Solid Electrolyte Bimodal Grain Structures for Improved Cycling Performance.

The application of solid-state electrolytes in Li batteries is hampered by the occurrence of Li-dendrite-caused short circuits. To avoid cell failure, the electrolytes can only be stressed with rather low current densities, severely restricting their performance. As grain size and pore distributions significantly affect dendrite growth in ceramic electrolytes such as Li7La3Zr2O12 and its variants; here, a "detour and buffer" strategy to bring the superiority of both coarse and fine grains into play, is proposed. To validate the mechanism, a coarse/fine bimodal grain microstructure is obtained by seeding unpulverized large particles in the green body. The rearrangement of coarse grains and fine pores is fine-tuned by changing the ratio of pulverized and unpulverized powders. The optimized bimodal microstructure, obtained when the two powders are equally mixed, allows, without extra interface decoration, cycling for over 2000 h as the current density is increased from 1.0 mA·cm-2, and gradually, up to 2.0 mA·cm-2. The "detour and buffer" effects are confirmed from postmortem analysis. The complex grain boundaries formed by fine grains discourage the direct infiltration of Li. Simultaneously, the coarse grains further increase the tortuosity of the Li path. This study sheds light on the microstructure optimization for the polycrystalline solid-state electrolytes.

Identification of Candidate Genes Associated with Pulp Color by Transcriptomic Analysis of 'Huaxiu' Plum (Prunus salicina Lindl.) during Fruit-Ripening.

The plum (Prunus salicina Lindl.) is one of the traditional and economically important stone fruit trees in China. Anthocyanins are important pigments in plums. However, little is known about the molecular mechanisms underlying anthocyanin accumulation in plum fruits, which has hindered research on the molecular mechanism of its utilization. Our research shows that the chlorophyll content was gradually decreased and the contents of anthocyanin and flavonoid increased during the coloring process of the pulp in 'Huaxiu' plums (P. salicina). Then, the RNA-Seq technique was used to analyze the transcriptome of pulp color changes with three different stages (yellow, orange, and red) in the 'Huaxiu' plum (P. salicina). A total of 57,119 unigenes with a mean length of 953 bp were generated, and 61.6% of them were annotated to public databases. The Gene Ontology (GO) database assigned 21,438 unigenes with biological process, cellular components, and molecular function. In addition, 32,146 unigenes were clustered into 25 categories for functional classification by the COG database, and 7595 unigenes were mapped to 128 KEGG pathways by the KEGG pathway database. Of these, 1095 (YS-versus-OS), 4947 (YS-versus-RS), and 3414 (OS-versus-RS) genes were significantly expressed differentially between two coloration stages. The GO and KEGG pathway enrichment analysis revealed that 20 and 1 differentially expressed genes (DEG) are involved in flavonoid biosynthesis and anthocyanin biosynthesis, respectively. Finally, we mainly identified three structural genes as candidate genes. The transcriptome information in this study provide a basis for further studies of pulp colors in plum and contribute to our understanding of the molecular mechanisms underlying anthocyanin biosynthesis in pulp.

Transcriptome Analysis Reveals a Comprehensive Virus Resistance Response Mechanism in Pecan Infected by a Novel Badnavirus Pecan Virus.

