Plant U-box E3 ligases PUB20 and PUB21 negatively regulate pattern-triggered immunity in Arabidopsis.

Plant U-box E3 ligases PUB20 and PUB21 are flg22-triggered signaling components and negatively regulate immune responses. Plant U-box proteins (PUBs) constitute a class of E3 ligases that are associated with various stress responses. Among the class IV PUBs featuring C-terminal Armadillo (ARM) repeats, PUB20 and PUB21 are closely related homologs.

A modified Agrobacterium-mediated transformation for two oomycete pathogens.

Oomycetes are a group of filamentous microorganisms that include some of the biggest threats to food security and natural ecosystems. However, much of the molecular basis of the pathogenesis and the development in these organisms remains to be learned, largely due to shortage of efficient genetic manipulation methods. In this study, we developed modified transformation methods for two important oomycete species, Phytophthora infestans and Plasmopara viticola, that bring destructive damage in agricultural production.

The Arabidopsis pattern recognition receptor EFR enhances fire blight resistance in apple.

Fire blight disease, caused by the bacterium Erwinia amylovora (E. amylovora), is responsible for substantial losses in cultivated apples worldwide. An important mechanism of plant immunity is based on the recognition of conserved microbial molecules, named pathogen-associated or microbe-associated molecular patterns (PAMPs or MAMPs), through pattern recognition receptors (PRRs), leading to pattern-triggered immunity (PTI).

Efficient CRISPR/Cas-Mediated Targeted Mutagenesis in Spring and Winter Wheat Varieties.

CRISPR/Cas technology has recently become the molecular tool of choice for gene function studies in plants as well as crop improvement. Wheat is a globally important staple crop with a well annotated genome and there is plenty of scope for improving its agriculturally important traits using genome editing technologies, such as CRISPR/Cas. As part of this study we targeted three different genes in hexaploid wheat : in the spring cultivar Cadenza as well as and in winter cultivars Cezanne, Goncourt and Prevert.

Remarkable recent changes in the genetic diversity of the avirulence gene AvrStb6 in global populations of the wheat pathogen Zymoseptoria tritici.

Septoria tritici blotch (STB), caused by the fungus Zymoseptoria tritici, is one of the most economically important diseases of wheat. Recently, both factors of a gene-for-gene interaction between Z. tritici and wheat, the wheat receptor-like kinase Stb6 and the Z.

Plastidial acyl carrier protein Δ9-desaturase modulates eicosapentaenoic acid biosynthesis and triacylglycerol accumulation in Phaeodactylum tricornutum.

The unicellular marine diatom Phaeodactylum tricornutum accumulates up to 35% eicosapentaenoic acid (EPA, 20:5n3) and has been used as a model organism to study long chain polyunsaturated fatty acids (LC-PUFA) biosynthesis due to an excellent annotated genome sequence and established transformation system. In P. tricornutum, the majority of EPA accumulates in polar lipids, particularly in galactolipids such as mono- and di-galactosyldiacylglycerol.

A modular cloning toolkit for genome editing in plants.

Background: CRISPR/Cas has recently become a widely used genome editing tool in various organisms, including plants. Applying CRISPR/Cas often requires delivering multiple expression units into plant and hence there is a need for a quick and easy cloning procedure. The modular cloning (MoClo), based on the Golden Gate (GG) method, has enabled development of cloning systems with standardised genetic parts, e.

Sequence-specific nucleases as tools for enhancing disease resistance in crops.

Genome editing technologies, such as CRISPR/Cas, have recently become valuable tools for plant reverse genetics as well as crop improvement, including enhancement of disease resistance. Targeting susceptibility (S) genes by genome editing has proven to be a viable strategy for generating resistance to both bacterial and fungal pathogens in various crops. Examples include generating loss-of-function mutations in promoter elements of the SWEET S genes, which are targeted by transcription activator-like effectors secreted by many phytopathogenic Xanthomonas bacteria, as well as in the conserved MLO locus that confers susceptibility to powdery mildew fungal pathogens in many monocots and dicots.

CRISPR/Cas precision: do we need to worry about off-targeting in plants?

The CRISPR/Cas technology has recently become the tool of choice for targeted genome modification in plants and beyond. Although CRSIPR/Cas offers a rapid and facile way of introducing changes at genomic loci of interest, its application is associated with off-targeting, i.e.

Genome Editing in Diatoms Using CRISPR-Cas to Induce Precise Bi-allelic Deletions.

Genome editing in diatoms has recently been established for the model species and . The present protocol, although developed for , can be modified to edit any diatom genome as we utilize the flexible, modular Golden Gate cloning system. The main steps include how to design a construct using Golden Gate cloning for targeting two sites, allowing a precise deletion to be introduced into the target gene.

Rapid generation of a transgene-free powdery mildew resistant tomato by genome deletion.

