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The thermal expansion coefficient is an important thermal parameter that influences the performance of nanodevices based on two-dimensional materials. To obtain the thermal expansion coefficient of few-layer MoS2, suspended MoS2 and supported MoS2 were systematically investigated using Raman spectroscopy in the temperature range from 77 to 557 K. The temperature-dependent evolution of the Raman frequency shift for suspended MoS2 exhibited prominent differences from that for supported MoS2, obviously demonstrating the effect due to the thermal expansion coefficient mismatch between MoS2 and the substrate. The intrinsic thermal expansion coefficients of MoS2 with different numbers of layers were calculated. Interestingly, negative thermal expansion coefficients were obtained below 175 K, which was attributed to the bending vibrations in the MoS2 layer during cooling. Our results demonstrate that Raman spectroscopy is a feasible tool for investigating the thermal properties of few-layer MoS2 and will provide useful information for its further application in photoelectronic devices.

In this work, magneto-Raman mapping was performed on monolayer MoS2 at 4 K, which exhibited a prominent magnetic field-induced modulation of phonon intensity. Interestingly, structural microinhomog...

Anther indehiscence is an important form of functional male sterility that can facilitate the production of hybrid seed; however, the molecular mechanisms of anther indehiscence-based male sterility have not been thoroughly explored in eggplant (Solanum melongena L.). Here, we used two-dimensional gel electrophoresis to compare the protein profiles in the anthers of normally developing (F142) and anther indehiscent (S16) S. melongena plants. Four differentially expressed proteins were identified using matrix-assisted laser desorption/ionization time-of-flight/time-of-flight mass spectrometry. Of these proteins, the transcript accumulation of the eggplant CORONATINE INSENSITIVE1 (SmCOI1) was significantly downregulated in S16 relative to F142. Phylogenetic analysis showed that SmCOI1 has high amino acid sequence similarity and clustered into the same subgroup as its homologs in other members of the Solanaceae. Subcellular localization analysis showed that SmCOI1 localized to the nucleus. Moreover, reverse-transcription quantitative PCR revealed that the jasmonic acid pathway genes SmJAZ1 and SmOPR3 are upregulated in F142 relative to S16. Protein-protein interaction studies identified a direct interaction between SmCOI1 and SmOPR3, but SmCOI1 failed to interact with SmJAZ1. These findings shed light on the regulatory mechanisms of anther dehiscence in eggplant.

Van der Waals magnets have emerged as a fertile ground for the exploration of highly tunable spin physics and spin-related technology. Two-dimensional (2D) magnons in van der Waals magnets are collective excitation of spins under strong confinement. Although considerable progress has been made in understanding 2D magnons, a crucial magnon device called the van der Waals magnon valve, in which the magnon signal can be completely and repeatedly turned on and off electrically, has yet to be realized. Here we demonstrate such magnon valves based on van der Waals antiferromagnetic insulator MnPS3. By applying DC electric current through the gate electrode, we show that the second harmonic thermal magnon (SHM) signal can be tuned from positive to negative. The guaranteed zero crossing during this tuning demonstrates a complete blocking of SHM transmission, arising from the nonlinear gate dependence of the non-equilibrium magnon density in the 2D spin channel. Using the switchable magnon valves we demonstrate a magnon-based inverter. These results illustrate the potential of van der Waals anti-ferromagnets for studying highly tunable spin-wave physics and for application in magnon-base circuitry in future information technology., 18 pages, 4 figures

Anther indehiscence is an important form of functional male sterility that can facilitate the production of hybrid seeds. However, the molecular mechanisms of anther indehiscence-based male sterility in eggplant (Solanum melongenaL.) have not been thoroughly explored. We performed transcriptome sequencing and real-time quantitative reverse transcription-PCR (qRT-PCR) assays to compare the fertile line (F142) and male sterile line (S12) eggplant. We identified 2,670 differentially expressed genes (DEGs) between lines. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses identified 31 DEGs related to hormone biosynthesis. We, therefore, measured phytohormone contents, such as jasmonic acid (JA), auxin (IAA), gibberellin (GA), and abscisic acid (ABA) in S12 and F142. There were differences in IAA, GA3, and ABA levels between S12 and F142, while JA levels were significantly lower in S12 than in F142. Five key genes in the JA signaling pathway were differentially expressed in S12 vs. F142. Of these,SmJAZ1andSmJAR1were significantly upregulated andSmDAD1, SmLOX, andSmCOI1were downregulated in S12 vs. F142. Protein–protein interaction studies identified a direct interaction between SmDAD1 and SmLOX, while SmDAD1 failed to interact with SmJAR1, SmCOI1, and SmJAZ1. The data represent a valuable resource for further exploration of regulatory mechanisms underlying anther dehiscence in eggplant.

