Diversity and metabolic potentials of microbial communities associated with pollinator and cheater fig wasps in fig-fig wasp mutualism system.

Microbial symbionts can influence a myriad of insect behavioral and physiological traits. However, how microbial communities may shape or be shaped by insect interactions with plants and neighboring species remains underexplored. The fig-fig wasp mutualism system offers a unique model to study the roles of microbiome in the interactions between the plants and co-habiting insects because a confined fig environment is shared by two fig wasp species, the pollinator wasp (Eupristina altissima and Eupristina verticillata) and the cheater wasp (Eupristina sp1 and Eupristina sp2). Here, we performed whole genome resequencing (WGS) on 48 individual fig wasps (Eupristina spp.) from Yunnan, China, to reveal the phylogenetic relationship and genetic divergence between pollinator and congeneric cheater wasps associated with the Ficus trees. We then extracted metagenomic sequences to explore the compositions, network structures, and functional capabilities of microbial communities associated with these wasps. We found that the cheaters and pollinators from the same fig species are sister species, which are highly genetically divergent. Fig wasps harbor diverse but stable microbial communities. Fig species dominate over the fig wasp genotype in shaping the bacterial and fungal communities. Variation in microbial communities may be partially explained by the filtering effect from fig and phylogeny of fig wasps. It is worth noting that cheaters have similar microbial communities to their sister pollinators, which may allow cheaters to coexist and gain resources from the same fig species. In terms of metabolic capabilities, some bacteria such as Desulfovibrio and Lachnospiraceae are candidates involved in the nutritional uptake of fig wasps. Our results provide novel insights into how microbiome community and metabolic functions may couple with the fig-wasp mutualistic systems.

Comparative chloroplast genome analysis of Ficus (Moraceae): Insight into adaptive evolution and mutational hotspot regions.

As the largest genus in Moraceae, Ficus is widely distributed across tropical and subtropical regions and exhibits a high degree of adaptability to different environments. At present, however, the phylogenetic relationships of this genus are not well resolved, and chloroplast evolution in Ficus remains poorly understood. Here, we sequenced, assembled, and annotated the chloroplast genomes of 10 species of Ficus, downloaded and assembled 13 additional species based on next-generation sequencing data, and compared them to 46 previously published chloroplast genomes. We found a highly conserved genomic structure across the genus, with plastid genome sizes ranging from 159,929 bp (Ficus langkokensis) to 160,657 bp (Ficus religiosa). Most chloroplasts encoded 113 unique genes, including a set of 78 protein-coding genes, 30 transfer RNA (tRNA) genes, four ribosomal RNA (rRNA) genes, and one pseudogene (infA). The number of simple sequence repeats (SSRs) ranged from 67 (Ficus sagittata) to 89 (Ficus microdictya) and generally increased linearly with plastid size. Among the plastomes, comparative analysis revealed eight intergenic spacers that were hotspot regions for divergence. Additionally, the clpP, rbcL, and ccsA genes showed evidence of positive selection. Phylogenetic analysis indicated that none of the six traditionally recognized subgenera of Ficus were monophyletic. Divergence time analysis based on the complete chloroplast genome sequences showed that Ficus species diverged rapidly during the early to middle Miocene. This research provides basic resources for further evolutionary studies of Ficus.

The complete chloroplast genome of two related fig species Ficus squamosa and Ficus heterostyla.

The Ficus squamosa and Ficus heterostyla share an undescribed pollinating fig wasp Ceratosolen sp. in Xishuangbanna region, which constitutes the most excellent model to study the role of convergent evolution and hybridization in the species-specific fig-wasp mutualism. The plastomes were 160,350 bp for Ficus squamosa and 160,300 bp for F. heterostyla, both in length with the typical quadripartite structure. In the two genomes, the LSC region was 88,615 bp (F. squamosa) and 88,535 bp (F. heterostyla), the SSC region was 20,071 bp (F. squamosa) and 20,101 bp (F. heterostyla), and the IR regions of both figs were 25,832 bp. They contained 113 unique genes, including a set of 78 protein-coding genes, 30 transfer RNA (tRNA) genes, four ribosomal RNA (rRNA) genes, and one pseudogene (infA). Phylogenetic analysis based on the complete chloroplast (cp) genomes within the Ficus genus suggests that they are closely related sister species.

[Bioinformatics analysis of safflower WD40 transcription factor family genes].

The WD40 transcription factor family is a gene superfamily widely found in eukaryotes, which is closely related to plant growth and development regulation. It has been reported that the WD40 transcription factor was involved in the synthesis of anthocyanins, which is one of the vital components of safflower flavonoid compounds. In this study, 40 CtWD40 members in the safflower genome were identified though bioinformatics tools and gene expression analysis methods. According to the WD40 protein sequence and phylogenetic characteristics of Arabidopsis and other plants, the safflower CtWD40 family was classified into 7 subfamilies. Conservative motif analysis was used to reveal the specific conserved motifs and gene structures of each subfamily member, and there exist a certain degree of similarities in the conserved motifs and gene structure between the closely related family members. Subsequently, the search for cis-acting elements of gene promoters found CtWD40-specific promoter elements, revealing the metabolic pathways which may involve. Next, enrichment of function analysis was employed to analyze the functional categories and cellular localization of the CtWD40 protein. Furthermore, the interactions between CtWD40 proteins predicted its potential regulatory function. Finally, 19 members of the safflower CtWD40 subfamily were analyzed by qRT-PCR, the result showed the expression patterns of these members were different in diverse tissue and flowering period. This study provides a basis for the functional and expression research of the CtWD40 genes.

