Oomycete Plant Pathogens Research Articles

Biological activity and systemic translocation of the new tetrazolyloxime fungicide picarbutrazox against plant-pathogenic oomycetes.

Picarbutrazox is a new tetrazolyloxime fungicide discovered in 2014 by Nippon Soda. It is mostly used to protect against Phytophthora spp. and Pythium spp. However, little is known of its inhibition spectrum, protective and curative activity, and systemic translocation in plants. While picarbutrazox did not show obvious antifungal activity, it exhibited significant activity against oomycetes, including Phytophthora spp., Pythium spp. and Phytopythium spp.. The effective concentration for 50% growth inhibition (EC50) values of picarbutrazox against 16 oomycetes ranged from 3.1 × 10-4 and 7.27 × 10-3 μg mL-1. Furthermore, picarbutrazox could markedly inhibited the mycelial development, sporangia production, zoospore release, and cyst germination of Phytophthora capsici, with EC50 values of 1.34 × 10-3, 1.11 × 10-3, 4.85 × 10-3, and 5.88 × 10-2 μg mL-1, respectively. Additionally, under greenhouse conditions, the protective and curative activities of picarbutrazox at 200 mg L-1 (100%, 41.03%) against the P. capsici infection in peppers were higher than those of the reference fungicide dimethomorph at 200 mg L-1 (77.52%, 36.15%). High-performance liquid chromatography analysis confirmed that picarbutrazox showed excellent systemic translocation in pepper plants. The results showed that picarbutrazox markedly inhibited the important plant oomycete pathogens including Phytophthora spp., Pythium spp. and Phytopythium spp.. It also displayed excellent protective, curative and systemic translocation activity. Picarbutrazox thus has significant potential for preventing and controlling diseases caused by oomycetes. © 2024 Society of Chemical Industry.

Combinatorial Synthesis of Indole Derivatives as Anti-oomycetes Agents.

Developing high-efficiency and low-risk small-molecule green fungicide is the key to effective control of the plant pathogenic oomycetes. Indole is an important raw material for drug synthesis. Due to its unique structural skeleton, indole, and its derivatives have exhibited a wide range of biological activities. However, a study on the synthesis of novel indole derivatives as fungicidal agents against Phytophthora capsici has not yet been reported. The important intermediates 2a-c and 3a-c were synthesized in high yields by Vilsmeier- Haack and Knoevenagel reactions with indole as the lead compound. Furthermore, different substituted benzenesulfonyl groups were introduced into the NH position of the indole ring, and twelve indole derivatives (I-a-l) were prepared. Their structures were well characterized by 1H NMR, HRMS, and melting point. The results showed that 2-[(N-(4-nitrobenzenesulfonyl)-indole-3)-methylene]-diethyl malonate (I-d) and 2-[(N-(4-nitrobenzenesulfonyl)-5-cyanoindole-3)-methylene]-diethyl malonate (I-l) showed more anti-oomycete activity against P. capsici than the commercialized fungicide zoxamide, with corresponding EC50 values of 26.53, 23.48 and 28.16 mg/L, respectively, and the protective effect of the compounds against P. capsici in vivo further confirmed the above results. The preliminary structure-activity relationship showed that the formyl group modification at the C-3 position of the indole ring was acceptable, and the different anti-oomycete activities of R1 and R2 were significantly different, with R1 being 5-CN > H > 6-Me, and R2 being 4-NO2 > 3-NO2, H > 4-Me.

Pangenome graph analysis reveals extensive effector copy-number variation in spinach downy mildew.

Plant pathogens adapt at speeds that challenge contemporary disease management strategies like the deployment of disease resistance genes. The strong evolutionary pressure to adapt, shapes pathogens' genomes, and comparative genomics has been instrumental in characterizing this process. With the aim to capture genomic variation at high resolution and study the processes contributing to adaptation, we here leverage an innovative, multi-genome method to construct and annotate the first pangenome graph of an oomycete plant pathogen. We expand on this approach by analysing the graph and creating synteny based single-copy orthogroups for all genes. We generated telomere-to-telomere genome assemblies of six genetically diverse isolates of the oomycete pathogen Peronospora effusa, the economically most important disease in cultivated spinach worldwide. The pangenome graph demonstrates that P. effusa genomes are highly conserved, both in chromosomal structure and gene content, and revealed the continued activity of transposable elements which are directly responsible for 80% of the observed variation between the isolates. While most genes are generally conserved, virulence related genes are highly variable between the isolates. Most of the variation is found in large gene clusters resulting from extensive copy-number expansion. Pangenome graph-based discovery can thus be effectively used to capture genomic variation at exceptional resolution, thereby providing a framework to study the biology and evolution of plant pathogens.