Bacterial wilt (BW) caused by Ralstonia solanacearum is a serious disease affecting the production of Solanaceae species, including eggplant (Solanum melongena). However, few resistance genes have been identified in eggplant, and therefore the underlying mechanism of BW resistance remains unclear. Hence, we investigated a spermidine synthase (SPDS) gene from eggplant and created knock-down lines with virus-induced gene silencing. After eggplant was infected with R. solanacearum, the SmSPDS gene was induced, concurrent with increased spermidine (Spd) content, especially in the resistant line. We speculated that Spd plays a significant role in the defense response of eggplant to BW. Moreover, using the yeast one-hybrid approach and dual luciferase-based transactivation assay, an R2R3-MYB transcription factor, SmMYB44, was identified as directly binding to the SmSPDS promoter, activating its expression. Overexpression of SmMYB44 in eggplant induced the expression of SmSPDS and Spd content, increasing the resistance to BW. In contrast, the SmMYB44-RNAi transgenic plants showed more susceptibility to BW compared with the control plants. Our results provide insight into the SmMYB44-SmSPDS-Spd module involved in the regulation of resistance to R. solanacearum. This research also provides candidates to enhance resistance to BW in eggplant.

Brassinosteroid (BR) is a kind of steroid hormone that is essential for the regulation of multiple processes of plant growth and development, including cell division and elongation, as well as plant resistance to diseases. The BR receptor BRASSINOSTEROID INSENSITIVE1 (BRI1), a multidomain transmembrane receptor-like kinase, roles in BR recognition and signaling. In this study, two putative tomato BR receptor genes were identified, SlBRI1-like 1 (SlBRL1) and SlBRI1-like 2 (SlBRL2). Together with the known receptor gene SlBRI1/CURL3, these three BR receptors had conserved sequence and conformation for their function in BR recognition and kinase activation. Among them, the SlBRI1 was highly expressed in multiple tissues while SlBRLs had a more abundant transcription in the stem, suggesting that they may have a diverse role in tomato growth and development. Corresponding to the expression specificity of SlBRI1, the SlBRI1-RNAi plants exhibited the typical phenotype of reduced plant height, curly dark green leaves and shortened internodes. Meanwhile, the down-regulation of SlBRI1 gave the flower a shorter style than that of wild-type possibly via a SlSTYLE2.1-independent pathway. Additionally, the elevated expression of BR biosynthesis genes SlCPD, SlDWF, SlDET2 and repressed expression of BR inactivation gene SlCYP734A7 revealed the critical role of SlBRI1 in BR pathway-mediated plant architecture and the feedback regulation.

In recent years, the magneto-optical properties of two-dimensional transition metal disulfides have attracted more and more attention due to their further device applications in spintronics and valleytronics. However, to our knowledge, the plasmonic effect on the magneto-optical properties of WS2 has not been studied. In this work, monolayer WS2 transferred on SiO2/Si substrate and Au film were investigated respectively using polarized-Raman spectroscopy at 4 K under different magnetic fields. Prominent magnetic field–induced variations in the Raman intensities of WS2 samples were observed, which also exhibited significant differences in the spectral evolution versus magnetic field. The resonance magnetic field was 5 T and 5.5 T for the WS2 on SiO2/Si substrate and Au film, respectively. Remarkably, the magneto-optical Raman intensities of A1′&nbsp, and 2LA(M) modes for WS2 on Au film were reduced to approximately 60% compared with that of WS2 on SiO2/Si. These results suggest that the plasmonic effect–induced charge transfer plays an important role in the magneto-optical Raman effect of WS2.

