Tag: Plant Defense

Although clusters of functionally related genes are common in prokaryotes, until recently it was thought that they were not a feature of eukaryotic genomes. However, several studies have identified biosynthetic gene clusters (BGCs) in plants. Many of these gene clusters include sets of enzymes that act…

Don’t miss this exciting Virtual Issue from New Phytologist on “plant-microbe-microbe” interactions. That’s not a typo – many of the articles address the signals that coordinate such multi-factorial interactions, as there is a growing recognition that interrelations between microbes influence…

Have you ever wondered how cells distinguish between the diverse array of external signals traveling through similar pathways? To understand the intricacies of plant signaling mechanisms, Ma et al. used single endodermal cells of Arabidopsis roots as a model to compare two receptor pathways. One pathway…

The obligate biotrophic pathogen Blumeria graminis f. sp. tritici (Bgt) is the cause of wheat powdery mildew, a foliar disease that results in significant yield loss in most wheat-growing regions across the globe. This research focuses on the identification and functional analysis of the powdery mildew…

Enhancing plant defense against pathogens and pests often incurs a cost to essential physiological functions such as growth and reproduction, creating a trade-off. This phenomenon is evident in genetic studies across various plant models and agricultural breeding programs. Salicylic acid (SA) is a well-known…

Plants, particularly long-lived trees, need to balance nutrient acquisition, herbivore and pathogen defence, and ultimately organic matter decomposition. The intricate relationship between these processes is crucial for the survival and growth of trees over their extended lifespans. Zheng et al. investigated…

Cell surface receptor complexes act as the first line of defense in detecting pathogens and preventing invasion. Upon recognizing extracellular immunogenic patterns, a cascade of signaling relays occurs, mediated by phosphorylation events among a large array of membrane-associated proteins. These proteins…

Light influences essentially all aspects of plant growth and development. Furthermore, plants are likely to adjust their stress responses based on fluctuations in energy availability during the dark-light cycle. Lin et al investigated a hormone downstream component, ETHYLENE RESPONSE FACTOR 1 (ERF1),…

Host plants recognize diverse bacterial epitopes, known as microbe-associated molecular patterns (MAMPs), and respond with an immune reaction to control bacterial growth. However, most studies have focused on single bacterial epitopes, limiting our understanding of plant-bacteria interaction outcomes…

Plants rely on an array of mineral nutrients for their growth, development, and reproductive processes. The molecular mechanisms governing the uptake, translocation, storage, and utilization of these essential minerals are orchestrated by specific nutrient transporters and their associated regulatory…

Thiolation of tRNA adds a sulfur-containing nucleotide modification at the tRNA wobble position, which is necessary for efficient translation. Zheng et al. investigated the role of tRNA thiolation in plant immunity, revealing its necessity for robust defense responses in Arabidopsis. They identified…

The defensive alkaloid gramine, present in barley and other grass species, plays an important role in protecting the plant from insect damage but poses challenges for ruminant palatability. Breeding strategies balance these factors by maintaining the protective function and making the grain palatable…

The identification and characterization of resistosome complexes, formed by the oligomerization of intracellular nucleotide-binding leucine-rich repeat receptors (NLRs), has recently been a major focus in the field of plant immunity. Some NLR genes occur as head-to-head pairs encoding proteins that function…

In the interesting world of plant defenses, plants have secret weapons called defense metabolites that stay quiet until a pathogen comes knocking. Plants have evolved two-component chemical defence systems to protect against pathogens while striking a balance between growth promotion and defence mechanisms.…

Salicylic acid (SA) is a pivotal natural compound in plant science and finds applications in herbal medicine; specifically, aspirin, the renowned anti-inflammatory drug and pain reliever, is a derivative of SA. As summarized in this review by Spoel and Dong, within plants SA serves as a crucial phytohormone…

Plants are colonized by numerous beneficial microorganisms in the rhizosphere, including Pseudomonas fluorescens, that provide benefits including nutrient acquisition and pathogen protection. Host plants must tune their immune systems to restrict microbial overgrowth, while avoiding overstimulation of…

