文章基本信息

标题：Stacked genetically modified soybean harboring herbicide resistance and insecticide rCry1Ac shows strong defense and redox homeostasis disturbance after glyphosate-based herbicide application
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作者：Caroline Bedin Zanatta ; Rafael Fonseca Benevenuto ; Rubens Onofre Nodari 等
期刊名称：Environmental Sciences Europe
印刷版ISSN：2190-4715
出版年度：2020
卷号：32
期号：1
页码：1-17
DOI：10.1186/s12302-020-00379-6
出版社：BioMed Central
摘要：World agricultural production of genetically modified (GM) products, in particular, the combination of different traits/genes in the same plant has been a trend over the last decade. There have been concerns raised over stacking multiple herbicide and insect-resistant transgenes that could result in fitness costs depending on the type and strength of selection pressures exerted by the environment. Here, we report the results of transcriptomic analysis comparing the effect of glyphosate-based herbicide (GBH) in the single-transgene versus stacked, herbicide-resistant soybean varieties on various biological processes, metabolic pathways, and key shikimic enzymes. Gene expression data showed that defense metabolism and redox homeostasis were equally modulated in single-transgene and stacked-variety samples. Carbon accumulation and energy metabolisms were distinct between the varieties and photosynthesis metabolism was found negatively affected in the single-transgene variety only. In the stacked variety, the shikimate pathway was modulated by the accumulation of transcripts from phenylalanine gene and other cascade genes. As expected, the expression of native EPSPS was upregulated in both varieties when herbicide was applied. On the other hand, transgenic EPSPS expression was down-regulated in both GM varieties upon herbicide application which cannot be explained. Glyphosate-based herbicides toxicity suggests its effects on carbon central metabolism and flux, redox metabolism, photosynthesis, and to hormone and defense response in plants. The observed unintended effects in GM herbicide-tolerant varieties unravel the deleterious effects previously observed on GM-tolerant varieties growth and production. The impact of GBH on shikimate and cascade pathways was observed in terms of both native and transgenic insensitive EPSPS modulation, alteration of jasmonic acid and lignin metabolism in both single-transgene and stacked variety. The energy metabolism and carbon flux were differently affected in these varieties. Oxidative stress, more specifically glutathione metabolism, induced by GBH, was also observed in this study. The stacked variety showed a more pronounced stress response (activation of specific stress defense proteins, Rboh, WRKY) and secondary compounds (β-glucosidase, isoflavone 7-O-methyltransferase). Omics profiling techniques, such as transcriptomics, can be considered tools to support risk assessment in detecting unintended effects due to the GBH application.
关键词：Roundup;Transcriptomic;Gene expression;Metabolic pathways;Shikimate pathway;Beta-glucosidase;Glutathione;Trehalose;Recombinant Cry1Ac