Biology subjects

van der Hoorn, R. A. L.

Publications and source records attributed to van der Hoorn, R. A. L..

21 records · Page 2Linked to original sources

bioRxiv2020

Agromonas: a rapid disease assay for Pseudomonas syringae growth in agroinfiltrated leaves

The lengthy process to generate transformed plants is a limitation in current research on the interactions of the model plant pathogen Pseudomonas syringae with plant hosts. Here we present an easy method called agromonas, where we quantify P. syringae growth in agroinfiltrated leaves of Nicotiana benthamiana using a cocktail of antibiotics to select P. syringae on plates. As a proof of concept, we demonstrate that transient expression of PAMP receptors reduces bacterial growth and that transient depletion of a host immune gene and transient expression of a T3 effector increase P. syringae growth in agromonas assays. We show that we can rapidly achieve structure-function analysis of immune components and test the function of immune hydrolases. The agromonas method is easy, fast and robust for routine disease assays with various Pseudomonas strains without transforming plants or bacteria. The agromonas assay offers reliable opportunity for further comprehensive analysis of plant immunity. One sentence summaryAgromonas is a rapid and robust disease assay to monitor Pseudomonas syringae growth in agroinfiltrated leaves expressing immune components and their suppressors.

plant biology↗

bioRxiv2019

Cleavage of a pathogen apoplastic protein by plant subtilases activates immunity

The plant apoplast is a harsh environment in which hydrolytic enzymes, especially proteases, accumulate during pathogen infection. However, the defense functions of most apoplastic proteases remains largely elusive. Here, we show that a newly identified small cysteine-rich secreted protein PC2 from the potato late blight pathogen Phytophthora infestans induces immunity in Solanum plant species only after cleavage by plant apoplastic subtilisin-like proteases, such as tomato P69B. A minimal 61-amino-acid core peptide carrying two key cysteines and widely conserved among most oomycete species is sufficient for PC2 activity. Kazal-like protease inhibitors, such as EPI1 produced by P. infestans can prevent PC2 cleavage and dampen PC2 elicited host immunity. This study reveals that cleavage of pathogen proteins to release immunogenic peptides is an important function of apoplastic proteases but that pathogens interfere with these functions using protease inhibitor effectors.

plant biology↗

bioRxiv2018

Re-annotated Nicotiana benthamiana gene models for enhanced proteomics and reverse genetics

Nicotiana benthamiana is an important model organism and representative of the Solanaceae (Nightshade) family. N. benthamiana has a complex ancient allopolyploid genome with 19 chromosomes, and an estimated genome size of 3.1Gb. Several draft assemblies of the N. benthamiana genome have been generated, however, many of the gene-models in these draft assemblies appear incorrect. Here we present a nearly non-redundant database of 42,855 improved N. benthamiana gene-models. With an estimated 97.6% completeness, the new predicted proteome is more complete than the previous proteomes. We show that the database is more sensitive and accurate in proteomics applications, while maintaining a reasonable low gene number. As a proof-of-concept we use this proteome to compare the leaf extracellular (apoplastic) proteome to a total extract of leaves. Several gene families are more abundant in the apoplast. For one of these apoplastic protein families, the subtilases, we present a phylogenetic analysis illustrating the utility of this database. Besides proteome annotation, this database will aid the research community with improved target gene selection for genome editing and off-target prediction for gene silencing.

plant biology↗