Based on observing the cytological characteristics of the flower buds of the functional male sterile line (S13) and the fertile line (F142) in eggplant, it was found that the disintegration period of the annular cell clusters in S13 anther was 2 days later than that of F142, and the cells of stomiun tissue and tapetum in F142 disintegrated on the blooming day, while it did not happen in S13. The comparative transcriptomic analysis showed that there were 1 436 differential expression genes (DEGs) (651 up-regulated and 785 down-regulated) in anthers of F142 and S13 at 8, 5 days before flowering and flowering day. The significance analysis of GO enrichment indicated that there were more unigene clusters involved in single cell biological process, metabolism process and cell process, and more catalytic activity and binding function were involved in molecular functions. Through KEGG annotation we found that the common DEGs were mainly enriched in the biosynthesis of secondary metabolites, metabolic pathway, protein processing in endoplasmic reticulum, biosynthesis of amino acids, carbon metabolism and plant hormone signal transduction. The fifteen genes co-expression modules were identified from 16 465 selected genes by weighted gene co-expression network analysis (WGCNA), three of which (Plum2, Royalblue and Bisque4 modules) were highly related to S13 during flower development. KEGG enrichment showed that the specific modules could be enriched in phenylpropanoid biosynthesis, photosynthesis, porphyrin and chlorophyll metabolism, α-linolenic acid metabolism, polysaccharide biosynthesis and metabolism, fatty acid degradation and the mutual transformation of pentose and glucuronic acid. These genes might play important roles during flower development of S13. It provided a reference for further study on the mechanism of anther dehiscence in eggplant.以茄子功能雄性不育系 (S13) 和可育系 (F142) 为材料，对花蕾不同发育时期的细胞学特征进行观察，发现S13花药中环形细胞簇的解体时期比F142延迟2 d，开花当天F142的裂口组织及内绒毡层的细胞解体，而S13中无此现象发生。转录组测序分析表明，F142和S13开花前8天、5天和开花当天的花药共有1 436个差异表达基因 (DEGs) (651个表达上调，785个表达下调)。GO显著性分析表明差异基因主要富集在生物学过程中涉及单细胞生物过程、代谢过程和细胞过程的单基因簇 (Unigene) 较多，分子功能中涉及较多的有催化活性和结合功能；KEGG注释发现，差异基因主要富集在次生代谢产物的生物合成、代谢途径、内质网蛋白质加工、氨基酸的生物合成、碳代谢和植物激素信号转导。选取16 465个基因进行加权基因共表达网络构建分析 (Weighted gene co-expression network analysis，WGCNA)，共鉴定到15个基因共表达模块，其中3个为S13在3个花蕾发育时期高度相关特异性模块 (Plum2、Royalblue和Bisque4模块)；KEGG富集表明，特异性模块可以富集到苯丙烷类生物合成、光合作用、卟啉与叶绿素代谢、α-亚麻酸代谢、多糖的生物合成和代谢、脂肪酸降解以及戊糖与葡萄糖醛酸的相互转化等相关通路，这些基因可能在S13花蕾发育过程中发挥重要作用。研究结果为进一步探索茄子花药开裂机制提供了一定的参考。.

Spin-orbit coupling (SOC) can provide essential tools to manipulate electron spins in two-dimensional materials like graphene, which is of great interest for both fundamental physics and spintronics application. In this paper, we report the low-field magnetotransport of in situ hydrogenated graphene where hydrogen atoms are attached to the graphene surface in continuous low temperature and vacuum environment. Transition from weak localization to weak antilocalization with increasing hydrogen adatom density is observed, indicating enhancing Bychkov-Rashba-type SOC in a mirror symmetry broken system. From the low-temperature saturation of phase breaking scattering rate, the existence of spin-flip scattering is identified, which corroborates the existence of magnetic moments in hydrogenated graphene.

Two-dimensional materials provide extraordinary opportunities for exploring phenomena arising in atomically thin crystals. Beginning with the first isolation of graphene, mechanical exfoliation has been a key to provide high-quality two-dimensional materials, but despite improvements it is still limited in yield, lateral size and contamination. Here we introduce a contamination-free, one-step and universal Au-assisted mechanical exfoliation method and demonstrate its effectiveness by isolating 40 types of single-crystalline monolayers, including elemental two-dimensional crystals, metal-dichalcogenides, magnets and superconductors. Most of them are of millimeter-size and high-quality, as shown by transfer-free measurements of electron microscopy, photo spectroscopies and electrical transport. Large suspended two-dimensional crystals and heterojunctions were also prepared with high-yield. Enhanced adhesion between the crystals and the substrates enables such efficient exfoliation, for which we identify a gold-assisted exfoliation method that underpins a universal route for producing large-area monolayers and thus supports studies of fundamental properties and potential application of two-dimensional materials.