Detection of oomycete pathogens in UK peat-free growing media and implications for plant health

ABSTRACT Peat-based growing media products are being phased out in the UK. Alternative constituents may be at risk of harbouring oomycete plant pathogens. Thirty-five peat-free growing media samples were tested for oomycete pathogens by baiting and DNA metabarcoding. No Phytophthora species was detected by baiting, but seven species of Pythium, Phytopythium and Elongisporangium, including four species not previously reported in the UK, were baited. DNA matching eleven Phytophthora species was detected by metabarcoding across a range of samples. A coir sample was also found to contain DNA of Peronosclerospora, a genus of tropical downy mildew pathogens. DNA matching six Phytophthora pathogens, including P. bishii, a pathogen of strawberry not previously reported in the UK, was detected in recycled coir that had been used for strawberry production in The Netherlands. We discuss the implications of the species detected in terms of risks to plant health and the need for further evidence-gathering.

A pathogen effector co-opts a host RabGAP protein to remodel pathogen interface and subvert defense-related secretion.

Pathogens have evolved sophisticated mechanisms to manipulate host cell membrane dynamics, a crucial adaptation to survive in hostile environments shaped by innate immune responses. Plant-derived membrane interfaces, engulfing invasive hyphal projections of fungal and oomycete pathogens, are prominent junctures dictating infection outcomes. Understanding how pathogens transform these host-pathogen interfaces to their advantage remains a key biological question. Here, we identified a conserved effector, secreted by plant pathogenic oomycetes, that co-opts a host Rab GTPase-activating protein (RabGAP), TOPGAP, to remodel the host-pathogen interface. The effector, PiE354, hijacks TOPGAP as a susceptibility factor to usurp its GAP activity on Rab8a, a key Rab GTPase crucial for defense-related secretion. By hijacking TOPGAP, PiE354 purges Rab8a from the plasma membrane, diverting Rab8a-mediated immune trafficking away from the pathogen interface. This mechanism signifies an uncanny evolutionary adaptation of a pathogen effector in co-opting a host regulatory component to subvert defense-related secretion, thereby providing unprecedented mechanistic insights into the reprogramming of host membrane dynamics by pathogens.

Phytophthora zoospores display klinokinetic behaviour in response to a chemoattractant.

Microswimmers are single-celled bodies powered by flagella. Typical examples are zoospores, dispersal agents of oomycete plant pathogens that are used to track down hosts and infect. Being motile, zoospores presumably identify infection sites using chemical cues such as sugars, alcohols and amino acids. With high-speed cameras we traced swimming trajectories of Phytophthora zoospores over time and quantified key trajectory parameters to investigate chemotactic responses. Zoospores adapt their native run-and-tumble swimming patterns in response to the amino acid glutamic acid by increasing the rate at which they turn. Simulations predict that tuneable tumble frequencies are sufficient to explain zoospore aggregation, implying positive klinokinesis. Zoospores thus exploit a retention strategy to remain at the plant surface once arriving there. Interference of G-protein mediated signalling affects swimming behaviour. Zoospores of a Phytophthora infestans G⍺-deficient mutant show higher tumbling frequencies but still respond and adapt to glutamic acid, suggesting chemoreception to be intact.

Newly synthesized benzimidazole–2–carbamate molecules show suppressive activities against plant pathogenic fungi and oomycetes

Newly synthesized benzimidazole–2–carbamate molecules show suppressive activities against plant pathogenic fungi and oomycetes

Isolation, identification and multi-locus sequence typing of Phytophthora capsici from capsicum fields and its cross-infectivity in different crop species

