# Molecular Genetic Research and Genetic Engineering of _Taraxaxacum kok-saghyz_ [PERSON]
By the beginning of the 21 st century, many economically developed countries of the world realized the importance of finding alternative sources of NR. TKS, which has already been successfully grown on an industrial scale in the USSR and some other countries in the middle of the 20 th century, takes first place in these searches. In the USSR, from one hectare of annual plantations of TKS, about 80 centhers of roots were harvested; in terms of rubber, this is 176 kg per hectare [15]. TKS was first described in 1931 by the botanist of the Botanical Institute of the USSR Academy of Sciences [PERSON] after it was pointed out by local residents [PERSON] and [PERSON]. Detailed information about the use of alternative sources of rubber in the USSR is given in [16]. In the 21 st century, in many countries, the collection of germplasm resources began again and basic research on this plant began [17; 18]. TKS belongs to the Asteraceae family and originates from the Tekes river basin near the mountainous border in the Tien Shan between Kazakhstan and China [19]. In Kazakhstan, the TKS range is associated with the intermountain valleys of the Kegen and Tekes rivers of the Eastern Tien Shan [20; 21]. According to some reports, TKS also grows in Uzbekistan [2]. TKS grows most often in non-saline or slightly saline floodplain meadows and canals of agricultural land [22]. TKS can be cultivated in most temperate regions [23]. At the same time, it is possible to use fully mechanized farming in a standard annual crop [2], while _H. brasiliensis_ plantations use manual labor. The most important thing is that the molecular characteristics and mechanical properties of TKS NR are similar to those of _H. brasiliensis_ rubber. TKS rubber is of particular interest primarily to the tire industry due to its high molecular weight (polymer index) and fast crop maturation (six months for TKS versus seven years for _H. brasiliensis_) [3; 5; 17; 24; 25]. The relevance of alternative sources of NR can also be indicated by the fact that a number of companies have become interested and have already participated in or are participating in the implementation of projects with TKS; these are well-known companies such as American Sustainable Rubber, Bridgestone, Continental, Ford, Goodyear, KeyGene, Kultivat, Linglong, NovaBioRubber, and Sumitomo [2]. The roots of TKS contain about 2.89-27.89% NR (_cis_-1,4-polyisoprene) on a dry weight basis, with very similar macromolecular structure and composition characteristics to _H. _brasiliensis_[22; 26; 27]. The rubber in TKS is also reported to have a higher molecular weight than \(H\). _brasiliensis_[28]. In addition to high-quality rubber, the roots of TKS can produce a large amount of inulin (up to 40% of dry weight) [27; 29], which is an important raw material for the food and medical industries, including bioethanol production. TKS roots also contain sucrose (10%), proteins (15%), cellulose (9%), hemicellulose (7%), lignin (5%), pectin (3%), and sterols (less than 1.7%) [3]. Inulin (Figure 1B) is the main storage carbohydrate in dandelions [30] and inulin carbon, if necessary, can be redirected towards rubber biosynthesis through acetyl-CoA, which occurs in nature towards the end of the growing season [31]. One study showed that in addition to rubber and inulin, TKS contains a wide variety of valuable metabolites, such as sesquiterpenoids, fatty acids and their derivatives, and phenolic compounds (caftaric and chicoric acids) [32]. It was pointed out that TKS leaves are a valuable source of chicoric acid, with potential use as an antioxidant for use as herbal medicine and nutrition for health food/fodder production [33]. However, TKS still has several inherent problems, such as the need for constant soil moisture during germination, slow growth rate, low competitiveness with weeds, significant rubber yield only at maturity, high heterozygosity, and self-incompatibility [2; 5]. Therefore, the main efforts should be aimed at overcoming these shortcomings in TKS using speed breeding and biotechnology [14].