The EBNA1 protein of Epstein-Barr virus (EBV) supports replication and maintenance of the circularized viral chromosome in cells that are latently infected. We have isolated, sequenced, and functionally characterized the EBNA1 gene of herpesvirus papio (HVP), an EBV-like virus that infects baboons. The amino acid sequences of EBNA1 of HVP and EBV are 56% identical, if the difference in the length of the glycine and alanine containing repetitive region, which is much shorter for HVP EBNA1, is omitted for the calculation. The key structural features of the DNA-binding/dimerization domain (the carboxyl-terminal domain) appear to have been conserved, as have amino acids in the two regions thought to be most critical for DNA binding. Most of the salient features of the amino-terminal two-thirds of EBNA1 (the amino-terminal domain), including a dearth of sequences predictive of alpha-helical or beta-sheet structures, are shared by the two sequences, although numerous gaps in this region were needed for alignment of the sequences. The amino-terminal fifty amino acids of EBNA1 of both EBV and HVP weakly resemble the amino terminus of rat ribosomal protein S2. Plasmids carrying oriP of either virus replicated stably in mammalian cells and supported efficient outgrowth of colonies under selection when supported by EBNA1 from either virus, although with each oriP there was a noticeable preference for EBNA1 to be from the same virus. HVP EBNA1 was less effective than EBV EBNA1 at activating the enhancer function of EBV oriP and under certain conditions was less effective than EBV EBNA1 at supporting maintenance of plasmids carrying EBV oriP. Results obtained with hybrid EBNA1 molecules indicated that differences in the amino-terminal and carboxyl-terminal domains, respectively, are primarily responsible for the differences in transcriptional activation and plasmid maintenance, respectively. The results showed that changes within EBNA1 can differentially alter its transcriptional and replicational activities.

Bermudagrass (Cynodon dactylon (L.) Pers) turf is the most widely used turfgrass in urban landscapes. Large amounts of fertilizer are usually applied for maximum turf performance, while relatively little attention has been paid to efficient nutrient management of bermudagrass turf. The design opted for was a 3-factor and 5-level Central Composite Rotatable Design (CCRD) consisting of 24 experimental runs in the greenhouse with response surface methodology (RSM) and simulated regression modeling. The experiment covered in this study was carried out at Sichuan Agricultural University with the objectives of understanding the interactive effects of nitrogen, (N), phosphorus (P), and potassium (K) fertilization on the bermudagrass integrated turf performance (ITP) and optimizing the amount of N, P, and K required for optimum turf performance during establishment. The qualitative and quantitative relationships between bermudagrass and fertilization significantly affected the ITP. The N, P, and K Fertilization significantly influenced the percent grass cover, turf height, shoot dry weight, root dry weight, and total chlorophyll content. Fertilization with N and P significantly enhanced the tiller length, turf density, color, and total protein levels. Root length was augmented with the application of P and K. We found that 3-D surface plots indicated significant interactive effects of NP, NK, and PK on the ITP. A simulation optimization and frequency analysis indicated that the optimal combined amounts of these nutrients were N: 26.0–27.6 g m−2, P: 24.2–26.4 g m−2, and K: 3.1–5.0 g m−2 during the establishment phase. The results suggest that optimized fertilization is key to sustainable nutrient management of bermudagrass integrated turf performance.

Influences of planting density and nitrogen rate have been investigated frequently in targeted wheat (Triticum aestivum L.) research. Few studies have investigated interactions between these inputs. The objective was to determine the combine effect of N and seeding rates on culm morph‐physiological traits for lodging tolerance and grain yield. The experiment used a split‐split randomized block design using two wheat varieties ‘AnNong0711’ and ‘YanNong19’, split by four seeding (180, 240, 300, and 375 × 104 ha−1) and four N rates (0, 180, 240, and 300 kg ha−1). Lodging traits of plant height, culm height center of gravity, and internode length, increased (p < .05) however, stem diameter, wall thickness, and stem breaking strength decreased with increasing N and seeding rate. Stem breaking strength was negatively correlated with culm height center of gravity (r = −.869, p = .01), internode length (r = −.872, p < .01), and lignin (r = −.746, p < .01) but positively correlated with internode diameter (r = .715, p < .05) and wall thickness (r = .696, p < .05). Culm lodging index and cellulose showed positive correlation (r = .807 and .913 respectively) with lignin. Compared to YanNong19, AnNong0711 showed higher grain yield and culm lodging index of 9 and 20.49%, respectively. For improved grain yield, 180 plants m−2 was optimal in surface combinations with 210 kg N ha−1 for AnNong0711 and 200 kg N ha−1 for YanNong19. These combinations of seeding and N rates could successfully mitigate lodging and improve grain yield.

