Genetic Transformation for Developing Improved Plant Varieties

The changing environment poses many challenges for crop plants to withstand and fulfil the food demands of the current population. To combat these challenges, the development of genetically manipulated crop varieties with improved traitsTraits is crucial. Genetically modified plants are usually generated through Agrobacterium tumefaciensAgrobacterium tumefaciens, microprojectile bombardmentMicroprojectile Bombardment, electroporationElectroporation, microinjection, transposonsRNA interference (RNAi), RNA interference (RNAi), virus-induced gene silencing (VIGS)Virus-induced gene silencing (VIGS), Transcription Activator-like Effector Nucleases (TALENs)Transcription Activator-like Effector Nucleases (TALENs), Zinc Finger Nucleases (ZFNs)Zinc Finger Nucleases (ZFNs), Clustered Regularly Interspaced Palindromic Repeats (CRISPR)Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) etc. Agrobacterium-mediated genetic transformationGenetic transformation helps ensure both stable and transient genetic transformations by utilizing its vir genes to transfer its T-DNA. T-DNAT-DNA contains genes for bacterial food production and can be manipulated easily by replacing them with genes of interest for crop improvement. Microprojectiles involve the bombardment of microbullets coated with DNA using a gene gun and are efficient in plastid transformationsPlastid transformation. In electroporationElectroporation, electric current is used to produce tiny holes in the cell wall of plants or cell membranes of protoplasts to facilitate the transfer of foreign DNADNA into plant cells. Using these techniques, sustainable agriculture is achieved with resilient plant varieties having improved yield and nutritional value. MicroinjectionMicroinjection is a precise technique in which foreign DNA is injected into a recipient cell (usually an animal cell) directly using a glass microcapillary. Being a time-consuming and expensive technique and successful in generating transgenic barley, tobacco and petunia, it is not well recommended for plant transformations because of low transformation frequencies and chimeric plant generation. Transposable elementsTransposable elements (TEs) also play significant roles by producing genetic mutations and influencing gene expression. In techniques like TALENsTranscription Activator-like Effector Nucleases (TALENs) and ZFNsZinc Finger Nucleases (ZFNs), the FokI restriction enzyme helped generate transgenic crops and ornamental plants with improved traits. The CRISPR-Cas9 technology exploits the bacterial adaptive immunity system and has revolutionized transgenic plant generation by modifying the genetic makeup of plants very precisely and efficiently. Using CRISPRClustered Regularly Interspaced Short Palindromic Repeats (CRISPR), plant varieties with improved biotic and abiotic stressesAbiotic stress, improved disease resistance and improved crop yield were generated.