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Summary: We investigated the mining mode of insect feeding, involving larval consumption of a plant's internal tissues, from the Middle Jurassic (165 million years ago) Daohugou locality of Northeastern China. Documentation of mining from the Jurassic Period is virtually unknown, and results from this time interval would address mining evolution during the temporal gap of mine–seed plant diversifications from the previous Late Triassic to the subsequent Early Cretaceous.Plant fossils were examined with standard microscopic procedures for herbivory and used the standard functional feeding group–damage‐type system of categorizing damage. All fossil mines were photographed and databased.We examined 2014 plant specimens, of which 27 occurrences on 14 specimens resulted in eight, new, mine damage types (DTs) present on six genera of bennettitalean, ginkgoalean, and pinalean gymnosperms.Three conclusions emerge from this study. First, these mid‐Mesozoic mines are morphologically conservative and track plant host anatomical structure rather than plant phylogeny. Second, likely insect fabricators of these mines were three basal lineages of polyphagan beetles, four basal lineages of monotrysian moths, and a basal lineage tenthredinoid sawflies. Third, the nutrition hypothesis, indicating that miners had greater access to nutritious, inner tissues of new plant lineages, best explains mine evolution during the mid‐Mesozoic. See also the Commentary on this article by McLoughlin & Santos, 242: 2391–2393. [ABSTRACT FROM AUTHOR]

Root exudates mediate plant interactions in the environment, and they are affected by physical, chemical and biological factors. Biocontrol agents can modify root exudates and influence plant–pathogen interactions. In this study, we showed that lettuce (Lactuca sativa), a host of the root-knot nematode Meloidogyne incognita, produced root exudates that attracted the second-stage juveniles (J2s) of this nematode and garlic (Allium sativum), an antagonistic plant, produced exudates that repelled them. However, the application of a commercial product containing Bacillus subtilis on lettuce roots made the exudates repellent to J2s of M. incognita, whereas treated garlic exudates were as attractive to the J2s as untreated lettuce. The repulsive behavior of M. incognita to exudates of roots colonized by biocontrol agents is common; however, the attractiveness of treated garlic root exudates was unexpected and not previously reported for non-host plants. Chemotaxis assays also showed that the commercial formulation of B. subtilis was repellent to J2s of M. incognita. The metabolomic analysis conducted on these samples unveiled a combined total of 34 compounds. There was an elevation in the levels of amino acids and peptides in samples that were inoculated with the commercial product. Additionally, certain metabolites appear to be connected to chemotaxis. These metabolic changes induced by the commercial product are interesting for field utilization in a dual control strategy, where lettuce is protected against the nematode due to its repellence and garlic becomes attractive, but is not infected by the nematode. [ABSTRACT FROM AUTHOR]

The root-knot nematode Meloidogyne paranaensis is one of the main problems for coffee production in Latin American countries. In Mexico, this nematode is found damaging shaded coffee plantations, with a wide variety of associated vegetation. The plant species present in these agroecosystems could serve as nematode alternative hosts, helping to maintain and disperse the population of M. paranaensis even when control measures are carried out for coffee trees. The aim of this work was to evaluate the ability of M. paranaensis to reproduce in 13 plant species commonly associated with shade-grown coffee plantations. The plants were inoculated with eggs and J2 of M. paranaensis, 10 months later, the host susceptibility index and the resistance level were calculated based on the nematode population density. Meloidogyne paranaensis reproduced in 11 of the evaluated plants which presented different resistance levels. Citrus aurantium, Citrus reticulata, Inga jinicuil, Inga vera and Musa AA, were highly susceptible compared to Coffea arabica and Coffea canephora. On the other hand, Macadamia integrifolia and Psidium guajava are considered resistant to moderately resistant with a reproduction rate less than one and a susceptibility index less than 10 with respect to C. arabica and less than 25 with respect to C. canephora. Persea schiedeana and Syzygium jambos did not allow M. paranaensis reproduction, so they are considered highly resistant. The results of this study provide important information for the M. paranaensis management in infested shade-grown coffee plantations. It is necessary to evaluate other woody and herbaceous plant species to improve control measures for this nematode. [ABSTRACT FROM AUTHOR]

Phenology is a key adaptive trait of organisms, shaping biotic interactions in response to the environment. It has emerged as a critical topic with implications for societal and economic concerns due to the effects of climate change on species' phenological patterns. Fungi play essential roles in ecosystems, and plant pathogenic fungi have significant impacts on global food security. However, the phenology of plant pathogenic fungi, which form a huge and diverse clade of organisms, has received limited attention in the literature. This diversity may have limited the use of a common language for comparisons and the integration of phenological data for these taxonomic groups. Here, we delve into the concept of 'phenology' as applied to plant pathogenic fungi and explore the potential drivers of their phenology, including environmental factors and the host plant. We present the PhenoFun scale, a phenological scoring system suitable for use with all fungi and fungus‐like plant pathogens. It offers a standardised and common tool for scientists studying the presence, absence, or predominance of a particular phase, the speed of phenological phase succession, and the synchronism shift between pathogenic fungi and their host plants, across a wide range of environments and ecosystems. The application of the concept of 'phenology' to plant pathogenic fungi and the use of a phenological scoring system involves focusing on the interacting processes between the pathogenic fungi, their hosts, and their biological, physical, and chemical environment, occurring during the life cycle of the pathogen. The goal is to deconstruct the processes involved according to a pattern orchestrated by the fungus's phenology. Such an approach will improve our understanding of the ecology and evolution of such organisms, help to understand and anticipate plant disease epidemics and their future evolution, and make it possible to optimise management models, and to encourage the adoption of cropping practices designed from this phenological perspective. [ABSTRACT FROM AUTHOR]

Anthracnose, caused by several Colletotrichum species, is a major restricting factor for guava production, but no comprehensive study of the causal agent has been conducted from the plant host centre of diversity. This work characterizes isolates from guava, mainly from the fruit, but also leaves and flowers, representing most Brazilian physiographies according to the partial sequences of the rDNA‐ITS, ApMAT, TUB2, HIS3 and GAPDH gene regions. In addition, the pathogenicity and aggressiveness to fruits of two widely planted guava varieties (SLG and RM) are described. Guava‐derived Colletotrichum isolates were found in five complexes: gloeosporioides, acutatum, boninense, gigasporum and orchidearum. The gloeosporioides complex was the most prevalent (81%), followed by the acutatum complex (14%). A total of 16 Colletotrichum species were naturally associated with guava anthracnose: C. aeschynomenes, C. asianum, C. chrysophilum, C. fructicola, C. gigasporum, C. gloeosporioides, C. karsti, C. melonis, C. musae, C. nymphaeae, C. paranaense, C. siamense, C. sojae, C. syzygicola, C. theobromicola and C. tropicale. Apart from C. nymphaeae and C. gloeosporioides, all the remaining 14 taxa are reported for the first time in P. guajava. The most aggressive species belonged to the C. gloeosporioides complex. C. siamense was the most prevalent, especially in warmer regions, followed by C. chrysophilum, mostly in temperate environments. The most aggressive species were C. siamense, C. chrysophilum, C. fructicola and C. tropicale. Fruits of the variety SLG were consistently more resistant to anthracnose than the fruits of RM. [ABSTRACT FROM AUTHOR]

Aphid genomic resources enable the study of complex life history traits and provide information on vector biology, host adaption and speciation. The currant–lettuce aphid (Nasonovia ribisnigri(Hemiptera: Aphididae) (Mosley)) is a cosmopolitan pest of outdoor lettuce (Lactuca sativa (Asterales: Asteraceae) (Linnaeus)). Until recently, the use of resistant cultivars was an effective method for managing N. ribisnigri. A resistant cultivar containing a single gene (Nr‐locus), introduced in the 1980s, conferred complete resistance to feeding. Overreliance of this Nr‐locus in lettuce resulted in N. ribisnigri's ability to break resistance mechanism, with first reports during 2003. Our work attempts to understand which candidate gene(s) are associated with this resistance‐breaking mechanism. We present two de novo draft assembles for N. ribisnigri genomes, corresponding to both avirulent (Nr‐locus susceptible) and virulent (Nr‐locus resistant) biotypes. Changes in gene expression of the two N. ribisnigri biotypes were investigated using transcriptomic analyses of RNA‐sequencing (RNA‐seq) data to understand the potential mechanisms of resistance to the Nr‐locus in lettuce. The draft genome assemblies were 94.2% and 91.4% complete for the avirulent and virulent biotypes, respectively. Out of the 18,872 differentially expressed genes, a single gene/locus was identified in N. ribisnigri that was shared between two resistant‐breaking biotypes. This locus was further explored and validated in Real‐Time Quantitative Reverse Transcription PCR (qRT‐PCR) experiments and has predicted localisations in both the cytoplasm and nucleus. This is the first study to provide evidence that a single gene/locus is likely responsible for the ability of N. ribisnigri to overcome the Nr‐locus resistance in the lettuce host. [ABSTRACT FROM AUTHOR]