This interesting and well-written review by Derbyshire and Raffaele takes a step back from the molecular interactions between plant and pathogen and discusses them in light of co-evolutionary processes. The review starts with a useful introduction and definition of concepts about “robustness” in…

The German physician Paul Ehrlich (not to be confused with the American scientist of the same name) coined the term “magic bullet” (zauberkugel) to describe something that is perfectly and accurately effective. As much as we dream of magic bullets, they are rarely found, but the idea of using spray-on…

It’s well established that damaged plant tissues emit volatile compounds that bolster defense responses in nearby plants, but how those neighbors sense these compounds has remained obscure. This new work by Wang et al. reveals some important clues. First, as the title indicates, immature leaves are…

Marchantia polymorpha, the common (but adorable) liverwort, has earned its spot in the ranks of very important plant model systems, joining Physcomitrium patens as representatives of the bryophyte clade. Many systems first characterized in Arabidopsis and other angiosperms are now being studied in these…

It’s a well-established fact that some proteins are highly variable across species, and others such as histones hardly vary at all. Highly conserved proteins such as histones have very little wiggle room in their structure; small changes can lead to a loss of function. However, for some other proteins…

Developing broad-spectrum disease resistant crops without compromising the yield has been a persistent challenge in maintaining global food security. In a breakthrough study, Sha et al. developed a promising multi-pathogen resistant rice mutant that retains the crop’s yield, using forward genetic screen…

The vertebrate adaptive immune system is truly an evolutionary marvel. With its ability to mix-and-match segments of immunoglobulin genes, a nearly unlimited diversity of antigens can be recognized. Plants lack this ability, greatly limiting the number of antigens (and pathogens) any individual can recognize.…

Bitter gourds (or bitter melon) have been a childhood nightmare of mine. I remember that as a child, my grandparents used to force me to consume these really bitter gourds (Momordica charantia) telling me that they had ‘many benefits’. In addition to being a rich source of antioxidants, M. charantia…

Increasing plant resistance to specific pathogens through genome editing is a very active branch of crop engineering. In a recent paper, Veley et al. propose to edit the epigenome to boost resistance to cassava bacterial blight by increasing the levels of DNA methylation at specific sites, while leaving…

Plant immunity is crucial for adaptation to pathogen attack and subsequent survival. Two systems support plant immunity. Cell-surface pattern-recognition receptors (PRRs) recognize pathogen-associated molecular patterns (PAMPs) and prompt pattern-triggered immunity. Intracellular nucleotide-binding leucine-rich…

Herbivore attack can trigger release of volatile organic compounds (VOCs) in numerous plant species. These airborne compounds from an infected plant act as messengers in plant-plant interactions causing adaptation to the stress in adjacent plants. Globally, rice is a staple food for millions of people,…

In plants, microbial invasion is sensed by membrane-bound and cytoplasmic receptors. Our knowledge on the immune signaling that follows microbial recognition is mostly derived from studies on Arabidopsis thaliana. In this plant, receptor activation triggers immune responses that are distinct for each…

Many different pathogens attack plants, and many genes have been identified that confer pathogen-specific resistance.  In a recent study, Hao et al. identified a signaling cascade that regulates broad-spectrum disease resistance. This pathway is composed of a rice ubiquitin ligase OsPUB73, a VQ motif-containing…

Programmed cell death (PCD) plays roles in both developmental and environmental responses across plant species. During pathogen attack, the hypersensitive response can limit spread of infection by orchestrating an organised death of cells around the infection area. A recent study by Lukan et al. demonstrated…

Programmed cell death (PCD) is a ubiquitous eukaryotic process in which specific cells are eliminated during development or in response to stress. Here, Fuqiang Cui and colleagues confirm for the first time the exact role of the BOS1 gene in the regulation of PCD in Arabidopsis thaliana. Originally identified…

Plants demonstrate increased susceptibility to pathogens upon exposure to heat stress, apparently due to suppressed salicylic acid (SA) accumulation and subsequently decreased effector-triggered immunity. How exactly does heat stress cause this suppression, and how can we take advantage of genetics to…

Tolerance against a pathogen can be achieved by either overexpressing a resistance-related gene, or removing a susceptibility-related gene. Overexpression of defense-related genes generally comes with side effects such as decreased growth and yield. On the other hand, a susceptibility factor might have…

