The Mutational Consequences of Plant Transformation

Abstract

Plant transformation is a genetic engineering tool for introducing transgenes into plant genomes. It is now being used for the breeding of commercial crops. A central feature of transformation is insertion of the transgene into plant chromosomal DNA. Transgene insertion is infrequently, if ever, a precise event. Mutations found at transgene insertion sites include deletions and rearrangements of host chromosomal DNA and introduction of superfluous DNA. Insertion sites introduced using Agrobacterium tumefaciens tend to have simpler structures but can be associated with extensive chromosomal rearrangements, while those of particle bombardment appear invariably to be associated with deletion and extensive scrambling of inserted and chromosomal DNA. Ancillary procedures associated with plant transformation, including tissue culture and infection with A tumefaciens, can also introduce mutations. These genome-wide mutations can number from hundreds to many thousands per diploid genome. Despite the fact that confidence in the safety and dependability of crop species rests significantly on their genetic integrity, the frequency of transformation-induced mutations and their importance as potential biosafety hazards are poorly understood.

A Set of Modular Binary Vectors for Transformation of Cereals

“…Compared to biolistic techniques (Stoeger et al, 1999;Bhalla et al, 2006) Agrobacterium-mediated transformation offers several advantages (Tzfira and Citovsky, 2006), such as simpler integration patterns resulting in lower mutational consequences for the transgenic plant (Latham et al, 2006) and limited transgene silencing via cosuppression. In addition, the option for fine tuning the Agrobacterium-based transformation protocols renders more and more cereal species amenable for efficient genetic engineering (Shrawat and Loerz, 2006;Conner et al, 2007).…”

Expression of drought tolerance in transgenic cotton

“…The plasmid construct used in this study was made as pCambia 1301 T-DNA region contained a GUS gene along with hygromycin plant selection gene driven by the CaMV 35S promoter. Lint was removed from the seeds with concentrated H 2 SO 4 and washed with tap water. The seeds which floated at the surface of water were discarded.…”

“…The diploid cotton species is not only the reservoir of important biotic and abiotic stress resistance genes, but it also offers better opportunities to study gene structure and function through techniques of gene knockouts 3 . As compared with classical breeding, transgenic technology not only introduced valuable genes into cotton and other agriculturally important crops, but also made it possible to study function and regulation of such genes 4,5 . Abiotic stresses, such as drought, salinity, and heat, currently have a massive impact on crop productivity and agricultural supply.…”

Genetically-Modified Organisms in United States Agriculture: Mandate for Food Labeling

“…Additional sources for potential toxicity stem from the numerous insertion sites of GMO genes in the host plant genome, which may disrupt normal plant genes, further increasing the potential for toxicity [12]. Hundreds to thousands of mutations in normal genes are caused by the genetic engineering required to introduce the transgene to plants [12].…”

“…Hundreds to thousands of mutations in normal genes are caused by the genetic engineering required to introduce the transgene to plants [12]. This results in plants that are dissimilar to native or non-GMO plants.…”