Evidences of inhibited arbuscular mycorrhizal fungal development and colonization in multiple lines of Bt cotton

Chen, Xiuhua; Fengling, Wang; Zhang, Rui; Ji, Lingling; Yang, Zhenglun; Hu, Lin; Zhao, Bin

doi:10.1016/j.agee.2016.05.008

Cited by 11 publications

(6 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Even with the higher transgene expression in ‘Darling 54’ and ‘Darling 58’ compared to the ‘Darling 4’ tested previously, there were no significant differences in colonization by ectomycorrhizal fungi in roots compared to non-transgenic controls. These results corroborate other studies that generally show no significant differences between transgenic and non-transgenic plants with respect to colonization of mycorrhizal fungi ( Kaldorf et al, 2002 ; Newhouse et al, 2007 ; Cheeke et al, 2015 ; Turrini et al, 2015 ; Chen et al, 2016 ; Kaur et al, 2017 ).…”

Section: Discussionsupporting

confidence: 92%

Transgenic American Chestnuts Do Not Inhibit Germination of Native Seeds or Colonization of Mycorrhizal Fungi

et al. 2018

View full text Add to dashboard Cite

The American chestnut (Castanea dentata) was once an integral part of eastern United States deciduous forests, with many environmental, economic, and social values. This ended with the introduction of an invasive fungal pathogen that wiped out over three billion trees. Transgenic American chestnuts expressing a gene for oxalate oxidase successfully tolerate infections by this blight fungus, but potential non-target environmental effects should be evaluated before new restoration material is released. Two greenhouse bioassays evaluated belowground interactions between transgenic American chestnuts and neighboring organisms found in their native ecosystems. Potential allelopathy was tested by germinating several types of seeds, all native to American chestnut habitats, in the presence of chestnut leaf litter. Germination was not significantly different in terms of number of seeds germinated or total biomass of germinated seedlings in transgenic and non-transgenic leaf litter. Separately, ectomycorrhizal associations were observed on transgenic and non-transgenic American chestnut roots using field soil inoculum. Root tip colonization was consistently high (>90% colonization) on all plants and not significantly different between any tree types. These observations on mycorrhizal fungi complement previous studies performed on older transgenic lines which expressed oxalate oxidase at lower levels. Along with other environmental impact comparisons, these conclusions provide further evidence that transgenic American chestnuts are not functionally different with regard to ecosystem interactions than non-transgenic American chestnuts.

show abstract

Section: Discussionsupporting

confidence: 92%

Transgenic American Chestnuts Do Not Inhibit Germination of Native Seeds or Colonization of Mycorrhizal Fungi

et al. 2018

View full text Add to dashboard Cite

show abstract

“…Similar phenomena were observed by Nagar et al (2014), who found that DAS-59122-7 Bt maize had a negative effect on the initial development of AMF under field conditions. Other studies (Chen et al, 2016, 2017) hypothesized that the appressorium density, colonization intensity and arbuscule abundance were lower in Bt cotton roots (Jin26, GK12, and Jin 44, all of which expressedCry1Ac protein) than in roots in non-transgenic isolines (Jin7, Si3, and Ji492).…”

Section: Introductionmentioning

confidence: 95%

The Influence of Bt Maize Cultivation on Communities of Arbuscular Mycorrhizal Fungi Revealed by MiSeq Sequencing

et al. 2019

View full text Add to dashboard Cite

The cultivation of transgenic Bacillus thuringiensis (Bt) has received worldwide attention since Bt crops were first released. Its ecological risks on arbuscular mycorrhizal fungi (AMF) have been widely studied. In this study, after cultivation for five seasons, the AMF diversity and community composition of two Bt maize varieties, 5422Bt1 (event Bt11) and 5422CBCL (event MO10), which both express Cry1Ab protein, and their isoline non-Bt maize 5422, as well as Bt straw after cultivation had been returned to subsequent conventional maize variety, were analyzed using Illumina MiSeq sequencing. A total of 263 OTUs (operational taxonomic units) from 511,847 sequenced affiliated with the AMF which belonged to Mucoromycota phylum Glomeromycotina subphylum were obtained. No significant difference was detected in the AMF diversity and richness (Shannon, Simpson, ACE, and Chao 1 indices) and community composition in rhizosphere soils and roots between Bt and non-Bt treatment revealed by NMDS (non-metric multidimensional scaling) and NPMANOVA (non-parametric multivariate analysis). Moreover, Glomus was the most dominant genus in all samples. Although there was no significant difference in the AMF community in roots and rhizosphere soils between the Bt and non-Bt maize treatments, total phosphorus (TP), total nitrogen (TN), organic carbon (OC), and pH were driving factors affecting the AMF community, and their composition varied between rhizosphere soils and roots during the maturity period of the fifth season. Compared to our previous study, the results were identical. In conclusion, no significant difference was observed between the Bt and non-Bt treatments, and the Illumina MiSeq method had higher throughput and higher quality read cover, which gave us comprehensive insight into AMF communities in agro-ecosystems.