Background: Anther indehiscence is an important form of functional male sterility that can facilitate the production of hybrid seeds. However, the molecular mechanisms of anther indehiscence-based male sterility in eggplant (Solanum melongena L.) have not been thoroughly explored. Therefore, we performed RNA-seq analysis to investigate the molecular mechanisms of anther dehiscence in eggplant. Results: We used transcriptome sequencing and qRT-PCR assays to compare the anthers of normally developing (F142) and anther indehiscent (S12) eggplant. We identified 2670 differentially expressed genes between lines. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses identified 31 differentially expressed genes related to hormone biosynthesis. We therefore measured the contents of the phytohormones jasmonic acid (JA), IAA, GA3 and ABA in S12 and F142. There were no significant differences in IAA, GA3 or ABA levels between S12 and F142. However, JA levels were significantly lower in S12 than in F142. Five key genes in the JA signaling pathway were differentially expressed in S12 vs. F142. Of these, SmJAZ and SmJAR-like were significantly up-regulated and SmDAD1, SmLOX and SmCOI1 were down-regulated in S12 vs. F142. In DNA-protein interaction studies, SmLOX, SmAOC, SmOPR3, SmCOI1 and SmJAZ1 failed to be enriched on the chromatin of SmDAD1. Protein–protein interaction studies identified a direct interaction between SmDAD1 and SmLOX, but SmDAD1 failed to interact with SmAOC, SmOPR3, SmCOI1 and SmJAZ1. Conclusion: JA is an essential factor affecting anther dehiscence in eggplant. SmDAD1 interacts with SmLOX to alter JA levels, thereby regulating anther dehiscence. Our data represent a valuable resource for further exploring the regulatory mechanisms underlying anther dehiscence in eggplant.

Anther dehiscence releases pollen and therefore is a key event in plant sexual reproduction. Although anther dehiscence has been intensively studied in some plants, such as Arabidopsis thaliana and rice (Oryza sativa), the molecular mechanism of anther dehiscence in eggplant (Solanum melongena) is largely unknown. To provide insight into this mechanism, we used RNA-sequencing (RNA-seq) to analyze the transcriptomic profiles of one natural male-fertile line (F142) and two male-sterile lines (S12 and S13). We assembled 88,414 unigenes and identified 3446 differentially expressed genes (DEGs). GO and KEGG analysis indicated that these DEGs were mainly involved in "metabolic process", "catalytic activity", "biosynthesis of amino acids", and "carbon metabolism". The present study provides comprehensive transcriptomic profiles of eggplants that do and do not undergo anther dehiscence, and identifies a number of genes and pathways associated with anther dehiscence. The information deepens our understanding of the molecular mechanisms of anther dehiscence in eggplant.

As an important carbon material, a nano-crystalline diamond (NCD) film is very promising in the field of science and technology. However, there are little knowledge about surface physics and chemistry of nanoscale in NCD films. Here, we perform nanoscale imaging of NCD films grown by hot filament chemical vapor deposition, using tip-enhanced Raman spectroscopy. With ~20 nm spatial resolution, we resolve nanoscale spatial correlations of trans-polyacetylene segments on the surface with characterized Raman modes at 1150 cm−1 and 1480 cm−1 that originate from the motion of conjugate polymer skeletons with a substantial contribution from the in-plane bending of carbon‑hydrogen bonds and stretching vibrations of the double carbon‑carbon bonds. Our work is helpful to understand the role of TPA in NCD synthesis reaction in nanoscale and improve the device application based on this material.

The OVATE gene was initially identified in tomato and serves as a key regulator of fruit shape. There are 31 OFP members in the tomato genome. However, their roles in tomato growth and reproductive development are largely unknown. Here, we cloned the OFP transcription factor SlOFP20. Tomato plants overexpressing SlOFP20 displayed several phenotypic defects, including an altered floral architecture and fruit shape and reduced male fertility. SlOFP20 overexpression altered the expression levels of some brassinosteroid (BR)-associated genes, implying that SlOFP20 may play a negative role in the BR response, similar to its ortholog OsOFP19 in rice. Moreover, the transcript accumulation of gibberellin (GA)-related genes was significantly affected in the transgenic lines. SlOFP20 may play an important role in the crosstalk between BR and GA. The pollen germination assay suggested that the pollen germination rate of SlOFP20-OE plants was distinctly lower than that of WT plants. In addition, the tomato pollen-associated genes SlCRK1, SlPMEI, LePRK3, SlPRALF, and LAT52 were all suppressed in the transgenic lines. Our data imply that SlOFP20 may affect floral organ and pollen development by modulating BR and GA signaling in tomato.

Dedicated Raman investigation was performed on the graphene suspended on the round holes, compared with graphene supported on Si/SiO2 substrate, in the temperature range from 173 K to 673 K. We observed an unexpected result that the temperature-dependent Raman frequency shift of suspended graphene was similar as that of supported graphene. This evidenced that the strain caused by thermal expansion coefficient mismatch between graphene and substrate cannot be neglected from suspended graphene. We predicted that the unsupported graphene zone and its surrounding graphene that adhered to substrate should be considered as a whole while studying the thermodynamic properties of this suspended graphene, and thus a semi-quantitative factor was introduced to the estimate the contribution from substrate to the suspended graphene, explaining well this result. Our results suggest that the thermal expansion coefficient mismatch induced strain should be taken into consideration in the study of electronic and transport properties of suspended graphene devices, in which the self-heating effect cannot be eliminated during operation.

