Immunocompetent mouse models revealed that S100A4+ monocytes/macrophages facilitate long-term Zika virus infection in the testes.

During its global epidemic, Zika virus (ZIKV) attracted widespread attention due to its link with various severe neurological symptoms and potential harm to male fertility. However, the understanding of how ZIKV invades and persists in the male reproductive system is limited due to the lack of immunocompetent small animal models. In this study, immunocompetent murine models were generated by using anti-IFNAR antibody blocked C57BL/6 male mice and human STAT2 (hSTAT2) knock in (KI) male mice. After infection, viral RNA could persist in the testes even after the disappearance of viremia. We also found a population of ZIKV-susceptible S100A4+ monocytes/macrophages that were recruited into testes from peripheral blood and played a crucial role for ZIKV infection in the testis. By using single-cell RNA sequencing, we also proved that S100A4+ monocytes/macrophages had a great impact on the microenvironment of ZIKV-infected testes, thus promoting ZIKV-induced testicular lesions. In conclusion, this study proposed a novel mechanism of long-term ZIKV infection in the male reproductive system.

Improved chromosome-level genome assembly of Indian sandalwood (Santalum album).

Santalum album is a well-known aromatic and medicinal plant that is highly valued for the essential oil (EO) extracted from its heartwood. In this study, we present a high-quality chromosome-level genome assembly of S. album after integrating PacBio Sequel, Illumina HiSeq paired-end and high-throughput chromosome conformation capture sequencing technologies. The assembled genome size is 207.39 M with a contig N50 of 7.33 M and scaffold N50 size of 18.31 M. Compared with three previously published sandalwood genomes, the N50 length of the genome assembly was longer. In total, 94.26% of the assembly was assigned to 10 pseudo-chromosomes, and the anchor rate far exceeded that of a recently released value. BUSCO analysis yielded a completeness score of 94.91%. In addition, we predicted 23,283 protein-coding genes, 89.68% of which were functionally annotated. This high-quality genome will provide a foundation for sandalwood functional genomics studies, and also for elucidating the genetic basis of EO biosynthesis in S. album.

A Cloned Gene HuBADH from Hylocereus undatus Enhanced Salt Stress Tolerance in Transgenic Arabidopsis thaliana Plants.

BACKGROUND: Betaine aldehyde dehydrogenase (BADH) catalyzes the synthesis of glycine betaine and is considered to be a type of osmoregulator, so it can play a role in plants' responses to abiotic stresses. METHODS: In this study, a novel HuBADH gene from Hylocereus undatus (pitaya) was cloned, identified, and sequenced. The full-length cDNA included a 1512 bp open reading frame that encoded a 54.17 kDa protein consisting of 503 amino acids. Four oxidation-related stress-responsive marker genes (FSD1, CSD1, CAT1, and APX2) were analyzed by Quantitative real-time reverse transcription (qRT-PCR) in wild type (WT) and transgenic A. thaiana overexpression lines under NaCl stress. RESULTS: HuBADH showed high homology (79-92%) with BADH of several plants. The HuBADH gene was genetically transformed into Arabidopsis thaliana and overexpressed in transgenic lines, which accumulated less reactive oxygen species than WT plants, and had higher activities of antioxidant enzymes under NaCl stress (i.e., 300 mM). All four marker genes were significantly upregulated in WT and HuBADH-overexpressing transgenic A. thaliana plants under salt stress. Glycine betaine (GB) content was 32-36% higher in transgenic A. thaliana lines than in WT in the control (70-80% in NaCl stress). CONCLUSIONS: Our research indicates that HuBADH in pitaya plays a positive modulatory role when plants are under salt stress.

The yellowhorn AGL transcription factor gene XsAGL22 contributes to ABA biosynthesis and drought tolerance in poplar.