Many plants trigger a form of cell death, known as the hypersensitive response (HR), immediately upon pathogen recognition. To minimize damage to the plant, this cell death must be highly localized to the site of attack, while more distal cells survive and activate other immune responses. However, the…

Polyamines are endogenous cationic amines that have been shown to regulate a plethora of biological processes in plants, including the hypersensitive response. However, the importance of polyamines in other aspects of plant immunity has not yet been fully explored. In this new preprint, Zhang and colleagues…

The studies on the apoplastic interactions of plants and fungi often focus on the fungal cell-wall, but recent studies indicate various plant colonizing fungi also have an exopolysaccharide (EPS) layer outside their cell wall. Chandrasekar et al. observed that the composition of this fungal EPS is distinct…

Plant pathogenic bacteria of the genus Clavibacter tend to have a narrow host range, but different species affect many important crops. Clavibacter michiganensis (Cm) causes bacterial wilt and canker in tomato, pepper and a few varieties of eggplant. There are no Cm-resistant tomato varieties but many…

Rain contributes to plant disease.  Rain can contain high concentrations of pathogens (like Pseudomonas, Xanthomonas, Alternaria, Fusarium sp., etc.), and high humidity associated with rain antagonizes stomatal closure, leaving open entry points for some pathogens. Matsumura and colleagues have demonstrated…

Phytophthora are a group of oomycete pathogens that infect a wide range of plants and cause disease in many important crop species. Large scale mutant screens have previously been used to identify Arabidopsis thaliana mutants with enhanced resistance to P. parasitica. Here, Yang and colleagues investigate…

Much of our understanding of plant immunity comes from studies of pathogens that infect mesophyll tissues, (e.g., Pseudomonas syringae). However, there are many pathogens that specifically invade vascular tissues (e.g., Xanthomonas oryzae pv. oryzae; Xoo), which causes rice bacterial blight. In a recent…

I remember when I joined my PhD lab, the first article I was recommanded was a review by Jones and Dangl (2006) titled “The plant immune system”. Even today it remains the first article given to newbies in the lab. But the field has progressed way ahead in the more than fifteen years since that article…

If you work with grasses, you are probably familiar with the scutellum –the shield-like cotyledon typical of seeds from these plants. This structure has a renowned role in transferring nutrients to the growing embryo. However, Murphy and colleagues show us that not only does this structure look like…

In plants, immune signalling and the corresponding defence responses are initiated by direct or indirect recognition of pathogen molecules via immune receptors. In the plasma membrane, pattern-recognition-receptors (PRRs) recognize signs of invasion and pattern-triggered immunity (PTI) is initiated.…

In Arabidopsis, NONEXPRESSOR OF PR GENES 1 (NPR1) plays an important role in the antagonistic crosstalk of salicylic acid (SA) and jasmonic acid (JA) signalling. It activates SA-induced genes that protect against biotrophic pathogens and suppresses JA-induced genes that protect against necrotrophic pathogens.…

‘Fine tuning’ is a very significant process that takes place in the cell to correctly modulate plant responses. BOTRYTIS-INDUCED KINASE 1 (BIK1) is an important hub protein that is at the center of the signaling hub that controls defense responses. Hence, plants fine tune this important protein through…

Phytophthora sojae is an oomycete pathogen that causes huge yield losses in soybean. Genetic studies have identified several loci that confer resistance (Resistance-to-P. sojae loci, or Rps). Here, Wang et al. have cloned Rps11 and found that it encodes a very large NLR (nucleotide-binding site leucine-rich…

Small RNAs have big effects and can serve to shut down or silence gene expression. Recently, studies have found that small RNAs can contribute to plant defense beyond the boundary of the plant, by being packed into extracellular vesicles (EVs) and delivered to a pathogen. Cai et al. review our current…

Covid has turned our focus to human viral pathogens, but the challenges we face from cellular pathogens has not gone away, and is increasingly exacerbated by the development of resistance to antibiotics and other antimicrobials. This fine review by Tiwari et al. provides an overview of how antimicrobials…

