved intrinsic activity and stability for hydrogen evolution reaction (HER) and glucose oxidation reaction. Compared with Pt/C||Ir/C in alkaline media, the glucose electrolysis assembled with electrodes exhibits a cell voltage of 1.38 V at 10 mA cm-2, durability for >12 h at 50 mA cm-2, and resistance to glucose/gluconic acid poisoning. In addition, electrocatalysts can also be applied in ethanol oxidation reactions. Systematic characterizations reveal the strong interactions between NiCo and N-doped carbon support-induced partial charge transfer at the interface and regulate the local electronic structure of active sites. Density functional theory calculations demonstrate that the synergistic effect between N-doped carbon supports, metallic NiCo, and NiCo oxides/sulfides optimize the adsorption energy of H2O and the H* free energy for HER. The energy barrier of the dehydrogenation of glucose effectively decreased. This work will attract attention to the role of metal-support interactions in enhancing the intrinsic activity and stability of electrocatalysts.

Tetraphenylethene-Based Ni8-Pyrazolate Metal-Organic Framework for Photoredox/Nickel Dual Catalysis of C-S Cross-Coupling.

As a prototypical aggregation-induced emission luminogen (AIEgen), the tetraphenylethene (TPE) moiety has been judiciously modified as organic linkers for constructing various functional metal-organic frameworks (MOFs). However, these AIEgen-based MOFs have rarely received research attention in photocatalytic applications due to their limited stability in harsh reaction conditions. In this work, we report a robust Ni8-pyrazolate-based MOF (denoted as TPE4Pz-Ni) under the guidance of reticular chemistry, which is assembled by an AIE-active tetratopic linker of 1,1,2,2-tetrakis(4-(1H-pyrazol-4-yl)phenyl)ethane (H4-TPE4Pz) with a 12-connected Ni8-cluster of [Ni8(OH)4(H2O)2Pz12] (Pz = pyrazolate) in a (4,12)-connected ftw-a topological network. Notably, MOF TPE4Pz-Ni exhibits excellent stability in a wide range of solvents and even in a saturated NaOH solution. Moreover, its luminescent emission is effectively quenched via a ligand-to-metal charge transfer (LMCT) process originating from the TPE-cored linker to the Ni8 cluster, which enables TPE4Pz-Ni to act as an efficient photoredox/nickel dual catalyst for light-mediated C-S cross-coupling reactions between various aryl iodides and thiols.

Effects of sulfur nanoparticles on rhizosphere microbial community changes in oilseed rape plantation soil under mercury stress.

In the present study, experiments were conducted to assess the influence of nanoscale sulfur in the microbial community structure of metallophytes in Hg-contaminated rhizosphere soil for planting rapeseed. The results showed that the richness and diversity of the rhizobacteria community decreased significantly under Hg stress, but increased slightly after SNPs addition, with a reduction in the loss of Hg-sensitive microorganisms. Moreover, all changes in the relative abundances of the top ten phyla influenced by Hg treatment were reverted when subjected to Hg + SNPs treatment, except for Myxococcota and Bacteroidota. Similarly, the top five genera, whose relative abundance decreased the most under Hg alone compared to CK, increased by 19.05%-54.66% under Hg + SNPs treatment compared with Hg alone. Furthermore, the relative abundance of Sphingomonas, as one of the dominant genera for both CK and Hg + SNPs treatment, was actively correlated with plant growth. Rhizobacteria, like Pedobacter and Massilia, were significantly decreased under Hg + SNPs and were positively linked to Hg accumulation in plants. This study suggested that SNPs could create a healthier soil microecological environment by reversing the effect of Hg on the relative abundance of microorganisms, thereby assisting microorganisms to remediate heavy metal-contaminated soil and reduce the stress of heavy metals on plants.