Pecan leaf-variegated plant, which was infected with a novel badnavirus named pecan mosaic virus (PMV) detected by small RNA deep sequencing, is a vital model plant for studying the molecular mechanism of retaining green or chlorosis of virus-infected leaves. In this report, PMV infection in pecan leaves induced PAMP-triggered immunity (PTI) and effector-triggered immunity (ETI). PMV infection suppressed the expressions of key genes of fatty acid, oleic acid (C18:1), and very-long-chain fatty acids (VLCFA) biosynthesis, indicating that fatty acids-derived signaling was one of the important defense pathways in response to PMV infection in pecan. PMV infection in pecans enhanced the expressions of pathogenesis-related protein 1 (PR1). However, the transcripts of phenylalanine ammonia-lyase (PAL) and isochorismate synthase (ICS) were downregulated, indicating that salicylic acid (SA) biosynthesis was blocked in pecan infected with PMV. Meanwhile, disruption of auxin signaling affected the activation of the jasmonic acid (JA) pathway. Thus, C18:1 and JA signals are involved in response to PMV infection in pecan. In PMV-infected yellow leaves, damaged chloroplast structure and activation of mitogen-activated protein kinase 3 (MPK3) inhibited photosynthesis. Cytokinin and SA biosynthesis was blocked, leading to plants losing immune responses and systemic acquired resistance (SAR). The repression of photosynthesis and the induction of sink metabolism in the infected tissue led to dramatic changes in carbohydrate partitioning. On the contrary, the green leaves of PMV infection in pecan plants had whole cell tissue structure and chloroplast clustering, establishing a strong antiviral immunity system. Cytokinin biosynthesis and signaling transductions were remarkably strengthened, activating plant immune responses. Meanwhile, cytokinin accumulation in green leaves induced partial SA biosynthesis and gained comparatively higher SAR compared to that of yellow leaves. Disturbance of the ribosome biogenesis might enhance the resistance to PMV infection in pecan and lead to leaves staying green.

Identification and Analysis of NBS-LRR Genes in Actinidia chinensis Genome.

Nucleotide-binding site and leucine-rich repeat (NBS-LRR) genes represent the most important disease resistance genes in plants. The genome sequence of kiwifruit (Actinidia chinensis) provides resources for the characterization of NBS-LRR genes and identification of new R-genes in kiwifruit. In the present study, we identified 100 NBS-LRR genes in the kiwifruit genome and they were grouped into six distinct classes based on their domain architecture. Of the 100 genes, 79 are truncated non-regular NBS-LRR genes. Except for 37 NBS-LRR genes with no location information, the remaining 63 genes are distributed unevenly across 18 kiwifruit chromosomes and 38.01% of them are present in clusters. Seventeen families of cis-acting elements were identified in the promoters of the NBS-LRR genes, including AP2, NAC, ERF and MYB. Pseudomonas syringae pv. actinidiae (pathogen of the kiwifruit bacterial canker) infection induced differential expressions of 16 detected NBS-LRR genes and three of them are involved in plant immunity responses. Our study provides insight of the NBS-LRR genes in kiwifruit and a resource for the identification of new R-genes in the fruit.

Photosystem Disorder Could be the Key Cause for the Formation of Albino Leaf Phenotype in Pecan.

Pecan is one of the most famous nut species in the world. The phenotype of mutants with albino leaves was found in the process of seeding pecan, providing ideal material for the study of the molecular mechanisms leading to the chlorina phenotype in plants. Both chlorophyll a and chlorophyll b contents in albino leaves (ALs) were significantly lower than those in green leaves (GLs). A total of 5171 differentially expression genes (DEGs) were identified in the comparison of ALs vs. GLs using high-throughput transcriptome sequencing; 2216 DEGs (42.85%) were upregulated and 2955 DEGs (57.15%) were downregulated. The expressions of genes related to chlorophyll biosynthesis (HEMA1, encoding glutamyl-tRNA reductase; ChlH, encoding Mg-protoporphyrin IX chelatase (Mg-chelatase) H subunit; CRD, encoding Mg-protoporphyrin IX monomethylester cyclase; POR, encoding protochlorophyllide reductase) in ALs were significantly lower than those in GLs. However, the expressions of genes related to chlorophyll degradation (PAO, encoding pheophorbide a oxygenase) in ALs were significantly higher than those in GLs, indicating that disturbance of chlorophyll a biosynthesis and intensification of chlorophyll degradation lead to the absence of chlorophyll in ALs of pecan. A total of 72 DEGs associated with photosynthesis pathway were identified in ALs compared to GLs, including photosystem I (15), photosystem II (19), cytochrome b6-f complex (3), photosynthetic electron transport (6), F-type ATPase (7), and photosynthesis-antenna proteins (22). Moreover, almost all the genes (68) mapped in the photosynthesis pathway showed decreased expression in ALs compared to GLs, declaring that the photosynthetic system embedded within the thylakoid membrane of chloroplast was disturbed in ALs of pecan. This study provides a theoretical basis for elucidating the molecular mechanism underlying the phenotype of chlorina seedlings of pecan.

