scholarly journals Isolation of Fungal Cellobiohydrolase I Genes from Sporocarps and Forest Soils by PCR

2008 ◽  
Vol 74 (11) ◽  
pp. 3481-3489 ◽  
Author(s):  
Ivan P. Edwards ◽  
Rima A. Upchurch ◽  
Donald R. Zak

ABSTRACT Cellulose is the major component of plant biomass, and microbial cellulose utilization is a key step in the decomposition of plant detritus. Despite this, little is known about the diversity of cellulolytic microbial communities in soil. Fungi are well known for their cellulolytic activity and mediate key functions during the decomposition of plant detritus in terrestrial ecosystems. We developed new oligonucleotide primers for fungal exocellulase genes (cellobiohydrolase, cbhI) and used these to isolate distinct cbhI homologues from four species of litter-decomposing basidiomycete fungi (Clitocybe nuda, Clitocybe gibba, Clitopilus prunulus, and Chlorophyllum molybdites) and two species of ascomycete fungi (Xylaria polymorpha and Sarcoscypha occidentalis). Evidence for cbhI gene families was found in three of the four basidiomycete species. Additionally, we isolated and cloned cbhI genes from the forest floor and mineral soil of two upland forests in northern lower Michigan, one dominated by oak (Quercus velutina, Q. alba) and the other dominated by sugar maple (Acer saccharum) and American basswood (Tilia americana). Phylogenetic analysis demonstrated that cellobiohydrolase genes recovered from the floor of both forests tended to cluster with Xylaria or in one of two unidentified groups, whereas cellobiohydrolase genes recovered from soil tended to cluster with Trichoderma, Alternaria, Eurotiales, and basidiomycete sequences. The ability to amplify a key fungal gene involved in plant litter decomposition has the potential to unlock the identity and dynamics of the cellulolytic fungal community in situ.

2015 ◽  
Vol 45 (4) ◽  
pp. 452-462 ◽  
Author(s):  
Vanessa Pilon ◽  
Serge Payette

The sugar maple (Acer saccharum Marsh.) forest is a widespread temperate forest prevailing south of 48°N in Quebec. Windthrows are the principal disturbance maintaining the old-growth status of the forest supposedly since its postglacial establishment. Nonetheless, the presence of wood charcoal buried in several sugar maple forest soils attests to the occurrence of fire during the Holocene. In this study, we aimed to elucidate the long-term fire dynamics and species composition of three sites (Témiscamingue, Saguenay, and Gaspé peninsula) currently dominated by sugar maple situated at its northern range limit. The botanical identification and 14C dating of charcoal fragments extracted from the soil surface and the mineral soil indicate that the development of the sugar maple sites was influenced by recurrent fires at least over the last 1000 to 3500 years. Two of the studied sugar maple stands are of recent origin, with the Témiscamingue forest being established after the most recent fire in the late 18th to early 19th centuries. Our data highlight the resilience of sugar maple forests in a disturbance regime dominated by frequent fires and suggest that the northernmost sugar maple forests are young ecosystems at the Holocene timescale.


2021 ◽  
Author(s):  
guo xiali ◽  
Valentina Buttò ◽  
Yann Surget-Groba ◽  
Jian-Guo Huang ◽  
Sylvain Delagrange ◽  
...  

Abstract Global changes affect the growing conditions of terrestrial ecosystems, mismatching the phenological adaptation of plants to local climates at mid and high latitudes. Their long lifespan and slow reproductive cycles prevent trees from tracking the quick shift in their usual climatic conditions, thus endangering the survival of local populations. In this study, we explored the phenological plasticity and adaptive potential of bud burst in sugar maple (Acer saccharum Marsh.) seedlings from 30 Canadian origins with contrasting climates planted in two common gardens near and at the northern boundary of the species range. Bud development and leafing occurred in April-May, with complete bud burst lasting between 21 and 29 days. On average, bud swelling differed by 12 days between common gardens. However, this difference decreased to 4 days for complete leafing. Both factors site and seed origin affected bud burst, which represented the phenological plasticity and adaptation of sugar maple, respectively. Overall, the former (7.4–88.3%) contributed more than the latter (9.2–25.5%) to the variance in bud burst, despite the wide climatic range among the provenance origins compared with that at the two common gardens. Adaptation to local conditions provide the genetic tools for the survival of species across wide climatic ranges. Plasticity enables physiological responses of individuals to quick environmental changes. Our study demonstrated the major role of plasticity in bud phenology, and revealed the importance of investing resources in mechanisms dealing with the climatic challenges due to inter-annual variations in weather events.