In this manuscript, we first comprehensively investigated the changes in the rhizosphere microbial community structure of metallophytes in Hg-contaminated soil with SNPs addition, as well as the relationship between soil microbiology and plant resistance to Hg stress. Our results demonstrated that SNPs exhibit a significant advantage in improving rhizosphere microecology by increasing the abundance of beneficial rhizobacteria, thereby alleviating heavy metal toxicity, and promoting plant growth. This study is the first study describing the response of soil microorganisms coexposed to heavy metals and SNPs, providing valuable information for the potential use of SNPs to assist phytoremediation of toxic metal pollution and its impact on soil microbial communities.

The accelerated organ senescence and proteotoxicity in thyrotoxicosis mice.

The mechanism of aging has always been the focus of research, because aging is related to disease susceptibility and seriously affects people's quality of life. The diseases also accelerate the aging process, especially the pathological changes of substantive organs, such as cardiac hypertrophy, severely shortened lifespan. So, lesions in organs are both a consequence and a cause of aging. However, the disease in a given organ is not in isolation but is a systemic problem. Our previous study found that thyrotoxicosis mice model has aging characteristics including immunosenescence, lipotoxicity, malnutrition. But all these characteristics will lead to organ senescence, therefore, this study continued to study the aging changes of important organs such as heart, liver, and kidney in thyrotoxicosis mice using tandem mass tags (TMT) proteomics method. The results showed that the excess thyroxine led to cardiac hypertrophy. In the liver, the ability to synthesize functional proteins, detoxify, and metabolism were declined. The effect on the kidney was the decreased ability of detoxify and metabolism. The main finding of the present study was that the acceleration of organ senescence by excess thyroxine was due to proteotoxicity. The shared cause of proteotoxicity in the three organs included the intensify of oxidative phosphorylation, the redundancy production of ribosomes, and the lack of splicing and ubiquitin proteasome system function. Totally, proteotoxicity was another parallel between thyrotoxicosis and aging in addition to lipotoxicity. Our research provided a convenient and appropriate animal model for exploring aging mechanism and antiaging drugs.

Co-exposure of sulfur nanoparticles and Cu alleviate Cu stress and toxicity to oilseed rape Brassica napus L.

Experiments were performed to explore the impact of sulfur nanoparticles (SNPs) on growth, Cu accumulation, and physiological and biochemical responses of oilseed rape (Brassica napus L.) inoculated with 5 mg/L Cu-amended MS medium supplemented with or without 300 mg/L SNPs exposure. Cu exerted severe phytotoxicity and inhibited plant growth. SNPs application enhanced the shoot height, root length, and dry weight of shoot and root by 34.6%, 282%, 41.7% and 37.1%, respectively, over Cu treatment alone, while the shoot and root Cu contents and Cu-induced lipid perodixation as the malondialdehyde (MDA) levels in shoots and roots were decreased by 37.6%, 35%, 28.4% and 26.8%. Further, the increases in superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), glutathione reductase (GR) and glutathione S-transferase (GST) enzyme activities caused by Cu stress were mitigated in shoots (10.9%-37.1%) and roots (14.6%-35.3%) with SNPs addition. SNPs also positively counteracted the negative effects on shoot K, Ca, P, Mg, Mn, Zn and Fe contents and root K, Ca, Mg and Mn contents from Cu exposure alone, and significantly promoted the nutrients accumulation in plant. Additionally, in comparison with common bulk sulfur particles (BSPs) and sulfate, SNPs showed more positive effects on promoting growth in shoots (6.7% and 19.5%) and roots (10.9% and 15.1%), as well as lowering the shoot Cu content (40.1% and 43.3%) under Cu stress. Thus, SNPs application has potential to be a green and sustainable technology for increasing plant productivity and reducing accumulation of toxic metals in heavy metal polluted soils.

Sly-miR159 regulates fruit morphology by modulating GA biosynthesis in tomato.

