Rht-B1c, allelic to the DELLA protein-encoding gene Rht-B1a, is a natural mutation documented in common wheat (Triticum aestivum). It confers variation to a number of traits related to cell and plant morphology, seed dormancy, and photosynthesis. The present study was conducted to examine the sequence variations of Rht-B1c and their functional impacts. The results showed that Rht-B1c was partially dominant or co-dominant for plant height, and exhibited an increased dwarfing effect. At the sequence level, Rht-B1c differed from Rht-B1a by one 2kb Veju retrotransposon insertion, three coding region single nucleotide polymorphisms (SNPs), one 197bp insertion, and four SNPs in the 1kb upstream sequence. Haplotype investigations, association analyses, transient expression assays, and expression profiling showed that the Veju insertion was primarily responsible for the extreme dwarfing effect. It was found that the Veju insertion changed processing of the Rht-B1c transcripts and resulted in DELLA motif primary structure disruption. Expression assays showed that Rht-B1c caused reduction of total Rht-1 transcript levels, and up-regulation of GATA-like transcription factors and genes positively regulated by these factors, suggesting that one way in which Rht-1 proteins affect plant growth and development is through GATA-like transcription factor regulation.

2D graphene with tremendous novel properties is an ideal material for optical and optoelectronic applications. Meanwhile, photonic crystal fibers (PCFs) have been recognized as next-generation optical fibers that possess a designable porous structure, rich functions, and different working mechanisms. Recently, the integration of graphene with a PCF has formed a new hybrid fiber, a graphene photonic crystal fiber (Gr-PCF), which exhibits an extremely strong and tunable light-matter interaction across a broadband spectrum range and opens up a new interdisciplinary research direction. In this review, recent studies on, and achievements in graphene-traditional fibers and Gr-PCFs have been summarized from the aspects of the development process, preparation method, and device application. First, the graphene properties and the development and characteristics of PCFs are introduced. The discussion is continued with the existing fabrication technologies for hybrid graphene-traditional fibers. Next, the chemical vapor deposition method for Gr-PCFs is elaborated. Then, fiber devices based on graphene-traditional fibers, Gr-PCFs, and other 2D material fibers are presented. To conclude, challenges and perspectives are presented to encourage advanced Gr-PCF study.

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Background Wheat (Triticum aestivum L.) is a major cereal crop that is grown worldwide, and it is highly dependent on sufficient N supply. The molecular mechanisms associated with nitrate uptake and assimilation are still poorly understood in wheat. In plants, NRT2 family proteins play a crucial role in NO3– acquisition and translocation under nitrate limited conditions. However, the biological functions of these genes in wheat are still unclear, especially their roles in NO3– uptake and assimilation. Results In this study, a comprehensive analysis of wheat TaNRT2 genes was conducted using bioinformatics and molecular biology methods, and 49 TaNRT2 genes were identified. A phylogenetic analysis clustered the TaNRT2 genes into three clades. The genes that clustered on the same phylogenetic branch had similar gene structures and nitrate assimilation functions. The identified genes were further mapped onto the 13 wheat chromosomes, and the results showed that a large duplication event had occurred on chromosome 6. To explore the TaNRT2 gene expression profiles in wheat, we performed transcriptome sequencing after low nitrate treatment for three days. Transcriptome analysis revealed the expression levels of all TaNRT2 genes in shoots and roots, and based on the expression profiles, three highly expressed genes (TaNRT2-6A.2, TaNRT2-6A.6, and TaNRT2-6B.4) were selected for qPCR analysis in two different wheat cultivars (‘Mianmai367’ and ‘Nanmai660’) under nitrate-limited and normal conditions. All three genes were upregulated under nitrate-limited conditions and highly expressed in the high nitrogen use efficiency (NUE) wheat ‘Mianmai367’ under low nitrate conditions. Conclusion We systematically identified 49 NRT2 genes in wheat and analysed the transcript levels of all TaNRT2s under nitrate deficient conditions and over the whole growth period. The results suggest that these genes play important roles in nitrate absorption, distribution, and accumulation. This study provides valuable information and key candidate genes for further studies on the function of TaNRT2s in wheat.

