Genomic survey, expression profile and co-expression network analysis of OsWD40 family in rice

<p>Abstract</p> <p>Background</p> <p>WD40 proteins represent a large family in eukaryotes, which have been involved in a broad spectrum of crucial functions. Systematic characterization and co-expression analysis of <it>OsWD40 </it>genes enable us to understand the networks of the WD40 proteins and their biological processes and gene functions in rice.</p> <p>Results</p> <p>In this study, we identify and analyze 200 potential <it>OsWD40 </it>genes in rice, describing their gene structures, genome localizations, and evolutionary relationship of each member. Expression profiles covering the whole life cycle in rice has revealed that transcripts of <it>OsWD40 </it>were accumulated differentially during vegetative and reproductive development and preferentially up or down-regulated in different tissues. Under phytohormone treatments, 25 <it>OsWD40 </it>genes were differentially expressed with treatments of one or more of the phytohormone NAA, KT, or GA3 in rice seedlings. We also used a combined analysis of expression correlation and Gene Ontology annotation to infer the biological role of the <it>OsWD40 </it>genes in rice. The results suggested that <it>OsWD40 </it>genes may perform their diverse functions by complex network, thus were predictive for understanding their biological pathways. The analysis also revealed that <it>OsWD40 </it>genes might interact with each other to take part in metabolic pathways, suggesting a more complex feedback network.</p> <p>Conclusions</p> <p>All of these analyses suggest that the functions of <it>OsWD40 </it>genes are diversified, which provide useful references for selecting candidate genes for further functional studies.</p

Analysis and evaluation of rice grain quality in Indica rice (Oryza sativa L.)

Rice quality is a comprehensive quantitative trait greatly influenced by heredity and environment. Here, 11 rice quality traits and Rapid Visco-Analyser (RVA) profiles of 30 indica rice germplasms were detected and analyzed. In addition, we used grain size genes and starch synthesis gene Wx to detect the rice quality genotypes of rice. The results showed different degrees of correlation among rice quality traits. In addition, principal component analysis (PCA) divided rice quality traits into four principal components, and the cumulative contribution rate reached 82.478%. Cluster analysis divided 30 rice varieties into five categories. The first four types had better rice quality. Identification of rice quality genes indicated that most of the genotypes were GS3, GS9, GW5, GW8 and Wxb, and a few were GW7 and Wxa. Identifying rice quality characteristics and genotypes of rice varieties may lay a theoretical foundation for promoting the cultivation of new rice varieties, enabling breeders andresearchers to develop better rice varieties

Exciton-phonon interaction in quasi-two dimensional layered (PEA)2(CsPbBr3)n-1PbBr4 perovskite.

Two-dimensional (2D) Ruddlesden-Popper perovskites with bulky organic cations have attracted extensive attention in light-emitting devices and photovoltaics due to their robust environment stability, tunable luminescent color, strong exciton binding and promising efficiency. A quantum well (QW) structure is spontaneously formed by sandwiching PbBr4 layers into bulky organic cations. However, some intrinsic excitonic mechanisms in these materials still need to be elucidated. In this study, the exciton-phonon interaction of quasi-2D (PEA)2(CsPbBr3)n-1PbBr4 with different PbBr4 layer numbers (n) was analyzed by temperature-varied photoluminescence (PL), scanning electron microscopy (SEM) and powder X-ray diffraction (PXRD). The mechanism of bandgap shifting with temperature was found to be dominated by the thermal expansion effect in the large-n 2D and bulk perovskite, and gradually switched to exciton-phonon interaction in the n = 1 (PEA)2PbBr4 phase, indicating enhanced exciton-phonon interaction in the thinner quantum well structure. Further analysis showed that the enhanced exciton-phonon interaction originated from the longitudinal optical phonon-exciton Fröhlich interaction rather than acoustic phonon-exciton coupling. We believe that our results will benefit the further optimization of light-emitting devices based on 2D perovskites

Genome-wide identification and co-expression network analysis of the OsNF-Y gene family in rice

Nuclear factor Y (NF-Y) is a ubiquitous transcription factor that regulates important physiological and developmental processes. In this study, we identified 34 OsNF-Y genes in rice, including 6 newly identified genes. Expression profile analysis covering the whole life cycle revealed that transcripts of OsNF-Y differentially accumulated in a tissue-specific, preferential or constitutive manner. In addition, gene duplication studies and expression analyses were performed to determine the evolutionary origins of the OsNF-Y gene family. Nine OsNF-Y genes were differentially expressed after treatment of seedlings with one or more abiotic stresses such as drought, salt and cold. Analysis of expression correlation and Gene Ontology annotation suggested that OsNF-Y genes were co-expressed with genes that participated in stress, accumulation of seed storage reserves, and plant development. Co-expression analysis also revealed that OsNF-Y genes might interact with each other, suggesting that NF-Y subunits formed complexes that take part in transcriptional regulation. These results provide useful information for further elucidating the function of the NF-Y family and their regulatory pathways

Migration of Toxic Metals from Ceramic Food Packaging Materials into Acid Food Simulants

Long-term extraction experiments were carried out on glazed tile specimens with 4 and 10% (v/v) acetic acid, 1% (w/v) citric acid, and 1% (v/v) lactic acid solution in three temperature conditions (20, 40, and 60°C) to investigate the effect of temperature and pH value on extraction of lead, cobalt, nickel, and zinc from ceramic food packaging materials and to study the extraction kinetics of toxic metals. Results showed that except at 60°C the amount of extraction of lead, cobalt, nickel, and zinc had linear dependence on time at longer times and removal of these toxic metals under other conditions increased linearly with the square root of the time, indicating a diffusion-controlled process. The amount of these toxic metals leached out from ceramic food packaging materials into the leachate, and the leaching rate increased with temperature and decreased with pH value of the food simulants. In addition, among these four toxic metals lead was the least leachable element, and nickel was the most leachable one. Disagreement between the ratios of the oxide of lead, cobalt, nickel, and zinc in the glaze and their release in the leachate suggested that extraction of these toxic metals was an incongruent dissolution process

Effect of positive and negative corona discharge field on vigor of millet seeds

To investigate the effects of corona discharge field treatment of different electric field strength with the different polarities on the vigor of millet seeds, the positive and negative corona discharge fields generated with arc-shaped prick electrodes and plate electrodes are different for millet seeds respectively. The treatment voltage was (2 × n kV, n = 1, 2. . .10) and the time treated was 2 min. The results showed that after treatment by the corona discharge field, the germination potential, germination rate, germination index and vigor index of millet seeds increased to different degrees compared with the control. The optimal treatment voltages of the positive and negative corona discharge field were 12 kV. Under the optimal treatment voltage, the germination indexes (germination potential, germination rate, germination index, vigor index) of millet seeds were significantly different from the control (p <; 0.01), and the millet seeds treated by the positive corona discharge field compared with the control group, the germination potential, germination rate, germination index and vigor index increased by 21.2%, 23.0%, 19.9% and 23.2% respectively. The germination indexes of the millet seeds treated by the negative corona discharge field increased by 29.1%, 28.5%, 26.9% and 32.1%. It was also found that under the same treatment voltage, the electrical conductivity of the leachates of the millet seed treated with the negative corona discharge field was lower than that of the positive, which indicated that the negative corona discharge field would repair the cell membrane more effectively. According to various indicators, it can be concluded that the negative corona discharge field treatment was better than the positive.Published versio