AdRAP2.3, a Novel Ethylene Response Factor VII from Actinidia deliciosa, Enhances Waterlogging Resistance in Transgenic Tobacco through Improving Expression Levels of PDC and ADH Genes.

APETALA2/ethylene-responsive factor superfamily (AP2/ERF) is a transcription factor involved in abiotic stresses, for instance, cold, drought, and low oxygen. In this study, a novel ethylene-responsive transcription factor named AdRAP2.3 was isolated from Actinidia deliciosa 'Jinkui'. AdRAP2.3 transcription levels in other reproductive organs except for the pistil were higher than those in the vegetative organs (root, stem, and leaf) in kiwi fruit. Plant hormones (Salicylic acid (SA), Methyl-jasmonate acid (MeJA), 1-Aminocyclopropanecarboxylic Acid (ACC), Abscisic acid (ABA)), abiotic stresses (waterlogging, heat, 4 °C and NaCl) and biotic stress (Pseudomonas Syringae pv. Actinidiae, Psa) could induce the expression of AdRAP2.3 gene in kiwi fruit. Overexpression of the AdRAP2.3 gene conferred waterlogging stress tolerance in transgenic tobacco plants. When completely submerged, the survival rate, fresh weight, and dry weight of transgenic tobacco lines were significantly higher than those of wile type (WT). Upon the roots being submerged, transgenic tobacco lines grew aerial roots earlier. Overexpression of AdRAP2.3 in transgenic tobacco improved the pyruvate decarboxylase (PDC) and alcohol dehydrogenase (ADH) enzyme activities, and improved the expression levels of waterlogging mark genes NtPDC, NtADH, NtHB1, NtHB2, NtPCO1, and NtPCO2 in roots under waterlogging treatment. Overall, these results demonstrated that AdRAP2.3 might play an important role in resistance to waterlogging through regulation of PDC and ADH genes in kiwi fruit.

Genome-Wide Bioinformatics Analysis of MAPK Gene Family in Kiwifruit (Actinidia Chinensis).

Mitogen activated protein kinase (MAPK) cascades are universal signal transduction modules that play crucial roles in various biotic and abiotic stresses, hormones, cell division, and developmental processes in plants. Mitogen activated protein kinase (MAPK/MPK), being a part of this cascade, performs an important function for further appropriate cellular responses. Although MAPKs have been investigated in several model plants, no systematic analysis has been conducted in kiwifruit (Actinidia chinensis). In the present study, we identified 18 putative MAPKs in the kiwifruit genome. This gene family was analyzed bioinformatically in terms of their chromosome locations, sequence alignment, gene structures, and phylogenetic and conserved motifs. All members possess fully canonical motif structures of MAPK. Phylogenetic analysis indicated that AcMAPKs could be classified into five subfamilies, and these gene motifs in the same group showed high similarity. Gene structure analysis demonstrated that the number of exons in AcMAPK genes ranged from 2 to 29, suggesting large variation among kiwifruit MAPK genes. The expression profiles of these AcMAPK genes were further investigated using quantitative real-time polymerase chain reaction (qRT-PCR), which demonstrated that AcMAPKs were induced or repressed by various biotic and abiotic stresses and hormone treatments, suggesting their potential roles in the biotic and abiotic stress response and various hormone signal transduction pathways in kiwifruit. The results of this study provide valuable insight into the putative physiological and biochemical functions of MAPK genes in kiwifruit.

Chlorophyll, carotenoid and vitamin C metabolism regulation in Actinidia chinensis 'Hongyang' outer pericarp during fruit development.

Ascorbic acid (AsA), chlorophyll and carotenoid contents and their associated gene expression patterns were analysed in Actinidia chinensis 'Hongyang' outer pericarp. The results showed chlorophyll degradation during fruit development and softening, exposed the yellow carotenoid pigments. LHCB1 and CLS1 gene expressions were decreased, while PPH2 and PPH3 gene expressions were increased, indicating that downregulation of chlorophyll biosynthesis and upregulation of its degradation, caused chlorophyll degradation. A decrease in the expression of the late carotenoid biosynthesis and maintenance genes (LCYB1, LCYE1, CYP1, CYP2, ZEP1, VDE1, VDE2, and NCED2) and degradation gene (CCD1), showed biosynthesis and degradation of carotenoid could be regulatory factors involved in fruit development. Most genes expression data of L-galactose and recycling pathway were agreement with the AsA concentrations in the fruit, suggesting these are the predominant pathways of AsA biosynthesis. GMP1, GME1 and GGP1 were identified as the key genes controlling AsA biosynthesis in 'Hongyang' outer pericarp.