Phytophthora capsici is a major soil-borne oomycete plant pathogen, which severely affects the productivity of peppers including Capsicum annuum L., by causing fruit rot, root rot, and foliar blight diseases. It has a broad host range beyond Capsicum species and evolves rapidly to find new potential hosts for survival under different climatic conditions. In the present study, P. capsici was isolated from soil using castor seed baiting, and characterized through growth patterns and spore morphology. The species identification and molecular characterization were achieved through multi-locus sequence and phylogenetic analysis of three genomic loci (ITS, tef1 and cox), and also attributed given P. capsici isolate Pc_UHF into India-specific ITS-based evolutionary lineage Pc-X. Interestingly, dN/dS estimates revealed reasonably high positive selection in the tef1 gene, which could have possible implications on the pathogen's adaptation and/or virulence. Pathogenicity of this isolate was tested in three commercially growing bell pepper varieties and also in other crop species using detached leaf and/or in planta disease screening. Differential disease symptoms were induced by Pc_UHF in three bell pepper varieties, such as both collar rot and foliar blight symptoms observed in "Yolo Wonder" and "California Wonder", whereas only foliar blight symptoms were recorded in "Solan Bharpur". Furthermore, cross-pathogenicity was also recorded in tomato, citrus, cucumber and eggplant. This is the first report of molecular characterization and cross-pathogenically assessment of P. capsici isolate from farm soils in the North Western Himalayan region of India, which has a dynamic virulence profile and distinct host range.

Roadmap to Success: How Oomycete Plant Pathogens Invade Tissues and Deliver Effectors.

Filamentous plant pathogens threaten global food security and ecosystem resilience. In recent decades, significant strides have been made in deciphering the molecular basis of plant-pathogen interactions, especially the interplay between pathogens' molecular weaponry and hosts' defense machinery. Stemming from interdisciplinary investigations into the infection cell biology of filamentous plant pathogens, recent breakthrough discoveries have provided a new impetus to the field. These advances include the biophysical characterization of a novel invasion mechanism (i.e., naifu invasion) and the unraveling of novel effector secretion routes. On the plant side, progress includes the identification of components of cellular networks involved in the uptake of intracellular effectors. This exciting body of research underscores the pivotal role of logistics management by the pathogen throughout the infection cycle, encompassing the precolonization stages up to tissue invasion. More insight into these logistics opens new avenues for developing environmentally friendly crop protection strategies in an era marked by an imperative to reduce the use of agrochemicals.

BARC Biostimulant 1, a novel Streptomyces rochei C3-based formulation for disease biocontrol and plant growth promotion

Pythium aphanidermatum is a very destructive plant pathogen causing damping-off disease of vegetable seedlings in nurseries. In addition, this plant pathogenic oomycete causes seed, stem and rhizome rot, as well as post-harvest diseases. Currently, the disease management relies heavily on high dosages of chemicals like metalaxyl and copper oxychloride biocides, which are not only expensive, but are hazardous to the ecosystem. In our quest for developing a disease management strategy that is economical and safe, we isolated a strain of an actinobacterium that is highly inhibitory to P. aphanidermatum, the major cause of damping-off disease. Based on morphology and 16S rRNA sequence analysis, we identified this isolate as Streptomyces rochei. Using an LC-MS/MS analysis, the inhibitory principle has been tentatively identified as (4 S)-4,5-dihydro-4-hydroxygeldanamycin.We developed a novel formulation “BARC Biostimulant 1” using split tamarind seeds as a substrate and talcum powder as a carrier and S. rochei as the active ingredient. In P. aphanidermatum-infested soil, seed treatment and drenching resulted in about 50 % improvement in germination in greenhouse assay and protected field experiments. Under open field conditions, the germination improved to the extent of 20 %. In addition to suppression of the disease, the formulation also improved plant growth parameters like weight and height of seedlings, and induced defense responses. We further undertook multi-location replicated field trials to evaluate this purely organic formulation as a biostimulant across four states of India. Seed treatment with BARC Biostimulant 1 at the rate of 5 g/ kg seeds enhanced germination of seedlings by 80 % and enhanced fresh weight by 105 % (average of four locations), indicating a good commercial potential of this formulation.

Activity of OSBPI fungicide fluoxapiprolin against plant-pathogenic oomycetes and its systemic translocation in plants

Fluoxapiprolin, a novel piperidinyl thiazole isoxazoline fungicide, was developed by Bayer Crop Science in 2012. Despite its well-documented inhibitory activity against plant pathogenic oomycetes such as Phytophthora capsici and Phytophthora infestans, limited information regarding its antifungal spectrum and protective and curative activity is available. Fluoxapiprolin exhibited strong inhibitory activity against Phytophthora spp. and several Pythium spp., with EC50 values ranging from 2.12 × 10−4 to 2.92 μg/mL. It was much more effective against P. capsici in inhibiting mycelial growth, sporangium production, and cystospore germination than at reducing zoospore release. Moreover, fluoxapiprolin displayed both protective and curative activity against P. capsici infection in pepper plants under greenhouse conditions, with systemic translocation capability confirmed by High Performance Liquid Chromatography (HPLC) analysis. The results demonstrated the strong inhibitory activity of fluoxapiprolin against economically important plant oomycete pathogens, including Phytophthora spp. and several Pythium spp., and its certain translocation activity in pepper plants.

