Biodiversity of foliar fungal endophytes in white spruce (Picea glauca) from southern Québec

2006 ◽  
Vol 84 (5) ◽  
pp. 777-790 ◽  
Author(s):  
F.O.P. Stefani ◽  
J.A. Bérubé
Keyword(s):  
Picea Glauca ◽  
Sequence Similarity ◽  
Fungal Endophytes ◽  
Biological Significance ◽  
Its Region ◽  
White Spruce ◽  
Nuclear Ribosomal Dna ◽  
High Sequence Similarity ◽  
Forestry Practices ◽  
The Impact

The objective of this study was to investigate the foliar endophyte biodiversity of white spruce ( Picea glauca (Moench) Voss to establish a baseline for future comparative studies examining the impact of forestry practices. It identifies for the first time endophytic fungi living inside the needles of white spruce from 280 needles collected in seven natural stands in southern Québec. The endophyte colonization rate on surface sterilized needles was 53.2%. We performed a PCR-RFLP and sequence analysis on the ITS region of the nuclear ribosomal DNA to achieve molecular identification. Isolate ITS sequences were compared with data from GenBank presenting the best similarity and were analyzed by a maximum of parsimony and Bayesian inference. Relationships between morphological groups, digestion groups, and sequence groups were investigated. In all, 23 morphotypes were found to belong to 14 sequence groups and we demonstrated that morphological groups are poor indicators for estimating species diversity. This study is the first to establish species richness values for foliar endophytes. Among the 141 isolates in this study, 75.15% have a high sequence similarity with Lophodermium piceae , 10.95% with an unknown species of Mycosphaerella , and 5.5% with two species of the genus Hypoxylon . Distribution, incidence and biological significance of all the endophytes found in this study are discussed.

Distribution of the foliar fungal endophyte Phialocephala scopiformis and its toxin in the crown of a mature white spruce tree as revealed by chemical and qPCR analyses

2014 ◽  
Vol 44 (9) ◽  
pp. 1138-1143 ◽  
Author(s):  
Samantha L. Frasz ◽  
Allison K. Walker ◽  
Tienabe K. Nsiama ◽  
Gregory W. Adams ◽  
J. David Miller
Keyword(s):  
Picea Glauca ◽  
Limit Of Detection ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Its Region ◽  
White Spruce ◽  
Fungal Endophyte ◽  
Qpcr Assay ◽  
Small Samples ◽  
Dna Targeting

Phialocephala scopiformis Kowalski & Kehr is a foliar fungal endophyte of white spruce (Picea glauca (Moench) Voss) that produces the anti-insect compound rugulosin and other compounds in lower amounts. Seedlings inoculated with this and other toxigenic endophytes have increased tolerance to the spruce budworm Choristoneura fumiferana (Clemens, 1865). The presence of rugulosin in the diet and in needles infected by P. scopiformis reduces the growth rate of the insect. One of 300 white spruce trees inoculated as a seedling in 2001 was chosen to investigate the distribution of P. scopiformis and its principal toxin rugulosin throughout the crown. To facilitate the detection of the fungus in small samples, a qPCR assay was developed based on the ITS region of fungal ribosomal DNA targeting a genetic polymorphism unique to P. scopiformis. The assay was specific, with a method limit of detection 100 ng mycelium per gram needle sample with high reproducibility and accuracy. We found that 11 years after inoculation, P. scopiformis DAOM 229536 and its toxin were detectable in needle samples distributed throughout the crown. Of the 109 samples tested, 100% of the rugulosin-positive samples also tested positive for P. scopiformis DAOM 229536 DNA in the qPCR assay. The mean and median needle rugulosin concentrations were >2 times that required to reduce the growth of spruce budworm.

scholarly journals The size, shape and specificity of the sugar-binding site of the jacalin-related lectins is profoundly affected by the proteolytic cleavage of the subunits