The spatially continuous control of the physical properties in semiconductor materials is an important strategy in increasing electron-capturing or light-harvesting efficiencies, which is highly desirable for the application of optoelectronic devices including photodetectors, solar cells and biosensors. Unlike the multi-layer growth of chemical composition modulation, local strain offers a convenient way to continuously tune the physical properties of a single semiconductor layer, and open up new possibility for band engineering within the 2D plane. Here, we demonstrate that the gradient refractive index and bandgap can be generated in atomically thin transition metal dichalcogenide flakes due to the effect of thermal strain difference. A highly resolved confocal scanning optical microscopy is used to perform a real-space light-reflection mapping of suspended atomically thin WSe2 flakes at the low temperature of 4.2 K, in which the parabolic light-reflection profiles have been observed on suspended monolayer and bilayer WSe2 flakes. This finding is corroborated by our theoretical model which includes the effect of strain on both the refractive index and bandgap of nanostructures. The inhomogeneous local strain observed here will allow new device functionalities to be integrated within 2D layered materials, such as in-plane photodetectors and photovoltaic devices.

Laboratory and field culture experiments have been carried out at two sites which show that temperature and soil moisture significantly affected nitrogen mineralization in the soil in a tobacco field. Intermittent leaching under aerobic incubation conditions was adopted to develop dynamic simulation models of organic nitrogen mineralization under different temperature regimes (10, 15, 20, 25, 30, 35, 30, 25, and 20 °C) and soil gravimetric moisture content (0.1, 7%, 13%, 20%, 27%, 33%, 40%, 47%, and 53%). The results show that the highest N mineralization rate appeared at 35°C and the lowest was 10°C. Soil N mineralization rate, as affected by soil moisture, is a single peak curve with a peak at 40%. The interaction of temperature and moisture on soil N mineralization is significant. Based on the results of a field trial, the combined model given by governing equation: has been established to simulate the dynamics of soil N mineralization under tobacco field conditions. A validation experiment showed that the measured values of mineralized N accumulation in the two experimental sites had a good correlation with the simulated values, indicating the practical value of the proposed model.

Bok choy (Brassica rapa var. chinensis) is an important dietary vegetable cultivated and consumed worldwide for its edible leaves. The purple cultivars rich in health-promoting anthocyanins are usually more eye-catching and valuable. Fifteen kinds of anthocyanins were separated and identified from a purple bok choy cultivar (Zi He) by high-performance liquid chromatography-electrospray ionization tandem mass spectrometry. To investigate the molecular mechanisms underlying anthocyanin accumulation in bok choy, the expression profiles of anthocyanin biosynthetic and regulatory genes were analyzed in seedlings and leaves of the purple cultivar and the green cultivar (Su Zhouqing). Compared with the other tissues, BrTT8 and most of the anthocyanin biosynthetic genes were significantly up-regulated in the leaves and light-grown seedlings of Zi He. The results that heterologous expression of BrTT8 promotes the transcription of partial anthocyanin biosynthetic genes in regeneration shoots of tomato indicate that BrTT8 plays an important role in the regulation of anthocyanin biosynthesis.

SlHDA3 functions as an inhibitor and regulates tomato fruit ripening and carotenoid accumulation. Post-translational modifications, including histones acetylation, play a pivotal role in the changes of chromatin structure dynamic modulation and gene activity. The regulation of histone acetylation is achieved by the action of histone acetyltransferases and deacetylases, which play crucial roles in the regulation of transcription activation. There is an increasing research focus on histone deacetylation in crops, but the role of histone deacetylase genes (HDACs) in tomato has not been elucidated. With the aim of characterizing the tomato RPD3/HDA1 family histone deacetylase genes, SlHDA3 was isolated and its RNA interference (RNAi) lines was obtained. The fruit of SlHDA3 RNAi lines exhibited accelerated ripening process along with short shelf life characteristics. The accumulation of carotenoid was increased due to the alteration of the carotenoid pathway flux. Climacteric ethylene production also stimulated along with significantly up-regulated expression of ethylene biosynthetic genes (ACS2, ACS4, ACO1 and ACO3) and fruit ripening-associated genes (RIN, E4, E8, PG, Pti4, LOXB, Cnr and TAGL1) in SlHDA3 RNAi lines. Besides, fruit cell wall metabolism-associated genes (HEX, MAN, TBG4, XTH5 and XYL) were enhanced in transgenic lines. Relative to wild type (WT) plants, SlHDA3 RNAi seedlings displayed shorter hypocotyls and more sensitivity to ACC (1-aminocyclopropane-1-carboxylate). These results indicated that SlHDA3 is involved in the regulation of fruit ripening by affecting ethylene biosynthesis and carotenoid accumulation.

