US EPA

4309421 

Journal Article 

Impact of TransgenicBrassica napusHarboring the Antifungal Synthetic Chitinase (NiC) Gene on Rhizosphere Microbial Diversity and Enzyme Activities 

Khan, MS; Sadat, SU; Jan, A; Munir, I 

2017 

Yes 

Frontiers in Plant Science
ISSN: 1664-462X 

8 

1307 

English 

28791039 

10.3389/fpls.2017.01307 

WOS:000406213300001 

TransgenicBrassica napusharboring the synthetic chitinase (NiC) gene exhibits broad-spectrum antifungal resistance. As the rhizosphere microorganisms play an important role in element cycling and nutrient transformation, therefore, biosafety assessment ofNiCcontaining transgenic plants on soil ecosystem is a regulatory requirement. The current study is designed to evaluate the impact ofNiCgene on the rhizosphere enzyme activities and microbial community structure. The transgenic lines with the synthetic chitinase gene (NiC) showed resistance toAlternaria brassicicola, a common disease causing fungal pathogen. The rhizosphere enzyme analysis showed no significant difference in the activities of fivesoil enzymes: alkalyine phosphomonoestarase, arylsulphatase, β-glucosidase, urease and sucrase between the transgenic and non-transgenic lines ofB. napusvarieties, Durr-e-NIFA (DN) and Abasyne-95 (AB-95). However, varietal differences were observed based on the analysis of molecular variance. Some individual enzymes were significantly different in the transgenic lines from those of non-transgenic but the results were not reproducible in the second trail and thus were considered as environmental effect. Genotypic diversity of soil microbes through 16S-23S rRNA intergenic spacer region amplification was conducted to evaluate the potential impact of the transgene. No significant diversity (4% for bacteria and 12% for fungal) between soil microbes ofNiC B. napusand the non-transgenic lines was found. However, significant varietal differences were observed between DN and AB-95 with 79% for bacterial and 54% for fungal diversity. We conclude that theNiC B. napuslines may not affect the microbial enzyme activities and community structure of the rhizosphere soil. Varietal differences might be responsible for minor changes in the tested parameters.