Entries by Mary Williams

Peptide-mediated regulation of receptor scaffolding in plant immune signaling ($)

Continuing the theme of peptide signaling, Stegmann et al. showed that a subset of the RALF (RAPID ALKALINIZATION FACTOR) family of plant peptides can negatively regulate plant immune responses. When plants are treated with flg22, a peptide epitope of bacterial flagellin, they produce reactive oxygen species (ROS) as part of their defense response. The flg22 […]

Peptide diffusion as a signal for Casparian strip diffusion barrier formation ($)

The Casparian strip is a permeability barrier that seals the spaces between root endodermis cells and so prevents bulk-flow uptake of solutes. Previously, a leucine-rich repeat receptor kinase called SCHENGEN3 or GASSHO1 (GSO1/SGN3) was identified as necessary for normal Casparian strip formation. Now, two papers in Science show that the interaction between diffusible peptides and […]

Review: mlo-based resistance: An apparently universal “weapon” to defeat powdery mildew disease ($)

Powdery mildew disease is a broad term that encompasses more than 650 species of powdery mildew fungi that affect about 10,000 plant species, with serious economic consequences.  In the 1930s/40s, broad-spectrum resistance to powdery mildew was found in barley with a loss-of-function of the Mildew resistance locus o (Mlo) gene. Subsequently, resistance conferred by induced […]

Review: The sexual advantage of looking, smelling and tasting good, the metabolic network that produces signals for pollinators ($)

The interaction between angiosperms and their pollinators provides an excellent system to study co-evolution, and underpins the evolution of the biosynthesis of numerous interesting and useful specialized metabolites, from pigments to fragrances. Borghi et al. review the metabolic pathways that produce these signals and rewards for pollinators. Classes of compounds discussed in terms of synthesis […]

Basal vs. Non-basal Polarity: Different Endomembrane Trafficking Pathways Establish Different Patterns

IN BRIEF: Nancy R. Hofmann nhofmann@aspb.org Plant development and responses to the environment hinge on the ability to target proteins to different areas of the plasma membrane within a cell. Indeed, the establishment of polar distributions of proteins such as PIN auxin transporters is among the key responsibilities of the endomembrane trafficking system (reviewed in […]

Effector-binding by integrated decoy domain of immune receptor RGA5 required for resistance activation

Magnaporthe oryzae is the fungus that causes rice blast disease, which is a serious threat to food security. Ortiz et al. explore the interaction between AVR-Pia, a fungal effector protein, and RGA5, a rice NLR (nucleotide-binding domain and leucine-rich repeat protein) immune receptor protein. RGA5 has a C-terminal domain, RATX1, that acts as an integrated […]

ROS accumulation and antiviral defence control by microRNA528 in rice

Several studies have implicated microRNAs in plant defenses against pathogens. Wu et al. previously showed that virus resistance is facilitated by the interaction of viral-inducible AGO18 (which is cleavage-inactive) and rice miR528. In this work, they identified the role of miR528 in viral resistance. Rice susceptibility to rice-stripe virus is positively correlated with miR528 expression […]

GET with it: Targeting of tail-anchored proteins via the GET system

Students learn that membrane proteins are inserted into the endoplasmic-reticulum (ER) membrane co-translationally, but this mechanism does not hold for so-called tail-anchored (TA) proteins which carry a single C-terminal membrane spanning domain and insert into the ER membrane post-translationally. The mechanism of TA protein insertion was recently described in yeast as the GET (Guided Entry […]

CATchUP: A web database providing information on spatiotemporal specific gene expression

Nakamura et al. have created a searchable database, CATchUP (http://plantomics.mind.meiji.ac.jp/CATchUP) that allows the user to explore the spatiotemporal expression of genes across eight plant species (monocots and dicots) using data from publically available databases of large-scale RNA-Seq data. The authors define a parameter, Δdmax, which defines the “maximum difference in relative gene expression levels between […]