Horizontal gene transfer (HGT) involves the nonsexual transmission of genetic material across species boundaries. Although often detected in prokaryotes, examples of HGT involving animals are ...relatively rare, and any evolutionary advantage conferred to the recipient is typically obscure. We identified a gene (HhMAN1) from the coffee berry borer beetle, Hypothenemus hampei, a devastating pest of coffee, which shows clear evidence of HGT from bacteria. HhMAN1 encodes a mannanase, representing a class of glycosyl hydrolases that has not previously been reported in insects. Recombinant HhMAN1 protein hydrolyzes coffee berry galactomannan, the major storage polysaccharide in this species and the presumed food of H. hampei. HhMAN1 was found to be widespread in a broad biogeographic survey of H. hampei accessions, indicating that the HGT event occurred before radiation of the insect from West Africa to Asia and South America. However, the gene was not detected in the closely related species H. obscurus (the tropical nut borer or "false berry borer"), which does not colonize coffee beans. Thus, HGT of HhMAN1 from bacteria represents a likely adaptation to a specific ecological niche and may have been promoted by intensive agricultural practices.
Summary
Evasion or active suppression of host defenses are critical strategies employed by biotrophic phytopathogens and hemibiotrophs whose infection mechanism includes sequential biotrophic and ...necrotrophic stages. Although defense suppression by secreted effector proteins has been well studied in bacteria, equivalent systems in fungi and oomycetes are poorly understood. We report the characterization of SNE1 (suppressor of necrosis 1), a gene encoding a secreted protein from the hemibiotrophic oomycete Phytophthora infestans that is specifically expressed at the transcriptional level during biotrophic growth within the host plant tomato (Solanum lycopersicum). Using transient expression assays, we show that SNE1 suppresses the action of secreted cell death‐inducing effectors from Phytophthora that are expressed during the necrotrophic growth phase, as well as programmed cell death mediated by a range of Avr–R protein interactions. We also report that SNE1 contains predicted NLS motifs and translocates to the plant nucleus in transient expression studies. A conceptual model is presented in which the sequential coordinated secretion of antagonistic effectors by P. infestans first suppresses, but then induces, host cell death, thereby providing a highly regulated means to control the transition from biotrophy to necrotrophy.
Hot pepper (Capsicum annuum), one of the oldest domesticated crops in the Americas, is the most widely grown spice crop in the world. We report whole-genome sequencing and assembly of the hot pepper ...(Mexican landrace of Capsicum annuum cv. CM334) at 186.6× coverage. We also report resequencing of two cultivated peppers and de novo sequencing of the wild species Capsicum chinense. The genome size of the hot pepper was approximately fourfold larger than that of its close relative tomato, and the genome showed an accumulation of Gypsy and Caulimoviridae family elements. Integrative genomic and transcriptomic analyses suggested that change in gene expression and neofunctionalization of capsaicin synthase have shaped capsaicinoid biosynthesis. We found differential molecular patterns of ripening regulators and ethylene synthesis in hot pepper and tomato. The reference genome will serve as a platform for improving the nutritional and medicinal values of Capsicum species.
Hemibiotrophs, such as Phytophthora infestans, exhibit distinct phases of their life cycle: an early asymptomatic biotrophic phase and a late necrotrophic stage that is characterized by tissue ...degradation and disease symptoms. To date, little is known of the molecular mechanisms that promote each distinct phase, nor those that mediate the transition between the two. We hypothesized that these phytopathogens might secrete distinct classes of effector proteins that first suppress plant defense responses and associated programmed cell death (PCD), and later induce large scale necrosis. To this end, we have identified proteins that are secreted by P. infestans early or late in the infection cycle. Recently we described the characterization of SNE1, which is specifically expressed during early biotrophic growth in the host plant tomato (Solanum lycopersicum). We found that SNE1 suppresses the action of necrosis-inducing effectors (Nep1-like proteins), including PiNPP1.1 and PsojNIP, which are secreted by Phytophthora during necrotrophic growth, as well as PCD mediated by a broad spectrum of Avr-R protein interactions. This suggests that SNE1 and PiNPP1.1 act antagonistically, thereby providing a highly regulated means to control the transition from biotrophy to necrotrophy.
The aim of this study was to evaluate the effect of dimensional stability of splinting material on the accuracy of master casts.
A stainless steel metal model with 6 implants embedded was used as a ...master model. Implant level impressions were made after square impression copings were splinted using 5 different techniques as follows. (1) Splinted with autopolymerizing resin and sectioned, reconnected to compensate polymerization shrinkage before the impression procedure. (2) Splinted with autopolymerizing resin just before impression procedure. (3) Primary impression made with impression plaster and secondary impression were made over with polyether impression material. (4) Splinted with impression plaster. (5) Splinted with VPS bite registration material. From master model, 5 impressions and 5 experimental casts, total 25 casts were made for each of 5 splinting methods. The distortion values of each splinting methods were measured using coordinate measuring machine, capable of recordings in the x-, y-, z-axes. A one-way analysis of variance (ANOVA) at a confidence level of 95% was used to evaluate the data and Tukey's studentized range test was used to determine significant differences between the groups.