2002 ◽  
Vol 367 (3) ◽  
pp. 817-824 ◽  
Author(s):  
Corinne HOULÈS ASTOUL ◽  
Willy J. PEUMANS ◽  
Els J.M. van DAMME ◽  
Annick BARRE ◽  
Yves BOURNE ◽  
...  
Keyword(s):  
Binding Site ◽  
Plant Pathogens ◽  
Higher Plants ◽  
Sequence Similarity ◽  
Binding Specificity ◽  
Proteolytic Cleavage ◽  
Carbohydrate Binding ◽  
High Sequence Similarity ◽  
Intracellular Location ◽  
The Impact

Mannose-specific lectins with high sequence similarity to jacalin and the Maclura pomifera agglutinin have been isolated from species belonging to the families Moraceae, Convolvulaceae, Brassicaceae, Asteraceae, Poaceae and Musaceae. Although these novel mannose-specific lectins are undoubtedly related to the galactose-specific Moraceae lectins there are several important differences. Apart from the obvious differences in specificity, the mannose- and galactose-specific jacalin-related lectins differ in what concerns their biosynthesis and processing, intracellular location and degree of oligomerization of the protomers. Taking into consideration that the mannose-specific lectins are widely distributed in higher plants, whereas their galactose-specific counterparts are confined to a subgroup of the Moraceae sp. one can reasonably assume that the galactose-specific Moraceae lectins are a small-side group of the main family. The major change that took place in the structure of the binding site of the diverging Moraceae lectins concerns a proteolytic cleavage close to the N-terminus of the protomer. To corroborate the impact of this change, the specificity of jacalin was re-investigated using surface plasmon resonance analysis. This approach revealed that in addition to galactose and N-acetylgalactosamine, the carbohydrate-binding specificity of jacalin extends to mannose, glucose, N-acetylmuramic acid and N-acetylneuraminic acid. Owing to this broad carbohydrate-binding specificity, jacalin is capable of recognizing complex glycans from plant pathogens or predators.

scholarly journals Long-read cDNA sequencing identifies functional pseudogenes in the human transcriptome

2021 ◽  
Author(s):  
Robin-Lee Troskie ◽  
Yohaann Jafrani ◽  
Tim R Mercer ◽  
Adam D Ewing ◽  
Geoffrey J Faulkner ◽  
...  
Keyword(s):  
Cultured Cells ◽  
Sequence Similarity ◽  
Open Reading Frames ◽  
Cdna Sequencing ◽  
High Sequence Similarity ◽  
Protein Coding ◽  
Dynamic Component ◽  
Gene Copies ◽  
Sequencing Platforms ◽  
The Impact

Pseudogenes are gene copies presumed to mainly be functionless relics of evolution due to acquired deleterious mutations or transcriptional silencing. When transcribed, pseudogenes may encode proteins or enact RNA-intrinsic regulatory mechanisms. However, the extent, characteristics and functional relevance of the human pseudogene transcriptome are unclear. Short-read sequencing platforms have limited power to resolve and accurately quantify pseudogene transcripts owing to the high sequence similarity of pseudogenes and their parent genes. Using deep full-length PacBio cDNA sequencing of normal human tissues and cancer cell lines, we identify here hundreds of novel transcribed pseudogenes. Pseudogene transcripts are expressed in tissue-specific patterns, exhibit complex splicing patterns and contribute to the coding sequences of known genes. We survey pseudogene transcripts encoding intact open reading frames (ORFs), representing potential unannotated protein-coding genes, and demonstrate their efficient translation in cultured cells. To assess the impact of noncoding pseudogenes on the cellular transcriptome, we delete the nucleus- enriched pseudogene PDCL3P4 transcript from HAP1 cells and observe hundreds of perturbed genes. This study highlights pseudogenes as a complex and dynamic component of the transcriptional landscape underpinning human biology and disease.

scholarly journals Avian Predation in a Declining Outbreak Population of the Spruce Budworm, Choristoneura fumiferana (Lepidoptera: Tortricidae)