Transcriptome Analysis of Kiwifruit in Response to Pseudomonas syringae pv. actinidiae Infection.

Kiwifruit bacterial canker caused by Pseudomonas syringae pv. actinidiae (Psa) has brought about a severe threat to the kiwifruit industry worldwide since its first outbreak in 2008. Studies on other pathovars of P. syringae are revealing the pathogenesis of these pathogens, but little about the mechanism of kiwifruit bacterial canker is known. In order to explore the species-specific interaction between Psa and kiwifruit, we analyzed the transcriptomic profile of kiwifruit infected by Psa. After 48 h, 8255 differentially expressed genes were identified, including those involved in metabolic process, secondary metabolites metabolism and plant response to stress. Genes related to biosynthesis of terpens were obviously regulated, indicating terpens may play roles in suppressing the growth of Psa. We identified 283 differentially expressed resistant genes, of which most U-box domain containing genes were obviously up regulated. Expression of genes involved in plant immunity was detected and some key genes showed differential expression. Our results suggest that Psa induced defense response of kiwifruit, including PAMP (pathogen/microbe-associated molecular patterns)-triggered immunity, effector-triggered immunity and hypersensitive response. Metabolic process was adjusted to adapt to these responses and production of secondary metabolites may be altered to suppress the growth of Psa.

Functional Characterization of Waterlogging and Heat Stresses Tolerance Gene Pyruvate decarboxylase 2 from Actinidia deliciosa.

A previous report showed that both Pyruvatedecarboxylase (PDC) genes were significantly upregulated in kiwifruit after waterlogging treatment using Illumina sequencing technology, and that the kiwifruit AdPDC1 gene was required during waterlogging, but might not be required during other environmental stresses. Here, the function of another PDC gene, named AdPDC2, was analyzed. The expression of the AdPDC2 gene was determined using qRT-PCR, and the results showed that the expression levels of AdPDC2 in the reproductive organs were much higher than those in the nutritive organs. Waterlogging, NaCl, and heat could induce the expression of AdPDC2. Overexpression of kiwifruit AdPDC2 in transgenic Arabidopsis enhanced resistance to waterlogging and heat stresses in five-week-old seedlings, but could not enhance resistance to NaCl and mannitol stresses at the seed germination stage and in early seedlings. These results suggested that the kiwifruit AdPDC2 gene may play an important role in waterlogging resistance and heat stresses in kiwifruit.

Low expression of phosphatase and tensin homolog in clear­cell renal cell carcinoma contributes to chemoresistance through activating the Akt/HDM2 signaling pathway.

Clear-cell renal cell carcinoma (CCRCC) is the most frequent primary malignancy in the adult kidney. Most patients with advanced CCRCC have poor prognosis as CCRCC remains resistant to chemotherapy. The present study explored the possible mechanism underlying CCRCC resistance to chemotherapy and found that loss of PTEN in CCRCC may be involved. Knockdown of PTEN in the CCRCC cell line ACHN blocked etoposide-induced apoptosis and etoposide-impaired cell proliferation was also inhibited. It has been demonstrated that most chemotherapy drugs exert their anti-cancer effects via p53-mediated apoptosis, and in accordance, with this, the present study showed that treatment with etoposide significantly increased p53 levels. Silencing of PTEN in ACHN inhibited the Akt/HDM2 signaling cascade and depressed p53 expression, and the interaction between HDM2 and p53 was also enhanced. This was further verified in CCRCC tissue specimens from patients The results of the present study suggested that loss of PTEN, which deactivated Akt/HDM2 signaling followed by degradation of p53, may contribute to the development of etoposide resistance in CCRCC.