Female herbivorous insects are expected to oviposit on the host plant providing the best performance of the offspring. However, in some insects the larvae are mobile and are not totally dependent on the mother's choice. They can change host plant when conditions for development or exposure to natural enemies vary between individual plants within a patch. Here we study larval migration and preference between two host plants, cotton and alfalfa, in the Egyptian leafworm, Spodoptera littoralis (Boisduval) (Lepidoptera: Noctuidae). Previous studies have shown that although larval performance is better on cotton, females prefer to oviposit on alfalfa, and this preference corresponds to a higher survival of the eggs. In this study, S. littoralis larvae showed directed movement between host plants and were found to prefer alfalfa over cotton in field test in Egypt, as well as in laboratory selection of feeding site assays. To determine effects by natural enemies, the parasitism rates and various life‐history traits were measured for one larval parasitoid, Microplitis rufiventris Kokujev (Hymenoptera: Braconidae), on several host plants including cotton and clover (equivalent host plant to alfalfa). Overall, parasitism was higher on cotton and parasitoid performance (cocoon mass, adult longevity, and female egg load) was better on cotton compared to clover. This fact suggests an enemy‐free space on clover and alfalfa, as parasitism rate is higher on cotton, and the parasitoid performance is also better on cotton‐fed larvae. [ABSTRACT FROM AUTHOR]

Root-knot nematodes (RKNs) infect host plants and obtain nutrients such as sugars for their own development. Therefore, inhibiting the nutrient supply to RKNs may be an effective method for alleviating root-knot nematode disease. At present, the pathway by which sucrose is unloaded from the phloem cells to giant cells (GCs) in root galls and which genes related to sugar metabolism and transport play key roles in this process are unclear. In this study, we found that sugars could be unloaded into GCs only from neighboring phloem cells through the apoplastic pathway. With the development of galls, the contents of sucrose, fructose and glucose in the galls and adjacent tissue increased gradually. SUT1, SUT2, SWEET7a, STP10, SUS3 and SPS1 may provide sugar sources for GCs, while STP1, STP2 and STP12 may transport more sugar to phloem parenchyma cells. At the early stage of Meloidogyne incognita infestation, the sucrose content in tomato roots and leaves increased, while the glucose and fructose contents decreased. SWEET7a, SPS1, INV-INH1, INV-INH2, SUS1 and SUS3 likely play key roles in root sugar delivery. These results elucidated the pathway of sugar unloading in tomato galls and provided an important theoretical reference for eliminating the sugar source of RKNs and preventing root-knot nematode disease. [ABSTRACT FROM AUTHOR]

Fertilizers and plant diseases contribute positively and negatively to crop production, respectively. Macro- and micronutrients provided by the soil and fertilizers are transported by various plant nutrient transporters from the soil to the roots and shoots, facilitating growth and development. However, the homeostasis of different nutrients has different effects on plant disease. This review is aimed at providing insights into the interconnected regulation between nutrient homeostasis and immune responses, and it highlights strategies to enhance disease resistance by optimal manipulation of nutrient transporters in rice. First, we highlight the essential roles of six macronutrients (nitrogen, phosphorus, potassium, sulfur, calcium, magnesium) and eight micronutrients (iron, manganese, zinc, copper, boron, molybdenum, silicon, nickel), and summarize the diverse effects of each on rice diseases. We then systematically review the molecular mechanisms of immune responses modulated by nutrient transporters and the genetic regulatory pathways that control the specific nutrient-mediated immune signaling that is regulated by the pathogens and the host plant. Finally, we discuss putative strategies for breeding disease-resistant rice by genetic engineering of nutrient transporters. [ABSTRACT FROM AUTHOR]

Restoration of root hemiparasite trees, such as Hawaiʻi's endemic Santalum species (ʻiliahi), may benefit from underplanting in stands of suitable hosts like the nitrogen‐fixing native tree, Acacia koa (koa). At a pasture site on Hawaiʻi Island previously reforested with koa, we underplanted seedlings of the island‐endemic sandalwood species, Santalum paniculatum, to examine the tradeoff between access to an established root network (distance to the nearest koa tree) under variable overstory shading (8.8–90.1% canopy openness range) during regeneration establishment. We hypothesized that there is an optimal parasite–host spacing and canopy openness that balance parasitic resource transfer with light availability. ʻIliahi seedling survival was 96% with no survival treatment differences. ‘Iliahi seedling growth was positively related to canopy openness but negatively related to the distance to the nearest koa tree, and the slope of these relationships increased over time. Leaf photosynthetic light compensation points, light saturation points, and stomatal density mostly followed similar trends as growth. These results demonstrate that ‘iliahi can be successfully underplanted in an established koa stand, which benefits ‘iliahi plantings and contributes to diversifying initial restoration and reforestation plantings. There appears to be a significant tradeoff in planting distance between benefits from and competition with the host; however, the improvement in growth with increased canopy openness appeared to be much greater than the effect of planting distance. Underplanting into an established host stand with sufficient canopy openness can help restore functionally compatible and abundant ‘iliahi regeneration into forests. [ABSTRACT FROM AUTHOR]

Background: The lifestyle transition from autotrophy to heterotrophy often leads to extensive degradation of plastomes in parasitic plants, while the evolutionary trajectories of plastome degradation associated with parasitism in hemiparasitic plants remain poorly understood. In this study, phylogeny-oriented comparative analyses were conducted to investigate whether obligate Loranthaceae stem-parasites experienced higher degrees of plastome degradation than closely related facultative root-parasites and to explore the potential evolutionary events that triggered the 'domino effect' in plastome degradation of hemiparasitic plants. Results: Through phylogeny-oriented comparative analyses, the results indicate that Loranthaceae hemiparasites have undergone varying degrees of plastome degradation as they evolved towards a heterotrophic lifestyle. Compared to closely related facultative root-parasites, all obligate stem-parasites exhibited an elevated degree plastome degradation, characterized by increased downsizing, gene loss, and pseudogenization, thereby providing empirical evidence supporting the theoretical expectation that evolution from facultative parasitism to obligate parasitism may result in a higher degree of plastome degradation in hemiparasites. Along with infra-familial divergence in Loranthaceae, several lineage-specific gene loss/pseudogenization events occurred at deep nodes, whereas further independent gene loss/pseudogenization events were observed in shallow branches. Conclusions: The findings suggest that in addition to the increasing levels of nutritional reliance on host plants, cladogenesis can be considered as another pivotal evolutionary event triggering the 'domino effect' in plastome degradation of hemiparasitic plants. These findings provide new insights into the evolutionary trajectory of plastome degradation in hemiparasitic plants. [ABSTRACT FROM AUTHOR]

The powdery mildew fungi (Erysiphaceae) are globally distributed plant pathogens with a range of more than 10,000 plant hosts. In this review, we discuss the long‐ and short‐term evolution of these obligate biotrophic fungi and outline their diversity with respect to morphology, lifestyle, and host range. We highlight their remarkable ability to rapidly overcome plant immunity, evolve fungicide resistance, and broaden their host range, for example, through adaptation and hybridization. Recent advances in genomics and proteomics, particularly in cereal powdery mildews (genus Blumeria), provided first insights into mechanisms of genomic adaptation in these fungi. Transposable elements play key roles in shaping their genomes, where even close relatives exhibit diversified patterns of recent and ongoing transposon activity. These transposons are ubiquitously distributed in the powdery mildew genomes, resulting in a highly adaptive genome architecture lacking obvious regions of conserved gene space. Transposons can also be neofunctionalized to encode novel virulence factors, particularly candidate secreted effector proteins, which may undermine the plant immune system. In cereals like barley and wheat, some of these effectors are recognized by plant immune receptors encoded by resistance genes with numerous allelic variants. These effectors determine incompatibility ("avirulence") and evolve rapidly through sequence diversification and copy number variation. Altogether, powdery mildew fungi possess plastic genomes that enable their fast evolutionary adaptation towards overcoming plant immunity, host barriers, and chemical stress such as fungicides, foreshadowing future outbreaks, host range shifts and expansions as well as potential pandemics by these pathogens. [ABSTRACT FROM AUTHOR]

