Functional screening of the Arabidopsis 2C protein phosphatases family identifies PP2C15 as a negative regulator of plant immunity by targeting BRI1-associated receptor kinase 1.

Genetic engineering using negative regulators of plant immunity has the potential to provide a huge impetus in agricultural biotechnology to achieve a higher degree of disease resistance without reducing yield. Type 2C protein phosphatases (PP2Cs) represent the largest group of protein phosphatases in plants, with a high potential for negative regulatory functions by blocking the transmission of defence signals through dephosphorylation. Here, we established a PP2C functional protoplast screen using pFRK1::luciferase as a reporter and found that 14 of 56 PP2Cs significantly inhibited the immune response induced by flg22.

Orosomucoid proteins limit endoplasmic reticulum stress in plants.

Sphingolipids are cell membrane components and signaling molecules that induce endoplasmic reticulum (ER) stress responses, but the underlying mechanism is unknown. Orosomucoid proteins (ORMs) negatively regulate serine palmitoyltransferase activity, thus helping maintain proper sphingolipid levels in humans, yeast, and plants. In this report, we explored the roles of ORMs in regulating ER stress in Arabidopsis thaliana.

Plasma membrane-nucleo-cytoplasmic coordination of a receptor-like cytoplasmic kinase promotes EDS1-dependent plant immunity.

Plants use cell-surface immune receptors to recognize pathogen-specific patterns to evoke basal immunity. ENHANCED DISEASE SUSCEPTIBILITY (EDS1) is known to be crucial for plant basal immunity, whereas its activation mechanism by pattern recognition remains enigmatic. Here, we show that the fungal pattern chitin induced the plasma membrane-anchored receptor-like cytoplasmic kinase PBS1-LIKE 19 (PBL19) to undergo nuclear translocation in Arabidopsis.

Arabidopsis lysin motif/F-box-containing protein InLYP1 fine-tunes glycine metabolism by degrading glycine decarboxylase GLDP2.

Lysin motif (LysM) is a carbohydrate-binding module often found in secreted or transmembrane proteins in living organisms from prokaryotes to eukaryotes. Thus far, all characterized LysM-containing proteins in plants are plasma membrane-resident receptors or co-receptors playing roles in plant-microbe interactions. Here, we interrogate the Arabidopsis LysM/F-box-containing protein InLYP1 and reveal its function in glycine metabolism.

Multiplex and optimization of dCas9-TV-mediated gene activation in plants.

Synthetic gene activators consisting of nuclease-dead Cas9 (dCas9) for single-guide RNA (sgRNA)-directed promoter binding and a transcriptional activation domain (TAD) represent new tools for gene activation from endogenous genomic locus in basic and applied plant research. However, multiplex gene coactivation by dCas9-TADs has not been demonstrated in whole plants. There is also room to optimize the performance of these tools.

The bacterial quorum sensing signal DSF hijacks sterol biosynthesis to suppress plant innate immunity.

Quorum sensing (QS) is a recognized phenomenon that is crucial for regulating population-related behaviors in bacteria. However, the direct specific effect of QS molecules on host biology is largely understudied. In this work, we show that the QS molecule DSF (-11-methyl-dodecenoic acid) produced by pv.

Hide-and-Seek: Chitin-Triggered Plant Immunity and Fungal Counterstrategies.

Fungal pathogens are major destructive microorganisms for land plants and pose growing challenges to global crop production. Chitin is a vital building block for fungal cell walls and also a broadly effective elicitor of plant immunity. Here we review the rapid progress in understanding chitin perception and signaling in plants and highlight similarities and differences of these processes between arabidopsis and rice.

Cross-Microbial Protection via Priming a Conserved Immune Co-Receptor through Juxtamembrane Phosphorylation in Plants.

Living organisms can be primed for potentiated responses to recurring stresses based on prior experience. However, the molecular basis of immune priming remains elusive in plants that lack adaptive immunity. Here, we report that bacterial challenges can prepare plants for fungal attacks by inducing juxtamembrane phosphorylation of CERK1, the co-receptor indispensable for signaling in response to the fungal elicitor chitin.

Split Nano luciferase complementation for probing protein-protein interactions in plant cells.

Deciphering protein-protein interactions (PPIs) is fundamental for understanding signal transduction pathways in plants. The split firefly luciferase (Fluc) complementation (SLC) assay has been widely used for analyzing PPIs. However, concern has risen about the bulky halves of Fluc interfering with the functions of their fusion partners.

BAK1-mediated phosphorylation of canonical G protein alpha during flagellin signaling in Arabidopsis.

Heterotrimeric G proteins consisting of Gα, Gβ and Gγ are conserved signaling hubs in eukaryotes. Without analogs to canonical animal G protein-coupled receptors, plant cells are thought to use RGS1 and a yet unknown mechanism to regulate the activity of Gα. Meanwhile, the exact role of canonical Gα in plant innate immunity remains controversial.

Engineering Artificial MicroRNAs for Multiplex Gene Silencing and Simplified Transgenic Screen.

Artificial microRNA (amiRNA) technology offers reversible and flexible gene inactivation and complements genome-editing technologies. However, obtaining transgenic plants with maximal gene silencing remains a major technical challenge in current amiRNA applications. Here, we incorporated an empirically determined feature of effective amiRNAs to the amiRNA design and in silico generated a database containing 533,429 gene-specific amiRNAs for silencing 27,136 genes in Arabidopsis (), with a genome coverage of 98.

A Tyrosine Phosphorylation Cycle Regulates Fungal Activation of a Plant Receptor Ser/Thr Kinase.

Plants initiate immunity by cell-surface pattern-recognition receptors (PRRs), which perceive non-self molecules. PRRs are predominantly receptor serine/threonine (Ser/Thr) kinases that are evolutionarily related to animal interleukin-1 receptor-associated kinase (IRAK)/Pelle-soluble kinases. However, how the activity of these receptor kinases is modulated remains poorly understood.

Dynamic G protein alpha signaling in Arabidopsis innate immunity.

Heterotrimeric G proteins composed of Gα, Gβ and Gγ subunits are evolutionarily conserved signaling modules involved in diverse biological processes in plants and animals. The role and action of Gα remain largely enigmatic in plant innate immunity. We have recently demonstrated that Arabidopsis Gα (GPA1) is a key component of a new immune signaling pathway activated by bacteria-secreted proteases.