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Inflorescence represents the highly specialized plant tissue producing the grains. Although key genes regulating flower initiation and development are conserved, the mechanism regulating fertility is still not well explained. To identify genes and gene network underlying inflorescence morphology and fertility of bread wheat, expressed sequence tags (ESTs) from different tissues were analyzed using a comparative transcriptomics approach. Based on statistical comparison of EST frequencies of individual genes in EST pools representing different tissues and verification with RT-PCR and RNA-seq data, 170 genes of 59 gene sets predominantly expressed in the inflorescence were obtained. Nearly one-third of the gene sets displayed differentiated expression profiles in terms of their subgenome orthologs. The identified genes, most of which were predominantly expressed in anthers, encode proteins involved in wheat floral identity determination, anther and pollen development, pollen-pistil interaction, and others. Particularly, 25 annotated gene sets are associated with pollen wall formation, of which 18 encode enzymes or proteins participating in lipid metabolic pathway, including fatty acid ω-hydroxylation, alkane and fatty alcohol biosynthesis, and glycerophospholipid metabolism. We showed that the comparative transcriptomics approach was effective in identifying genes for reproductive development and found that lipid metabolism was particularly active in wheat anthers.

Background: Wheat (Triticum aestivum L.) is a major crop that is grown worldwide, but it is highly dependent on sufficient N supply. The molecular mechanisms associated with nitrate uptake and assimilation are still poorly understood in wheat. In plants, NRT2 family proteins play a crucial role in NO3– acquisition and translocation under limited nitrate conditions. However, the biological functions of these genes in wheat are still unclear, especially their roles in NO3– uptake and assimilation. Results: In this study, a comprehensive analysis of wheat TaNRT2 genes was conducted using bioinformatics and molecular biology methods and 49 TaNRT2 genes were identified. A phylogenetic analysis clustered the TaNRT2 genes into three clades. The genes clustered on the same phylogenetic branch had similar gene structures and nitrate assimilation functions. The identified genes were further mapped onto the 13 wheat chromosomes and the results showed that a large duplication event had occurred on chromosome 6. To explore the TaNRT2 genes expression profiles in wheat, we performed transcriptome sequencing after low nitrate treatment for three days. The transcriptome analysis revealed that expression levels of all TaNRT2 genes in shoot and root and, based on the expression profiles, three highly expressed genes (TaNRT2-6A.2, TaNRT2-6A.6, and TaNRT2-6B.4) were selected for a qPCR analysis in two different wheat cultivars (‘Mianmai367’ and ‘Nanmai660’) under nitrogen limited and normal conditions. All three genes were up-regulated under nitrate limited conditions and highly expressed in the high nitrogen use efficiency (NUE) wheat ‘Mianmai36’ under low nitrate conditions. Conclusion: We systematically identified 49 NRT2 gens in wheat and analyzed the transcript levels of all the TaNRT2s under nitrogen deficiency conditions and over the whole growth period. These results suggest that these genes play important roles in nitrate absorption, distribution, and accumulation. This study provides valuable information and key candidate genes for further studies on the function TaNRT2s in wheat.

Premium wheat with a high end-use quality is generally lacking in China, especially high-quality hard and soft wheat. Pina-D1 and Pinb-D1 (puroindoline genes) influence wheat grain hardness (i.e., important wheat quality-related parameter) and are among the main targets in wheat breeding programs. However, the mechanism by which puroindoline genes control grain hardness remains unclear. In this study, three hard wheat puroindoline variants (MY26, GX3, and ZM1) were compared with a soft wheat variety (CM605) containing the wild-type puroindoline genotype. Specifically, proteomic methods were used to screen for differentially abundant proteins (DAPs). In total, 6253 proteins were identified and quantified via a high-throughput tandem mass tag quantitative proteomic analysis. Of the 208 DAPs, 115, 116, and 99 proteins were differentially expressed between MY26, GX3, and ZM1 (hard wheat varieties) and CM605, respectively. The cluster analysis of protein relative abundances divided the proteins into six clusters. Of these proteins, 67 and 41 proteins were, respectively, more and less abundant in CM605 than in MY26, GX3, and ZM1. Enrichment analyses detected six GO terms, five KEGG pathways, and five IPR terms that were shared by all three comparisons. Furthermore, 12 proteins associated with these terms or pathways were found to be differentially expressed in each comparison. These proteins, which included cysteine proteinase inhibitors, invertases, low-molecular-weight glutenin subunits, and alpha amylase inhibitors, may be involved in the regulation of grain hardness. The candidate genes identified in this study may be relevant for future analyses of the regulatory mechanism underlying grain hardness.