Genome editing has emerged as a technology with a potential to revolutionize plant breeding. In this study, we report on generating, in less than ten months, Tomelo, a non-transgenic tomato variety resistant to the powdery mildew fungal pathogen using the CRISPR/Cas9 technology. We used whole-genome sequencing to show that Tomelo does not carry any foreign DNA sequences but only carries a deletion that is indistinguishable from naturally occurring mutations.

Editing of the urease gene by CRISPR-Cas in the diatom .

Background: CRISPR-Cas is a recent and powerful addition to the molecular toolbox which allows programmable genome editing. It has been used to modify genes in a wide variety of organisms, but only two alga to date. Here we present a methodology to edit the genome of , a model centric diatom with both ecological significance and high biotechnological potential, using CRISPR-Cas.

Boosting plant immunity with CRISPR/Cas.

CRISPR/Cas has recently been transferred to plants to make them resistant to geminiviruses, a damaging family of DNA viruses. We discuss the potential and the limitations of this method.See related Research: http://www.

Correction: Transgenic expression of the dicotyledonous pattern recognition receptor EFR in rice leads to ligand-dependent activation of defense responses.

[This corrects the article DOI: 10.1371/journal.ppat.

Transgenic expression of the dicotyledonous pattern recognition receptor EFR in rice leads to ligand-dependent activation of defense responses.

Plant plasma membrane localized pattern recognition receptors (PRRs) detect extracellular pathogen-associated molecules. PRRs such as Arabidopsis EFR and rice XA21 are taxonomically restricted and are absent from most plant genomes. Here we show that rice plants expressing EFR or the chimeric receptor EFR::XA21, containing the EFR ectodomain and the XA21 intracellular domain, sense both Escherichia coli- and Xanthomonas oryzae pv.

The phylogenetically-related pattern recognition receptors EFR and XA21 recruit similar immune signaling components in monocots and dicots.

During plant immunity, surface-localized pattern recognition receptors (PRRs) recognize pathogen-associated molecular patterns (PAMPs). The transfer of PRRs between plant species is a promising strategy for engineering broad-spectrum disease resistance. Thus, there is a great interest in understanding the mechanisms of PRR-mediated resistance across different plant species.

Editing plant genomes with CRISPR/Cas9.

CRISPR/Cas9 is a rapidly developing genome editing technology that has been successfully applied in many organisms, including model and crop plants. Cas9, an RNA-guided DNA endonuclease, can be targeted to specific genomic sequences by engineering a separately encoded guide RNA with which it forms a complex. As only a short RNA sequence must be synthesized to confer recognition of a new target, CRISPR/Cas9 is a relatively cheap and easy to implement technology that has proven to be extremely versatile.

Efficient gene editing in tomato in the first generation using the clustered regularly interspaced short palindromic repeats/CRISPR-associated9 system.

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Plant genome editing made easy: targeted mutagenesis in model and crop plants using the CRISPR/Cas system.

Targeted genome engineering (also known as genome editing) has emerged as an alternative to classical plant breeding and transgenic (GMO) methods to improve crop plants. Until recently, available tools for introducing site-specific double strand DNA breaks were restricted to zinc finger nucleases (ZFNs) and TAL effector nucleases (TALENs). However, these technologies have not been widely adopted by the plant research community due to complicated design and laborious assembly of specific DNA binding proteins for each target gene.

Control of the pattern-recognition receptor EFR by an ER protein complex in plant immunity.

In plant innate immunity, the surface-exposed leucine-rich repeat receptor kinases EFR and FLS2 mediate recognition of the bacterial pathogen-associated molecular patterns EF-Tu and flagellin, respectively. We identified the Arabidopsis stromal-derived factor-2 (SDF2) as being required for EFR function, and to a lesser extent FLS2 function. SDF2 resides in an endoplasmic reticulum (ER) protein complex with the Hsp40 ERdj3B and the Hsp70 BiP, which are components of the ER-quality control (ER-QC).

Specific ER quality control components required for biogenesis of the plant innate immune receptor EFR.

Plant innate immunity depends in part on recognition of pathogen-associated molecular patterns (PAMPs), such as bacterial flagellin, EF-Tu, and fungal chitin. Recognition is mediated by pattern-recognition receptors (PRRs) and results in PAMP-triggered immunity. EF-Tu and flagellin, and the derived peptides elf18 and flg22, are recognized in Arabidopsis by the leucine-rich repeat receptor kinases (LRR-RK), EFR and FLS2, respectively.

CITRX thioredoxin is a putative adaptor protein connecting Cf-9 and the ACIK1 protein kinase during the Cf-9/Avr9- induced defence response.

Tomato Cf-9, a receptor-like protein (RLP), confers resistance to races of the fungal pathogen Cladosporium fulvum that express the Avr9 avirulence gene. CITRX (Cf-9-interacting thioredoxin) was previously identified in a yeast two-hybrid screen as a protein interacting with the cytoplasmic domain of Cf-9 and shown to be a negative regulator of the cell death induced after Cf-9/Avr9 interaction. ACIK1 is a Ser/Thr protein kinase that is specifically required for the Cf-9 and Cf-4 dependent defence response in tomato.