Genetic basis of the historical iron-accumulating dgl and brz mutants in pea.

The Pisum sativum (pea) mutants degenerate leaves (dgl) and bronze (brz) accumulate large amounts of iron in leaves. First described several decades ago, the two mutants have provided important insights into iron homeostasis in plants but the underlying mutations have remained unknown. Using exome sequencing we identified an in-frame deletion associated with dgl in a BRUTUS homolog.

Effector target-guided engineering of an integrated domain expands the disease resistance profile of a rice NLR immune receptor.

A subset of plant intracellular NLR immune receptors detect effector proteins, secreted by phytopathogens to promote infection, through unconventional integrated domains which resemble the effector's host targets. Direct binding of effectors to these integrated domains activates plant defenses. The rice NLR receptor Pik-1 binds the effector AVR-Pik through an integrated heavy metal-associated (HMA) domain.

The Piks allele of the NLR immune receptor Pik breaks the recognition of AvrPik effectors of rice blast fungus.

Arms race co-evolution of plant-pathogen interactions evolved sophisticated recognition mechanisms between host immune receptors and pathogen effectors. Different allelic haplotypes of an immune receptor in the host mount distinct recognition against sequence or non-sequence related effectors in pathogens. We report the molecular characterization of the Piks allele of the rice immune receptor Pik against rice blast pathogen, which requires two head-to-head arrayed nucleotide-binding sites and leucine-rich repeat proteins.

Protein lipoylation in mitochondria requires Fe-S cluster assembly factors NFU4 and NFU5.

Plants have evolutionarily conserved NifU (NFU)-domain proteins that are targeted to plastids or mitochondria. "Plastid-type" NFU1, NFU2, and NFU3 in Arabidopsis (Arabidopsis thaliana) play a role in iron-sulfur (Fe-S) cluster assembly in this organelle, whereas the type-II NFU4 and NFU5 proteins have not been subjected to mutant studies in any plant species to determine their biological role. Here, we confirmed that NFU4 and NFU5 are targeted to the mitochondria.

The function of glutaredoxin GRXS15 is required for lipoyl-dependent dehydrogenases in mitochondria.

Iron-sulfur (Fe-S) clusters are ubiquitous cofactors in all life and are used in a wide array of diverse biological processes, including electron transfer chains and several metabolic pathways. Biosynthesis machineries for Fe-S clusters exist in plastids, the cytosol, and mitochondria. A single monothiol glutaredoxin (GRX) is involved in Fe-S cluster assembly in mitochondria of yeast and mammals.

Assessment of Pathogen Effector Binding to Host Proteins by Surface Plasmon Resonance.

The mechanisms of virulence and immunity are often governed by molecular interactions between pathogens and host proteins. The study of these interactions has major implications on understanding virulence activities, and how the host immune system recognizes the presence of pathogens to initiate an immune response. Frequently, the association between pathogen molecules and host proteins are assessed using qualitative techniques.

The allelic rice immune receptor Pikh confers extended resistance to strains of the blast fungus through a single polymorphism in the effector binding interface.

Arms race co-evolution drives rapid adaptive changes in pathogens and in the immune systems of their hosts. Plant intracellular NLR immune receptors detect effectors delivered by pathogens to promote susceptibility, activating an immune response that halts colonization. As a consequence, pathogen effectors evolve to escape immune recognition and are highly variable.

Multiple variants of the fungal effector AVR-Pik bind the HMA domain of the rice protein OsHIPP19, providing a foundation to engineer plant defense.

Microbial plant pathogens secrete effector proteins, which manipulate the host to promote infection. Effectors can be recognized by plant intracellular nucleotide-binding leucine-rich repeat (NLR) receptors, initiating an immune response. The AVR-Pik effector from the rice blast fungus Magnaporthe oryzae is recognized by a pair of rice NLR receptors, Pik-1 and Pik-2.