Evolution of Phytophthora infestans on its potato host since the Irish potato famine

Phytophthora infestans is a major oomycete plant pathogen, responsible for potato late blight, which led to the Irish Potato Famine from 1845–1852. Since then, potatoes resistant to this disease have been bred and deployed worldwide. Their resistance (R) genes recognize pathogen effectors responsible for virulence and then induce a plant response stopping disease progression. However, most deployed R genes are quickly overcome by the pathogen. We use targeted sequencing of effector and R genes on herbarium specimens to examine the joint evolution in both P. infestans and potato from 1845–1954. Currently relevant effectors are historically present in P. infestans, but with alternative alleles compared to modern reference genomes. The historic FAM-1 lineage has the virulent Avr1 allele and the ability to break the R1 resistance gene before breeders deployed it in potato. The FAM-1 lineage is diploid, but later, triploid US-1 lineages appear. We show that pathogen virulence genes and host resistance genes have undergone significant changes since the Famine, from both natural and artificial selection.

Microscopic and Transcriptomic Analyses to Elucidate Antifungal Mechanisms of Bacillus velezensis TCS001 Lipopeptides against Botrytis cinerea.

Botrytis cinerea is an important fungal pathogen that causes gray mold disease in plants. Previously, Bacillus velezensis TCS001 live culture presented broad-spectrum antifungal activity against various plant pathogenic fungi and oomycetes, particularly B. cinerea. Here, the bioactivity of lipopeptides produced by TCS001 against B. cinerea was investigated. The IC50 values of the crude lipopeptide extract (CLE) from TCS001 to suppress mycelial growth and conidial germination were 14.20 and 49.39 mg/L, respectively. SEM and TEM imaging revealed that CLE caused morphological deformities and ultrastructural changes in the mycelium. Transcriptomic analyses combined with ΔBcpsd mutant construction demonstrated that the CLE could confer antifungal activity via suppressing Bcpsd expression in the pathogen. In addition, the CLE activated the plant immune system by increasing the content of defense-related enzymes and the expression of marker genes in immunity signaling pathways in cucumber plants. Therefore, TCS001 CLE could be potentially developed into biopesticides for the biocontrol of gray mold disease.

Oomycete Metabolism Is Highly Dynamic and Reflects Lifestyle Adaptations.

The selective pressure of pathogen-host symbiosis drives adaptations. How these interactions shape the metabolism of pathogens is largely unknown. Here, we use comparative genomics to systematically analyze the metabolic networks of oomycetes, a diverse group of eukaryotes that includes saprotrophs as well as animal and plant pathogens, with the latter causing devastating diseases with significant economic and/or ecological impacts. In our analyses of 44 oomycete species, we uncover considerable variation in metabolism that can be linked to lifestyle differences. Comparisons of metabolic gene content reveal that plant pathogenic oomycetes have a bipartite metabolism consisting of a conserved core and an accessory set. The accessory set can be associated with the degradation of defense compounds produced by plants when challenged by pathogens. Obligate biotrophic oomycetes have smaller metabolic networks, and taxonomically distantly related biotrophic lineages display convergent evolution by repeated gene losses in both the conserved as well as the accessory set of metabolisms. When investigating to what extent the metabolic networks in obligate biotrophs differ from those in hemibiotrophic plant pathogens, we observe that the losses of metabolic enzymes in obligate biotrophs are not random and that gene losses predominantly influence the terminal branches of the metabolic networks. Our analyses represent the first metabolism-focused comparison of oomycetes at this scale and will contribute to a better understanding of the evolution of oomycete metabolism in relation to lifestyle adaptation. Numerous oomycete species are devastating plant pathogens that cause major damage in crops and natural ecosystems. Their interactions with hosts are shaped by strong selection, but how selection affects adaptation of the primary metabolism to a pathogenic lifestyle is not yet well established. By pan-genome and metabolic network analyses of distantly related oomycete pathogens and their nonpathogenic relatives, we reveal considerable lifestyle- and lineage-specific adaptations. This study contributes to a better understanding of metabolic adaptations in pathogenic oomycetes in relation to lifestyle, host, and environment, and the findings will help in pinpointing potential targets for disease control. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Paths of Least Resistance: Unconventional Effector Secretion by Fungal and Oomycete Plant Pathogens.