Group 1 showed best accuracy followed by Group 3 & 4. Group 2 and 5 showed relatively larger distortion value than other groups. No significant difference was found between group 3, 4, 5 in x-axis, group 2, 3, 4 in y-axis and group 1, 3, 4, 5 in z-axis (P<.0001).
Both Splinting impression copings with autopolymerizing resin following compensation of polymerization shrinkage and splinting method with impression plaster can enhance the accuracy of master cast and impression plaster can be used simple and effective splinting material for implant impression procedure.
Secreted and cell surface proteins play essential roles in numerous essential biological processes in eukaryotic organisms, but are often more difficult to isolate and identify than proteins that are ...localized in intracellular compartments. However, several high-throughput 'gene-trap' techniques have been developed to characterize these 'secretomes', including the yeast secretion trap (YST) screen. This method involves fusing cDNA libraries from the tissue or cell type of interest to a yeast (Saccharomyces cerevisiae) invertase reporter gene, transforming the resulting fusion library into an invertase-deficient yeast strain and plating the transformants on a medium containing sucrose as the sole carbon source. A yeast cell with a transgene encoding a secreted or cell surface protein can synthesize a secreted invertase fusion protein that can rescue the mutant, and the plasmid DNA can then be sequenced to identify the gene that encodes it. We describe a recently improved version of this screen, which allows the identification of genes encoding secreted proteins in 1-2 months.
Complex suites of proteins that are secreted by plants and phytopathogens into the plant apoplast play crucial roles in surveillance, assault, defense, and counter-defense. High-throughput ...genome-scale strategies are being developed to better understand the nature of these “secretomes” and the identity of pathogen-derived effector proteins that subvert plant defenses and promote pathogenicity. Although combined bioinformatic and experimental approaches recently have provided comprehensive coverage of secreted proteins from bacterial phytopathogens, far less is known about the secretomes and batteries of effectors of eukaryotic phytopathogens; notably fungi and oomycetes. The yeast secretion trap (YST) represents a potentially valuable technique to simultaneously target pathogen and host secretomes in infected plant material. A YST screen, using a new vector system, was applied to study the interaction between tomato (Solanum lycopersicum) and the oomycete Phytophthora infestans, revealing sets of genes encoding secreted proteins from both pathogen and host. Most of those from the oomycete had no identifiable function and were detectable in planta only during pathogenesis, underlining the value of YST as a tool to identify new candidate effectors and pathogenicity factors. In addition, the majority of the P. infestans proteins had homologs in the genomes of the related oomycetes P. sojae and P. ramorum.
The repair method for pavements should be selected considering the structural capacity of sublayers, in addition to the conditions observed at the pavement surface, to reduce the recurrence of ...distress in the repaired area. However, it is practically impossible to include the structural capacity of sublayers in the database of the pavement management system (PMS) because this would require additional tests in all expressway sections. Therefore, an artificial neural network model for predicting the indirect tensile strength (ITS) of the intermediate layer of all asphalt pavement sections in an expressway was developed in this study, taking the international roughness index, rut depth, surface distress, and equivalent single axle load as independent variables. The ITS of specimens cored from target sections was measured in the laboratory, and the PMS data for the target sections were collected. The ITS was predicted by conducting a feedforward process prior to the training step. When the error between the predicted and measured ITSs exceeded the allowable error, the model was repetitively trained using the resilient backpropagation method until the error fell within the acceptable boundary. The model was validated by analyzing the correlations between the ITSs predicted from the data of the training and test sets. Finally, the model was complemented by the corresponding minimum and maximum values of the ITS measured at the target section.
Several clinical factors have been used to predict the response for concurrent chemoradiotherapy (CCRT); however, these factors are insufficient for prognostic predictions. We investigated clinical ...factors to assess whether they could be used to predict the response to CCRT and the survival of patients with esophageal cancer.
Patients with esophageal cancer underwent CCRT from January 2005 to December 2015. Response to CCRT was classified as progressive disease (PD), stationary disease (SD), partial remission (PR), or complete remission (CR). Factors to predict the response to CCRT and patient survival were subsequently investigated.
A total of 535 esophageal cancer patients underwent CCRT. Four hundred ninety-three patients were followed up, and patient outcomes were investigated. In the adjusted analysis, patients with advanced stage disease (relative risk RR, 0.28 in stage III and 0.12 in stage IV compared to stage I), poor performance status, circumferential involvement (RR, 0.61), and male sex (RR, 0.31) were less likely to achieve CR. Advanced stage disease (hazard ratio HR, 1.71 in stage III/IV), poor CCRT response (HR, 2.82 in PR, 4.47 in SD, 4.77 in PD compared to CR), and poor performance status (HR, 1.38 in ECOG 2-4) were found to increase mortality.
Advanced stage disease, poor performance status, male sex, and circumferential involvement were independent predictive factors for a poor response to CCRT. Advanced stage, poor performance status, and poor CCRT response were independent factors for decreased survival.
PDF