Regulation of abscisic acid (ABA) biosynthesis helps plants adapt to drought stress, but the underlying molecular mechanisms are largely unclear. Here, a drought-induced transcription factor XsAGL22 was isolated from yellowhorn (Xanthoceras sorbifolium Bunge). Yeast one-hybrid and electrophoretic mobility shift assays indicated that XsAGL22 can physically bind to the promoters of the ABA biosynthesis-related genes XsNCED6 and XsBG1, and a dual-luciferase assay showed that XsAGL22 activates the promoters of the later two genes. Transient overexpression of XsAGL22 in yellowhorn leaves also increased the expression of XsNCED6 and XsBG1 and increased cellular ABA levels. Finally, heterologous overexpression of XsAGL22 in poplar increased ABA content, reduced stomatal aperture and increased drought resistance. Our results suggest that XsAGL22 is a powerful regulator of ABA biosynthesis and plays a critical role in drought resistance in plants.

Analysis of Populus glycosyl hydrolase family I members and their potential role in the ABA treatment and drought stress response.

Glycoside hydrolase family 1 (GH1) ß-glucosidases (BGLUs) are encoded by a large number of genes and are involved in many developmental processes and stress responses in plants. Due to their importance in plant growth and development, genome-wide analyses have been conducted in the model plant species Arabidopsis thaliana, rice and maize but not in woody plant species, which have important economic and ecological value. In this study, we systematically analyzed Populus BGLUs (PtBGLUs) and demonstrated the involvement of several genes under stress conditions. Forty-four PtBGLUs were identified in Populus databases; these genes were located on 11 chromosomes, and the proteins of several PtBGLU genes were highly similar. More than 90% of PtBGLUs contain three conserved motifs. Collinearity results showed that 44 PtBGLU genes resulted from 12 tandem and 5 segmental duplication events. Phylogenetic analysis revealed that 128 BGLU genes from Populus trichocarpa, A. thaliana and Oryza sativa could be classified into 4 subgroups and subgroup Ⅱ and Ⅳ were differently having PtBGLUs and AtBGLUs. We further investigated whether several PtBGLUs responded to drought stress and ABA treatment, and the results showed that most of the selected BGLU genes were expressed in response to stress, which is consistent with previous studies involving rice and Arabidopsis homologous genes. Large numbers of stress-, hormone-, and development-related elements in the PtBGLU promoters suggest that BGLU genes may be involved in complex networks. Taken together, our results provide valuable information for an improved understanding of ß-glucosidase function in woody plants.

Jasmonate Signaling Enhances RNA Silencing and Antiviral Defense in Rice.

Small RNA-mediated RNA silencing is an important antiviral mechanism in higher plants. It has been shown that RNA silencing components can be upregulated by viral infection. However, the mechanisms underlying the upregulation remain largely unknown. Here, we show that jasmonate (JA) signaling transcriptionally activates Argonaute 18 (AGO18), a core RNA silencing component that promotes rice antiviral defense through sequestering miR168 and miR528, which repress key antiviral defense proteins. Mechanistically, the JA-responsive transcription factor JAMYB directly binds to the AGO18 promoter to activate AGO18 transcription. Rice stripe virus (RSV) coat protein (CP) triggers JA accumulation and upregulates JAMYB to initiate this host defense network. Our study reveals that regulatory crosstalk exists between the JA signaling and antiviral RNA silencing pathways and elucidates a molecular mechanism for CP-mediated viral resistance in monocot crops.

PeSHN1 regulates water-use efficiency and drought tolerance by modulating wax biosynthesis in poplar.

Wax, a hydrophobic structure that provides an effective waterproof barrier to the leaves, is an important drought adaptation trait for preventing water loss. However, limited knowledge exists regarding the molecular mechanisms underlying wax biosynthesis in trees. Here, PeSHN1, an AP2/ethylene response factor transcription factor, was isolated from a fast-growing poplar Populus × euramericana cv. 'Neva' clone. To study the potential biological functions of PeSHN1, transgenic 84K poplar (Populus alba × Populus glandulosa) plants overexpressing PeSHN1 were generated. PeSHN1 overexpression resulted in decreased transpiration, increased water-use efficiency (WUE) and increased drought tolerance. The transgenic poplar plants exhibited increased wax accumulation and altered wax composition, mainly because of a substantial increase in long-chain (>C30) fatty acids, aldehydes and alkanes. Gene expression analyses revealed that many genes involved in wax biosynthesis were induced in the PeSHN1 overexpression plants. In addition, chromatin immunoprecipitation-PCR assays and dual luciferase assays revealed that at least one of those genes, LACS2, is likely targeted by PeSHN1. Moreover, the PeSHN1 overexpression plants maintained higher photosynthetic activity and accumulated more biomass under drought stress conditions. Taken together, these results suggest that PeSHN1 regulates both WUE and drought tolerance in poplar by modulating wax biosynthesis and that altered PeSHN1 expression could represent a novel approach (altering the wax trait on leaf surfaces to increase WUE) for breeding drought-tolerant plants.

