scholarly journals Culturable Seed Microbiota of Populus trichocarpa

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 653
Author(s):  
Sabrina Heitmann ◽  
Gillian E. Bergmann ◽  
Edward Barge ◽  
Mary Ridout ◽  
George Newcombe ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Populus Trichocarpa ◽  
Inoculation Experiment ◽  
Seedling Mortality ◽  
Vegetative Tissues ◽  
Seed Mortality ◽  
Functional Consequences ◽  
Diverse Community ◽  
Bacteria And Fungi ◽  
Future Work

Plants harbor a diverse community of microbes, whose interactions with their host and each other can influence plant health and fitness. While microbiota in plant vegetative tissues has been extensively studied, less is known about members of the seed microbiota. We used culture-based surveys to identify bacteria and fungi found in the seeds of the model tree, Populus trichocarpa, collected from different sites. We found that individual P. trichocarpa seeds typically contained zero or one microbe, with common taxa including species of Cladosporium, Aureobasidium, Diaporthe, Alternaria, and Pseudomonas, a bacterium. Pseudomonas isolates were associated with seed mortality and were negatively associated with the occurrence of fungal isolates within Epicoccum, Alternaria, and Aureobasidium from the same seed. Next, we conducted an inoculation experiment with one of the isolated seed microbes, Pseudomonas syringae pv. syringae, and found that it reduced seed germination and increased seedling mortality for P. trichocarpa. Our findings highlight common fungi and bacteria in the seeds of P. trichocarpa, prompting further study of their functional consequences. Moreover, our study confirms that P. syringae pv. syringae is a seed pathogen of P. trichocarpa and is the first report that P. syringae pv. syringae is a lethal seedling pathogen of P. trichocarpa, allowing for future work on the pathogenicity of this bacterium in seedlings and potential antagonism with other seed microbes.

scholarly journals Chemical Composition and Anti-phytopathogenic Activity of the Essential Oil of Beilschmiedia miersii

2016 ◽  
Vol 11 (9) ◽  
pp. 1934578X1601100 ◽  
Author(s):  
Marcela A. Carvajal ◽  
Alejandra P. Vergara ◽  
Rocío Santander ◽  
Mauricio E. Osorio
Keyword(s):  
Chemical Composition ◽  
Essential Oil ◽  
Pseudomonas Syringae ◽  
Phytophthora Cinnamomi ◽  
Central Zone ◽  
Erwinia Carotovora ◽  
Stem Bark ◽  
Gibberella Fujikuroi ◽  
Agricultural Industries ◽  
Bacteria And Fungi

Beilschmiedia miersii (Gay) Kosterm. (Lauraceae) (“Belloto del Norte”) is a little-studied tree endemic of the Central Zone of Chile. Hydrodistillation of leaves and stem bark of B. miersii yielded 0.2% essential oil. GC-MS analysis allowed identification of 31 components. The most abundant compounds were three phenylpropanoids: Sarisan (45.8%), eugenol methyl ether (27.7%) and safrole (5.8%). The oil of B. miersii showed high antioxidant content (TEAC: 750.8 ± 9.6 μmol/100 g of essential oil). The anti-phytopathogenic activity was evaluated against pathogens of plants: Fungi (Botrytis cinerea, Gibberella fujikuroi and Phytophthora cinnamomi) and bacteria: (Erwinia carotovora, Pseudomonas syringae and Agrobacterium tumefaciens). The oil showed anti-phytopathogenic activity against all tested bacteria and fungi, especially against A tumefaciens (IC50 = 5 μg / mL) and P. cinnamomi (IC50 = 200 μg / mL). This study demonstrates that the essential oil of B. miersii has great potential for applications in food and agricultural industries.

scholarly journals Pantoea spp. Associated with Smooth Crabgrass (Digitaria ischaemum) Seed Inhibit Competitor Plant Species

