**1. Introduction**

Potatoes form an integral component of human food diet and rank as the third most important staple food crop in the world after wheat and rice [1]. The tubers are important dietary source of carbohydrates, proteins, carotenoids, antioxidants, minerals, phenolics, anti-nutrients, and vitamins [2–5]. These bioactive compounds are known to prevent and combat chronic diseases such as hypertension, cancer, diabetes, and heart disease [6–9]. Potatoes also contains recommended amounts of minerals such as potassium, magnesium, iron, and bioactive compounds such as chlorogenic acid, the flavonoids apigenin, rutin, and kaempferol 3-O-rutinoside, polyamines and alkaloids such as calystegines, solanine, tomatine, and chaconine [10, 11]. It is widely

used as a raw marketable product and in industry for making processed food stuffs such as chips and french fries etc. [12]. Although, they provide most of the calories and protein needed, potatoes are not nutritionally complete foods [13, 14]. To overcome the challenges of poverty and hunger worldwide, potato is considered as one of the promising crops for nutritional enhancement [15]. Traditional processing and preparation methods such as peeling, roasting, microwaving, boiling, frying, and baking alter nutritional quality of potatoes including loss of key micronutrients, adsorption of fat, and conversion of naturally resistant starch into highly digestible starch [16, 17]. Biotechnology could enhance micronutrient content and has the potential to reduce malnutrition especially among poor people from developing countries [13]. This approach will only be successful if clear advantages are demonstrated to both growers and consumers and the necessary safety precautions are addressed [18].

Potatoes are an excellent model crop for the genetic modification of metabolic pathways. Large-scale metabolomic studies have identified significant variation in nutrient content, minerals, and bioactive compounds in potatoes leading to the selection of specific cultivars for consumption of raw or processed potatoes [19–21]. Metabolite and mineral variation in raw and cooked potatoes can be used to predict the nutrient and bioactive content in cooked potato tuber for improved health traits [22]. Although conventional breeding efforts are underway for producing potato

#### **Figure 1.**

*Important quality traits in potato. Figure highlights the important tuber quality traits. A very special thanks to Prof. Dr. David G. Holm, Department of Horticulture and Landscape Architecture, Colorado State University, USA and Dr. Sanjay Gupta, Department of Soil, Water and Climate, University of Minnesota, USA for providing the potato photographs used in the figure. Also, I would like to extend my thanks to https://www. idahopacific.com/potato-granules and Waltz (2015; 10.1038/nbt0115-12) from which the photographs have been obtained and modified.*

#### *Transgenic Approaches for Nutritional Enhancement of Potato DOI: http://dx.doi.org/10.5772/intechopen.106898*

cultivars with altered nutritional properties [23, 24], the efforts are complicated by the tetrasomic inheritance and high level of heterozygosity of potatoes [25]. Transgenic technology and genome editing tools [26] offer significant opportunities for tailored improvement of nutritional quality traits in potato, such as starch and sugar content, chipping quality, flesh color, and taste, as well as ascorbic acid, anthocyanin, carotenoid, and glycoalkaloid content [27–32].

**Figure 1** outlines the important quality traits that have been modified by transgenic technologies or other genome editing tools in potato. These technologies include production of transgenic potatoes by overexpression or antisense repression of genes, RNA interference (RNAi) and gene editing tools such as Transcription Activator-Like Effector Nucleases (TALENs), and Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR/Cas9) [26, 27, 31, 33, 34]. TALENs and CRISPR/ Cas9 systems make site-specific gene modification by creating double-stranded DNA break. While TALEN recognizes the target site based on DNA protein interaction, the CRISPR system is based on site specific RNA protein interactions. CRISPR/Cas9 is a targeted mutagenesis technique to generate knockout mutations via non-homologous end-joining as well as gene targeting to edit an endogenous gene by homologous recombination [26, 27, 31, 33, 34]. CRISPR/cas9 avoids foreign DNA insertions in the plant genome, an important criterion in the development of crop varieties not subjected to the cumbersome GMO regulation process [26–28, 34]. Moreover, the availability of the potato genome sequence [35] has facilitated the development of comparative genomic analyses and functional studies of candidate genes to improve several important traits in potato [36]. In this review we discuss the past developments, and future perspectives of nutritional enhancement in potato using transgenic technologies.