Reduced expression of Raf kinase inhibitor protein correlates with poor prognosis in pancreatic cancer.

AIM: Raf kinase inhibitory protein (RKIP) is an inhibitor of the Raf/MEK/MAP kinase signaling cascade and a suppressor of cancer metastasis. But its function in pancreatic cancer was not yet clarified completely. The aim of this study was to investigate the involvement of RKIP in pancreatic cancer. METHODS: RKIP expression was investigated retrospectively by immunohistochemistry in paraffin-embedded primary tumor tissue samples from a series (n = 99) of consecutive patients with pancreatic cancer. Survival was calculated using Kaplan-Meier curves. Parameters found to be of prognostic significance in univariate analysis were verified in a multivariate Cox regression model. RESULTS: RKIP expression was high in normal pancreatic epithelium and retained to varying degrees in pancreatic cancer tissues. However, in tumor tissues with lymph node metastasis (P = 0.008) and high UICC stage (P = 0.006), RKIP expression was highly significantly reduced or lost. Furthermore, the reduced expression of RKIP significantly correlated with both poor overall and disease-free survival (P = 0.008 and 0.01, respectively). Multivariate analyses revealed RKIP to be an independent prognosticator. CONCLUSION: These findings suggest that RKIP could be a promising marker for predicting a better prognosis in pancreatic cancer.

[The IR spectra of complexes of N-(phenyl, ferrocenyl)methyl-beta-hydroxyethylamine with Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II)].

The reaction of ferrocenylphenylcarbinol with the ethereal solution of boron trifluoride in dichloride methane resulted in the relevant ferrocenylphenylmethyl carbocation. Without separation from the reaction mixture, the ion reacted with ethanolamine to from N-(phenyl,ferrocenyl) methyl-beta-hydroxyethylamine(FcY). A series of coordinate complexes-FcY-Ni(II), FcY-Cu (II), FcY-Zn(II), FcY-Cd(II) and FcY-Hg(II) were obtained through coordination of this ligand with MCl2 (M = Ni, Cu, Zn, Cd, Hg). The complexes and ligand were taken for FTIR in the range of 4 000-400 cm(-1). Their major bonds were assigned and compared. The results showed that in all the complexes some bands (v(O-H), v(N-H) , delta(O-H), delta(N-H)) showed a certain shift to lower wave number, and bands(V(C-N), v(O-N)) exhibited a certain shift to higher wave number. The aminoalcohol groups and metal ions were bonding with coordinated bond.

[The IR spectra of complexes of 2-hydroxy-2-ferrocenylpropylamine with Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II)].

alpha-Cyano-alpha-ferrocenylethoxytrimethylsilame was prepared by the addition of trimethysilyl cyanide to acetylferrocene. 2-Hydroxy-2-ferrocenylpropylamine(FcA) was synthesized by the reduction of alpha-cyano-alpha-ferrocenylethoxytrimethylsilame with lithium aluminum hydride. A series of coordinate complexes--FcA-Ni(II), FcA-Cu(II), FcA-Zn(II), FcA-Cd(II) and FcA-Hg(II) were obtained through coordination of this ligand with MCl2 (M= Ni, Cu, Zn, Cd and Hg). The FTIR spectra of the complexes and ligand were obtained in the range of 4 000-400 cm(-1). Their major bands were assigned and compared. The results showed that in all complexes some bands(upsilonO-H, upsilonN-H sigmaO-H, sigmaN-H) were shifted to lower wave number, and some(upsilonC-N, upsilonO-N) were shifted to higher wave number. The aminoalcohol groups and metal ions were bound with coordinated bond.