2019 ◽  
Vol 7 (5) ◽  
pp. 143 ◽  
Author(s):  
Matthew T. Elmore ◽  
James F. White ◽  
Kathryn L. Kingsley ◽  
Katherine H. Diehl ◽  
Satish K. Verma
Keyword(s):  
Trifolium Repens ◽  
Bacterial Isolate ◽  
Axenic Culture ◽  
Taraxacum Officinale ◽  
Bacterial Isolates ◽  
Seedling Mortality ◽  
Pantoea Ananatis ◽  
Fungal Isolates ◽  
Successional Species ◽  
Bacteria And Fungi

Digitaria ischaemum (Schreb.) Schreb. ex Muhl. and Poa annua L. are competitive, early successional species which are usually considered weeds in agricultural and turfgrass systems. Bacteria and fungi associated with D. ischaemum and P. annua seed may contribute to their competitiveness by antagonizing competitor forbs, and were studied in axenic culture. Pantoea spp. were the most common bacterial isolate of D. ischaemum seed, while Epicoccum and Curvularia spp. were common fungal isolates. A variety of species were collected from non-surface sterilized P. annua. Certain Pantoea spp. isolates were antagonistic to competitor forbs Taraxacum officinale, Trifolium repens. All bacterial isolates that affected T. officinale mortality were isolated from D. ischaemum seed while none of the P. annua isolates affected mortality. Two selected bacterial isolates identified as Pantoea ananatis were evaluated further on D. ischaemum, T. repens (a competitor forb) and P. annua (a competitor grass) alone and in combination with a Curvularia sp. fungus. These bacteria alone caused >65% T. repens seedling mortality but did not affect P. annua seedling mortality. These experiments demonstrate that Pantoea ananatis associated with D. ischaemum seeds is antagonistic to competitor forbs in axenic culture. The weedy character of D. ischaemum could at least in part stem from the possession of bacteria that are antagonistic to competitor species.

scholarly journals Invertebrate Community Associated with the Asexual Generation of Bassettia pallida Ashmead (Hymenoptera: Cynipidae)

2020 ◽  
Author(s):  
Kelly L. Weinersmith ◽  
Andrew A. Forbes ◽  
Anna K.G. Ward ◽  
Pedro F. P. Brandão-Dias ◽  
Y. Miles Zhang ◽  
...  
Keyword(s):  
Natural Enemies ◽  
Gulf Coast ◽  
Insect Communities ◽  
Gall Wasp ◽  
Major Question ◽  
Wasp Species ◽  
Asexual Generation ◽  
Gall Wasps ◽  
Diverse Community ◽  
Future Work

AbstractCynipid gall wasps play an important role in structuring oak invertebrate communities. Wasps in the Cynipini tribe typically lay their eggs in oaks (Quercus L.), and induce the formation of a “gall”, which is a tumor-like growth of plant material that surrounds the developing wasp. As the wasp develops, the cynipid and its gall are attacked by a diverse community of natural enemies, including parasitoids, hyperparasitoids, and inquilines. Determining what structures these species-rich natural enemy communities across cynipid gall wasp species is a major question in gall wasp biology. Additionally, gall wasps are ecosystem engineers, as the abandoned gall is used by other invertebrates. The gall-associated insect communities residing on live oaks (Quercus geminata Small and Q. virginiana Mill.) are emerging as a model system for answering ecological and evolutionary questions ranging from community ecology to the evolution of new species. Documenting the invertebrates associated with cynipids in this system will expand our understanding of the mechanisms influencing eco-evolutionary processes, record underexplored axes of biodiversity, and facilitate future work. Here, we present the community of natural enemies and other associates of the asexual generation of the crypt gall wasp, Bassettia pallida Ashmead. We compare the composition of this community to communities recently documented from two other cynipid gall wasps specializing on live oaks along the U.S. Gulf coast, Disholcaspis quercusvirens Ashmead and Belonocnema treatae Mayr. B. pallida and their crypts support a diverse arthropod community, including over 25 parasitoids, inquilines, and other associated invertebrates spanning 5 orders and 16 families.