2016 ◽  
Vol 46 (1) ◽  
pp. 114-121 ◽  
Author(s):  
Jean-Bastien Lambert ◽  
Aitor Ameztegui ◽  
Sylvain Delagrange ◽  
Christian Messier

Small-seeded tree species such as yellow birch (YB, Betula alleghaniensis Britt.) require deadwood or mineral soil for their establishment. Although much research has been done comparing YB germination on leaf litter vs. exposed mineral soil, less is known about deadwood as a seedbed and how different seedbeds affect YB early growth along light availability and size gradients. We examine how three common seedbeds (deadwood, moss cover on deadwood, and mineral soil) affected establishment and growth, biomass partitioning, and morphological traits of YB juveniles growing in the understory of temperate mixed deciduous and coniferous forests in southern Quebec. A total of 274 YB were sampled in four sugar maple (Acer saccharum Marsh.) dominated northern hardwood stands where selective cuts had been applied 6 and 15 years prior to sampling. Over 75% of the YB found on deadwood were on material of birch and conifer origin, although these species made less than 40% of the basal area. YB juveniles growing on deadwood showed traits that improve survival in shade such as reduced height growth for tall plants, higher efficiency in resource capture, and multilayered crowns. Our results demonstrate the importance of deadwood of birch and conifer origin in maintaining an abundant, natural, spatially well-distributed, and multistoried regeneration of YB.


2020 ◽  
Vol 52 (3) ◽  
pp. 292-297
Author(s):  
Tara Lee Bal ◽  
Katherine Elizabeth Schneider ◽  
Dana L. Richter

2017 ◽  
Vol 129 (2) ◽  
pp. 209-221 ◽  
Author(s):  
Amritpal S. Singh ◽  
A. Maxwell P. Jones ◽  
Mukund R. Shukla ◽  
Praveen K. Saxena

2015 ◽  
Vol 45 (6) ◽  
pp. 632-638 ◽  
Author(s):  
Kim Bannon ◽  
Sylvain Delagrange ◽  
Nicolas Bélanger ◽  
Christian Messier

Studies have reported divergent results on the effect of soil fertility and canopy opening on understory density and growth of sugar maple (AS; Acer saccharum Marsh.) and American beech (FG; Fagus grandifolia Ehrh.). The main objective of this study was to evaluate the effect of a gradient of canopy opening and soil fertility on the density and growth of AS and FG saplings in southwestern Quebec, Canada. We investigated 56 stands containing both AS and FG that were subjected to different disturbance history types (DHTs) (UF, unmanaged forest; PC, partial cut; and CC, clearcut) on various soil types. AS and FG absolute and relative sapling density varied greatly among the 56 stands; however, no significant effects of DHT, soil nutrient availability, or their interaction were found. Both species responded positively in terms of radial growth to canopy openings, with FG growth being slightly better than AS growth in PC stands compared with other canopy treatments. Contrary to our hypothesis, AS did not show significantly higher growth than FG following clear-cutting. These results do not support the idea that AS abundance and growth could be promoted by increasing the intensity of the canopy opening during harvest, at least on the generally acidic and base-poor soils that were investigated.


Microbiology ◽  
2011 ◽  
Vol 157 (10) ◽  
pp. 2904-2911 ◽  
Author(s):  
Michael Wyrebek ◽  
Cristina Huber ◽  
Ramanpreet Kaur Sasan ◽  
Michael J. Bidochka

Here we tested the hypothesis that species of the soil-inhabiting insect-pathogenic fungus Metarhizium are not randomly distributed in soils but show plant-rhizosphere-specific associations. We isolated Metarhizium from plant roots at two sites in Ontario, Canada, sequenced the 5′ EF-1α gene to discern Metarhizium species, and developed an RFLP test for rapid species identification. Results indicated a non-random association of three Metarhizium species (Metarhizium robertsii, Metarhizium brunneum and Metarhizium guizhouense) with the rhizosphere of certain types of plant species (identified to species and categorized as grasses, wildflowers, shrubs and trees). M. robertsii was the only species that was found associated with grass roots, suggesting a possible exclusion of M. brunneum and M. guizhouense. Supporting this, in vitro experiments showed that M. robertsii conidia germinated significantly better in Panicum virgatum (switchgrass) root exudate than did M. brunneum or M. guizhouense. M. guizhouense and M. brunneum only associated with wildflower rhizosphere when co-occurring with M. robertsii. With the exception of these co-occurrences, M. guizhouense was found to associate exclusively with the rhizosphere of tree species, predominantly Acer saccharum (sugar maple), while M. brunneum was found to associate exclusively with the rhizosphere of shrubs and trees. These associations demonstrate that different species of Metarhizium associate with specific plant types.


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