Background Phytophthora capsici root rot (PRR) is a disastrous disease in peppers (Capsicum spp.) caused by soilborne oomycete with typical symptoms of necrosis and constriction at the basal stem and consequent plant wilting. Most studies on the QTL mapping of P. capsici resistance suggested a consensus broad-spectrum QTL on chromosome 5 named Pc.5.1 regardless of P. capsici isolates and resistant resources. In addition, all these reports proposed NBS-ARC domain genes as candidate genes controlling resistance. Results We screened out 10 PRR-resistant resources from 160 Capsicum germplasm and inspected the response of locus Pc.5.1 and NBS-ARC genes during P. capsici infection by comparing the root transcriptomes of resistant pepper 305R and susceptible pepper 372S. To dissect the structure of Pc.5.1, we anchored genetic markers onto pepper genomic sequence and made an extended Pc5.1 (Ext-Pc5.1) located at 8.35 Mb–38.13 Mb on chromosome 5 which covered all Pc5.1 reported in publications. A total of 571 NBS-ARC genes were mined from the genome of pepper CM334 and 34 genes were significantly affected by P. capsici infection in either 305R or 372S. Only 5 inducible NBS-ARC genes had LRR domains and none of them was positioned at Ext-Pc5.1. Ext-Pc5.1 did show strong response to P. capsici infection and there were a total of 44 differentially expressed genes (DEGs), but no candidate genes proposed by previous publications was included. Snakin-1 (SN1), a well-known antimicrobial peptide gene located at Pc5.1, was significantly decreased in 372S but not in 305R. Moreover, there was an impressive upregulation of sugar pathway genes in 305R, which was confirmed by metabolite analysis of roots. The biological processes of histone methylation, histone phosphorylation, DNA methylation, and nucleosome assembly were strongly activated in 305R but not in 372S, indicating an epigenetic-related defense mechanism. Conclusions Those NBS-ARC genes that were suggested to contribute to Pc5.1 in previous publications did not show any significant response in P. capsici infection and there were no significant differences of these genes in transcription levels between 305R and 372S. Other pathogen defense-related genes like SN1 might account for Pc5.1. Our study also proposed the important role of sugar and epigenetic regulation in the defense against P. capsici.

Chinese chives is a popular herb vegetable and medicine in Asian countries. Southwest China is one of the centers of origin, and the mountainous areas in this region are rich in wild germplasm. In this study, we collected four samples of germplasm from different altitudes: a land race of cultivated Chinese chives (Allium tuberosum), wide-leaf chives and extra-wide-leaf chives (Allium hookeri), and ovoid-leaf chives (Allium funckiaefolium). Leaf metabolites were detected and compared between A. tuberosum and A. hookeri. A total of 158 differentially accumulated metabolites (DAM) were identified by Gas Chromatography—Mass Spectrometry (GC-MS) and Liquid Chromatography—Mass Spectrometry (LC-MS), among which there was a wide range of garlic odor compounds, free amino acids, and sugars. A. hookeri contains a higher content of fructose, garlic odor compounds, and amino acids than A. tuberosum, which is supported by the higher expression level of biosynthetic genes revealed by transcriptome analysis. A. hookeri accumulates the same garlic odor compound precursors that A. tuberosum does (mainly methiin and alliin). We isolated full-length gene sequences of phytochelatin synthase (PCS), γ-glutamyltranspeptidases (GGT), flavin-containing monooxygenase (FMO), and alliinase (ALN). These sequences showed closer relations in phylogenetic analysis between A. hookeri and A. tuberosum (with sequence identities ranging from 86% to 90%) than with Allium cepa or Allium sativum (which had a lower sequence identity ranging from 76% to 88%). Among these assayed genes, ALN, the critical gene controlling the conversion of odorless precursors into odor compounds, was undetected in leaves, bulbs, and roots of A. tuberosum, which could account for its weaker garlic smell. Moreover, we identified a distinct FMO1 gene in extra-wide-leaf A. hookeri that is due to a CDS-deletion and frameshift mutation. These results above reveal the molecular and metabolomic basis of impressive strong odor in wild Chinese chives.