Fruit morphology is an important agronomical trait of many crops. Here, we identify Sly-miR159 as an important regulator of fruit morphology in tomato, a model species of fleshy-fruit development. We show that Sly-miR159 functions through its target SlGAMYB2 to control fruit growth. Suppression of Sly-miR159 and overexpression of SlGAMYB2 result in larger fruits with a reduced length/width ratio, while loss of function of SlGAMYB2 leads to the formation of smaller and more elongated fruits. Gibberellin (GA) is a major phytohormone that regulates fruit development in tomato. We show the Sly-miR159-SlGAMYB2 pathway controls fruit morphology by modulating GA biosynthesis. In particular, we demonstrate that Sly-miR159 promotes GA biosynthesis largely through the direct repression of the GA biosynthetic gene SlGA3ox2 by SlGAMYB2. Together, our findings reveal the action of Sly-miR159 on GA biosynthesis as a previously unidentified mechanism that controls fruit morphology in tomato. Modulating this pathway may have potential applications in tomato breeding for manipulating fruit growth and facilitating the process of fruit improvement.

SlMIR164A regulates fruit ripening and quality by controlling SlNAM2 and SlNAM3 in tomato.

MiRNAs are important posttranscriptional regulators of plant development. Many miRNAs, such as the conserved miR164 species, are encoded by families of MIRNA genes, but the specific roles of individual MIRNA genes are largely undefined. Here, we characterize the functions and regulatory mechanisms of SlMIR164A, one of the primary genes of Sly-miR164, in tomato. We show that SlMIR164A is preferentially expressed at late stages of fruit development and plays a vital role in controlling fruit ripening and quality. Loss of function of SlMIR164A by CRISPR/Cas9-mediated mutagenesis results in accelerated fruit ripening and enhanced chloroplast development, which leads to altered sugar and organic acid contents and affects the nutritional quality of fruits. We also show that SlMIR164A modulates fruit ripening and quality through specific target genes, SlNAM2 and SlNAM3, which control key regulators of chloroplast function and fruit ripening processes. MIR164 genes have been shown to play conserved roles in regulating organ ageing, such as leaf senescence and fruit ripening, in a variety of plants, but whether and how their family members in tomato exert the same function remain to be elucidated. Our results reveal a previously undiscovered role of SlMIR164A in ripening control, which will further our understanding of the actions of MIR164 family, as well as the mechanisms of fruit ripening and quality control in tomato. Moreover, as loss of SlMIR164A exhibits minor impacts on organ morphology, our results can be leveraged in tomato breeding for specific manipulation of fruit ripening and quality to facilitate tomato improvement in agriculture.

Plant U-box E3 ligases PUB25 and PUB26 control organ growth in Arabidopsis.

Plant organs often grow into a genetically determined size and shape. How organ growth is finely regulated to achieve a well defined pattern is a fascinating, but largely unresolved, question in plant research. We utilised the Arabidopsis petal to study the genetic control of plant organ growth, and identify two closely related U-box E3 ligases PUB25 and PUB26 as important growth regulators by screening the targets of the petal-specific growth-promoting transcription factor RABBIT EARS (RBE). We showed that PUB25 is directly controlled by RBE in petal development in a spatial- and temporal-specific manner and acts as a major target to mediate RBE's function in petal growth. We also showed that PUB25 and PUB26 repress petal growth by restricting the period of cell proliferation, and their regulation appears to be independent of other plant E3 ligase genes implicated in growth control. PUB25 and PUB26 are among the first U-box E3 ligases shown to function in plant growth control. Furthermore, as they were also found to play a vital role in plant stress responses, PUB25 and PUB26 may act as a key hub to integrate developmental and environmental signals for balancing growth and defence in plants.

TCP5 controls leaf margin development by regulating KNOX and BEL-like transcription factors in Arabidopsis.