Insects ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 720
Author(s):  
Jacques Régnière ◽  
Lisa Venier ◽  
Dan Welsh
Keyword(s):  
Foraging Behavior ◽  
Picea Glauca ◽  
Choristoneura Fumiferana ◽  
Feeding Activity ◽  
Abies Balsamea ◽  
Bird Species ◽  
Spruce Budworm ◽  
White Spruce ◽  
Avian Predation ◽  
The Impact

The impact of avian predation on a declining population of the spruce budworm, Choristoneura fumifereana (Clem.), was measured using single-tree exclosure cages in a mature stand of balsam fir, Abies balsamea (L.), and white spruce, Picea glauca (Moench.) Voss. Bird population censuses and observations of foraging and nest-feeding activity were also made to determine the response of budworm-linked warblers to decreasing food availability. Seasonal patterns of foraging. as well as foraging success in the declining prey population was compared to similar information from birds observed in another stand where the spruce budworm population was rising. Avian predation was an important source of mortality between the 4th instar and moth emergence in the declining outbreak population. Mortality by predation increased from negligible to over 98% as budworm density dropped from 100 to <1 larva/kg of host foliage, over 3 years. Calculations based on nest-feeding activity and basic metabolic demands support these observed rates. Seasonal and yearly differences in predation rates observed between the two host-tree species correspond to equivalent shifts in bird foraging behavior in response to dropping insect density. In particular, a preference for searching on white spruce disappeared, although budworm-linked birds remained more efficient at finding food on this plant. The ability to change foraging behavior as prey density dropped differed between bird species.

Exponential fertilization and plant competition effects on the growth and N nutrition of trembling aspen and white spruce seedlings

2015 ◽  
Vol 45 (1) ◽  
pp. 78-86 ◽  
Author(s):  
Ya-Lin Hu ◽  
Yue Hu ◽  
De-Hui Zeng ◽  
Xiao Tan ◽  
Scott X. Chang
Keyword(s):  
Growth Performance ◽  
Populus Tremuloides ◽  
Picea Glauca ◽  
N Uptake ◽  
White Spruce ◽  
Trembling Aspen ◽  
N Nutrition ◽  
Nursery Production ◽  
Exponential Fertilization ◽  
The Impact

Exponential fertilization has been shown to be a useful technique for improving seedling quality during nursery production. In this study, we evaluated (i) the impact of exponential vs. conventional fertilization on trembling aspen (Populus tremuloides Michx.) and white spruce (Picea glauca (Moench) Voss) seedlings during nursery production and (ii) the growth performance and nitrogen (N) utilization of those seedlings in response to foxtail barley (Hordeum jubatum L.) competition after the transplantation of seedlings in a greenhouse experiment. Exponential fertilization with an application rate higher than the conventional fertilization increased the internal N reserve in trembling aspen and white spruce seedlings during nursery production and also increased new leaf, new stem, and old stem biomass and N retranslocation rates in trembling aspen seedlings but not in white spruce seedlings after transplantation. Foxtail barley competition decreased N concentrations in seedlings and soil N uptake by the seedlings; however, increased N retranslocation rates with foxtail barley competition were observed in white spruce seedlings but not in trembling aspen seedlings. Our results suggest that the growth performance of seedlings was improved by N loading, whereas the impact of vegetation management was species specific.

scholarly journals Birch (Betula papyrifera) × white spruce (Picea glauca) interactions in mixedwood stands: implications for management

2013 ◽  
Vol 59 (No. 4) ◽  
pp. 137-149 ◽  
Author(s):  
Ch.D.B. Hawkins ◽  
A. Dhar
Keyword(s):  
Regression Analysis ◽  
Picea Glauca ◽  
Mixed Model ◽  
Basal Area ◽  
White Spruce ◽  
Betula Papyrifera ◽  
Vegetation Control ◽  
Mixed Model Anova ◽  
Paper Birch ◽  
The Impact

