Agrobacterium rhizogenes-Mediated Transformation and Its Biotechnological Applications in Crops

Abstract

The history of Agrobacterium-related plant biotechnology goes back for more than three decades with the discovery of molecular mechanisms of crown gall disease in plants. After 1980s, gene technologies began developing rapidly and today, related with the improved gene transfer methods, plant biotechnology has become one of the most important branches in science. Till now, the most important genes related with agricultural affairs have been utilized for cloning of plants with the deployment of different techniques used in genetic engineering. Especially, Agrobacterium tumefaciens was used extensively for transferring desired genetic materials to plants rapidly and effectively by the researchers to create transgenic plants. Recognition of the biology of Agrobacterium species and newly developed applications of their T-DNA systems has been a great step in plant biotechnology. This chapter provides the reader with extensive information on A. rhizogenes which is responsible for the development of hairy root disease in a wide range of dicotyledonous plants and its T-DNA system. This knowledge will be useful in improving utilization of crops and the formulation of new and up-graded transgenic based food products.

Development of a fast and efficient root transgenic system for functional genomics and genetic engineering in peach

“…In this report, embryo-section was proved to be ideal explant for genetic transformation, while no plant generation or extremely low transformation efficiency were observed for hypocotyl and cotyledon explants. Besides A. tumefaciens, A. rhizogenes is also widely utilized to infect various explants, such as hypocotyl, leaf, stem, shoot and cotyledon, to induce transgenic tissues and/or plants 20,45 . Here, our study also showed that all tested explants, including hypocotyl, leaf and shoot, are suitable for A. rhizogenes-mediated transformation.…”

“…A. rhizogenes-mediated tissue production, an alternative method for A. tumefaciens-mediated transformation, is often used to induce adventitious root development, i.e. hairy roots, at the site of wounding and infection 20,21 . The ability of A. rhizogenes to induce the formation of neoplastic and plagiotropic roots is attributed to its extrachromosomal replicon root-inducing (Ri) plasmid.…”

A highly efficient protocol for transformingCuscuta reflexabased on artificially induced infection sites

“…The high transformation rates of adhesive disk cells is certainly noteworthy. Agrobacteria are known to be attracted to polyphenolic substances exuded by plant roots (Ozyigit et al, 2013). Haustorial sites are also rich in hydroxycinnamic acid derivatives, caffeic acid depsides and other polyphenols (Löffler et al, 1995), which is evident by the rapid browning of infection sites upon their exposure to air (Johnsen et al, 2015).…”

“…Besides A. tumefaciens, Agrobacterium rhizogenes has become a popular agent for transforming plant genomes (Ozyigit et al, 2013). A. rhizogenes is a soil-borne bacterium infecting many angiosperms and causing them to produce a copious number of roots which became known as the “hairy root syndrome” (Bahramnejad et al, 2019).…”

“…The transfer process is controlled by virulence ( vir ) genes that are induced by phenolic signal molecules (Gelvin, 2003). The A. rhizogenes T- DNA is stably integrated into the plant nuclear genome where it expresses the rol ( r ooting l ocus ) genes required for excessive adventitious root growth (Ozyigit et al, 2013). What has made these hairy roots popular for plant biotechnology is that they can be propagated in the absence of exogenous plant hormones.…”