Development of leaf margins is an important process in leaf morphogenesis. CIN-clade TCP (TEOSINTE BRANCHED1/CYCLOIDEA/PCF) transcription factors are known to have redundant roles in specifying leaf margins, but the specific mechanisms through which individual TCP genes function remain elusive. In this study, we report that the CIN-TCP gene TCP5 is involved in repressing the initiation and outgrowth of leaf serrations by activating two key regulators of margin development, the Class II KNOX factor KNAT3 and BEL-like SAW1. Specifically, TCP5 directly promotes the transcription of KNAT3 and indirectly activates the expression of SAW1. We also show that TCP5 regulates KNAT3 and SAW1 in a temporal- and spatial- specific manner that is largely in accordance with the progress of formation of serrations. This regulation might serve as a key mechanism in patterning margin morphogenesis and in sculpting the final form of the leaf.

Diagnostic nomogram based on intralesional and perilesional radiomics features and clinical factors of clinically significant prostate cancer.

Previous studies on the value of radiomics for diagnosing clinically significant prostate cancer (csPCa) only utilized intralesional features. However, the role of tumor microenvironment is important in tumor generation and progression. The aim of this study is to build and validate a nomogram based on perilesional and intralesional radiomics features and clinical factors for csPCa. This is a retrospective study, which included 140 patients who underwent prostate magnetic resonance imaging (MRI). This study used 3.0T T2-weighted imaging, apparent diffusion coefficient maps (derived from diffusion-weighted images), and dynamic contrast-enhanced MRI. Region of interest (ROI)s were segmented by two radiologists. Intralesional and combined radiomics signatures were built based on radiomics features extracted from intralesional and the combination of radiomics features extracted from intralesional and perilesional volumes. Serum total prostate-specific antigen level and combined radiomics signature scores were used to construct a diagnostic nomogram. Intraclass correlation efficient analysis was used to test intra- and inter-rater agreement of radiomics features. Min-max scalar was used for normalization. One-way analysis of variance or the Mann-Whitney U-test was used for univariate analysis. Receiver operating characteristic curve analysis, accuracy, balanced accuracy, and F1-score were used to evaluate radiomics signatures and the nomogram. Also, the nomogram was evaluated using decision curve analysis in testing cohort. Delong test was used to compare area under the curves (AUCs). Statistical significance was set at p < 0.05. In testing cohort, AUC, accuracy, balanced accuracy, and F1-score of combined radiomics signature (0.94, 0.83, 0.80, and 0.87, respectively) were all higher than that of intralesional radiomics signature (0.90, 0.77, 0.74, and 0.83, respectively). The difference between AUCs was insignificant (p of 0.19). AUC, accuracy, balanced accuracy, and F1-score of the nomogram were 0.96, 0.94, 0.95, and 0.95, respectively. Nomogram was clinically useful when threshold probability of a patient is higher than 0.06. Perilesional radiomics features improved the discrimination ability of the radiomics signature. Diagnostic nomogram had a good performance. LEVEL OF EVIDENCE: 3. TECHNICAL EFFICACY STAGE: 2.

H19/miR-107/HMGB1 axis sensitizes laryngeal squamous cell carcinoma to cisplatin by suppressing autophagy in vitro and in vivo.

Laryngeal squamous cell carcinoma (LSCC) is the most common malignant tumor, which occurs in the head and neck. Current treatments for LSCC are all largely weakened by increasing drug resistance. Our study aimed to investigate the effects of long noncoding RNA (lncRNA) H19 on drug resistance in LSCC. In our study, we found that the level of H19 was sharply upregulated in LSCC tissues and drug-resistant cells compared with the control. Besides, the expression of high-mobility group B1 (HMGB1) was elevated, and microRNA107 (miR-107) was suppressed in drug-resistant cells compared with the control. Further study revealed that the interference of H19 by short hairpin RNA (shRNA) effectively suppressed high autophagy level and obvious drug resistance in drug-resistant cells. Besides that, miR-107 was predicted as a target of H19 and inhibiting effects of H19 shRNA on autophagy and drug resistance were both reversed by miR-107 inhibitor. Moreover, HMGB1 was predicted as a target of miR-107 in LSCC cells and knockdown of HMGB1 was able to suppress autophagy and drug resistance in LSCC cells. In addition, our investigation demonstrated that H19 shRNA exerted an inhibiting effect on autophagy and drug resistance by downregulating HMGB1 by targeting miR-107. Finally, the in vivo experiment revealed that LV-H19 shRNA strongly suppressed drug resistance compared with the usage of cisplatin individually. Taken together, our research indicated an H19-miR-107-HMGB1 axis in regulating the autophagy-induced drug resistance in LSCC in vitro and in vivo, providing novel targets for molecular-targeted therapy and broadening the research for LSCC.