Current British Columbia forest regulations drive the regeneration management towards pure conifer stands rather than remaining in a mixed-species condition. This approach may result in unnecessary vegetation control. The main objective of this investigation was to study the impact of variable paper birch densities on white spruce growth in 15&ndash;20 years old stands for management implications. Regression analysis was used to examine the effect of birch density and two competition indices to predict spruce growth. A mixed model ANOVA showed that spruce mean annual DBH and basal area increment differed significantly among sites and density. From the regression analysis it appears that birch density up to 4,000 stems&middot;ha<sup>&ndash;1</sup> had no significant influence on spruce growth which is much higher than the current BC reforestation guideline (1,000 stems&middot;ha<sup>&ndash;1</sup> broadleaves). Similarly, birch relative density index (RDI) had to exceed 3 to affect spruce DBH growth significantly on all sites except one. On most sites, spruce had a larger DBH than birch. Our results also suggest that rather than following the current broadcast approach to vegetation management, a targeted approach could enhance forest productivity and stand diversity. &nbsp;

scholarly journals Evaluating the impact of stand composition and competition on white spruce and aspen wood attributes in the boreal mixedwood

2021 ◽  
Author(s):  
◽  
Ryan Jackalin
Keyword(s):  
Populus Tremuloides ◽  
Picea Glauca ◽  
Wood Quality ◽  
White Spruce ◽  
Aspen Wood ◽  
Mixed Stands ◽  
Spruce Wood ◽  
Intimate Mixture ◽  
Volume Production ◽  
The Impact

I evaluated how intra- and inter-specific competition affects the development of eleven wood attributes of trembling aspen (Populus tremuloides Michx.) and white spruce (Picea glauca (Moench) Voss) over 34 years. My analysis was conducted in a mixedwood trial site in Northern British Columbia, Canada, that included treatments consisting of 0, 1000, 2000, 5000, and 10000 stems per hectare of aspen. Competition was found to negatively influence wood attribute development in aspen and positively impact spruce (at low levels of competition). Plot level competition indices were the best predictor of variation in aspen wood attributes, while stand level competition (population density) best explained the majority of spruce wood attributes. Maintaining aspen at lower densities in intimate mixture can have a positive effect on spruce wood quality, while incurring relatively small reductions in spruce volume production and also retaining the ecological benefits associated with managing for mixed stands.

scholarly journals Impact of Endochitinase-Transformed White Spruce on Soil Fungal Biomass and Ectendomycorrhizal Symbiosis

2010 ◽  
Vol 76 (8) ◽  
pp. 2607-2614 ◽  
Author(s):  
Franck O. P. Stefani ◽  
Philippe Tanguay ◽  
Gervais Pelletier ◽  
Yves Pich� ◽  
Richard C. Hamelin
Keyword(s):  
Root Exudates ◽  
Picea Glauca ◽  
Fungal Biomass ◽  
White Spruce ◽  
Soil Samples ◽  
Analysis Of Covariance ◽  
Root Tips ◽  
Dark Septate Endophyte ◽  
Phialocephala Fortinii ◽  
The Impact

ABSTRACT The impact of transgenic white spruce [Picea glauca (Moench) Voss] containing the endochitinase gene (ech42) on soil fungal biomass and on the ectendomycorrhizal fungi Wilcoxina spp. was tested using a greenhouse trial. The measured level of endochitinase in roots of transgenic white spruce was up to 10 times higher than that in roots of nontransformed white spruce. The level of endochitinase in root exudates of three of four ech42-transformed lines was significantly greater than that in controls. Analysis soil ergosterol showed that the amount of fungal biomass in soil samples from control white spruce was slightly larger than that in soil samples from ech42-transformed white spruce. Nevertheless, the difference was not statistically significant. The rates of mycorrhizal colonization of transformed lines and controls were similar. Sequencing the internal transcribed spacer rRNA region revealed that the root tips were colonized by the ectendomycorrhizal fungi Wilcoxina spp. and the dark septate endophyte Phialocephala fortinii. Colonization of root tips by Wilcoxina spp. was monitored by real-time PCR to quantify the fungus present during the development of ectendomycorrhizal symbiosis in ech42-transformed and control lines. The numbers of Wilcoxina molecules in the transformed lines and the controls were not significantly different (P > 0.05, as determined by analysis of covariance), indicating that in spite of higher levels of endochitinase expression, mycorrhization was not inhibited. Our results indicate that the higher levels of chitinolytic activity in root exudates and root tissues from ech42-transformed lines did not alter the soil fungal biomass or the development of ectendomycorrhizal symbiosis involving Wilcoxina spp.