Summary: Ectomycorrhizal (ECM) fungi are crucial for tree nitrogen (N) nutrition; however, mechanisms governing N transfer from fungal tissues to the host plant are not well understood. ECM fungal isolates, even from the same species, vary considerably in their ability to support tree N nutrition, resulting in a range of often unpredictable symbiotic outcomes.In this study, we used isotopic labelling to quantify the transfer of N to the plant host by isolates from the ECM genus Pisolithus, known to have significant variability in colonisation and transfer of nutrients to a host.We considered the metabolic fate of N acquired by the fungi and found that the percentage of plant N acquired through symbiosis significantly correlated to the concentration of free amino acids in ECM extra‐radical mycelium. Transcriptomic analyses complemented these findings with isolates having high amino acid content and N transfer showing increased expression of genes related to amino acid transport and catabolic pathways.These results suggest that fungal N metabolism impacts N transfer to the host plant in this interaction and that relative N transfer may be possible to predict through basic biochemical analyses. [ABSTRACT FROM AUTHOR]

Summary: Many fungi that form ectomycorrhizas exhibit a degree of host specialisation, and individual trees are frequently colonised by communities of mycorrhizal fungi comprising species that fall on a gradient of specialisation along genetic, functional and taxonomic axes of variation. By contrast, arbuscular mycorrhizal fungi exhibit little specialisation. Here, we propose that host tree root morphology is a key factor that gives host plants fine‐scale control over colonisation and therefore opportunities for driving specialisation and speciation of ectomycorrhizal fungi. A gradient in host specialisation is likely driven by four proximate mechanistic 'filters' comprising partner availability, signalling recognition, competition for colonisation, and symbiotic function (trade, rewards and sanctions), and the spatially restricted colonisation seen in heterorhizic roots enables these mechanisms, especially symbiotic function, to be more effective in driving the evolution of specialisation. We encourage manipulation experiments that integrate molecular genetics and isotope tracers to test these mechanisms, alongside mathematical simulations of eco‐evolutionary dynamics in mycorrhizal symbioses. [ABSTRACT FROM AUTHOR]

Summary: Arbuscular (AM) and orchid (OrM) mycorrhiza are the most widespread mycorrhizal symbioses among flowering plants, formed by distinct fungal and plant species. They are both endosymbioses because the fungal hyphae can enter inside the plant cell to develop intracellular fungal structures that are surrounded by the plant membrane. The symbiotic plant–fungus interface is considered to be the major site of nutrient transfer to the host plant. We summarize recent data on nutrient transfer in OrM and compare the development and function of the arbuscules formed in AM and the pelotons formed in OrM in order to outline differences and conserved traits. We further describe the unexpected similarities in the form and function of the intracellular mycorrhizal fungal structures observed in orchids and in the roots of mycoheterotrophic plants forming AM. We speculate that these similarities may be the result of convergent evolution of mycorrhizal types in mycoheterotrophic plants and highlight knowledge gaps and new research directions to explore this scenario. [ABSTRACT FROM AUTHOR]

Background: The electrophoretic mobility shift assay (EMSA) is a common technology to detect DNA-protein interactions. However, in most cases, the protein used in EMSA is obtained via prokaryotic expression, and rarely from plants. At the same time, the proteins expressed from prokaryotic systems usually cannot fold naturally and have no post translationally modification, which may affect the binding of proteins to DNA. Results: Here, we develop a technique to quickly isolate proteins of interest from host plants and then analyze them using fluorescent EMSA. This technology system is called: protein from plants fluorescent EMSA method (PPF-EMSA). In PPF-EMSA, a special transient transformation method is employed to transiently deliver genes into the plant, enabling efficient synthesis the encoded proteins. Then, the target protein is isolated using immunoprecipitation, and the DNA probes were labeled with cyanine 3 (Cy3). Both fluorescent EMSA and super-shift fluorescent EMSA can be performed using the proteins from plants. Three kinds of plants, Betula platyphylla, Populus. davidiana×P. bolleana and Arabidopsis thaliana, are used in this study. The proteins isolated from plants are in a natural state, can fold naturally and are posttranslationally modified, enabling true binding to their cognate DNAs. Conclusion: As transient transformation can be performed quickly and not depended on whether stable transformation is available or not, we believe this method will have a wide application, enabling isolation of proteins from host plant conveniently. [ABSTRACT FROM AUTHOR]

Background: 'Candidatus Phytoplasma mali', the causal agent of apple proliferation disease, exerts influence on its host plant through various effector proteins, including SAP11CaPm which interacts with different TEOSINTE BRANCHED1/ CYCLOIDEA/ PROLIFERATING CELL FACTOR 1 and 2 (TCP) transcription factors. This study examines the transcriptional response of the plant upon early expression of SAP11CaPm. For that purpose, leaves of Nicotiana occidentalis H.-M. Wheeler were Agrobacterium-infiltrated to induce transient expression of SAP11CaPm and changes in the transcriptome were recorded until 5 days post infiltration. Results: The RNA-seq analysis revealed that presence of SAP11CaPm in leaves leads to downregulation of genes involved in defense response and related to photosynthetic processes, while expression of genes involved in energy production was enhanced. Conclusions: The results indicate that early SAP11CaPm expression might be important for the colonization of the host plant since phytoplasmas lack many metabolic genes and are thus dependent on metabolites from their host plant. [ABSTRACT FROM AUTHOR]

Magnaporthe AVRs and ToxB-like (MAX) effectors constitute a family of secreted virulence proteins in the fungus Pyricularia oryzae (syn. Magnaporthe oryzae), which causes blast disease on numerous cereals and grasses. In spite of high sequence divergence, MAX effectors share a common fold characterized by a ß-sandwich core stabilized by a conserved disulfide bond. In this study, we investigated the structural landscape and diversity within the MAX effector repertoire of P. oryzae. Combining experimental protein structure determination and in silico structure modeling we validated the presence of the conserved MAX effector core domain in 77 out of 94 groups of orthologs (OG) identified in a previous population genomic study. Four novel MAX effector structures determined by NMR were in remarkably good agreement with AlphaFold2 (AF2) predictions. Based on the comparison of the AF2-generated 3D models we propose a classification of the MAX effectors superfamily in 20 structural groups that vary in the canonical MAX fold, disulfide bond patterns, and additional secondary structures in N- and C-terminal extensions. About one-third of the MAX family members remain singletons, without strong structural relationship to other MAX effectors. Analysis of the surface properties of the AF2 MAX models also highlights the high variability within the MAX family at the structural level, potentially reflecting the wide diversity of their virulence functions and host targets. Author summary: MAX effectors are a family of virulence proteins from the plant pathogenic fungus Pyricularia (syn. Magnaporthe) oryzae that share a similar 3D structure despite very low amino-acid sequence identity. Characterizing the function and evolution of these proteins requires a detailed understanding of their structural diversity. With this in mind, we have determined the NMR structures of four new MAX effectors and shown a near-perfect match with the corresponding AlphaFold2 (AF2) models. We then applied a prediction pipeline based on similarity searches with structural modeling using the AF2 software to predict MAX effectors in a collection of 120 P. oryzae genomes. The resulting models and experimental structures revealed that the MAX core while preserved is highly permissive to secondary structure variations and may coexists with extensive structural diversity in terms of structured N- or C-terminal extensions permitting their classification. For a subset of AF2 models, we have also analyzed the physico-chemical properties of the core domain surfaces, adding another, more functional perspective, notably surface electrostatics and stickiness. This work constitutes a major step in understanding the relationships among MAX effectors by analyzing their structural landscape and cataloguing specific physico-chemical properties. It also provides valuable insights for guiding research into the putative targets of these effectors in infected plant hosts. [ABSTRACT FROM AUTHOR]

Many plant pathogens secrete effector proteins into the host plant to suppress host immunity and facilitate pathogen colonization. The necrotrophic pathogen Sclerotinia sclerotiorum causes severe plant diseases and results in enormous economic losses, in which secreted proteins play a crucial role. SsCVNH was previously reported as a secreted protein, and its expression is significantly upregulated at 3 h after inoculation on the host plant. Here, we further demonstrated that deletion of SsCVNH leads to attenuated virulence. Heterologous expression of SsCVNH in Arabidopsis enhanced pathogen infection, inhibited the host PAMP‐triggered immunity (PTI) response and increased plant susceptibility to S. sclerotiorum. SsCVNH interacted with class III peroxidase AtPRX71, a positive regulator of innate immunity against plant pathogens. SsCVNH could also interact with other class III peroxidases, thus reducing peroxidase activity and suppressing plant immunity. Our results reveal a new infection strategy employed by S. sclerotiorum in which the fungus suppresses the function of class III peroxidases, the major component of PTI to promote its own infection. [ABSTRACT FROM AUTHOR]

