Agrobacterium-Mediated Gene Transfer in Plants and Biosafety Considerations

Abstract

Agrobacterium, the natures' genetic engineer, has been used as a vector to create transgenic plants. Agrobacterium-mediated gene transfer in plants is a highly efficient transformation process which is governed by various factors including genotype of the host plant, explant, vector, plasmid, bacterial strain, composition of culture medium, tissue damage, and temperature of co-cultivation. Agrobacterium has been successfully used to transform various economically and horticulturally important monocot and dicot species by standard tissue culture and in planta transformation techniques like floral or seedling infilteration, apical meristem transformation, and the pistil drip methods. Monocots have been comparatively difficult to transform by Agrobacterium. However, successful transformations have been reported in the last few years based on the adjustment of the parameters that govern the responses of monocots to Agrobacterium. A novel Agrobacterium transferred DNA-derived nanocomplex method has been developed which will be highly valuable for plant biology and biotechnology. Agrobacterium-mediated genetic transformation is known to be the preferred method of creating transgenic plants from a commercial and biosafety perspective. Agrobacterium-mediated gene transfer predominantly results in the integration of foreign genes at a single locus in the host plant, without associated vector backbone and is also known to produce marker free plants, which are the prerequisites for commercialization of transgenic crops. Research in Agrobacterium-mediated transformation can provide new and novel insights into the understanding of the regulatory process controlling molecular, cellular, biochemical, physiological, and developmental processes occurring during Agrobacterium-mediated transformation and also into a wide range of aspects on biological safety of transgenic crops to improve crop production to meet the demands of ever-growing world's population.

Agrobacterium-Mediated Plant Transformation: Biology and Applications

“…With advances in recombinant DNA technology, T-DNA binary vectors have evolved over the past years to be highly developed and more specialized for different purposes (Hellens et al, 2000;Chung et al, 2005;Komari et al, 2006;Mehrotra and Goyal, 2012;Anami et al, 2013). T-DNA-based binary vectors generally consist of several features, including (1) the T-DNA right and left border repeat sequences that define the T-DNA region; (2) selectable marker genes to function in bacteria (E. coli and A. tumefaciens) and in plants; (3) restriction endonuclease sites within the T-DNA to allow insertion of one or more gene(s) of interest; (4) origin(s) of replication to allow plasmids to replicate in bacteria.…”

Bringing New Plant Varieties to Market: Plant Breeding and Selection Practices Advance Beneficial Characteristics while Minimizing Unintended Changes

“…Agrobacterium tumefaciens Smith & Townsend is a soil bacterium that naturally inserts pieces of DNA into relatively random spots within plant genomes (Mehrotra and Goyal, 2012;Bourras et al, 2015). Agrobacterium is unique among plant pathogens in that it causes disease (called "crown gall") by transferring genes into plant cells that produce compounds that aid further infection.…”

Molecular Farming: Hosting Plants as Green Factories

“…One of the major beneficial outcomes of this technology is genetically modified (GM, transgenic) plants in which one or several genes have been inserted into plant genome from various sources by using different means such as Agrobacterium tumefaciens or particle bombardment [1,2]. Organel genome of certain plant species also become as target to generate transplastomic plants [3,4].…”

“…Organel genome of certain plant species also become as target to generate transplastomic plants [3,4]. Although GM plants have come along with a number of controvertial issues [1], the global planting area of GM plants constantly increased during last two decades and reached to 181.5 billion ha all around the world [5]. Therefore, agricultural biotechnology is one of the most adaptive technologies used in…”