The pleiotropic effects of thebargene and glufosinate on theArabidopsistranscriptome

Abstract

SummaryThe Arabidopsis transcriptome was studied using the Affymetrix Arabidopsis ATH1 GeneChip in wild-type plants and glufosinate-tolerant transgenic plants expressing the bialaphos resistance ( bar ) gene. Pleiotropic effects were specifically generated in the transcriptomes of transgenic plants by both the bar gene and glufosinate treatments. In the absence of glufosinate, four genes were differentially expressed in the transgenic lines and another 80 genes were differentially expressed in the presence of glufosinate, 29 of which were specific to transgenic plants. In contrast, the number of differentially expressed genes specific to wild-type plants was 194 during the early response at 6 h of glufosinate treatment, and increased to 3711 during the late response at 48 h. Although the wild-type plants undergo extensive transcriptional reprofiling in response to herbicide-induced stress and, finally, plant death, the transgenic plants appear to activate other detoxification processes to offset the toxic effects of the residual herbicide or its derivatives. This study provides the first description of the pleiotropic effects of the bar gene and glufosinate on the plant transcriptome.

Biosynthesis of the Major Tetrahydroxystilbenes in Spruce, Astringin and Isorhapontin, Proceeds via Resveratrol and Is Enhanced by Fungal Infection

“…Genetic transformation can produce unintended pleiotropic effects on occasion (Yabor et al, 2006;Abdeen and Miki, 2009) that negatively affect plant phenotype. In tobacco (Nicotiana tabacum), for example, stilbene overexpression led to male sterility (Fischer et al, 1997;Hö fig et al, 2006), probably due to shortages of substrates for flavonoid and sporopollenin production.…”

Towards application of genetic engineering in citriculture: 1) assessing dispersal, long-term stability and phenotypic impact of transgenes in citrus trees and 2) improving nutri-functional quality of orange fruit through metabolic engineering

“…Furthermore, the mating competence of plot B decreased as the distance to the recipients increased, as expected based on the behavior of bees in citrus orchards [12].…”

“…Cross-pollination in citrus is accomplished by insects, and honeybees are the most successful pollinators [12]. In insect-pollinated plants, pollen dispersal is generally the main component of gene flow [13].…”

“…Although the existence of such unintended effects does not necessarily generate concerns in terms of safety (for human health and/or the environment), it is important to evaluate their extent to validate or discard the application of each genetic engineering product in agriculture [10]. Some studies have reported unintended pleiotropic effects generated by the expression of selectable marker genes [11][12][13], despite the fact that such transgenes are not generally believed to alter biological processes in plants [14][15][16]. These findings indicate that the pleiotropic effects associated with selectable marker genes also need to be assessed in a range of plants, particularly in those that are expected to remain in the field for many years and be subjected to highly variable environmental conditions.…”

Evaluation of Genetically Engineered Crops Using Transcriptomic, Proteomic, and Metabolomic Profiling Techniques

“…In that study, cold treatment triggered changes in only 10 protein spots. In another study, Abdeen and Miki (2009) found only four genes differentially expressed in transgenic lines expressing bar.…”