Silencing SlAGL6 in tomato leads to fused sepal and green petal by influencing the expression of A-, B-class genes. AGAMOUS-LIKE6 (AGL6) lineage is an important clade MADS-box transcription factor and plays essential roles in various developmental programs especially in flower meristem and floral organ development. Here, we isolated a tomato AGL6 lineage gene SlAGL6 and successfully obtained several RNA interference (RNAi) lines. Silencing SlAGL6 led to abnormal fused sepals and light green petals with smaller size. The total chlorophyll content in transgenic petals increased and the morphology of epidermis cells altered. Further analysis showed that A-class gene MACROCALYX (MC) participating in sepal development and a NAC-domain gene GOBLET involving in boundary establishment were down-regulated in transgenic lines. In transgenic petals, two chlorophyll synthesis genes, Golden2-like1 (SlGLK1) and Golden2-like2 (SlGLK2), two photosystem-related genes, ribulose bisphosphate carboxylase small chain 3B (SlrbcS3B) and chlorophyll a/b-binding protein 7 (SlCab-7) were induced and three B-class genes TM6, TAP3 and SlGLO1 were repressed. These results suggest that SlAGL6 involves in tomato sepal and petal development.

MADS-box family genes encode transcription factors that are involved in multiple developmental processes in plants, especially in floral organ specification, fruit development, and ripening. However, a comprehensive analysis of tomato MADS-box family genes, which is an important model plant to study flower fruit development and ripening, remains obscure. To gain insight into the MADS-box genes in tomato, 131 tomato MADS-box genes were identified. These genes could be divided into five groups (M&alpha, M&beta, M&gamma, M&delta, and MIKC) and were found to be located on all 12 chromosomes. We further analyzed the phylogenetic relationships among Arabidopsis and tomato, as well as the protein motif structure and exon&ndash, intron organization, to better understand the tomato MADS-box gene family. Additionally, owing to the role of MADS-box genes in floral organ identification and fruit development, the constitutive expression patterns of MADS-box genes at different stages in tomato development were identified. We analyzed 15 tomato MADS-box genes involved in floral organ identification and five tomato MADS-box genes related to fruit development by qRT-PCR. Collectively, our study provides a comprehensive and systematic analysis of the tomato MADS-box genes and would be valuable for the further functional characterization of some important members of the MADS-box gene family.

Anthocyanins, natural pigments with high antioxidant activities, are widely distributed in the plant kingdom and play important roles in various physiological processes. Much effort has been committed to enhancing the anthocyanin content of these health-promoting pigments in vegetables and grains, for their eye-catching colors and special nutrients. Previously, we reported that the SmMYB1 gene encoding a R2R3 MYB transcription factor participated in the regulation of anthocyanin biosynthesis in the peel of eggplant. In this work, we introduced SmMYB1 into a non-anthocyanin-accumulating eggplant cultivar (Solanum aethiopicum group Gilo) via Agrobacterium-mediated transformation. Genetically engineered plants exhibited high concentrations of anthocyanin in leaves, petals, stamens, and fruit peels under normal growth conditions, especially in fruit flesh. Furthermore, highly methylated anthocyanins, malvidin 3-(p-coumaroyl)rhamnoside(glucoside)-5-glucoside and malvidin 3-(feruloyl)rhamnoside(glucoside)-5-glucoside, were separated from the purple fruit flesh and identified by HPLC–ESI–MS/MS. qRT-PCR analysis revealed that most anthocyanin structural genes were dramatically up-regulated in the tissues of transgenic lines compared with non-transformed plants. In addition, the transgenic seedlings had greater tolerance to freezing stress and better recovery under rewarming conditions. These results provide a good foundation for the breeding of new eggplant cultivars with more healthy agronomic traits in future studies.

A fast reactive ion etching (RIE) treatment method is presented for dramatic enhancement of the field emission performances of nanocrystalline diamond (NCD) films. In this method a moment RIE treatment is able to modify the surface morphologies of NCD films and form a large area of nanoneedle-like arrays on the NCD films, in which the diamond nanoparticles were seeded on the film to serve as an etching mask. These elaborated diamond nanoneedle-like structures showed good uniformity and dense morphology with a controllable aspect ratio and distribution density and thereby significantly increased the electron field emission properties of the NCD films due to the formation of more emitting tips and enhanced field enhancement factor.

