Chromosome-Scale Assembly and Annotation of Eight Arabidopsis thaliana Ecotypes.

The plant Arabidopsis thaliana is a model system used by researchers through much of plant research. Recent efforts have focused on discovering the genomic variation found in naturally occurring ecotypes isolated from around the world. These ecotypes have come from diverse climates and therefore have faced and adapted to a variety of abiotic and biotic stressors.

Differential expansion and retention patterns of LRR-RLK genes across plant evolution.

To maximize overall fitness, plants must accurately respond to a host of growth, developmental, and environmental signals throughout their life. Many of these internal and external signals are perceived by the leucine-rich repeat receptor-like kinases, which play roles in regulating growth, development, and immunity. This largest family of receptor kinases in plants can be divided into subfamilies based on the conservation of the kinase domain, which demonstrates that shared evolutionary history often indicates shared molecular function.

Map of physical interactions between extracellular domains of Arabidopsis leucine-rich repeat receptor kinases.

Plants use surface receptors to perceive information about many aspects of their local environment. These receptors physically interact to form both steady state and signalling competent complexes. The signalling events downstream of receptor activation impact both plant developmental and immune responses.

Multiproduct Resin Reuse for Clinical and Commercial Manufacturing-Methodology and Acceptance Criteria.

Chromatography resins used for purifying biopharmaceuticals are generally dedicated to a single product. In good manufacturing practice (GMP) facilities that manufacture a limited amount of any particular product, this practice can result in the resin being used for a fraction of its useful life. A methodology for extending resin reuse to multiple products is described.

Publisher Correction: An extracellular network of Arabidopsis leucine-rich repeat receptor kinases.

In this Letter, an incorrect version of the Supplementary Information file was inadvertently used, which contained several errors. The details of references 59-65 were missing from the end of the Supplementary Discussion section on page 4. In addition, the section 'Text 3.

An extracellular network of Arabidopsis leucine-rich repeat receptor kinases.

The cells of multicellular organisms receive extracellular signals using surface receptors. The extracellular domains (ECDs) of cell surface receptors function as interaction platforms, and as regulatory modules of receptor activation. Understanding how interactions between ECDs produce signal-competent receptor complexes is challenging because of their low biochemical tractability.

A High-Sensitivity, Microtiter-Based Plate Assay for Plant Pattern-Triggered Immunity.

The first step in the plant immune response to pathogen challenge involves the perception of conserved epitopes, called microbe-associated molecular patterns (MAMPs), by cell-surface pattern recognition receptors (PRRs). Given the key roles that MAMPs and PRRs play in plant innate immunity, great effort has been expended to identify these molecules. Current methods for assaying these immune responses are often limited in their resolution and throughput, and consequently, there is a need for medium- to high-throughput methodologies.

An Alternative Strategy for Trypanosome Survival in the Mammalian Bloodstream Revealed through Genome and Transcriptome Analysis of the Ubiquitous Bovine Parasite Trypanosoma (Megatrypanum) theileri.

There are hundreds of Trypanosoma species that live in the blood and tissue spaces of their vertebrate hosts. The vast majority of these do not have the ornate system of antigenic variation that has evolved in the small number of African trypanosome species, but can still maintain long-term infections in the face of the vertebrate adaptive immune system. Trypanosoma theileri is a typical example, has a restricted host range of cattle and other Bovinae, and is only occasionally reported to cause patent disease although no systematic survey of the effect of infection on agricultural productivity has been performed.

Genomic screens identify a new phytobacterial microbe-associated molecular pattern and the cognate Arabidopsis receptor-like kinase that mediates its immune elicitation.

Background: The recognition of microbe-associated molecular patterns during infection is central to the mounting of an effective immune response. In spite of their importance, it remains difficult to identify these molecules and the host receptors required for their perception, ultimately limiting our understanding of the role of these molecules in the evolution of host-pathogen relationships.