Effects of partial cutting on the ectomycorrhizae of Picea glauca forests in northwestern Alberta

2005 ◽  
Vol 35 (6) ◽  
pp. 1442-1454 ◽  
Author(s):  
Lance W Lazaruk ◽  
Gavin Kernaghan ◽  
S Ellen Macdonald ◽  
Damase Khasa
Keyword(s):  
Picea Glauca ◽  
Effective Means ◽  
White Spruce ◽  
Root Tip ◽  
Root Tips ◽  
Partial Cutting ◽  
Disturbance Intensity ◽  
Tree Retention ◽  
Green Tree Retention ◽  
The Impact

This study assessed the impact of various harvesting practices (including those designed to emulate natural disturbances) on ectomycorrhizae (ECM) associated with white spruce (Picea glauca (Moench) Voss) in northwestern Alberta, Canada. Treatments included clearcuts, partial cuts (dispersed green-tree retention with 20%, 50%, and 75% residual live trees, and aggregated green-tree retention), unharvested control sites, and a burned stand. The percentage of active white spruce root tips and ECM richness and diversity, as observed in soil cores collected throughout the study site, all decreased with increasing disturbance intensity. Effects were particularly pronounced in clearcuts, machine corridors used for access by harvesting equipment in the dispersed green-tree retention stands, and in burned areas. Reductions in ECM biodiversity could be attributed to the sensitivity of late-stage ectomycorrhizae (e.g., Cortinarius spp., Lactarius spp., and Russula spp.) to soil disturbances and changes in microclimate associated with harvesting or burning. Areas of dispersed and aggregated green-tree retention were not dramatically different than unharvested forest in terms of root tip density and ECM richness, diversity, and composition. Harvesting practices that retain a percentage of residual live trees, either dispersed throughout the cutting unit or in aggregated patches, could be an effective means of maintaining ectomycorrhizal biodiversity at the stand level.

Needle properties of host white spruce (Picea glauca [Moench] Voss) experiencing eastern dwarf mistletoe (Arceuthobium pusillum Peck) infections of differing severity

Botany ◽  
2017 ◽  
Vol 95 (3) ◽  
pp. 295-305 ◽  
Author(s):  
Johnathon A. de Villier ◽  
Jaret S. Reblin ◽  
Barry A. Logan
Keyword(s):  
Picea Glauca ◽  
Photosynthetic Capacity ◽  
Full Range ◽  
Severe Infection ◽  
White Spruce ◽  
Biochemical Properties ◽  
Dwarf Mistletoe ◽  
Needle Size ◽  
The Impact ◽  
Physiological And Biochemical

Eastern dwarf mistletoe (Arceuthobium pusillum Peck) parasitizes the branches of white spruce (Picea glauca [Moench] Voss) and ultimately kills this host species. Previous studies of host needle physiology generally focused on trees experiencing infections of moderate severity; here, we expanded upon previous research to investigate the morphological, physiological, and biochemical properties of needles from white spruce trees experiencing the full range of infection severities. We found that the impact of parasitism on host needle parameters did not scale uniformly with infection severity. Rather, parasitism reduced host needle size distal to infection and resulted in more negative carbon isotope ratios across all infection severities. Reduced foliar nitrogen and chlorophyll content were only evident in trees with moderate or severe infection, while photosynthetic capacity was depressed in only severely infected trees. Furthermore, while some impacts were confined to infected host branches, others, such as smaller needles and reduced photosynthetic capacity, were also evident in branches showing no visible signs of infection. We conclude that symptoms of infection appearing only after infection worsened in severity or appearing in uninfected branches may in whole or in part also be manifestations of a decline in resource availability and vigor of the whole tree.

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