The Medicago truncatula Vacuolar iron Transporter-Like proteins VTL4 and VTL8 deliver iron to symbiotic bacteria at different stages of the infection process.

The symbiotic relationship between legumes and rhizobium bacteria in root nodules has a high demand for iron, and questions remain regarding which transporters are involved. Here, we characterize two nodule-specific Vacuolar iron Transporter-Like (VTL) proteins in Medicago truncatula. Localization of fluorescent fusion proteins and mutant studies were carried out to correlate with existing RNA-seq data showing differential expression of VTL4 and VTL8 during early and late infection, respectively.

Protein engineering expands the effector recognition profile of a rice NLR immune receptor.

Plant nucleotide binding, leucine-rich repeat (NLR) receptors detect pathogen effectors and initiate an immune response. Since their discovery, NLRs have been the focus of protein engineering to improve disease resistance. However, this approach has proven challenging, in part due to their narrow response specificity.

Arabidopsis BRUTUS-LIKE E3 ligases negatively regulate iron uptake by targeting transcription factor FIT for recycling.

Organisms need to balance sufficient uptake of iron (Fe) with possible toxicity. In plant roots, a regulon of uptake genes is transcriptionally activated under Fe deficiency, but it is unknown how this response is inactivated when Fe becomes available. Here we describe the function of 2 partially redundant E3 ubiquitin ligases, BRUTUS-LIKE1 (BTSL1) and BTSL2, in and provide evidence that they target the transcription factor FIT, a key regulator of Fe uptake, for degradation.

Cross-reactivity of a rice NLR immune receptor to distinct effectors from the rice blast pathogen provides partial disease resistance.

Unconventional integrated domains in plant intracellular immune receptors of the nucleotide-binding leucine-rich repeat (NLRs) type can directly bind translocated effector proteins from pathogens and thereby initiate an immune response. The rice () immune receptor pairs Pik-1/Pik-2 and RGA5/RGA4 both use integrated heavy metal-associated (HMA) domains to bind the effectors AVR-Pik and AVR-Pia, respectively, from the rice blast fungal pathogen These effectors both belong to the MAX effector family and share a core structural fold, despite being divergent in sequence. How integrated domains in NLRs maintain specificity of effector recognition, even of structurally similar effectors, has implications for understanding plant immune receptor evolution and function.

Gene Duplication and Mutation in the Emergence of a Novel Aggressive Allele of the Effector in the Rice Blast Fungus.

Higher yield potential and greater yield stability are common targets for crop breeding programs, including those in rice. Despite these efforts, biotic and abiotic stresses continue to impact rice production. Rice blast disease, caused by , is the most devastating disease affecting rice worldwide.

Publisher Correction: Polymorphic residues in rice NLRs expand binding and response to effectors of the blast pathogen.

In the version of this Article originally published, in Fig. 1b the single-letter code for the amino acid polymorphism at position 46 in the schematic of the AVR-PikE variant was incorrectly given as 'H'. The correct amino acid is 'N'.

Polymorphic residues in rice NLRs expand binding and response to effectors of the blast pathogen.

Accelerated adaptive evolution is a hallmark of plant-pathogen interactions. Plant intracellular immune receptors (NLRs) often occur as allelic series with differential pathogen specificities. The determinants of this specificity remain largely unknown.

Lessons in Effector and NLR Biology of Plant-Microbe Systems.

A diversity of plant-associated organisms secrete effectors-proteins and metabolites that modulate plant physiology to favor host infection and colonization. However, effectors can also activate plant immune receptors, notably nucleotide-binding domain and leucine-rich repeat region (NLR)-containing proteins, enabling plants to fight off invading organisms. This interplay between effectors, their host targets, and the matching immune receptors is shaped by intricate molecular mechanisms and exceptionally dynamic coevolution.

Effectors of Filamentous Plant Pathogens: Commonalities amid Diversity.