We present the thickness-dependent electrical properties of mechanically exfoliated single crystal Ta4Pd3Te16 nanoribbons. By decreasing the nanoribbon thickness in the range of 500–20 nm, we observed a suppression of superconductivity driven by both the thickness and the external magnetic field. In particular, for the thinner nanoribbons with the thickness less than 40 nm, there is a non-zero resistance state extending down to low temperature, followed by the loss of superconductivity when the thickness is decreased to the order of the coherence length. We found that the theory of a thermally activated phase slip can well describe the temperature dependence of the resistance below Tc. The disorder-induced enhanced Coulomb interaction with the decrease in the thickness is expected to be dominant in the gradual crossover behavior from superconducting to normal or very weakly insulating behavior in the low-dimensional system.

Kohlrabi (Brassica oleracea var. gongylodes L.) is an important dietary vegetable cultivated and consumed widely for the round swollen stem. Purple kohlrabi shows abundant anthocyanin accumulation in the leaf and swollen stem. Here, different kinds of anthocyanins were separated and identified from the purple kohlrabi cultivar (Kolibri) by high-performance liquid chromatography-electrospray ionization tandem mass spectrometry. In order to study the molecular mechanism of anthocyanin biosynthesis in purple kohlrabi, the expression of anthocyanin biosynthetic genes and regulatory genes in purple kohlrabi and a green cultivar (Winner) was examined by quantitative PCR. In comparison with the colorless parts in the two cultivars, most of the anthocyanin biosynthetic genes and two transcription factors were drastically upregulated in the purple tissues. To study the effects of light shed on the anthocyanin accumulation of kohlrabi, total anthocyanin contents and transcripts of associated genes were analyzed in sprouts of both cultivars grown under light and dark conditions.

In this work, the magneto-resistance (MR) of ultra-thin WTe2/BN heterostructures far away from electron–hole equilibrium is measured. The change of MR of such devices is found to be determined largely by a single tunable parameter, i.e. the amount of imbalance between electrons and holes. We also found that the magnetoresistive behavior of ultra-thin WTe2 devices is well-captured by a two-fluid model. According to the model, the change of MR could be as large as 400 000%, the largest potential change of MR among all materials known, if the ultra-thin samples are tuned to neutrality when preserving the mobility of 167 000 cm2 V−1 s−1 observed in bulk samples. Our findings show the prospects of ultra-thin WTe2 as a variable magnetoresistance material in future applications such as magnetic field sensors, information storage and extraction devices, and galvanic isolators. The results also provide important insight into the electronic structure and the origin of the large MR in ultra-thin WTe2 samples.

Vertically aligned diamond nanoneedles were fabricated on nanocrystalline diamond (NCD) films by reactive ion etching (RIE), in which diamond nanoparticles ~10nm in diameter seeded on the nanodiamond film to serve as an etching mask. The sensing ability of the elaborated diamond nanoneedle arrays was measured at room temperature with NH"3 and NO"2 diluted in air. The results showed that the diamond nanoneedle arrays had a greatly enhanced chemical sensing ability compared with the unmodified nanodiamond films, mainly due to the increased surface area-to-volume ratio and nanotip effect of the diamond nanoneedles. In addition, the diamond nanoneedle arrays evidenced different gas sensing processes when exposed to reducing and oxidizing gases, in which the direction of electron transport plays an important role.

Control of the wetting property of diamond surface has been a challenge because of its maximal hardness and good chemical inertness. In this work, the micro/nanoarray structures etched into diamond film surfaces by a maskless plasma method are shown to fix a surface's wettability characteristics, and this means that the change in morphology is able to modulate the wettability of a diamond film from weakly hydrophilic to either superhydrophilic or superhydrophobic. It can be seen that the etched diamond surface with a mushroom-shaped array is superhydrophobic following the Cassie mode, whereas the etched surface with nanocone arrays is superhydrophilic in accordance with the hemiwicking mechnism. In addition, the difference in cone densities of superhydrophilic nanocone surfaces has a significant effect on water spreading, which is mainly derived from different driving forces. This low-cost and convenient means of altering the wetting properties of diamond surfaces can be further applied to underlying wetting phenomena and expand the applications of diamond in various fields.

