Agromonas: a rapid disease assay forPseudomonas syringaegrowth in agroinfiltrated leaves

Abstract

SUMMARYThe 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.

AgroLux: bioluminescent Agrobacterium to improve molecular pharming and study plant immunity

“…Finally, AgroLux may be used to express defence‐related proteins in agroinfiltrated leaves and subsequently evaluate the plant’s level of resistance to other pathogens. Plant disease assays combining agroinfiltration and the inoculation of pathogens have proven efficient for studying plant immunity (Buscaill et al ., 2020). In summary, we think AgroLux will be a valuable tool for researchers who are interested in optimizing agroinfiltration and will inform our understanding of plant– Agrobacterium in planta interactions.…”

“…Recently, the transient overexpression of Nicotiana benthamiana BGAL1 glycosidase by agroinfiltration uncovered its role in releasing immunogenic flagellin peptides (Buscaill et al ., 2019). Furthermore, the infection of agroinfiltrated leaves with plant pathogens is a convenient strategy for the rapid study of components in plant immunity (Bos et al ., 2010; Buscaill et al ., 2020).…”

Loss of function of bHLH transcription factor Nrd1 in tomato induces an arabinogalactan protein-encoding gene and enhances resistance toPseudomonas syringaepv.tomato

“…To test the possible functions of the Nrd1-regulated genes in defense or susceptibility, we performed an agromonas assay (Buscaill et al, 2021). In this assay, agroinfiltration is used first to overexpress the gene of interest in N. benthamiana leaves followed 2 days later by syringeinoculation of the Pst strain DC3000ΔavrPtoΔavrPtoBΔhopQ1-1 or DC3000ΔhopQ1-1 at the same agroinfiltrated spots (Fig.…”

“…The agromonas assays were performed as described (Buscaill et al, 2021). Briefly, Agrobacterium strains 1D1249 carrying a binary vector (pGWB414) expressing the gene of interest was syringe-infiltrated into leaves of four-week-old N. benthamiana plants.…”

Citrus Vascular Proteomics Highlights the Role of Peroxidases and Serine Proteases during Huanglongbing Disease Progression

“…Plant proteases are involved in pathogen perception, defense priming, signaling, and programmed cell death (83). For example, proteases release immunogenic peptides from bacteria facilitating perception in host plants (101). To ensure tight control of protease activity, plants evolved protease inhibitors that fine-tune protease activity.…”