show abstract

“…Although such studies are rare when compared to those of predicted, unintended effects (e.g., effects of Btexpressing plants on nontarget insects, e.g., Axelsson et al, 2011), several have found no significant difference or detected only minor or temporary changes (Dunfield & Germida, 2003;Seppänen et al, 2007;Oliver et al, 2008;Lelmen et al, 2010;Vogler et al, 2010;Cheeke et al, 2015;Ricroch et al, 2018; see also transgenic chestnut nontarget studies mentioned in the Introduction). However, when significant effects have been found, they have often been restricted to a subset of hypotheses tested, vary among transgenic lines tested, or have magnitudes of effects within the range of untransformed isogenic plants (e.g., Brodeur-Campbell et al, 2006;Hjältén et al, 2007;Post & Parry, 2011;Turrini et al, 2015;Chen et al, 2016). For example, although Post and Parry (2011) found an increased relative growth rate for gypsy moth larvae on a different American chestnut event transformed with OxO compared to a nonisogenic wild-type control, no effects of transformation were found on either native insect species, Polyphemus or fall webworm.…”

Section: Discussionmentioning

confidence: 99%

Comparative efficacy of gypsy moth (Lepidoptera: Erebidae) entomopathogens on transgenic blight‐tolerant and wild‐type American, Chinese, and hybrid chestnuts (Fagales: Fagaceae)

et al. 2019

View full text Add to dashboard Cite

American chestnut (Castanea dentata [Marsh.] Borkh.) was once the dominant hardwood species in Eastern North America before an exotic fungal pathogen, Cryphonectria parasitica (Murrill) Barr, functionally eliminated it across its range. One promising approach toward restoring American chestnut to natural forests is development of blight‐tolerant trees using genetic transformation. However, transformation and related processes can result in unexpected and unintended phenotypic changes, potentially altering ecological interactions. To assess unintended tritrophic impacts of transgenic American chestnut on plant–herbivore interactions, gypsy moth (Lymantria dispar L.) caterpillars were fed leaf disks excised from two transgenic events, Darling 54 and Darling 58, and four control American chestnut lines. Leaf disks were previously treated with an LD50 dose of either the species‐specific Lymantria dispar multiple nucleopolyhedrovirus (LdMNPV) or the generalist pathogen Bacillus thuringiensis subsp. kurstaki (Btk). Mortality was quantified and compared to water blank controls. Tree genotype had a strong effect on the efficacies of both pathogens. Larval mortality from Btk‐treated foliage from only one transgenic event, Darling 54, differed from its isogenic progenitor, Ellis 1, but was similar to an unrelated wild‐type American chestnut control. LdMNPV efficacy was unaffected by genetic transformation. Results suggest that although genetic modification of trees may affect interactions with other nontarget organisms, this may be due to insertion effects, and variation among different genotypes (whether transgenic or wild‐type) imparts a greater change in response than transgene presence.

show abstract

Evidences of inhibited arbuscular mycorrhizal fungal development and colonization in multiple lines of Bt cotton

Cited by 11 publications

References 42 publications

Transgenic American Chestnuts Do Not Inhibit Germination of Native Seeds or Colonization of Mycorrhizal Fungi

Transgenic American Chestnuts Do Not Inhibit Germination of Native Seeds or Colonization of Mycorrhizal Fungi

The Influence of Bt Maize Cultivation on Communities of Arbuscular Mycorrhizal Fungi Revealed by MiSeq Sequencing

Comparative efficacy of gypsy moth (Lepidoptera: Erebidae) entomopathogens on transgenic blight‐tolerant and wild‐type American, Chinese, and hybrid chestnuts (Fagales: Fagaceae)

Contact Info

Product

Resources

About