Simple Summary: Differences in plant quality can alter patterns of ecological interactions, changing complex relationships among organisms within ecological communities. Hidden (asymptomatic) plant disease might have a previously little considered influence on insect ecology. This study investigated how a hidden fungal pathogen affects plants and their associated insects, using two varieties of lettuce as a model system. The presence of hidden disease changed plant quality, affecting insect populations differently depending on the lettuce variety. While the diversity and abundance of aphids remained unaffected in one variety, infection changed aphid assemblages in another. At the same time, aphids on infected lettuce varieties were less attractive to natural enemies, and so this reduced the benefits to aphids of colonising uninfected plants. Understanding the consequences of hidden pathogen infections for plant–insect interactions is important for pest management, biological control and broader ecological science, offering insights into both insect community ecology and sustainable agriculture. Few studies have considered whether hidden (asymptomatic) plant pathogen infection alters ecological interactions at the higher trophic levels, even though such infection still affects plant physiology. We explored this question in two field experiments, where two varieties of lettuce (Little Gem, Tom Thumb) infected with Botrytis cinerea were either (1) naturally colonised by aphids or (2) placed in the field with an established aphid colony. We then recorded plant traits and the numbers and species of aphids, their predators, parasitoids and hyperparasitoids. Infection significantly affected plant quality. In the first experiment, symptomatically infected plants had the fewest aphids and natural enemies of aphids. The diversity and abundance of aphids did not differ between asymptomatically infected and uninfected Little Gem plants, but infection affected the aphid assemblage for Tom Thumb plants. Aphids on asymptomatically infected plants were less attractive to predators and parasitoids than those on uninfected plants, while hyperparasitoids were not affected. In the second experiment, when we excluded natural enemies, aphid numbers were lower on asymptomatically and symptomatically infected plants, but when aphid natural enemies were present, this difference was removed, most likely because aphids on uninfected plants attracted more insect natural enemies. This suggests that hidden pathogen infection may have important consequences for multitrophic interactions. [ABSTRACT FROM AUTHOR]

Starting in the fall of 2019, mortality, blight symptoms, and signs of white fungal mycelia were observed on external host tissues of non-native landscape trees as well as numerous native trees, understory shrubs, and vines throughout northern and central Florida, USA. We determined that the fungus is an undescribed species of Basidiomycota based on morphological characteristics and DNA sequence analysis. Phylogenetic analyses of the internal transcribed spacer (ITS), large subunit (LSU), and translation elongation factor 1-alpha (tef1) regions revealed that this novel plant pathogen is an undescribed taxon of the genus Parvodontia (Cystostereaceae, Agaricales). We propose the name Parvodontia relampaga sp. nov. which describes its unique morphological features and phylogenetic placement. We confirmed the pathogenicity of P. relampaga in greenhouse inoculations on host plants from which strains of this novel pathogen were isolated, including the non-native gymnosperm Afrocarpus falcatus , the non-native and commercially important Ligustrum japonicum , and the native tree Quercus hemisphaerica. P. relampaga was also detected on a total of 27 different species of woody host plants, including such economically and ecologically important hosts as Fraxinus, Ilex, Magnolia, Persea, Prunus, Salix, Vitis , and Vaccinium. For this new plant disease, we propose the name "relampago blight," which refers to the lightning-like rhizomorph growth (relámpago means 'lightning' in Spanish). This study presents a newly discovered fungal taxon with a wide host range on both angiosperms and gymnosperms that may be an emerging pathogen of concern in Florida and the Gulf Coast region. • A novel thread blight pathogen is formally described as Parvodontia relampaga. • " Relampago blight" is the common name of the disease cause by P. relampaga. • This is the first report of any thread blight pathogen in continental USA. • Relampago blight was detected in plant seedlings in central and north Florida. [ABSTRACT FROM AUTHOR]

The pine wood nematode (PWN) uses several Monochamus species as vehicles, through a temporary hitchhiking process known as phoresy, enabling it to access new host plant resources. Monochamus saltuarius acts as a new and major vector of the PWN in Northeastern China, showing lower PWN carrying capacity and a shorter transmission cycle compared to established vectors. The apparently altered symbiotic relationship offers an interesting area for researching the costs and adaptions involved in nematode–beetle, a specialized phoresy. We analyzed the response and fitness costs of M. saltuarius through physiological measurements and transcriptomics. The PWN exerted adverse repercussions on the growth and development of M. saltuarius. The PWN accelerated larval development into pupae, while beetle adults carrying the PWN exhibited an elevated abnormality rate and mortality, and reduced starvation resistance. During the pupal stage, the expression of growth-related genes, including ecdysone-inducible genes (E74EA), cuticle proteins, and chitin genes (CHTs), markedly increased. Meanwhile, the induced immune response, mainly by the IMD and Toll signaling pathways, could be a contributing factor to adult abnormality and mortality. Adult gonads and trachea exhibited enrichment in pathways related to fatty acid elongation, biosynthesis, and metabolism. FASN, ELOVL, and SCD possibly contributed to resistance against PWN. Our research indicated that phoretic interactions between vector beetles and PWN vary throughout the vector's lifespan, particularly before and after entry into the trachea. This study highlighted the fitness costs of immunity and metabolism on the vector beetle, indicating the adaptation mechanisms and evolutionary trade-offs to PWN. [ABSTRACT FROM AUTHOR]

Hesperidin is a highly bioactive natural flavonoid whose role in ecological interactions is poorly known. In particular, the effects of hesperidin on herbivores are rarely reported. Flavonoids have been considered as prospective biopesticides; therefore, the aim of the present study was to examine the influence of hesperidin on the host plant selection behavior of three aphid (Hemiptera: Aphididae) species: Acyrthosiphon pisum Harrris, Rhopalosiphum padi (L.), and Myzus persicae (Sulz.). The aphid host plants were treated with 0.1% and 0.5% ethanolic solutions of hesperidin. Aphid probing behavior in the no-choice experiment was monitored using electropenetrography and aphid settling on plants in the choice experiment was recorded. The results demonstrated that hesperidin can be applied as a pre-ingestive, ingestive, and post-ingestive deterrent against A. pisum, as an ingestive deterrent against R. padi, and as a post-ingestive deterrent against M. persicae using the relatively low 0.1% concentration. While in A. pisum the deterrent effects of hesperidin were manifested as early as during aphid probing in peripheral plant tissues, in M. persicae, the avoidance of plants was probably the consequence of consuming the hesperidin-containing phloem sap. [ABSTRACT FROM AUTHOR]

Diverse secondary metabolites in plants, with their rich biological activities, have long been important sources for human medicine, food additives, pesticides, etc. However, the large-scale cultivation of host plants consumes land resources and is susceptible to pest and disease problems. Additionally, the multi-step and demanding nature of chemical synthesis adds to production costs, limiting their widespread application. In vitro cultivation and the metabolic engineering of plants have significantly enhanced the synthesis of secondary metabolites with successful industrial production cases. As synthetic biology advances, more research is focusing on heterologous synthesis using microorganisms. This review provides a comprehensive comparison between these two chassis, evaluating their performance in the synthesis of various types of secondary metabolites from the perspectives of yield and strategies. It also discusses the challenges they face and offers insights into future efforts and directions. [ABSTRACT FROM AUTHOR]

Transposable elements (TEs) are repetitive DNA that can create genome structure and regulation variability. The genome of Rhizophagus irregularis , a widely studied arbuscular mycorrhizal fungus (AMF), comprises ∼50% repetitive sequences that include TEs. Despite their abundance, two-thirds of TEs remain unclassified, and their regulation among AMF life stages remains unknown. Here, we aimed to improve our understanding of TE diversity and regulation in this model species by curating repeat datasets obtained from chromosome-level assemblies and by investigating their expression across multiple conditions. Our analyses uncovered new TE superfamilies and families in this model symbiont and revealed significant differences in how these sequences evolve both within and between R. irregularis strains. With this curated TE annotation, we also found that the number of upregulated TE families in colonized roots is 4 times higher than in the extraradical mycelium, and their overall expression differs depending on the plant host. This work provides a fine-scale view of TE diversity and evolution in model plant symbionts and highlights their transcriptional dynamism and specificity during host–microbe interactions. We also provide Hidden Markov Model profiles of TE domains for future manual curation of uncharacterized sequences (https://github.com/jordana-olive/TE-manual-curation/tree/main). [ABSTRACT FROM AUTHOR]