Effector secretion by different routes mediates the molecular interplay between host plant and pathogen, but mechanistic details in eukaryotes are sparse. This may limit the discovery of new effectors that could be utilized for improving host plant disease resistance. In fungi and oomycetes, apoplastic effectors are secreted via the conventional endoplasmic reticulum (ER)-Golgi pathway, while cytoplasmic effectors are packaged into vesicles that bypass Golgi in an unconventional protein secretion (UPS) pathway. In Magnaporthe oryzae, the Golgi bypass UPS pathway incorporates components of the exocyst complex and a t-SNARE, presumably to fuse Golgi bypass vesicles to the fungal plasma membrane. Upstream, cytoplasmic effector mRNA translation in M. oryzae requires the efficient decoding of AA-ending codons. This involves the modification of wobble uridines in the anticodon loop of cognate tRNAs and fine-tunes cytoplasmic effector translation and secretion rates to maintain biotrophic interfacial complex integrity and permit host infection. Thus, plant-fungal interface integrity is intimately tied to effector codon usage, which is a surprising constraint on pathogenicity. Here, we discuss these findings within the context of fungal and oomycete effector discovery, delivery, and function in host cells. We show how cracking the codon code for unconventional cytoplasmic effector secretion in M. oryzae has revealed AA-ending codon usage bias in cytoplasmic effector mRNAs across kingdoms, including within the RxLR-dEER motif-encoding sequence of a bona fide Phytophthora infestans cytoplasmic effector, suggesting its subjection to translational speed control. By focusing on recent developments in understanding unconventional effector secretion, we draw attention to this important but understudied area of host-pathogen interactions. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

A portable fluorescence-based recombinase polymerase amplification assay for the detection of mal secco disease by Plenodomus tracheiphilus

In this study, a new diagnostic assay to detect Plenodomus tracheiphilus, the causative agent of mal secco of citrus, was developed based on the recombinase polymerase amplification (RPA) technology. Mal secco is a well-known and damaging vascular disease, affecting primarily lemon (Citrus limon) and, to a lesser extent, other citrus species, including those in the genera Citrus, Fortunella, Poncirus and Severina. The disease poses a considerable threat to lemon production in most of the citrus-producing countries of the Mediterranean region and in the Black Sea area. RPA primers and probes were designed to amplify a 142 bp amplicon from the ITS regions of P. tracheiphilus. The inclusivity and specificity of the RPA assay were tested on gDNA isolated from a panel including 29 strains of various origin of P. tracheiphilus and 18 non-target fungal and oomycete plant pathogens typically isolated from citrus trees. The assay was specific to P. tracheiphilus and had a detection threshold of 1.0 pg of gDNA. Preliminary tests carried out on plant crude extract highlighted RPA's potential for the rapid, user-friendly, and cost-effective field diagnosis of mal secco.

The Need and Opportunity to Update the Inventory of Plant Pathogenic Fungi and Oomycetes in Mexico.

Mexico generates specific phytosanitary regulations for each product and origin to prevent the entry of quarantine pests and/or delay their spread within the national territory, including fungi and oomycetes. Phytosanitary regulations are established based on available information on the presence or absence of these pathogens in the country; however, the compilation and precise analysis of reports is a challenging task due to many publications lacking scientific rigor in determining the presence of a taxon of phytosanitary interest in the country. This review evaluated various studies reporting the presence of plant pathogenic fungi and oomycetes in Mexico and concluded that some lists of diseases and phytopathogenic organisms lack technical-scientific basis. Thus, it highlights the need and presents an excellent opportunity to establish a National Collection of Fungal Cultures and a National Herbarium for obligate parasites, as well as to generate a National Database of Phytopathogenic Fungi and Oomycetes present in Mexico, supported by the combination of morphological, molecular, epidemiological, pathogenicity, symptom, and micrograph data. If realized, this would have a direct impact on many future applications related to various topics, including quarantines, risk analysis, biodiversity studies, and monitoring of fungicide resistance, among others.