Fungi and oomycetes are filamentous microorganisms that include a diversity of highly developed pathogens of plants. These are sophisticated modulators of plant processes that secrete an arsenal of effector proteins to target multiple host cell compartments and enable parasitic infection. Genome sequencing revealed complex catalogues of effectors of filamentous pathogens, with some species harboring hundreds of effector genes.

Single amino acid mutations in the potato immune receptor R3a expand response to Phytophthora effectors.

Both plants and animals rely on nucleotide-binding domain and leucine-rich repeat-containing (NB-LRR or NLR) proteins to respond to invading pathogens and activate immune responses. How plant NB-LRR proteins respond to pathogens is poorly understood. We undertook a gain-of-function random mutagenesis screen of the potato NB-LRR immune receptor R3a to study how this protein responds to the effector protein AVR3a from the oomycete pathogen Phytophthora infestans.

Effects of chitosan on the protein profile of grape cell culture subcellular fractions.

Grapevine is a large source of healthy polyphenols for human diet, and red table-grapes and wines are the main source of stilbenes. These compounds are important both in the plant defence system and for human health. In the present study, Vitis vinifera cv.

Fungal virulence and development is regulated by alternative pre-mRNA 3'end processing in Magnaporthe oryzae.

RNA-binding proteins play a central role in post-transcriptional mechanisms that control gene expression. Identification of novel RNA-binding proteins in fungi is essential to unravel post-transcriptional networks and cellular processes that confer identity to the fungal kingdom. Here, we carried out the functional characterisation of the filamentous fungus-specific RNA-binding protein RBP35 required for full virulence and development in the rice blast fungus.

Common genetic pathways regulate organ-specific infection-related development in the rice blast fungus.

Magnaporthe oryzae is the most important fungal pathogen of rice (Oryza sativa). Under laboratory conditions, it is able to colonize both aerial and underground plant organs using different mechanisms. Here, we characterize an infection-related development in M.

Polyamine biosynthetic diversity in plants and algae.

Polyamine biosynthesis in plants differs from other eukaryotes because of the contribution of genes from the cyanobacterial ancestor of the chloroplast. Plants possess an additional biosynthetic route for putrescine formation from arginine, consisting of the enzymes arginine decarboxylase, agmatine iminohydrolase and N-carbamoylputrescine amidohydrolase, derived from the cyanobacterial ancestor. They also synthesize an unusual tetraamine, thermospermine, that has important developmental roles and which is evolutionarily more ancient than spermine in plants and algae.

Helianthus tuberosus and polyamine research: past and recent applications of a classical growth model.

The earliest studies concerning polyamines (PAs) in plants were performed by using in vitro cultured explants of Helianthus tuberosus dormant tuber. This parenchyma tissue was particularly useful due to its susceptibility to several growth substances, including PAs. During tuber dormancy, PA levels are too low to sustain cell division; thus Helianthus represents a natural PA-deficient model.

Gene deletion of 7,8-linoleate diol synthase of the rice blast fungus: studies on pathogenicity, stereochemistry, and oxygenation mechanisms.

Linoleate diol synthases (LDS) are heme enzymes, which oxygenate 18:2n-6 sequentially to (8R)-hydroperoxylinoleic acid ((8R)-HPODE) and to (5S,8R)-dihydroxy-, (7S,8S)-dihydroxy-, or (8R,11S)-dihydroxylinoleic acids (DiHODE). The genome of the rice blast fungus, Magnaporthe oryzae, contains two genes with homology to LDS. M.

Chitosan treatment induces changes of protein expression profile and stilbene distribution in Vitis vinifera cell suspensions.

Polyphenols, including stilbenes and flavonoids, are an essential part of human diet and constitute one of the most abundant and ubiquitous groups of plant secondary metabolites, and their level is inducible by stress, fungal attack or biotic and abiotic elicitors. Proteomic analysis of Vitis vinifera (L.) cultivar (cv.