Highly virulent Pseudomonas syringae pv. actinidiae biovar 3 (Psa3) causes kiwifruit bacterial canker, which seriously damages kiwifruits worldwide. We previously screened Psa3-transposon-inserted mutants and obtained reduced-virulence mutants with genes encoding the flagellar protein. Flagella are involved in the motility of bacteria and contribute to P. syringae invasion of plant leaves. However, whether flagella are required for the ability to enter stomata and then multiply in the plant apoplast is not known. Here, we sprayed kiwifruit leaves with Psa3-flagellar-defective mutants and found that their virulence was reduced compared to that of the Psa3 wild type, but their virulence was not reduced when the leaves were infiltrated with Psa3-flagellar-defective mutants using a syringe. Motility and bacterial entry into apoplastic space of the flagellar-defective mutants were also significantly reduced. These results indicate that flagella contribute to Psa3 motility and stomata-mediated entry, leading to disease development, but not multiplication in apoplast space after Psa3 entry. This study provides new insight into bacterial motility in host plants. [ABSTRACT FROM AUTHOR]

Polyploidy – whole genome duplication – is common in plants. Studies over the last several decades have documented numerous mixed‐ploidy populations. Whether arising via recurrent whole genome duplication events within a population, or from secondary contact, the persistence of mixed populations is possible by niche differentiation. Specifically, one mechanism facilitating ploidy co‐occurrence is microbially‐mediated niche differentiation (MMND), wherein cytotypes occupy different niches via interactions with different sets of microbes. Inherently cryptic, MMND is underexplored in polyploid plant populations. Here, we search for evidence of MMND in creosotebush Larrea tridentata, a dominant desert shrub of the southwestern US and northern Mexico. We sequenced root‐associated fungal taxa in soils of diploid, autotetraploid, and autohexaploid plants growing in two naturally‐occurring mixed‐cytotype populations. Within populations, we found substantial fungal assemblage overlap across host plant cytotypes. However, using indicator species analysis, we identified some fungi that are differentiated by host plant cytotype, satisfying a necessarycondition for MMND. Future study is needed to determine the degree of niche differentiation conferred, if any, and whether the identified fungi play a role in the long‐term persistence of multiple cytotypes within populations. [ABSTRACT FROM AUTHOR]

Summary: Viral diseases seriously threaten rice production. Plasmodesmata (PD)‐associated proteins are deemed to play a key role in viral infection in host plants. However, few PD‐associated proteins have been discovered in rice to afford viral infection. Here, inspired by the infection mechanism in insect vectors, we identified a member of the Flotillin family taking part in the cell‐to‐cell transport of rice stripe virus (RSV) in rice. Flotillin1 interacted with RSV nucleocapsid protein (NP) and was localized on PD. In flotillin1 knockout mutant rice, which displayed normal growth, RSV intercellular movement was retarded, leading to significantly decreased disease incidence. The PD pore sizes of the mutant rice were smaller than those of the wild type due to more callose deposits, which was closely related to the upregulation of two callose synthase genes. RSV infection stimulated flotillin1 expression and enlarged the PD aperture via RSV NP. In addition, flotillin1 knockout decreased disease incidences of southern rice black‐streaked dwarf virus (SRBSDV) and rice dwarf virus (RDV) in rice. Overall, our study reveals a new PD‐associated protein facilitating virus cell‐to‐cell trafficking and presents the potential of flotillin1 as a target to produce broad‐spectrum antiviral rice resources in the future. [ABSTRACT FROM AUTHOR]

The system of gulcosinoalte sulfatase–sulfatase‐modifying factors (Sumfs) in herbivorous insects fulfils an essential function in defending host plant glucosinolates (GLSs)—the compounds of cruciferous plants—by swiftly desulfurising them. Previously, eight HaSulfs and one HaSumf1 were identified in Helicoverpa armigera. GLSs have a significant impact on the growth and development of H. armigera larvae. They can induce the expression of HaSulf in the midgut of H. armigera at both gene and protein levels. In the present study, we utilised RNAi technology to silence the HaSumf1 gene and explored its potential impact on the growth, development, and adaptation of GLSs. The sequence analysis has indicated that the HaSumf1 gene in H. armigera shares a high degree of sequence identity with other insect genes and is expressed at its highest level in the fifth‐instar phase. Additionally, the qRT‐PCR results reveal that the expression of HaSumf1 was upregulated by 1.26 and 0.07 times in third‐instar and 1.65 and 0.19 times in fifth‐instar when fed with 0.004% and 0.04% GLS, respectively. The effectiveness of dsSumf1 silencing was observed in both third‐ and fifth‐instar stages, with silencing rates of 65.5%–88.9% and 61.3%–74.6%, respectively (p < 0.05). The findings of the bioassay indicate that H. armigera's body weight at fifth‐instar significantly increased after treatment with 0.004% GLS and 0.04% GLS, while the larval survival rate, pupation rate, and pupa weight decreased. Notably, when feeding dsRNA‐encapsulated carbon quantum dots (CQD‐dsRNA), this trend was significantly strengthened (p < 0.05). Taken together, these findings provide evidence supporting HaSumf1's conservation involvement in the adaptation of host plant GLSs during lepidopteran insect evolution. Therefore, it plays a critical role in the growth and development of H. armigera, offering molecular targets for developing novel pesticides and targeted control measures against this vital pest. [ABSTRACT FROM AUTHOR]

After non‐native herbivores arrive in a novel habitat and establish, they must then disperse to new host plants to continue invading. While flight‐capable insect herbivores can expand their non‐native ranges by flying to new hosts, insects that lack wings, such as female scale insects, are often aided in their spread by wind and phoretic dispersal vectors such as birds and mammals.After being detected in 2004 in a Texas nursery, crapemyrtle bark scale (CMBS), Acanthococcus lagerstroemiae (Kuwana) (Hemiptera: Eriococcidae), has established in 15 different states across the Southeast and Middle Atlantic regions of the USA.We quantified the wind speeds leading to scale insect dislodgement and, in the laboratory and field, evaluated the willingness of CMBS nymphs to crawl onto vector proxies (bird feathers and mammal fur).Our findings demonstrate that CMBS nymphs can become dislodged from ecologically relevant substrates at low wind speeds (~7 m/s) and provided evidence that CMBS nymphs willingly, though not preferentially, crawl onto vector proxies, a final step before dispersing phoretically. Our results indicate that trees with high‐density infestations of CMBS are frequent sources of propagules, given that (i) wind speeds that shake small tree branches are likely to dislodge active crawlers and (ii) active crawlers appear willing to walk onto birds and mammals.The apparent ease of between‐tree spread by CMBS via multiple modes of dispersal presents challenges for preventing the spread of this insect, but field confirmation of these mechanisms is needed to understand their relative importance. [ABSTRACT FROM AUTHOR]

Metamasius callizona (Chevrolat) (Coleoptera: Curculionidae) is an invasive weevil destroying Tillandsia utriculata L. (Bromeliaceae) populations in Florida, USA. A T. utriculata population in Belize coexists with M. callizona without adverse effects. Tillandsia utriculata and M. callizona from Belize and Florida were studied in the laboratory to determine how Belize T. utriculata can coexist with Belize M. callizona, using Florida and Belize T. utriculata, as well as pineapple, Ananas comosus (L.) Merr. (Bromeliaceae), as host plants. Florida M. callizona on pineapple leaves produced more eggs per female per day and had a shorter developmental time and pupation period, as well as a smaller adult width, than Belize M. callizona. Florida and Belize weevils did not differ significantly in rates of egg hatch, pupation, and adult emergence. Florida M. callizona laid similar numbers of eggs per day on Florida and Belize T. utriculata. Egg hatch rates were similar on pineapple and Florida and Belize T. utriculata. Pupation rates were similar on pineapple and Florida T. utriculata leaves; no larvae on Belize T. utriculata attained fourth instar. Field and laboratory observations revealed that Belize and Florida M. callizona mined Belize T. utriculata without destroying the meristem, allowing plants to survive, but Belize M. callizona destroyed the core of pineapple tops. Soluble solids were greatest in pineapple and least in Belize T. utriculata. Leaf toughness was greatest in pineapple and least in Florida T. utriculata. Metamasius callizona biology and behavior and T. utriculata plant characteristics may drive the severity of weevil damage on populations of T. utriculata. The discovery of a T. utriculata population in Belize coexisting with M. callizona offers a possible way to control M. callizona in Florida. [ABSTRACT FROM AUTHOR]