It’s like the plot of every spy movie you’ve ever seen. If you could infiltrate your opponent’s headquarters what would you target to disable your enemy? This is the question addressed in new work by Petre et al. More than ten years ago, a family of small proteins was identified, the RXLR proteins…

Two very exciting papers have come out this week in Nature that address a long-standing question about the relative contributions of two different plant immunity pathways. PTI (pathogen-triggered immunity) recognizes conserved pathogen signatures at the plant cell surface; a model system for PTI is the…

ACCELERATED CELL DEATH 6 (ACD6) positively regulates the signaling of the plant defense hormone salicylic acid (SA). It was originally identified by the study of natural variation in defense responses of Arabidopsis thaliana. The naturally hyperactive ACD6-Est-I allele confers broad-spectrum disease…

Citrus Huanglongbing (HLB) caused by the bacterium Candidatus Liberibacter asiaticus (CLas) is the most destructive disease of citrus and currently has no cure. Current management practices are also not effective. Huang et al. used comparative analysis of small RNAs and mRNAs between HLB-sensitive and…

Plant cells sense endogenous and exogenous molecules through proteins localized to the cell surface. While numerous ligands that mediate a variety of developmental and stress processes are known, cognate receptors for many ligands remain unidentified. Rhodes and colleagues have now shown the Arabidopsis…

Aging of plants is marked by the growth and differentiation of individual organs, as well as transitions of the whole plant through developmental phases: juvenile, vegetative adult, and reproductive phase. In their recent review, Rankenberg et al. discuss how abiotic stress responses vary in plants with…

Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are often presented as something of enigmas. They are damaging by-products of metabolism and stress, but also intentionally produced as a signal and defense response to pathogens. This excellent Update by Bleau and Spoel synthesizes new…

Crop damage and yield losses caused by herbivores have become major threats to global food security. Upon wounding and herbivory, plants rapidly accumulate high levels of jasmonates (JA). However, the mechanism underlying how JA biosynthesis is triggered by herbivore attack remains unclear. It is therefore…

Plant roots are composed of concentric cell layers with distinct gene regulatory programs. Cell layer-specific responses are likely critical for plants to cope with microbes with various lifestyles, but little is known about root responses against microbes at cell-layer resolution. Fröschel et al. tackled…

Meristem culture is widely used as a technique for plant propagation because meristems are usually virus-free, even in systemically infected plants. It has long been assumed that viruses are unable to enter the cells of the meristem due to the meristem’s lack of vascular connections to the plant. Here,…

Brassicas produce specialized metabolites called glucosinolates that can be enzymatically converted to release toxic compounds. The catalyzing enzyme is stored in a separate subcellular compartment, so upon wounding by a herbivore the enzyme and substrate mix and release the toxin. Phloem-feeding insects…

Domesticated tomato has been subjected to human selection to satisfy marketing and economic desires, leading to a loss of genetic diversity and elimination of fruits traits such as flavor, aroma and pathogen resistance. Introgression lines (ILs) that capture the genome of wild desert-adapted tomato Solanum…

Epigenetic reprogramming, such as DNA methylation changes, has emerged as a crucial regulator of plant defense responses. Homeostasis of DNA methylation is controlled by a balance between methylation and demethylation. ROS1 (Repressor Of Silencing 1) is an Arabidopsis demethylases that is known to…

In nature, roots are colonized by commensal bacteria that do not seem to influence host traits. Recently, studies showed some commensals can suppress plant immune responses when inoculated to plants alone. However, how such commensal activities are coordinated in the community context is poorly understood.…

Chloroplasts are involved in various plant cell functions outside of photosynthesis including defense activation. How is the chloroplast able to do so? In this study, Medina-Puche et al. characterized the molecular function and cellular localization of the Tomato yellow leaf curl virus-derived C4 protein.…

In plants, the perception of environmental threats induces a peak of calcium ions (Ca2+) in the cytosol that triggers signal transduction pathways leading to stomatal closure as defense response. In Arabidopsis, the mechanosensitive Ca2+ channel OSCA1 regulates water transpiration in response to…

Plants have developed multiple mechanisms to deal with the natural enemies they encounter through their life. In consequence, the Plant Defense Theory has arisen to assess how plants allocate resources to this purpose. However, much of the efforts in this matter has revolved around the defense that occurs…