Complete telomere-to-telomere genomes uncover virulence evolution conferred by chromosome fusion in oomycete plant pathogens

Variations in chromosome number are occasionally observed among oomycetes, a group that includes many plant pathogens, but the emergence of such variations and their effects on genome and virulence evolution remain ambiguous. We generated complete telomere-to-telomere genome assemblies for Phytophthora sojae, Globisporangium ultimum, Pythium oligandrum, and G. spinosum. Reconstructing the karyotype of the most recent common ancestor in Peronosporales revealed that frequent chromosome fusion and fission drove changes in chromosome number. Centromeres enriched with Copia-like transposons may contribute to chromosome fusion and fission events. Chromosome fusion facilitated the emergence of pathogenicity genes and their adaptive evolution. Effectors tended to duplicate in the sub-telomere regions of fused chromosomes, which exhibited evolutionary features distinct to the non-fused chromosomes. By integrating ancestral genomic dynamics and structural predictions, we have identified secreted Ankyrin repeat-containing proteins (ANKs) as a novel class of effectors in P. sojae. Phylogenetic analysis and experiments further revealed that ANK is a specifically expanded effector family in oomycetes. These results revealed chromosome dynamics in oomycete plant pathogens, and provided novel insights into karyotype and effector evolution.

Transcriptome analysis of Phytophthora cactorum infecting strawberry identified RXLR effectors that induce cell death when transiently expressed in Nicotiana benthamiana

Phytophthora cactorum is a plant pathogenic oomycete that causes crown rot in strawberry leading to significant economic losses every year. To invade the host, P. cactorum secretes an arsenal of effectors that can manipulate host physiology and impair its defense system promoting infection. A transcriptome analysis was conducted on a susceptible wild strawberry genotype (Fragaria vesca) 48 hours post inoculation with P. cactorum to identify effectors expressed during the early infection stage. The analysis revealed 4,668 P. cactorum genes expressed during infection of F. vesca. A total of 539 secreted proteins encoded by transcripts were identified, including 120 carbohydrate-active enzymes, 40 RXLRs, 23 proteolytic enzymes, nine elicitins, seven cysteine rich proteins, seven necrosis inducing proteins and 216 hypothetical proteins with unknown function. Twenty of the 40 RXLR effector candidates were transiently expressed in Nicotiana benthamiana using agroinfiltration and five previously unreported RXLR effector genes (Pc741, Pc8318, Pc10890, Pc20813, and Pc22290) triggered cell death when transiently expressed. The identified cell death inducing RXLR effectors showed 31–66% identity to known RXLR effectors in different Phytophthora species having roles in pathogenicity including both activation and suppression of defense response in the host. Furthermore, homology analysis revealed that these cell death inducing RXLR effectors were highly conserved (82 - 100% identity) across 23 different strains of P. cactorum originating from apple or strawberry.

A mitochondrial carrier transports glycolytic intermediates to link cytosolic and mitochondrial glycolysis in the human gut parasite Blastocystis

Stramenopiles form a clade of diverse eukaryotic organisms, including multicellular algae, the fish and plant pathogenic oomycetes, such as the potato blight Phytophthora, and the human intestinal protozoan Blastocystis. In most eukaryotes, glycolysis is a strictly cytosolic metabolic pathway that converts glucose to pyruvate, resulting in the production of NADH and ATP (Adenosine triphosphate). In contrast, stramenopiles have a branched glycolysis in which the enzymes of the pay-off phase are located in both the cytosol and the mitochondrial matrix. Here, we identify a mitochondrial carrier in Blastocystis that can transport glycolytic intermediates, such as dihydroxyacetone phosphate and glyceraldehyde-3-phosphate, across the mitochondrial inner membrane, linking the cytosolic and mitochondrial branches of glycolysis. Comparative analyses with the phylogenetically related human mitochondrial oxoglutarate carrier (SLC25A11) and dicarboxylate carrier (SLC25A10) show that the glycolytic intermediate carrier has lost its ability to transport the canonical substrates malate and oxoglutarate. Blastocystis lacks several key components of oxidative phosphorylation required for the generation of mitochondrial ATP, such as complexes III and IV, ATP synthase, and ADP/ATP carriers. The presence of the glycolytic pay-off phase in the mitochondrial matrix generates ATP, which powers energy-requiring processes, such as macromolecular synthesis, as well as NADH, used by mitochondrial complex I to generate a proton motive force to drive the import of proteins and molecules. Given its unique substrate specificity and central role in carbon and energy metabolism, the carrier for glycolytic intermediates identified here represents a specific drug and pesticide target against stramenopile pathogens, which are of great economic importance.