Genome-Wide Identification and Expression Analysis of BBX Transcription Factors in Iris germanica L.

The family of B-box (BBX) transcription factors contains one or two B-BOX domains and sometimes also features a highly conserved CCT domain, which plays important roles in plant growth, development and stress response. Nevertheless, no systematic study of the BBX gene family in Iris germanica L. has been undertaken. In this study, a set of six BBX TF family genes from I. germanica was identified based on transcriptomic sequences, and clustered into three clades according to phylogenetic analysis. A transient expression analysis revealed that all six BBX proteins were localized in the nucleus. A yeast one-hybrid assay demonstrated that IgBBX3 has transactivational activity, while IgBBX1, IgBBX2, IgBBX4, and IgBBX5 have no transcriptional activation ability. The transcript abundance of IgBBXs in different tissues was divided into two major groups. The expression of IgBBX1, IgBBX2, IgBBX3 and IgBBX5 was higher in leaves, whereas IgBBX4 and IgBBX6 was higher in roots. The stress response patterns of six IgBBX were detected under phytohormone treatments and abiotic stresses. The results of this study lay the basis for further research on the functions of BBX gene family members in plant hormone and stress responses, which will promote their application in I. germanica breeding.

A beta-glucosidase gene from Stevia rebaudiana may be involved in the steviol glycosides catabolic pathway.

We herein report the preparation of a full-length raucaffricine-O-beta-D-glucosidase gene of stevia rebaudiana Bertoni (named SrRG1, GenBank accession number MK920450). Sequence analysis indicated SrRG1 consists of a 1650 bp open reading frame encoding a protein of 549 amino acids. Its deduced amino acid sequence showed a high identity of 82% with a raucaffricine-O-beta-D-glucosidase from H. annuus of glycoside hydrolase family 1. The expression pattern analyzed by real-time quantitative PCR showed no significant difference among different tissues, developmental stages, and cultivars under normal growth conditions. Furthermore, the gene function of SrRG1 was preliminarily studied by agrobacterium-mediated transformation on instantaneous expression. In the test of agrobacterium-mediated transformation on instantaneous expression, it was observed that overexpression of SrRG1 increased the accumulation of steviol content and decreased the major components and total SGs contents. Such results demonstrated that SrRG1 may participate in the steviol glycosides catabolic pathway. However, the effect of silencing construct infiltration on steviol and SGs content was not significant and its expression pattern was constitutive, which most probably, attributed the hydrolysis of SGs to the secondary activity of SrRG1. This study firstly identified the bate-glucosidase in stevia and advances our understanding of steviol glycosides hydrolyzation.

Identification of GH1 gene family fgt members in Stevia rebaudiana and their expression when grown in darkness.

Stevia rebaudiana Bertoni is an important economic crop that is well known for its secondary metabolites, steviol glycosides (SGs), found in leaves. Because the enzymes of deglycosylation (glycoside hydrolases) play important roles in SGs biosynthetic processes, our study is focused on the functions of ß-glucosidases in SGs catabolism in stevia. We cloned and characterized 19 stevia GH1 genes based on transcriptomic sequences. The 19 genes were divided into five putative subfamilies in Arabidopsis. Conserved motifs in the SrGH1 proteins were analysed using the online motif-based sequence analysis tool, MEME. Most of the identified proteins contain the conserved 'TFNEP' motif (contains the catalytic acid/base) and 'ITENG' motif (contains the catalytic nucleophile). Furthermore, the steviol glycoside content and expression of these 19 genes were characterized under constant darkness. The dark treatment lowered the steviol glycoside content significantly, while SrBGLU16 responded to darkness and was markedly upregulated. This study is the first transcriptome-wide analysis of the GH1 family in Stevia rebaudiana. The sequences of 19 SrGH1 members and their expression when grown in darkness were characterized. Among the 19 genes, SrBGLU16 was markedly upregulated by darkness. Thus, we identified SrBGLU16 for further investigation as a possible steviol glycoside beta-glucosidase.

