T-DNA integration in plants requires MRE11- or TDP2-mediated removal of the 5’ bound Agrobacterium protein VirD2

Agrobacterium tumefaciens, a pathogenic bacterium capable of transforming plants through horizontal gene transfer, is nowadays the preferred vector for plant genetic engineering. The vehicle for transfer is the T-strand, a single-stranded DNA molecule bound by the bacterial protein VirD2, which guides T-DNA into the plants nucleus where it integrates. How VirD2 is removed from T-DNA, and which mechanism acts to attach the liberated end to the plant genome is currently unknown. Here, using newly developed technology that yields hundreds of T-DNA integrations in somatic tissue of Arabidopsis thaliana, we uncover two redundant mechanisms for the genomic capture of the T-DNA’s 5’ end. Different from capture of the 3’ end of the T-DNA, which is the exclusive action of polymerase theta-mediated end joining (TMEJ), 5’ attachment is accomplished either by TMEJ or by canonical non-homologous end joining (cNHEJ). We further find that TMEJ needs MRE11, whereas cNHEJ requires TDP2 to remove the 5’-end blocking protein VirD2. As a consequence, T-DNA integration is severely impaired in plants deficient for both MRE11 and TDP2 (or other cNHEJ factors). In support of MRE11 and cNHEJ specifically acting on the 5’ end, we demonstrate rescue of the integration defect of double-deficient plants by using T-DNAs that are capable of forming telomeres upon 3’ capture. Our study provides a mechanistic model for how Agrobacterium exploits the plant’s own DNA repair machineries to transform them.

An Overview of the Importance of Bacterial Elements for Plant Genetic Engineering

Plant genetic engineering is one of the most important aspects of biotechnology applied to plant systems. The stable introduction of exogenous genetic material in plant cells is a determining step for obtaining transgenic plants. In this context, bacteria are crucial for the development of transgenic plants. Gene cloning often involves the use of bacterial plasmids and DNAmodifying enzymes synthesized in genetically modified bacteria. In addition, among the several methods of introducing genes into plants, the method that uses Agrobacterium tumefaciens continues to be used to obtain genetically modified plants for the agricultural, pharmaceutical and materials industry sectors. This minireview aims to present the basic aspects of bacterial elements related gene manipulation for obtaining transgenic plants.

The Role of IPR in Plant Genetic Engineering

The role and status of Patent laws in the protection of plant species which have been genetically modified is currently uncertain in India. Discussions and debates regarding the same are rife and experts have different views regarding the whole aspect concerning economical and ethical considerations. Genetically engineered plants and modified crop plants are of significant economic value. In India, they face critical challenges, for instance, the requirement of dependable public policies and vigorous frameworks for regulatory control. This becomes much more vital since India desires to be an economic superpower primarily based on innovation. It is very important for a person from the legal field, especially those interested in the field of IPR, to have clarity regarding the protection of genetically modified plants. This humble attempt at a research paper seeks to clarify the same and discusses the various aspects on which one should think while concluding their views on the topic.