Proteomic and Metabolomic Evaluation of Insect- and Herbicide-Resistant Maize Seeds.

Label-free quantitative proteomic (LFQ) and widely targeted metabolomic analyses were applied in the safety evaluation of three genetically modified (GM) maize varieties, BBL, BFL-1, and BFL-2, in addition to their corresponding non-GM parent maize. A total of 76, 40, and 25 differentially expressed proteins (DEPs) were screened out in BBL, BFL-1, and BFL-2, respectively, and their abundance compared was with that in their non-GM parents. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis showed that most of the DEPs participate in biosynthesis of secondary metabolites, biosynthesis of amino acids, and metabolic pathways. Metabolomic analyses revealed 145, 178, and 88 differentially accumulated metabolites (DAMs) in the BBL/ZH58, BFL-1/ZH58, and BFL-2/ZH58×CH72 comparisons, respectively. KEGG pathway enrichment analysis showed that most of the DAMs are involved in biosynthesis of amino acids, and in arginine and proline metabolism. Three co-DEPs and 11 co-DAMs were identified in the seeds of these GM maize lines. The proteomic profiling of seeds showed that the GM maize varieties were not dramatically different from their non-GM control. Similarly, the metabolomic profiling of seeds showed no dramatic changes in the GM/non-GM maize varieties compared with the GM/GM and non-GM/non-GM maize varieties. The genetic background of the transgenic maize was found to have some influence on its proteomic and metabolomic profiles.

Integrated proteomics and metabolomics analysis of transgenic and gene-stacked maize line seeds.

Unintended effects of genetically modified (GM) crops may pose safety issues. Omics techniques provide researchers with useful tools to assess such unintended effects. Proteomics and metabolomics analyses were performed for three GM maize varieties, 2A-7, CC-2, and 2A-7×CC-2 stacked transgenic maize, and the corresponding non-GM parent Zheng58.Proteomics revealed 120, 271 and 135 maize differentially expressed proteins (DEPs) in the 2A-7/Zheng58, CC-2/Zheng58 and 2A-7×CC-2/Zheng58 comparisons, respectively. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis showed that most DEPs participated in metabolic pathways and the biosynthesis of secondary metabolite. Metabolomics revealed 179, 135 and 131 differentially accumulated metabolites (DAMs) in the 2A-7/Zheng58, CC-2/Zheng58 and 2A-7×CC-2/Zheng58 comparisons, respectively. Based on KEGG enrichment analysis, most DAMs are involved in the biosynthesis of secondary metabolite and metabolic pathways. According to integrated proteomics and metabolomics analysis, the introduction of exogenous EPSPS did not affect the expression levels of six other enzymes or the abundance of seven metabolites involved in the shikimic acid pathway in CC-2 and 2A-7×CC-2 seeds. Six co-DEPs annotated by integrated proteomics and metabolomics pathway analysis were further analyzed by qRT-PCR.This study successfully employed integrated proteomic and metabolomic technology to assess unintended changes in maize varieties. The results suggest that GM and gene stacking do not cause significantly unintended effects.

Halomonas huangheensis sp. nov., a moderately halophilic bacterium isolated from a saline-alkali soil.

A novel, Gram-stain-negative, aerobic, rod-shaped, non-motile and moderately halophilic bacterium, designated strain BJGMM-B45(T), was isolated from a saline-alkali soil collected from Shandong Province, China. Growth of strain BJGMM-B45(T) occurred at 10-45 °C (optimum, 30 °C) and pH 5.0-12.0 (optimum, pH 7.0) on Luria-Bertani agar medium with 1-20 % (w/v) NaCl (optimum, 7-10 %). The predominant respiratory quinone was Q-9. The major cellular fatty acids (>5 %) were C18 : 1ω7c, C16 : 0, C19 : 0 cyclo ω8c, summed feature 3, C12 : 0 3-OH and C12 : 0. The genomic DNA G+C content was 57.5 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain BJGMM-B45(T) belonged to the genus Halomonas in the class Gammaproteobacteria. The closest relatives were Halomonas cupida DSM 4740(T) (98.2 % 16S rRNA gene sequence similarity) and Halomonas denitrificans M29(T) (97.8 %). Levels of DNA-DNA relatedness between strain BJGMM-B45(T) and Halomonas cupida CGMCC 1.2312(T) and Halomonas denitrificans DSM 18045(T) were 57.0 and 58.9 %, respectively. On the basis of phenotypic, chemotaxonomic and phylogenetic features, strain BJGMM-B45(T) is considered to represent a novel species of the genus Halomonas, for which the name Halomonas huangheensis sp. nov. is proposed. The type strain is BJGMM-B45(T) ( = ACCC 05850(T) = KCTC 32409(T)).