Ecosystems are founded by relationships between organisms, such as the mutualism between plants and microbes. An example is the agriculturally important symbiosis between legumes and nitrogen-fixing bacteria that reside in nodules of legumes. Legumes must be able to differentiate, through undetermined…

Plant roots should prevent immune activation by innocuous soil microbiota, as constitutive immune activation is harmful to plant growth. Previous studies have indicated variable immune competence of different root cell types and developmental zones, but this is currently poorly understood with the fine…

In plant immunity, signal transduction is tightly modulated through mechanisms including controlled stoichiometry of key regulators. Dressano et al. identified the novel IMMUNOREGULATORY RNA-BINDING PROTEIN (IRR) as a negative regulator of immunity in both maize and Arabidopsis through a screen of Plant…

The plant apoplast is a sea of immune-related proteins that facilitate robust defense against pathogens. Rcr3 is a tomato secreted apoplastic protease that contributes to both basal defense and gene-for-gene resistance against pathogens. Rcr3 is activated by the cleavage of its autoinhibitory prodomain,…

Chemical communications between species are prevalent in nature. For instance, herbivorous insects can spot their host plants by sensing volatile organic compounds (VOCs) emitted by plants. Despite our knowledge about interactions between individual plant and herbivore species, little is known about…

Plant hormones such as jasmonates (JAs) and salicylic acid (SA) are known for their role in regulating plant growth under both abiotic and biotic stresses. These hormones, which are synthesized within the plant, can modulate cellular processes in targeted cells locally and can be moved to other parts…

Research from the last three decades has discovered many genes and pathways involved in plant immunity and how they are connected. Here, Zhou and Zhang highlight new research regarding activation and signaling of cell surface pattern recognition receptors (PRRs) and intracellular nucleotide-binding,…

Nucleotide-binding leucine-rich repeat receptors (NLRs) are important components of the plant immune system. They are intracellular receptors that act downstream of the cell-surface receptors, and initiate the so-called effector-triggered immunity (ETI). In most plants, the NLR gene family is large and…

Plants can recognize eggs of herbivorous insects deposited on leaves and mount defense responses to avoid the future threat of herbivory. Similar to plant hypersensitive response against pathogens, plants can cause localized cell death to defend themselves against insect eggs. This response is called…

While infection by pathogens and the reciprocal immune responses are well studied in plants, the influence of other abiotic factors on these processes is not very clear. In an attempt to understand the role of light on plant defense, Gao and colleagues have shown that the AVRvnt1 effector protein secreted…

Mycotoxins are fungal toxins with harmful health effects on humans and other animals. Fusarium head blight is a fungal disease of wheat inflorescences that can contaminate the grain and harm its consumers. Previously, Fhb7 was identified in the wheat relative Thinopyrum elongatum as a quantitative trait…

Phytophthora are plant-destroying oomycetes. Within this genus are several infamous disease-causing agents: P. infestans of the potato late-blight fame, P. sojae of soybean root rot, P. ramorum of sudden oak death, and many other lesser-known species. This fine new review by Boevink et al. explores the…

Bacterial infections are a serious issue for crop plants and it is thus imperative to understand the mechanisms employed by plants to develop resistance against pathogens. Malukani et al. have identified a receptor kinase in rice, WALL-ASSOCIATED KINASE-LIKE 21 (OsWAKL21.2) that perceives pathogen-induced…

Rust fungi are a diverse group (more than 7800 species) of phytopathogenic fungi that cause considerable economic loss. (Coincidently, I’m writing on Robigalia, the Roman “anti-rust” festival, which dates from before we understood that microbes, not gods, cause disease). Figurero et al. have written…

The large apoplastic intercellular space of plant leaves creates nutrient-rich niches for microbial colonization. To date, whether and how plants control the composition of leaf microbiota is poorly understood. Chen et al. reported that the Arabidopsis quadruple mutant (min7fls2efrcerk1 or mfec)…

High yielding crops are often less resistant to pathogens and vice versa, suggesting that there is an underlying mechanism co-regulating development and disease resistance in plants. Yan et al. identified a transcription factor in cucumber (CsIVP) that regulates vascular development and resistance to…