The rugose spiralling whitefly (RSW), an invasive polyphagous insect introduced into India in 2016, has threatened coconut and other crops. Natural infestation intensity data indicated, in order, the following most likely RSW hosts: Cocos nucifera L. (75.83%) > Dypsis lutescens H. Wendel (55.83%) > Annona squamosa L. (54.17%) > Musa paradisiaca L. (43.33%). A preference analysis of these four host plants showed that coconut was the most favoured (8.17 spirals per 30 cm2 and 33.04 eggs per spiral). Olfactometry of the headspace leaf volatiles revealed that C. nucifera (3.05 ± 0.27 min) and D. lutescens (1.67 ± 1.67 min) had longer residence durations and attracted more RSW females than the other hosts. According to principal component analysis, those potential hosts shared six volatile compounds, the most peculiar of which was 2-ethyl-1-hexanol. Gas chromatography coupled electroantennographic detection analysis revealed that 2-ethyl-1,3-dioxolane, 1,3-dioxolane, 2-propyl, butanoic acid, 2-hydroxy-2-methyl-methyl ester, m-ethyltoluene, p-dichlorobenzene and 2-ethyl-1-hexanol evoked consistent olfactory responses in RSW. More studies on these chemicals might help develop parakairomones for managing RSW. [ABSTRACT FROM AUTHOR]

Background: Fungal endophytes exhibit symbiotic relationships with their host plants but have recently emerged as sources for synthesizing important varieties of secondary metabolites (SMs). Many of these metabolites have shown significant importance as antibacterial, antifungal, antitumor, and anticancer drugs, leading to their exploration in medicine and pharmaceuticals. The endophytes' biosynthetic gene clusters (BGCs) are responsible for encoding enzymes that produce these SMs. The fungal endophytes' ability has been challenged due to their inability to trigger cryptic BGCs and their loss of ability to produce secondary metabolites over an extended period in an artificial culture medium. This review investigates the array of SMs produced by endophytic fungi. It identifies methods for awakening and exploiting silent BGCs to produce novel natural metabolites and explores recent advancements in metabolomics platforms used to profile SMs. Silent BGCs can be activated using various methods, including co-cultivation, one strain of many compounds, epigenetic modification, heterologous expression, and cluster-specific transcription factor methods. Short conclusion: These methods reviewed effectively enhance the production of silent BGCs, leading to a significant increase in secondary metabolite production. Meanwhile, metabolomics profiling using liquid or gas chromatography coupled with mass spectrometry could provide several chances to discover bioactive compounds' complexity and chemical diversity. This review has, thus, given insight into the significance of methods used to reactivate BGCs from endophytes and the importance of varying techniques of their metabolomic profiling. [ABSTRACT FROM AUTHOR]

Background: Viruses have notable effects on agroecosystems, wherein they can adversely affect plant health and cause problems (e.g., increased biosecurity risks and economic losses). However, our knowledge of their diversity and interactions with specific host plants in ecosystems remains limited. To enhance our understanding of the roles that viruses play in agroecosystems, comprehensive analyses of the viromes of a wide range of plants are essential. High-throughput sequencing (HTS) techniques are useful for conducting impartial and unbiased investigations of plant viromes, ultimately forming a basis for generating further biological and ecological insights. This study was conducted to thoroughly characterize the viral community dynamics in individual plants. Results: An HTS-based virome analysis in conjunction with proximity sampling and a tripartite network analysis were performed to investigate the viral diversity in chunkung (Cnidium officinale) plants. We identified 61 distinct chunkung plant-associated viruses (27 DNA and 34 RNA viruses) from 21 known genera and 6 unclassified genera in 14 known viral families. Notably, 12 persistent viruses (7 DNA and 5 RNA viruses) were exclusive to dwarfed chunkung plants. The detection of viruses from the families Partitiviridae, Picobirnaviridae, and Spinareoviridae only in the dwarfed plants suggested that they may contribute to the observed dwarfism. The co-infection of chunkung by multiple viruses is indicative of a dynamic and interactive viral ecosystem with significant sequence variability and evidence of recombination. Conclusions: We revealed the viral community involved in chunkung. Our findings suggest that chunkung serves as a significant reservoir for a variety of plant viruses. Moreover, the co-infection rate of individual plants was unexpectedly high. Future research will need to elucidate the mechanisms enabling several dozen viruses to co-exist in chunkung. Nevertheless, the important insights into the chunkung virome generated in this study may be relevant to developing effective plant viral disease management and control strategies. [ABSTRACT FROM AUTHOR]

Summary: The effect of pathogens on host diversity has attracted much attention in recent years, yet how the influence of pathogens on individual plants scales up to affect community‐level host diversity remains unclear.Here, we assessed the effects of foliar fungal pathogens on plant growth and species richness using allometric growth theory in population‐level and community‐level foliar fungal pathogen exclusion experiments. We calculated growth scaling exponents of 24 species to reveal the intraspecific size‐dependent effects of foliar fungal pathogens on plant growth. We also calculated the intercepts to infer the growth rates of relatively larger conspecific individuals.We found that foliar fungal pathogens inhibited the growth of small conspecific individuals more than large individuals, resulting in a positive allometric growth. After foliar fungal pathogen exclusion, species‐specific growth scaling exponents and intercepts decreased, but became positively related to species' relative abundance, providing a growth advantage for individuals of abundant species with a higher growth scaling exponent and intercept compared with rare species, and thus reduced species diversity.By adopting allometric growth theory, we elucidate the size‐dependent mechanisms through which pathogens regulate species diversity and provide a powerful framework to incorporate antagonistic size‐dependent processes in understanding species coexistence. [ABSTRACT FROM AUTHOR]

RNA viruses and viroids exist and evolve as quasispecies due to error-prone replication. Quasispecies consist of a few dominant master sequences alongside numerous variants that contribute to genetic diversity. Upon environmental changes, certain variants within quasispecies have the potential to become the dominant sequences, leading to the emergence of novel infectious strains. However, the emergence of new infectious variants remains unpredictable. Using mutant pools prepared by saturation mutagenesis of selected stem and loop regions, our study of potato spindle tuber viroid (PSTVd) demonstrates that mutants forming local three-dimensional (3D) structures similar to the wild type (WT) are more likely to accumulate in PSTVd quasispecies. The selection mechanisms underlying this biased accumulation are likely associated with cell-to-cell movement and long-distance trafficking. Moreover, certain trafficking-defective PSTVd mutants can be spread by functional sister genomes in the quasispecies. Our study reveals that the RNA 3D structure of stems and loops constrains the evolution of viroid quasispecies. Mutants with a structure similar to WT have a higher likelihood of being maintained within the quasispecies and can potentially give rise to novel infectious variants. These findings emphasize the potential of targeting RNA 3D structure as a more robust approach to defend against viroid infections. Author summary: Our study investigates the world of RNA viruses and viroids, which are constantly evolving due to error-prone replication. These pathogens exist as quasispecies, featuring dominant master sequences and numerous variants. Understanding how new infectious strains emerge from this genetic diversity remains challenging. Focusing on potato spindle tuber viroid (PSTVd), targeted mutagenesis of specific stem and loop regions was performed to generate mutant pools. Plants were infected with mutant pools, and progeny were analyzed following cell-to-cell movement and long-distance trafficking. Our results reveal that mutants with 3D structures similar to the wild type viroid are more likely to accumulate within quasispecies. This accumulation is associated with the ability to move between cells and travel long distances within the plant host. Even mutants with impaired mobility can be spread by functional counterparts within the quasispecies. This study highlights the role of RNA 3D structures in shaping viroid quasispecies evolution. Mutants resembling the wild type viroid have a greater chance of persisting within quasispecies and may give rise to new infectious variants. These findings offer insight into viroid quasispecies dynamics and identify RNA 3D structure as a promising avenue for resistance strategies. [ABSTRACT FROM AUTHOR]

New records of host plants are reported for three species of the genus Chrysobothris Eschscholtz, 1829 (Buprestidae) and four species respectively belonging to the genera Euderces LeConte, 1850, Ancylocera Audinet-Serville, 1834, Elytroleptus Dugés, 1879 and Sphaenothecus Dupont, 1838 (Cerambycidae). [ABSTRACT FROM AUTHOR]

Insects harbor a remarkable diversity of gut microbiomes critical for host survival, health, and fitness, but the mechanism of this structured symbiotic community remains poorly known, especially for the insect group consisting of many closely related species that inhabit the Qinghai‐Tibet Plateau. Here, we firstly analyzed population‐level 16S rRNA microbial dataset, comprising 11 Parnassius species covering 5 subgenera, from 14 populations mostly sampled in mountainous regions across northwestern‐to‐southeastern China, and meanwhile clarified the relative importance of multiple factors on gut microbial community structure and evolution. Our findings indicated that both host genetics and larval host plant modulated gut microbial diversity and community structure. Moreover, the effect analysis of host genetics and larval diet on gut microbiomes showed that host genetics played a critical role in governing the gut microbial beta diversity and the symbiotic community structure, while larval host plant remarkably influenced the functional evolution of gut microbiomes. These findings of the intimate insect–microbe–plant interactions jointly provide some new insights into the correlation among the host genetic background, larval host plant, the structure and evolution of gut microbiome, as well as the mechanisms of high‐altitude adaptation in closely related species of this alpine butterfly group. [ABSTRACT FROM AUTHOR]