scholarly journals MicroRNA844-Guided Downregulation of Cytidinephosphate Diacylglycerol Synthase3 (CDS3) mRNA Affects the Response of Arabidopsis thaliana to Bacteria and Fungi

2015 ◽  
Vol 28 (8) ◽  
pp. 892-900 ◽  
Author(s):  
Hwa Jung Lee ◽  
Young Ju Park ◽  
Kyung Jin Kwak ◽  
Donghyun Kim ◽  
June Hyun Park ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Pseudomonas Syringae ◽  
Defense Response ◽  
Cleavage Site ◽  
Severe Disease ◽  
Mrna Level ◽  
Transcript Level ◽  
Loss Of Function ◽  
Pathogen Challenge ◽  
Bacteria And Fungi

Despite the fact that a large number of miRNA sequences have been determined in diverse plant species, reports demonstrating the functional roles of miRNAs in the plant response to pathogens are severely limited. Here, Arabidopsis thaliana miRNA844 (miR844) was investigated for its functional role in the defense response to diverse pathogens. Transgenic Arabidopsis plants overexpressing miR844 (35S::miR844) displayed much more severe disease symptoms than the wild-type plants when challenged with the bacterium Pseudomonas syringae pv. tomato DC3000 or the fungus Botrytis cinerea. By contrast, a loss-of-function mir844 mutant showed an enhanced resistance against the pathogens. Although no cleavage was observed at the predicted cleavage site of the putative target mRNA, cytidinephosphate diacylglycerol synthase3 (CDS3), cleavage was observed at 6, 12, 21, or 52 bases upstream of the predicted cleavage site of CDS3 mRNA, and the level of CDS3 mRNA was downregulated by the overexpression of miR844, implying that miR844 influences CDS3 transcript level. To further confirm that the miR844-mediated defense response was due to the decrease in CDS3 mRNA level, the disease response of a CDS3 loss-of-function mutant was analyzed upon pathogen challenge. Increased susceptibility of both cds3 mutant and 35S::miR844 plants to pathogens confirmed that miR844 affected the defense response by downregulating CDS3 mRNA. The expression of miR844 was decreased, and the CDS3 transcript level increased upon pathogen challenge. Taken together, these results provide evidence that downregulation of miR844 and a concomitant increase in CDS3 expression is a defensive response of Arabidopsis to bacteria and fungi.

scholarly journals The Importance of Biological Particles to the Ice Nucleating Particle Concentration in a Coastal Tropical Site

2018 ◽  
Author(s):  
Luis A. Ladino ◽  
Graciela B. Raga ◽  
Harry Alvarez-Ospína ◽  
Manuel A. Andino-Enríquez ◽  
Irma Rosas ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Hydrological Cycle ◽  
Aerosol Particles ◽  
Relevant Information ◽  
Cloud Formation ◽  
Tropical Regions ◽  
Biological Particles ◽  
Need To Evaluate ◽  
Bacteria And Fungi ◽  
Few Data

Abstract. Atmospheric aerosol particles that can nucleate ice are referred to as ice nucleating particles (INP). Recent studies have confirmed that aerosol particles emitted by mid- and high-latitude oceans can act as INPs. This very relevant information can be included in climate and weather models to predict the formation of ice in clouds, given that most of them do not consider the oceans as a source of INPs. Very few studies to sample INPs have been carried out in tropical latitudes, and there is a need to evaluate their availability to understand the potential role that marine aerosol may play in the hydrological cycle of tropical regions. This study presents results from the first measurements obtained during a field campaign conducted in the topical village of Sisal, located on the coast of the Gulf of Mexico of the Yucatan peninsula in Mexico in January–February 2017, and one of the few data sets currently available at similar latitudes. Aerosol particles sampled in Sisal are shown to be very efficient INPs, with onset freezing temperatures as high as −3 °C (in some cases), similar to the onset temperature for Pseudomonas syringae. The results show that the INP concentration in Sisal is higher than at other locations sampled with the same type of INP counter. Air masses arriving in Sisal during the passage of cold fronts have, surprisingly, higher INP concentrations than the campaign-average, despite their lower total aerosol concentration. Biological particles were likely found to be very important in ice cloud formation at this tropical location, given the large concentration of INPs above −12 °C. A variety of bacteria and fungi were identified. Although the majority are of terrestrial origin, some of them are clearly oceanic.