Preparation and characterization of a high-affinity monoclonal antibody against human epididymis protein-4.

Human epididymis protein-4 (HE4) may serve as a putative biomarker for the early diagnosis, therapy and especially prognosis of ovarian, lung and breast cancer. Detection and targeting of HE4 using the anti-HE4 antibody could be one of the effective strategies for the cancer diagnosis and treatment in clinical practice. In this study, a high-efficiency expression system was established to purify recombinant HE4. We obtained high purity HE4 in 400 mg quantity from 1 L culture supernatant of HEK293F cells. CCK-8 and cell cycle assays indicated that the purified recombinant HE4 protein could promote SKOV3 cell cycle and proliferation at the concentration of 0.1 mg/L. Furthermore, an anti-HE4 high-affinity monoclonal antibody 9C3 (ka = 8.1 × 106 1/MS, kd = 4.4 × 10-5 1/S, KD = 5.5 × 10-12 M) was prepared using hybridoma technique and analyzed by surface plasmon resonance technology using this HE4 protein. Differential Scanning calorimeter (DSC) analysis showed that 9C3 had a commendable thermal stability with the Tm value of 73 °C. Analyses of western blot, immunohistochemistry and immunofluorescence showed that the 9C3 was highly specific to HE4 in human cancer cells and tissues. In conclusion, our study designed a method to prepare human recombinant HE4 with high yield and generated a high-affinity anti-HE4 monoclonal antibody that might have potential for basic research and clinical application.

Iris lactea var. chinensis (Fisch.) cysteine-rich gene llCDT1 enhances cadmium tolerance in yeast cells and Arabidopsis thaliana.

IlCDT1, a cysteine-rich protein, was isolated from Iris lactea var. chinensis (Fisch.) (I. lactea var. chinensis). Its transcription was up-regulated by the exogenous application of Cd. The truncated IlCDT1 (25-54) containing 14 Cys residues confers Cd tolerance to yeast as the intact IlCDT1, indicating that Cys residues are required for Cd tolerance presumably by chelating Cd. When the gene was constitutively expressed in A. thaliana, root length of transgenic lines was longer than that of wild-type under 100 µM or 200 µM Cd stress. However, Cd absorption in wild-type was more than in two trangenic lines under 100 µM Cd exposure. IlCDT1 may directly bind Cd, through chelating Cd and avoiding the Cd uptake into the cells. Together, IlCDT1 may be a promising gene for the Cd tolerance improvement. SUMMARY: Cysteine-rich gene llCDT1 enhances cadmium tolerance in yeast cells and Arabidopsis thaliana.

Transcriptome analysis reveals complex response of the medicinal/ornamental halophyte Iris halophila Pall. to high environmental salinity.

The remediation and subsequent use of saline-alkaline land are of great significance to ecological environment construction and sustainable agricultural development. Iris halophila Pall. is a salt-tolerant medicinal and ornamental plant, which has good application prospects in the ecological construction of saline-alkaline land; therefore, study of the molecular mechanisms of salt tolerance in I. halophila has important theoretical and practical value. To evaluate the molecular mechanism of the response of I. halophila to salt toxicity, I. halophila seedlings were treated with salt (300 mM NaCl) and subjected to deep RNA sequencing. The clean reads were obtained and assembled into 297,188 unigenes. Among them, 1120 and 100 salt-responsive genes were identified in I. halophila shoots and roots, respectively. Among them, the key flavonoid and lignin biosynthetic genes, hormone signaling genes, sodium/potassium ion transporter genes, and transcription factors were analyzed and summarized. Quantitative reverse-transcription PCR analysis strengthened the reliability of the RNA sequencing results. This work provides an overview of the transcriptomic responses to salt toxicity in I. halophila and identifies the responsive genes that may contribute to its reduced salt toxicity. These results lay an important foundation for further study of the molecular mechanisms of salt tolerance in I. halophila and related species.

