Impact of endochitinase-transformed white spruce on soil fungal communities under greenhouse conditions

Abstract

Chitinase genes isolated from plants, bacteria or fungi have been widely used in genetic engineering to enhance the resistance of crops and trees to fungal pathogens. However, there are concerns about the possible effect of chitinase-transformed plants on nontarget fungi. This study aimed at evaluating the impact of endochitinase-transformed white spruce on soil fungal communities. Endochitinase-expressing white spruce and untransformed controls were transplanted in soils from two natural forests and grown for 8 months in a greenhouse. Soil fungal biomass and diversity, estimated through species richness and Shannon and Rao diversity indices, were not different between transgenic and control tree rhizospheres. The fungal phylogenetic community structure was the same in soil samples from control and transgenic white spruces after 8 months. Soil type and presence of seedlings had a much more significant impact on fungal community structure than the insertion and expression of the ech42 transgene within the white spruce genome. The results suggest that the insertion and constitutive expression of the ech42 gene in white spruce did not significantly affect soil fungal biomass, diversity and community structure.

Comparisons of Ectomycorrhizal Colonization of Transgenic American Chestnut with Those of the Wild Type, a Conventionally Bred Hybrid, and Related Fagaceae Species

“…This demonstrates that for these EM fungal species, the transgenic chestnut does not appear to have any nontarget impacts. The result is consistent with studies that have demonstrated minimal to no impact on EM fungi by a number of transgenic tree species expressing a variety of transgenes (48)(49)(50)(51)(52). One such study, on a transgenic American elm expressing an antimicrobial peptide to improve Dutch elm disease resistance, found that there was no significant difference in mycorrhizal colonization during the field trial (53).…”

Assessing bacterial communities in the rhizosphere of 8-year-old genetically modified poplar (Populus spp.)

“…When data from all sampling dates were considered together, Lottmann et al (2010) found few statistical differences in the microbial communities associated with GM and control trees, which suggested that there was no significant impact of this genetic modification on rhizosphere microbial communities. Lamarche et al (2011) did not detect any significant differences in soil fungal biomass, diversity or community structure caused by white spruce that constitutively expressed the ech42 gene. By contrast, Andreote et al (2009) detected differences between bacterial communities, not only between transgenic and non-transgenic eucalyptus (Eucalyptus robusta Smith), but also among wild-type plants.…”

Scheffersomyces cryptocercus: a new xylose-fermenting yeast associated with the gut of wood roaches and new combinations in theSugiyamaellayeast clade

“…1). Sugiyamaella paludigena originally was isolated from high moor peat near Moscow, Russia (Golubev et al 1981), and more recently it was reported from rhizosphere soil of white spruce (Lamarche et al 2011). Sugiyamaella lignohabitans first was described from a decaying log of paper birch and associated insect frass in USA (Kurtzman 2007).…”