scholarly journals Evidence for Male Horn Dimorphism and Related Pronotal Shape Variation in Copris lunaris (Linnaeus, 1758) (Coleoptera: Scarabaeidae, Coprini)

Insects ◽  
2018 ◽  
Vol 9 (3) ◽  
pp. 108 ◽  
Author(s):  
Kaan Kerman ◽  
Angela Roggero ◽  
Antonio Rolando ◽  
Claudia Palestrini
Keyword(s):  
Body Size ◽  
Common Phenomenon ◽  
Shape Variation ◽  
Allometric Relationship ◽  
Geometric Morphometric ◽  
Horn Length ◽  
Functional Consequences ◽  
Males And Females ◽  
Morphological Differences ◽  
Future Work

Male horn dimorphism is a rather common phenomenon in dung beetles, where some adult individuals have well-developed head horns (i.e., major males), while others exhibit diminished horn length (i.e., minor males). We focused on horn dimorphism and associated head and pronotum shape variations in Copris lunaris. We examined the allometric relationship between horn length (i.e., cephalic and pronotal horns) and maximum pronotum width (as index of body size) by fitting linear and sigmoidal models for both sexes. We then asked whether head and pronotum shape variations, quantified using the geometric morphometric approach, contributed to this allometric pattern. We found that female cephalic and pronotal horn growth showed a typical isometric scaling with body size. Horn length in males, however, exhibited sigmoidal allometry, where a certain threshold in body size separated males into two distinct morphs as majors and minors. Interestingly, we highlighted the same allometric patterns (i.e., isometric vs. sigmoidal models) by scaling horn lengths with pronotum shape, making evident that male horn dimorphism is not only a matter of body size. Furthermore, the analysis of shape showed that the three morphs had similar heads, but different pronota, major males showing a more expanded, rounded pronotum than minor males and females. These morphological differences in C. lunaris can ultimately have important functional consequences in the ecology of this species, which should be explored in future work.

Differential effects of mammalian seed predators on the regeneration of five Papua New Guinean tree species and implications for sapling recruitment

2008 ◽  
Vol 24 (3) ◽  
pp. 259-267 ◽  
Author(s):  
Elizabeth R. Jones ◽  
Lisa M. Curran ◽  
Debra D. Wright ◽  
Andrew L. Mack
Keyword(s):  
Seed Predation ◽  
Tree Species ◽  
Life Stage ◽  
Seedling Mortality ◽  
Differential Effects ◽  
Focal Species ◽  
Seed Predators ◽  
Seed Mortality ◽  
Species Specific ◽  
Papua New Guinean

Abstract:Although herbivores may account for a significant source of seed and seedling mortality in many tropical tree species, plant species differ in their response to seed damage. Here we investigate the relative effects of seed predation on the regeneration of five tree species in a mid-elevation Papua New Guinean rain forest. Exclosure treatments and shade-house experiments were monitored from November 2004 to March 2006 to assess the differential effects of seed predation on seed viability and seedling growth. Results indicate that although seed predators attack all five focal species, they influence the seedling populations in two, Cerbera floribunda and Microcos grandiflora, and minimally affect the seedling populations of Terminalia impediens, Pandanus penicillus and Endiandra latifolia in the years measured. Predation and germination frequencies were compared to the abundance of focal species at several life stage classes to explore potential correlations between species-specific seed mortality patterns and life stage distributions. We found that the species-specific influence of mammalian seed predators correlated with abundance distributions in three life stages. Species with high survivorship after seed predator attacks displayed a significant decrease in abundance from the seedling-to-sapling transition, while those species with high seed mortality demonstrated relatively even distributions of seedlings, saplings and adults (> 10 cm dbh). These contrasting patterns suggest that differential seed predation effects on regeneration may play a key role in the recruitment of individuals to the sapling stage.