Epiphytic species are ecologically important and a significant component of biodiversity. To ensure their efficient conservation, we need to understand their ecology and host plant associations. It is also important to investigate how the predicted temperature change will affect their future distribution. Here, we use data collected in Nepal to investigate how epiphytic orchids are associated with host species, their distribution patterns, and how they may be threatened by the predicted increase in temperature towards the end of the 21st century. We used the phi coefficient (Φ) of association to calculate the associations of epiphytic orchid species with plants and rarefaction to describe the diversity of orchids associated with a particular host species. We used interpolation to estimate the distribution of epiphytic orchids and their host species along altitudinal gradients. The phi (Φ) coefficient of association revealed that 30 species of host plants showed more association with different orchid species than expected. The number of epiphytic orchids increased with the number of host individuals. We predict that an increase in temperature by ~3 °C, which is a more moderate value of temperature increase by the end of the 21st century, will affect at least 52 narrow-ranged species of orchids and 58 narrow-ranged species of host plants. Therefore, we should make efforts to prevent many plant species from becoming extinct, as an increase in temperature is likely to affect their existence. [ABSTRACT FROM AUTHOR]

In this paper, we discuss the evolutionary implications of the correlation between different species of Peucedanum plants and the distribution of Gortyna borelii moth populations in Romania. We highlight geographic separation and isolation among these populations due to anthropogenic landscape fragmentation, which hinders genetic exchange. A geometric morphometric analysis was utilized to visualize and compare the morphometric variations in relation to the environmental variables, particularly the host plant. Additionally, the distribution of G. borelii populations across Europe and in Romania that are correlated with the host plant was analyzed. The significant morphological and morphometric differences between the analyzed populations support our working hypothesis, according to which the use of different Peucedanum species by the larvae of G. borelii leads to an intraspecific diversification correlated with the host plant species. The newly discovered population of G. borelii in Romania holds substantial conservation importance, necessitating protection measures, including demarcating habitat areas and raising awareness among stakeholders. G. borelii is a protected species at the European level (Habitats Directive 92/43/EEC, Appendices II and IV), considered endangered due to the isolation of its populations and anthropogenic pressures exerted through agricultural practices. Understanding the impact of agricultural practices on their habitat is crucial for effective management strategies. Overall, this study sheds light on the complex interplay between ecological adaptation, host plant specialization, and speciation dynamics in phytophagous insects, emphasizing the importance of conservation efforts to preserve G. borelii populations and their habitats. [ABSTRACT FROM AUTHOR]

Microbotryum lychnidis-dioicae is an obligate fungal species colonizing the plant host, Silene latifolia. The fungus synthesizes and secretes effector proteins into the plant host during infection to manipulate the host for completion of the fungal lifecycle. The goal of this study was to continue functional characterization of such M. lychnidis-dioicae effectors. Here, we identified three putative effectors and their putative host-plant target proteins. MVLG_02245 is highly upregulated in M. lychnidis-dioicae during infection; yeast two-hybrid analysis suggests it targets a tubulin α-1 chain protein ortholog in the host, Silene latifolia. A potential plant protein interacting with MVLG_06175 was identified as CASP-like protein 2C1 (CASPL2C1), which facilitates the polymerization of the Casparian strip at the endodermal cells. Proteins interacting with MVLG_05122 were identified as CSN5a or 5b, involved in protein turnover. Fluorescently labelled MVLG_06175 and MVLG_05122 were expressed in the heterologous plant, Arabidopsis thaliana. MVLG_06175 formed clustered granules at the tips of trichomes on leaves and in root caps, while MVLG_05122 formed a band structure at the base of leaf trichomes. Plants expressing MVLG_05122 alone were more resistant to infection with Fusarium oxysporum. These results indicate that the fungus might affect the formation of the Casparian strip in the roots and the development of trichomes during infection as well as alter plant innate immunity. [ABSTRACT FROM AUTHOR]

The necrotrophic pathogen Botrytis cinerea infects a broad range of plant hosts and causes substantial economic losses to many crops. Although resistance to procymidone has been observed in the field, it remains uncertain why procymidone is usually involved in multidrug resistance (MDR) together with other fungicides. Nine mutants derived from the B. cinerea strain B05.10 through procymidone domestication exhibited high resistance factors (RFs) against both procymidone and fludioxonil. However, the fitness of the mutants was reduced compared to their parental strain, showing non-sporulation and moderate virulence. Furthermore, the RFs of these mutants to other fungicides, such as azoxystrobin, fluazinam, difenoconazole, and pyrimethanil, ranged from 10 to 151, indicating the occurrence of MDR. Transcriptive expression analysis using the quantitative polymerase chain reaction (qPCR) revealed that the mutants overexpressed ABC transporter genes, ranging from 2 to 93.7-fold. These mutants carried single-point mutations W647X, R96X, and Q751X within BcBos1 by DNA sequencing. These alterations in BcBos1 conferred resistance to procymidone and other fungicides in the mutants. Molecular docking analysis suggested distinct interactions between procymidone and Bos1 in the B. cinerea standard strain B05.10 or the resistant mutants, suggesting a higher affinity of the former towards binding with the fungicide. This study provides a comprehensive understanding of the biological characteristics of the resistant mutants and conducts an initial investigation into its fungicide resistance traits, providing a reference for understanding the causes of multidrug resistance of B. cinerea in the field. [ABSTRACT FROM AUTHOR]

Galls (also known as cecidia) have been studied by botanists, zoologists and microbiologists over the last century. Indeed, galls can be induced by different animals, bacteria, viruses and fungi, so that their presence simultaneously attested the presence of specific host plants and gall-inducing species. Consequently, gall collections, also known as cecidological herbaria or cecidological collections, can be interesting to study biodiversity changes over time. This review describes the main cecidological collections currently available in different European museums in order to stimulate their future study. The present analysis suggests that well-organized and preserved cecidological collections have great potential to guide research in taxonomy and systematics. Furthermore, this review aims to encourage future research on the conservation and digitisation standards of gall specimens in order to make cecidological data more accessible to researchers. [ABSTRACT FROM AUTHOR]

Simple Summary: The moth Semiothisa cinerearia (Lepidoptera: Geometridae) is a major pest of Chinese scholar trees (Sophora japonica L.). Olfaction is very important for insects to locate host plants and oviposition sites. Here, we identified the binding abilities of ScinGOBP2 for host plant volatiles using fluorescence-based competitive binding assays. We also confirmed the key amino acid residues that bind to plant volatiles in ScinGOBP2 via three-dimensional structure modeling and molecular docking. The ScinGOBP2 ligands had attractive or repellent behavioral effects on S. cinerearia for oviposition. Overall, ScinGOBP2 may play important roles in detecting host plant volatiles, and ScinGOBP2 ligands could be used as candidate olfactory regulators for the management of S. cinerearia. Herbivorous insects rely on volatile chemical cues from host plants to locate food sources and oviposition sites. General odorant binding proteins (GOBPs) are believed to be involved in the detection of host plant volatiles. In the present study, one GOBP gene, ScinGOBP2, was cloned from the antennae of adult Semiothisa cinerearia. Reverse-transcription PCR and real-time quantitative PCR analysis revealed that the expression of ScinGOBP2 was strongly biased towards the female antennae. Fluorescence-based competitive binding assays revealed that 8 of the 27 host plant volatiles, including geranyl acetone, decanal, cis-3-hexenyl n-valerate, cis-3-hexenyl butyrate, 1-nonene, dipentene, α-pinene and β-pinene, bound to ScinGOBP2 (KD = 2.21–14.94 μM). The electrical activities of all eight ScinGOBP2 ligands were confirmed using electroantennography. Furthermore, oviposition preference experiments showed that eight host volatiles, such as decanal, cis-3-hexenyl n-valerate, cis-3-hexenyl butyrate, and α-pinene, had an attractive effect on female S. cinerearia, whereas geranyl acetone, 1-nonene, β-pinene, and dipentene inhibited oviposition in females. Consequently, it can be postulated that ScinGOBP2 may be implicated in the perception of host plant volatiles and that ScinGOBP2 ligands represent significant semiochemicals mediating the interactions between plants and S. cinerearia. This insight could facilitate the development of a chemical ecology-based approach for the management of S. cinerearia. [ABSTRACT FROM AUTHOR]

