Genetic transformation methods and advancement of CRISPR/Cas9 technology in wheat

Wheat is one of the important cereal crops all over the world. The demand for wheat grains is increasing day by day in various countries. Therefore many genetic engineering methods have been used for wheat improvement. Nowadays, the innovation of CRISPR mediated genome engineering makes it easier to alter the wheat genome. The complex genome and low transformation efficiency are the main obstacle for engineering in the wheat. In this chapter, we will discuss the fundamental of the CRISPR/Cas9 mechanism and technology. The CRISPR/Cas9 construct delivery is a crucial step in efficient editing. Delivery methods such as Agrobacterium-mediated, biolistic, PEG-mediated, microspore-based, and DNA-free editing were used in wheat. Multiple technologies evolved from CRISPR, such as CRISPRi, CRISPRa, targeted DNA insertion, multiplexing with tRNA, and Csy4 methods were used in wheat to crop improvement. This technology is successfully applied to produce abiotic stress and biotic stress tolerant wheat. Apart from this, this technology was also applied to improve grain size and quality.