Plants took hundreds of million years to evolve from aquatic to land environments. Biotic and abiotic stress adaptation contributed to the transition. In this preprint, Romani et al. elucidated functions of the transcription factor CLASS I HOMEODOMAIN LEUCINE-ZIPPER (C1HDZ) in the early land plant Marchantia…

To fight against pathogenic microbes，plants have evolved intracellular nucleotide-binding, leucine-rich repeat (NB-LRR) receptors, known as NLRs, to monitor pathogen effector proteins and trigger robust immune responses. ZAR1 is a canonical NLR, and a forms a multimeric resistosome complex in vitro…

Hybrid necrosis occurs when the progeny of a cross between two different plants show widespread cell death. It can be caused by autoactivation of nucleotide-binding and leucine rich repeat domain (NLR) proteins, intracellular immune receptors that play a central role in plant resistance to diverse pathogens.…

In plants, disease resistance genes typically act in a dominant way – the presence of a resistance allele, even a single copy, is enough to confer resistance. The barley gene Mildew Resistance Locus O (MLO1) is different, as it acts in a recessive way; loss-of-function mlo1 plants are resistant to…

Plants are surrounded by diverse microbes and must avoid mounting an immune response against innocuous microbes, while properly activating defense against invading pathogens. As the initial plant-microbe contacts happen in a limited number of cells, understanding spatially-resolved plant immune responses…

Heterotrimeric G proteins transduce signals between receptors and downstream factors. Previous genetic studies have shown diverse roles for these proteins based on loss-of-function phenotypes; for example mutations in Arabidopsis Gα and Gβ subunits both lead to enlarged shoot apical meristems. Wu et…

Yellow rust is a fungal disease of wheat. Three mutants with enhanced resistance were identified in wild emmer wheat from different locations were previously mapped to the same region of chromosome 1B. Given that each locus showed a different degree of resistance, it was presumed that they were non-allelic.…

FLS2 is a well-characterized cell-surface receptor that recognizes a short epitope found on most bacterial flagellin proteins. The plant pathogen Agrobacterium tumefaciens, causative agent of crown gall disease, deviates strongly at this epitope region, and so is generally not recognized by FLS2 receptors,…

Plasmodesmata are regulated channels that connect adjacent cells, allowing movement of metabolites, RNA, proteins, and pathogens. Plants close their plasmodesmata as part of their immune response, but this closure can be interfered with by pathogens. Aung et al. examined the repertoire of effector proteins…

The first line of defense is detection. Plants have numerous cell-surface receptor proteins (Pattern Recognition Receptors, PRRs) that recognize potentially harmful pathogens as well as endogenous molecules that suggest damage, known as Damage Associated Molecular Patterns or DAMPS and phytocytokines…

Plant-pathogen interactions are shaped by a dynamic signaling crosstalk that often leads to an arms-race between plants and pathogens. The initial pathogenic invasion starts in the apoplast, which serves as a major battlefield. This extracellular space is a harsh environment enriched with hydrolytic…

Much of our understanding of plant defense response is built upon the responses that occur in leaves. Many pathogens colonize the phloem system, which is both nutrient-rich and provides an easy conduit for spreading through systemically through the plant body. These phloem-inhabiting prokaryotic pathogens…

Dynamic ubiquitination determines transcriptional activity of the plant immune coactivator NPR1 Plants (and animals) need to strike a delicate balance when activating their immune responses: not too much and not too little. The transcriptional coactivator NPR1 [nonexpressor of pathogenesis-related…

How exactly does the plant defense system target pathogens? Nobori et al. have analyzed interactions inside the plant between the foliar bacterial pathogen Pseudomonas syringae and Arabidopsis thaliana at transcriptomic and proteomic levels by using RNAseq and liquid chromatography mass spectrometry…

When pathogens attack, one line of defense is the production of a burst of reactive oxygen species (ROS) which triggers additional defences. ROS is produced by the action of NADPH oxidases, which require NADPH as a substrate; NADPH is derived from NADP+, but where does this come from? Previous studies…