Pyricularia oryzae (syn. Magnaporthe oryzae), is a filamentous ascomycete that causes a major disease called blast on cereal crops, as well as on a wide variety of wild and cultivated grasses. Blast diseases have a tremendous impact worldwide particularly on rice and on wheat, where the disease emerged in South America in the 1980s, before spreading to Asia and Africa. Its economic importance, coupled with its amenability to molecular and genetic manipulation, have inspired extensive research efforts aiming at understanding its biology and evolution. In the past 40 years, this plant‐pathogenic fungus has emerged as a major model in molecular plant–microbe interactions. In this review, we focus on the clarification of the taxonomy and genetic structure of the species and its host range determinants. We also discuss recent molecular studies deciphering its lifecycle. Taxonomy: Kingdom: Fungi, phylum: Ascomycota, sub‐phylum: Pezizomycotina, class: Sordariomycetes, order: Magnaporthales, family: Pyriculariaceae, genus: Pyricularia. Host range: P. oryzae has the ability to infect a wide range of Poaceae. It is structured into different host‐specialized lineages that are each associated with a few host plant genera. The fungus is best known to cause tremendous damage to rice crops, but it can also attack other economically important crops such as wheat, maize, barley, and finger millet. Disease symptoms: P. oryzae can cause necrotic lesions or bleaching on all aerial parts of its host plants, including leaf blades, sheaths, and inflorescences (panicles, spikes, and seeds). Characteristic symptoms on leaves are diamond‐shaped silver lesions that often have a brown margin and whose appearance is influenced by numerous factors such as the plant genotype and environmental conditions. USEFUL WEBSITESResourcesURLGenomic data repositorieshttp://genome.jouy.inra.fr/gemo/Genomic data repositorieshttp://openriceblast.org/Genomic data repositorieshttp://openwheatblast.net/Genome browser for fungi (including P. oryzae)http://fungi.ensembl.org/index.htmlComparative genomics databasehttps://mycocosm.jgi.doe.gov/mycocosm/homeT‐DNA mutant databasehttp://atmt.snu.kr/T‐DNA mutant databasehttp://www.phi‐base.org/SNP and expression datahttps://fungidb.org/fungidb/app/ [ABSTRACT FROM AUTHOR]

Microorganisms associated with nematodes or enriched in galls have been reported previously to aid plant-parasitic nematodes (PPNs) in infecting and establishing parasitism in the host plants. However, the rhizosphere-associated microbiota, which strengthens the pathogenicity of PPNs, remains largely unknown. This study illustrated rhizosphere bacteria enhancing Meloidogyne incognita infection on Arabidopsis thaliana by comparing the gall numbers of the treatments between natural soil and the sterile soil or soils drenched with antibiotics. By culture-dependent and pot testing methods, sixteen bacterial combinations from rhizosphere soils of A. thaliana were demonstrated to enhance M. incognita pathogenicity, including the most effective Nocardioides. Single-strain inoculation from the Nocardioides combination significantly resulted in M. incognita forming more galls on roots than the control, in which N. nematodiphilus R-N-C8 was the most effective strain. Strain R-N-C8 could substantially facilitate the M. incognita second-stage juveniles (J2s) moving towards the roots of A. thaliana and infecting the roots by releasing chemoattractant to attract J2s. The chemoattractant from strain R-N-C8 was determined to be L-lysine. This study furnishes vital insights for understanding the infection of root-knot nematodes associated with rhizosphere microbes. [ABSTRACT FROM AUTHOR]

Simple Summary: In Mississippi, the stink bug complex infesting soybean is mainly composed of the brown stink bug, southern green stink bug, green stink bug, and redbanded stink bug. This study conducted spray bioassays to assess the susceptibilities of these stink bugs to seven commonly used formulated insecticides. Stinks bugs were collected from soybeans in Leland, MS, USA, at the Southern Insect Management Research Unit (SIMRU) Farm during 2022 and 2023, as well as from wild host plants in Clarksdale, MS. While the green stink bug exhibited consistent susceptibility across two years, the redbanded stink bug showed slightly increased susceptibility to neonicotinoids in 2023 compared to 2022. In 2022, the susceptibility ranking among species was redbanded stink bug ≤ green stink bug ≈ southern green stink bug, whereas in 2023, it was redbanded stink bug ≤ green stink bug ≤ brown stink bug. Enzyme activity analysis revealed no significant differences between the southern green and the green stink bug. However, compared to SIMRU-2023, populations of brown stink bug and redbanded stink bug from SIMRU-2022 and Clasksdale-2023 exhibited elevated enzyme activities, indicating potential variations in resistance mechanisms. These findings provide valuable insights for monitoring and managing insecticide resistance in Mississippi soybean. In Mississippi, the Pentatomidae complex infesting soybean is primarily composed of Euschistus servus, Nezara viridula, Chinavia hilaris, and Piezodorus guildinii. This study employed spray bioassays to evaluate the susceptibilities of these stink bugs to seven commonly used formulated insecticides: oxamyl, acephate, bifenthrin, λ-cyhalothrin, imidacloprid, thiamethoxam, and sulfoxaflor. Stinks bugs were collected from soybeans in Leland, MS, USA during 2022 and 2023, as well as from wild host plants in Clarksdale, MS. There was no significant difference in the susceptibility of C. hilaris to seven insecticides between two years, whereas P. guildinii showed slightly increased susceptibility to neonicotinoids in 2023. Among all four stink bug species, susceptibility in 2022 was ranked as P. guildinii ≤ C. hilaris ≈ N. viridula, while in 2023, it was ranked as P. guildinii ≤ C. hilaris ≤ E. Servus. Additionally, populations of E. servus and P. guildinii collected from Clarksdale exhibited high tolerance to pyrethroids and neonicotinoids. Moreover, populations of E. servus and P. guildinii from SIMRU-2022 and Clarksdale-2023 showed elevated esterase and cytochrome P450 activity, respectively. These findings from spray bioassays and enzyme activity analyses provide a baseline for monitoring insecticide resistance in Pentatomidae and can guide insecticide resistance management strategies for Mississippi soybean. [ABSTRACT FROM AUTHOR]

Simple Summary: The fall armyworm (FAW) Spodoptera frugiperda is an invasive pest that causes damage to several crops including maize, its preferred host plant. Initial outbreaks of the pest on the African continent were recorded in early 2016. A variety of management options were explored in Africa to control the pest. The use of biopesticides and biological control was one of them. The current study aimed at measuring the susceptibility of FAW larvae to an entomopathogenic virus, SfMNPV, isolated from Nigeria (West Africa). The findings proved that the new SfMNPV isolate from Nigeria (SfMNPV-KA1) is more effective than its exotic counterpart from Argentina (SfMNPV-ARG), paving the way for bioinsecticide use to control the fall armyworm in Africa. The fall armyworm (FAW) Spodoptera frugiperda (Lepidoptera, Noctuidae) has now become an invasive pest of global concern. The pest was first detected in Central and Western Africa in early 2016. Sustainable management options explored by stakeholders during early FAW invasion in Africa included the use of biopesticides and biological control. The current study aimed to compare the susceptibility of FAW larvae to SfMNPV with the assumption that the virus isolated from FAW populations in Africa has higher virulence compared with an isolate from Argentina (SfMNPV-ARG). We also hypothesized that host plant plays a role in SfMNPV efficacy and that cannibalism mediates horizontal and vertical transmission of the virus. This work provides pioneering data on the virulence of the new SfMNPV isolate from Nigeria (SfMNPV-KA1), which proved more effective than its exotic counterpart from Argentina (SfMNPV-ARG). The host plant effect made a significant difference between maize and onion with more FAW death in the larvae fed with contaminated onion 5 days post treatment. The study demonstrates and discusses the effect of cannibalism on virus transmission. [ABSTRACT FROM AUTHOR]

There has been substantial progress in the Mediterranean countries regarding research on viroids. Twenty-nine viroid species, all belonging to Pospiviroidae and Avsunviroidae genera, have been detected in the Mediterranean Basin. Not only have detection methods, such as reverse transcription-quantitative polymerase chain reaction and next-generation sequencing, been used for viroid detection, along with molecular hybridization techniques allowing for rapid detection, identification, and characterization of known and novel viroids in these countries, but eradication measures have also been taken that allowed for the efficient elimination of certain viroids in a number of Mediterranean countries. The eradication measures were followed as recommended by the European and Mediterranean Plant Protection Organization, which is known by its abbreviation, EPPO. The Mediterranean Region has been a niche for viroids since ancient times due to the warm climate and the socio-cultural conditions that facilitate viroid transmission among different host plant species. [ABSTRACT FROM AUTHOR]

The present paper highlighted the occurrence of Timarcha turbida (Erichson 1841) as an artichoke pest for the first time in Tunisian crops. In fact, Timarcha was never be reported previously to develop on a Compositae (Asteraceae) host plant. Here, larva and adult stages of the pest are described and host plants affinities in genus Timarcha are discussed. [ABSTRACT FROM AUTHOR]