Results: We employ a comparative genomics screen to identify six new immune eliciting peptides from the phytopathogenic bacterium Pseudomonas syringae.

Immunomodulation by the Pseudomonas syringae HopZ type III effector family in Arabidopsis.

Pseudomonas syringae employs a type III secretion system to inject 20-30 different type III effector (T3SE) proteins into plant host cells. A major role of T3SEs is to suppress plant immune responses and promote bacterial infection. The YopJ/HopZ acetyltransferases are a superfamily of T3SEs found in both plant and animal pathogenic bacteria.

Calculation of the infrared spectra of proteins.

The CHARMM22 force field with associated partial charges is used to calculate the infrared spectra of a number of small proteins and some larger biothreat proteins. The calculated high-frequency region, from about 2,500 to 3,500 cm(-1), is dominated by stretching modes of hydrogen bonded to other atoms, and is very similar in all proteins. There is a peak at 3,430 cm(-1) whose intensity is predicted by these calculations to be a direct measure of arginine content.

Peptides and small molecules of the plant-pathogen apoplastic arena.

Plants reside within an environment rich in potential pathogens. Survival in the presence of such threats requires both effective perception of, and appropriate responses to, pathogenic attack. While plants lack an adaptive immune system, they have a highly developed and responsive innate immune system able to detect and inhibit the growth of the vast majority of potential pathogens.

The Pseudomonas syringae type III effector HopF2 suppresses Arabidopsis stomatal immunity.

Pseudomonas syringae subverts plant immune signalling through injection of type III secreted effectors (T3SE) into host cells. The T3SE HopF2 can disable Arabidopsis immunity through Its ADP-ribosyltransferase activity. Proteomic analysis of HopF2 interacting proteins identified a protein complex containing ATPases required for regulating stomatal aperture, suggesting HopF2 may manipulate stomatal immunity.

Calculated infrared spectra of nerve agents and simulants.

Since organophosphorus nerve agents are among the most toxic known chemical warfare agents, it is desirable to have a way to distinguish between one and another. Infrared spectroscopy is a common tool for identifying molecules. Given the difficulty in handling these chemicals, calculated IR spectra can be useful.

Targeting cattle-borne zoonoses and cattle pathogens using a novel trypanosomatid-based delivery system.

Trypanosomatid parasites are notorious for the human diseases they cause throughout Africa and South America. However, non-pathogenic trypanosomatids are also found worldwide, infecting a wide range of hosts. One example is Trypanosoma (Megatrypanum) theileri, a ubiquitous protozoan commensal of bovids, which is distributed globally.

A soluble factor from Trypanosoma cruzi inhibits transforming growth factor-ß-induced MAP kinase activation and gene expression in dermal fibroblasts.

The protozoan parasite Trypanosoma cruzi, which causes human Chagas' disease, exerts a variety of effects on host extracellular matrix (ECM) including proteolytic degradation of collagens and dampening of ECM gene expression. Exposure of primary human dermal fibroblasts to live infective T. cruzi trypomastigotes or their shed/secreted products results in a rapid down-regulation of the fibrogenic genes collagenIα1, fibronectin and connective tissue growth factor (CTGF/CCN2).

Modulation of host cell mechanics by Trypanosoma cruzi.

To investigate the effects of Trypanosoma cruzi on the mechanical properties of infected host cells, cytoskeletal stiffness and remodeling dynamics were measured in parasite-infected fibroblasts. We find that cell stiffness decreases in a time-dependent fashion in T. cruzi-infected human foreskin fibroblasts without a significant change in the dynamics of cytoskeletal remodeling.

The role of host cell lysosomes in Trypanosoma cruzi invasion.

The cell-invasive, trypomastigote form of Trypanosoma cruzi exhibits a unique relationship with lysosomes in target host cells. In contrast to many intracellular pathogens that are adept at avoiding contact with lysosomes, T. cruzi requires transient residence within this acidic organelle for productive infection.