Plants possess two immune strategies to prevent invasion by pathogens called pattern-triggered immunity (PTI, typically mediated by cell-surface receptors) and effector-triggered immunity (ETI). During ETI, intracellular resistance (R) proteins perceive specific pathogen effectors. Tang et al. describe…

Identification of protein- protein interactions helps understand the signaling cascade in multiple biological process including development, biotic and abiotic stress. Previously, a proximity-based labelling approach referred to as BioID had been used to identify proteins in close proximity to a protein…

Arabidopsis genetics has identified numerous genes required for pathogen perception and defense response activation. Some of these genes are functionally conserved across plants and others are not. Toll-Interleukin1-Receptor (TIR)-domain NLRs (TNLs) are immune receptors that function upstream of EDS1…

Plants have robust NLR (nucleotide-binding, leucine-rich repeat proteins) immune signaling networks consisting of sensor NLRs and helper NLRs that counteract diverse plant pathogens by inducing cell death at sites of pathogen infection. A recent preprint by Adachi et al. has defined an N terminal motif…

Calcium ions mediate calcium-based defense responses in pattern triggered immunity (PTI) upon detection of pathogen patterns by plant surface receptors. A new study by Tian et al. has elucidated the molecular events that activate the calcium response. The authors show that adequeate calcium nutrient…

Marchantia polymorpha is an emerging model for plant molecular biology and has contributed to studies on development and plant-microbe interactions. Here, using RNA-seq and proteomics, Carella et al. present a detailed time-course analysis of Marchantia molecular responses to pathogen infection triggered…

Plants are sessile organisms that have evolved sophisticated immune systems in defense of pathogens, thus maximizing the chance of survival. Most of our understanding of plant defenses comes from studies in angiosperms. Evolutionary molecular plant-microbe interactions (EvoMPMI) can reveal the origins…

Microbial pathogens secrete virulence effector proteins into host cells to suppress basal plant defenses. Plant resistance (R) receptors induce robust immune signaling after directly or indirectly detect such effector-mediated host manipulation. In Arabidopsis, immunity transduced through many TNL (TIR-NBS-LRR)…

To fight off invading pathogens, plants such as Arabidopsis are intrinsically programmed with a subset of defense responses often known as pattern-triggered immunity (PTI) and effector-triggered immunity (ETI). AvrRpt2, an effector secreted by the pathogen Pseudomonas syringe, is a protease that can…

Phytoalexins are important antimicrobial compounds that plants synthesize to fend off invading pathogens. In the Brassica family, the tryptophan (trp)-derived phytoalexin ‘camalexin’ provides broad-spectrum resistance against bacterial, fungal, and oomycete pathogens. The regulation of camalexin…

Jing et al. reveal how danger-associated peptides inhibit root growth in plants in response to pathogen attack. Plant Cell (2018) https://doi.org/10.1105/tpc.18.00145.   Background: Plants defend themselves against pathogens and pests through an innate immune system that is activated by pathogen-associated…

Interactions between plants and microorganisms occur in many different ways and on many different levels. Scientists have been attracted to this field of research because of the need to identify the agents causing infectious diseases in economically important crops. Models have been developed to describe…

Meena et al. identify a Ca2+ channel involved in herbivory recognition. Plant Cell https://doi.org/10.1105/tpc.19.00057 By Mukesh Kumar Meena, Ramgopal Prajapati, Deepthi Krishna and Jyothilakshmi Vadassery are from National Institute of Plant Genome Research (NIPGR), New Delhi, India Background:…

Plants and associated microbes co-exist and co-evolve over time. The rate of evolution is higher in pathogens as compared to plants. Although the phenotypic consequences of rapid evolution in pathogens are well studied, changes at genomic level are not as well known, and are the subject of a recent review…

This is a great review by Judelson and Ah-Fong on the diverse signals that occur between plants and their oomycete pathogens. The authors start by describing the life- and infectivity-cycles of disease-causing oomycetes, including the familiar plant pathogens, "aggressive" Pythium and "stealthy" Phytophthora.…

Nobori and Tsuda review how the plant immune system is able to function in heterogeneous environments through its properties of resilience, tunability and balance. They define a resilient system as one where “output remains stable even when part of the system is disabled.” Abiotic factors such as…