Exogenous glutathione increased lead uptake and accumulation in Iris lactea var. chinensis exposed to excess lead.

Long- and short-term hydroponic experiments were conducted to study the effect of different concentrations of exogenous glutathione (GSH) on Pb uptake, translocation, and gene expresses in Iris lactea var. chinensis exposed to excess lead (Pb). Exogenous GSH remarkedly promoted Pb uptake and translocation in long-term (14 d) experiment, and the GSH-dose-dependent increases in shoot and root Pb contents existed obviously when GSH concentrations were lower than 800 mg·L-1. The fresh weight in gradual rise in plants was observed with the increase of exogenous GSH concentration. In short-term (24 h) experiment, Pb contents in roots under Pb with L-buthionine sulfoximine (BSO, a known inhibitor of GSH biosynthesis) treatments were significantly lower than that under Pb exposure alone. The transcript levels of three genes (Ilγ-ECS, IlGS, and IlPCS) involved in GSH synthesis and metabolism, showed no significant change in expression pattern except that upregulation after 24 h of treatment with Pb and GSH in comparison with that of the single Pb treatment. Further, the level of IlGS transcript after exposure for 4 h was much higher than that of Ilγ-ECS and IlPCS transcripts. All these results obtained here suggest that exogenous GSH can increase Pb accumulation, detoxification, and translocation to the shoot.

De novo characterization of the Iris lactea var. chinensis transcriptome and an analysis of genes under cadmium or lead exposure.

Iris lactea var. chinensis (I. lactea var. chinensis) is tolerant to accumulations of cadmium (Cd) and lead (Pb). In this study, the transcriptome of I. lactea var. chinensis was investigated under Cd or Pb stresses. Using the gene ontology database, 31,974 unigenes were classified into biological process, cellular component and molecular function. In total, 13,132 unigenes were involved in enriched Encyclopedia of Genes and Genomes (KEGG) metabolic pathways, and the expression levels of 5904 unigenes were significantly changed after exposure to Cd or Pb stresses. Of these, 974 were co-up-regulated and 1281 were co-down-regulated under the two stresses. The transcriptome expression profiles of I. lactea var. chinensis under Cd or Pb stresses obtained in this study provided a resource for identifying common mechanisms in the detoxification of different heavy metals. Furthermore, the identified unigenes may be used for the genetic breeding of heavy-metal tolerant plants.

Comparative Proteomics Analyses of Pollination Response in Endangered Orchid Species Dendrobium Chrysanthum.

Pollination is a crucial stage in plant reproductive process. The self-compatibility (SC) and self-incompatibility (SI) mechanisms determined the plant genetic diversity and species survival. D. chrysanthum is a highly valued ornamental and traditional herbal orchid in Asia but has been declared endangered. The sexual reproduction in D. chrysanthum relies on the compatibility of pollination. To provide a better understanding of the mechanism of pollination, the differentially expressed proteins (DEP) between the self-pollination (SP) and cross-pollination (CP) pistil of D. chrysanthum were investigated using proteomic approaches-two-dimensional electrophoresis (2-DE) coupled with tandem mass spectrometry technique. A total of 54 DEP spots were identified in the two-dimensional electrophoresis (2-DE) maps between the SP and CP. Gene ontology analysis revealed an array of proteins belonging to following different functional categories: metabolic process (8.94%), response to stimulus (5.69%), biosynthetic process (4.07%), protein folding (3.25%) and transport (3.25%). Identification of these DEPs at the early response stage of pollination will hopefully provide new insights in the mechanism of pollination response and help for the conservation of the orchid species.