scholarly journals Isolation, Characterization, and Pathogenicity of Two Pseudomonas syringae Pathovars from Populus trichocarpa Seeds

2020 ◽  
Vol 8 (8) ◽  
pp. 1137 ◽  
Author(s):  
Patricia MB Saint-Vincent ◽  
Mary Ridout ◽  
Nancy L. Engle ◽  
Travis J. Lawrence ◽  
Meredith L. Yeary ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Virulence Factors ◽  
Host Response ◽  
Plant Pathogens ◽  
Populus Trichocarpa ◽  
Bacterial Pathogen ◽  
Effector Proteins ◽  
Agricultural Crop ◽  
Pseudomonas Syringae Pathovars ◽  
Woody Host

Pseudomonas syringae is a ubiquitous plant pathogen, infecting both woody and herbaceous plants and resulting in devastating agricultural crop losses. Characterized by a remarkable specificity for plant hosts, P. syringae pathovars utilize a number of virulence factors including the type III secretion system and effector proteins to elicit disease in a particular host species. Here, two Pseudomonas syringae strains were isolated from diseased Populustrichocarpa seeds. The pathovars were capable of inhibiting poplar seed germination and were selective for the Populus genus. Sequencing of the newly described organisms revealed similarity to phylogroup II pathogens and genomic regions associated with woody host-associated plant pathogens, as well as genes for specific virulence factors. The host response to infection, as revealed through metabolomics, is the induction of the stress response through the accumulation of higher-order salicylates. Combined with necrosis on leaf surfaces, the plant appears to quickly respond by isolating infected tissues and mounting an anti-inflammatory defense. This study improves our understanding of the initial host response to epiphytic pathogens in Populus and provides a new model system for studying the effects of a bacterial pathogen on a woody host plant in which both organisms are fully genetically sequenced.

scholarly journals Parasitism by endoparasitoid wasps alters the internal but not the external microbiome in host caterpillars

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Gabriele Gloder ◽  
Mitchel E. Bourne ◽  
Christel Verreth ◽  
Liesbet Wilberts ◽  
Sofie Bossaert ◽  
...  
Keyword(s):  
Community Structure ◽  
Close Association ◽  
Natural Populations ◽  
Biotic Interactions ◽  
Amplicon Sequencing ◽  
Laboratory Culture ◽  
Pieris Brassicae ◽  
Cotesia Glomerata ◽  
Diverse Community ◽  
Bacteria And Fungi

Abstract Background The microbiome of many insects consists of a diverse community of microorganisms that can play critical roles in the functioning and overall health of their hosts. Although the microbial communities of insects have been studied thoroughly over the past decade, little is still known about how biotic interactions affect the microbial community structure in and on the bodies of insects. In insects that are attacked by parasites or parasitoids, it can be expected that the microbiome of the host insect is affected by the presence of these parasitic organisms that develop in close association with their host. In this study, we used high-throughput amplicon sequencing targeting both bacteria and fungi to test the hypothesis that parasitism by the endoparasitoid Cotesia glomerata affected the microbiome of its host Pieris brassicae. Healthy and parasitized caterpillars were collected from both natural populations and a laboratory culture. Results Significant differences in bacterial community structure were found between field-collected caterpillars and laboratory-reared caterpillars, and between the external and the internal microbiome of the caterpillars. Parasitism significantly altered the internal microbiome of caterpillars, but not the external microbiome. The internal microbiome of all parasitized caterpillars and of the parasitoid larvae in the caterpillar hosts was dominated by a Wolbachia strain, which was completely absent in healthy caterpillars, suggesting that the strain was transferred to the caterpillars during oviposition by the parasitoids. Conclusion We conclude that biotic interactions such as parasitism have pronounced effects on the microbiome of an insect host and possibly affect interactions with higher-order insects.

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