The 2017 Chemistry Nobel Prize went to the developers of cryo-electron microscopy, and this method is transforming plant science as well as other life sciences. In a pair of back-to-back papers, Wang et al. used cryo-EM to examine how ZAR1, a CC-NLR protein [Coiled-coil (CC) nucleotide-binding (NB),…

Bacterial flagellin is a well-known microbial pattern that triggers plant immune responses. Flagellin is a glycosylated protein polymer. The immunogenic domain is buried within the protein structure as well as beneath a glycan layer. Buscaill et al. set out to identify how this immunogenic elicitor is…

Plants are sessile organisms that have evolved an extraordinary immune system to optimally adapt to the risky environment, which includes hazards such as insect chewing, weather damaging, and pathogen invasion. But the signaling mechanism of how the physical damage of cells triggers the intracellular…

The April 2019 issue of Plant Physiology includes a set of papers addressing biotic interactions between plant and pathogens or pests. As the editors indicate, progress on this topic has been rapid and significant. Key topics explored in reviews and research articles include: the roles of plant hormones,…

A strikingly vast array of phylogenetically distant plants are able to form intimate interactions with symbiotic arbuscular mycorrhizal (AM) fungi for the mutually beneficial exchange of nutrients. Several years of intensive research have revealed the complex regulatory networks and genetic ‘toolkits’…

The nematode infection process in plants involves secreted effector proteins that suppress the host defense mechanisms. However, the molecular interactions in which this is done is yet unclear. Here, Pogorelko et al. characterize the function of 4E02, an effector from the cyst nematode H. schachtii,…

To secure food availability for the world population, plant scientists study the interactions between crop species and pathogens. Plants have robust defense strategies that they employ when attacked. On the other hand, microbes have multiple strategies to manipulate host functions to suppress these defenses…

Plants have natural mechanisms against pathogen infections. Post-translational modifications (PTMs) on key proteins involved in RNAi pathways are needed to control these immune responses. Argonaute (AGO) proteins are targets of PTMs to direct the silencing of genes. Here, Hu et al. identified the role…

Herbivore-induced volatiles have been shown to prime plant defense response in multiple species. A new study by Ye et al. unveils some of the early signaling events in volatile-mediated defense priming in rice. The authors show that rice plants release increased amounts of the volatile indole when attacked…

To fight off invading pathogens, higher plants such as Arabidopsis are intrinsically programmed with a subset of defense responses known as pattern-triggered immunity (PTI). However, excessive defense responses may hamper plant’s normal growth, so fine-tuning PTI is important for plant survival. Recently,…

Chloroplasts have diverse roles in plant defense, including contributing to the production of defense compounds. Toufexi, Duggan et al. show new data indicating the dynamic relocation of chloroplasts to the contact point of the oomycete pathogen Phytophthora infestans. Infection also causes an increase…

Source: Institute of Genetics and Developmental Biology Published: 2019-01-11. Translated from the original. As an important plant hormone, jasmonic acid regulates plant defense responses and adaptive growth. When the plant is exposed to pests or other stresses, the active jasmonic…

To optimize their fitness in the field, plants need to respond rapidly, specifically and dynamically to an ever-changing and often hostile environment. By integrating external environmental cues with endogenous developmental programs, phytohormones play a critical role in the cross-talk between signal…

The plant trans-Golgi network (TGN) plays the role of early endosomes and acts as hub for the both secretory and vacuolar trafficking pathways. Two types of TGN, GA-TGN (Golgi-associated TGN) and GI-TGN (Golgi-released independent TGN), have been observed in plants. Here, Uemura et al. explore the cellular…

Rice is an important food crop in China, but the damage of rice blast fungus is an important factor affecting the high and stable yield of rice. Liu Jun's research group of the Institute of Microbiology, Chinese Academy of Sciences found in the previous study that when rice blast fungus infects rice,…

In plants, like people, having an overactive immune response is just as bad as having an underactive one. R genes in plants are key immune components that need to be kept quiet until needed. Previous studies have shown that miRNAs are involved in suppressing R gene expression, in a process that is amplified…