Metasurface lens with angular modulation for extended depth of focus imaging.

The depth of focus (DOF) indicates the tolerance of the imaging displacement. The axial long-focal-depth is significant in practical applications, including optical imaging and communication. The importance of extending the DOF is rapidly growing with the advance of metasurface lenses. Angular modulation, as a promising way to extend the DOF, offers an additional degree of freedom to improve the imaging quality. Here we theoretically and experimentally demonstrate an angular modulated metasurface lens for extended DOF imaging by means of applying the geometrical phase. Unlike previous studies of the geometrical phase, which is sensitive to the polarity of circular polarization incidence, the polarity of circular polarization independence and broadband characteristic of angular modulation yield the potential of robust and efficient extension of the DOF imaging, thus providing novel opportunities for highly integrated optical circuits.

Transcriptome-Wide Analysis Reveals Key DEGs in Flower Color Regulation of Hosta plantaginea (Lam.) Aschers.

BACKGROUND: Hosta plantaginea (Lam.) Aschers (HPA), a species in the family Liliaceae, is an important landscaping plant and herbaceous ornamental flower. However, because the flower has only two colors, white and purple, color matching applications are extremely limited. To date, the mechanism underlying flower color regulation remains unclear. METHODS: In this study, the transcriptomes of three cultivars-H. plantaginea (HP, white flower), H. Cathayana (HC, purple flower), and H. plantaginea 'Summer Fragrance' (HS, purple flower)-at three flowering stages (bud stage, initial stage, and late flowering stage) were sequenced with the Illumina HiSeq 2000 (San Diego, CA, USA). The RNA-Seq results were validated by qRT-PCR of eight differentially expressed genes (DEGs). Then, we further analyzed the relationship between anthocyanidin synthase (ANS), chalcone synthase (CHS), and P450 and the flower color regulation by Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Eukaryotic Orthologous Groups (KOG) network and pathway enrichment analyses. The overexpression of CHS and ANS in transgenic tobacco petals was verified using qRT-PCR, and the petal colors associated with the overexpression lines were confirmed using absorbance values. RESULTS: Over 434,349 transcripts were isolated, and 302,832 unigenes were identified. Additionally, through transcriptome comparisons, 2098, 722, and 606 DEGs between the different stages were found for HP, HC, and HS, respectively. Furthermore, GO and KEGG pathway analyses showed that 84 color-related DEGs were enriched in 22 pathways. In particular, the flavonoid biosynthetic pathway, regulated by CHS, ANS, and the cytochrome P450-type monooxygenase gene, was upregulated in both purple flower varieties in the late flowering stage. In contrast, this gene was hardly expressed in the white flower variety, which was verified in the CHS and ANS overexpression transgenic tobacco petals. CONCLUSIONS: The results suggest that CHS, ANS, and the cytochrome P450s-regulated flavonoid biosynthetic pathway might play key roles in the regulation of flower color in HPA. These insights into the mechanism of flower color regulation could be used to guide artificial breeding of polychrome varieties of ornamental flowers.

Tunable high-channel-count bandstop graphene plasmonic filters based on plasmon induced transparency.

A high-channel-count bandstop graphene plasmonic filter based on ultracompact plasmonic structure is proposed in this paper. It consists of graphene waveguide side-coupled with a series of graphene filtering units. The study shows that the waveguide-resonator system performs a multiple plasmon induced transparency (PIT) phenomenon. By carefully adjusting the Fermi level of the filtering units, any two adjacent transmitted dips which belong to different PIT units can produce coherent coupling superposition enhancement. This property prevents the attenuation of the high-frequency transmission dips of multiple PIT and leads to an excellent bandstop filter with multiple channels. Specifically, the bandwidth and modulation depth of the filters can be flexibly adjusted by tuning the Fermi energy of the graphene waveguide. This ultracompact plasmonic structure contributes to the achievement of frequency division multiplexing systems for optical computing and communications in highly integrated optical circuits.

Tunable bulk polaritons of graphene-based hyperbolic metamaterials.

The tunable hyperbolic metamaterial (HMM) based on the graphene-dielectric layered structure at THz frequency is presented, and the surface and bulk polaritons of the graphene-based HMM are theoretically studied. It is found that the dispersions of the polaritons can be tuned by varying the Fermi energy of graphene sheets, the graphene-dielectric layers and the layer number of graphene sheets. In addition, the highly confined bulk polariton mode can be excited and is manifested in an attenuated total reflection configuration as a sharp drop in the reflectance. Such properties can be used in tunable optical reflection modulation with the assistance of bulk polaritons.

Enhancing infrared extinction and absorption in a monolayer graphene sheet by harvesting the electric dipolar mode of split ring resonators.

Optical extinction and absorption enhancement in the infrared range of a monolayer graphene sheet by patterning split ring resonators (SRRs) is studied. It is found that the electric mode is stronger in enhancing infrared extinction and absorption compared to the magnetic mode and other higher-order modes. We improve the infrared extinction of the SRR graphene sheet by increasing the graphene area ratio in the SRR unit cell design. With the increase of the graphene area ratio, the radiation ability of the electric dipolar mode and dissipation of graphene compete for a maximum infrared absorption of about 50%. The findings on enhancing infrared extinction and absorption of the graphene sheet by harvesting the electric dipolar mode may have potential applications in terahertz and infrared detection and modulation for graphene photonics and optoelectronics.