Tumorous stem mustard (Brassica juncea var. tumida Tsen et Lee) is an economically and nutritionally important dietary vegetable in Asian countries. Purple tumorous stem mustard contains inflated tumorous stem and abundant anthocyanin accumulation in leaves. Here, 20 anthocyanins were separated and identified from the purple tumorous stem mustard by high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS). In order to investigate the regulatory anthocyanin production in purple tumorous stem mustard, the expression of anthocyanin biosynthetic and regulatory genes in leaves from purple and green cultivars were examined. Regulatory gene BjTT8 and all biosynthetic genes were dramatically upregulated in the purple variety. Moreover, the transcript level of BjTT8 and all structural genes, except BjPAL, were all significantly higher in light-treated sprouts than in the dark. These results indicate that transcriptional activation of BjTT8 is associated with upregulation of most anthocyanin biosynthetic genes, to produce anthocyanins in purple tumorous stem mustard.

Eggplant (Solanum melongena L.) is an edible fruit vegetable cultivated and consumed worldwide. The purple eggplant is more eye-catching and popular for the health-promoting anthocyanins contained in the fruit skin. Two kinds of anthocyanin were separated and identified from purple cultivar (Zi Chang) by high-performance liquid chromatography-electrospray ionization tandem mass spectrometry. To investigate the molecular mechanisms of anthocyanin accumulation in eggplant, the transcripts of anthocyanin biosynthetic and regulatory genes were analyzed in the fruit skin and the flesh of the purple cultivar and the white cultivar (Bai Xue). Compared with the other tissues, SmMYB1 and all anthocyanin biosynthetic genes except PAL were dramatically upregulated in the fruit skin of the purple cultivar. Overexpression of SmMYB1 activated abundant anthocyanin accumulation in the regenerating shoots of eggplant. These results prove that transcriptional activation of SmMYB1 accounts for constitutive upregulation of most anthocyanin biosynthetic genes and the onset of anthocyanin biosynthesis in the purple cultivar.

Our study shows that the expression of AtCBF3 and AtCOR15A improved the chilling tolerance in transgenic eggplant. In an attempt to improve chilling tolerance of eggplant (Solanum melongena L) plants, Arabidopsis C-repeat binding factor 3 (AtCBF3) and cold-regulated 15A (AtCOR15A) genes both driven by an Arabidopsis RESPONSIVE TO DESSICATION 29A promoter (AtRD29A) were transferred into the plants of eggplant cultivar Sanyueqie. Two independent homozygous transgenic lines were tested for their cold tolerance. The leaves of the transgenic plants in both lines withered much slower and slighter than the wild-type plants after exposure to cold stress treatment at 2 ± 1 °C. The gene expression of AtCBF3 and AtCOR15A was significantly increased as well as the proline content and the levels of catalase and peroxidase activities, while the relative electrical conductivity and the malondialdehyde content were remarkably decreased in the transgenic plants compared with the wild type at 4 ± 0.5 °C. The results showed that the expression of the exogenous AtCBF3 and AtCOR15A could promote the cold adaptation process to protect eggplant plants from chilling stress.

Nanostructured surface possessing ultrahigh adhesion like "gecko foot" or "rose petal" can offer more opportunities for bionic application. We grow flower-like few-layer graphene on silicon nanocone arrays to form graphene nanoclusters, showing robust adhesion. Their contact angle (CA) is 164° with a hysteresis CA of 155° and adhesive force for a 5 μL water droplet is about 254 μN that is far larger than present reported results. We bring experimental evidences that this great adhesion depends on large-area plentiful edges of graphene nanosheets tuned by conical nanostructure and intrinsic wetting features of graphene. Such new hierarchical few-layer graphene nanostructure provides a feasible strategy to understand the ultra-adhesive mechanism of the "gecko effect" or "rose effect" and enhance the wettability of graphene for many practical applications.

Vertically aligned single-crystal SnO(2) nanoshuttle arrays with uniform morphology and a relatively high aspect ratio were synthesized by a simple hot-wall chemical vapor deposition (CVD) method. It was found that regulating the growth temperature gradient could change the shape of the SnO(2) nanostructure from nanoshuttles to nanochisels and nanoneedles, and a self-catalyzing growth process was responsible for tunable morphologies of SnO(2) nanostructures. The as-synthesized SnO(2) nanoshuttles showed ultrahigh flexibility and strong toughness with a large elastic strain of ∼ 6.2, which is much higher than reported for Si and ZnO nanowire as well as most crystalline metallic materials. The field emitter fabricated using SnO(2) nanoshuttle arrays has a low turn-on electric field of around 0.6 V µm(-1), and a high field emission current density of above 10 mA cm(-2), which is comparable with the highest emission current density of carbon nanotube and nanowire field emitters.