# Molecular Genetic Research and Genetic Engineering of _Taraxaxacum kok-saghyz_ [PERSON]
Natural rubber consists mainly of linear rubber polymers (_cis_-1.4-polyisoprene, Figure 1A) and secondary components (non-rubber components) that distinguish it from synthetic rubber. Non-rubber components include proteins and resins (fatty acids, triglycerides, sterols, etc.). These elements may also be involved in the construction of the rubber network, which may be the basis for the outstanding mechanical properties of NR [3]. According to numerous data from the literature, more than 2500 species of dicotyle-donous plants can synthesize rubber [7]. The search for new rubber-bearing plant species remains relevant to this day. In our recent study in the flora of the Republic of Bashkortosan (Southern Ural region in Russia), we identified eight species of Asteraceae with a high content of natural rubber [8]. The role of rubber in protecting plants from herbivores and pathogens is generally recognized as the latex leaks out of the plant after injury. Many proteins produced in latex are clearly associated with defense, such as pathogenesis-associated polypeptides and chitinases. This evolutionary acquisition appears to have evolved independently several times, possibly to reduce herbivory and pathogen attacks [9]. However, no more than 10 plant species have been identified as a source of high-quality high-molecular-weight rubber that can be used on an industrial scale. The most famous of them are the Para rubber tree (_Heeva brasiliensis_ (Wild. ex A.Juss.) [PERSON]), guayule (_Parthenium argentatum_ [PERSON]), krym-saghyz (_Taraxacum hyberum_ Stev. ), and the Russian (Kazakh) dandelion (_Taraxacum kok-saghyz_ [PERSON]) (TKS) [5; 10]. At the same time, only _H. brasiliensis_, cultivated mainly in the countries of the Asia-Pacific region, is the source of almost all NR in the world [11]. Figure 1: (**A**). Chemical structure of natural rubber. (**B**). Chemical structure of inulin. However, the global demand for NR is growing every year. Since NR yields are highly dependent on natural conditions, price volatility is added to climate change concerns. In the decade from 2001 to 2011, rubber prices tripled and then declined [11]. The global NR market in 2016 amounted to approximately USD 24 billion, with a volume of NR consumption of 12.9 million tons; by 2023 its forecast consumption will increase to 16.5 million tons (International Rubber Study Group (IRSG), [[http://natural-rubber.ru](http://natural-rubber.ru)]([http://natural-rubber.ru](http://natural-rubber.ru)), accessed on 12 February 2023). Natural rubber demand could reach USD 68.5 billion by 2026 [12]. There is less and less suitable land for laying new _H. brasiliensis_ plantations. In addition, these trees begin to produce rubber only after 7 years of cultivation. Furthermore, _H. brasiliensis_ is susceptible to various infectious diseases, for example, caused by the well-known fungus _Microcyclus ulei_[11]. The small genetic diversity of _H. brasiliensis_ grown on plantations also remains a difficult problem to solve [13]. It is unlikely that _H. brasiliensis_ cultivation can be further expanded sufficiently to meet the growing global demand for NR due to both economic and environmental constraints [14]. It should also be borne in mind that, in order to meet the growing demand for rubber, it is necessary to destroy millions of hectares of tropical forests along with all their biodiversity. Moreover, _H. brasiliensis_ is losing competition for land and labor against the economically more profitable African oil palm _Elaeis quintensis_[5]. Unfortunately, the supply of _H. brasiliensis_ rubber is largely dependent on smallholders in Southeast Asia, so its industrial production is not subject to any global control and can quickly collapse under the influence of climate change and disease. Based on the understanding of these problems, the introduction of alternative rubber crops that provide geographic and genetic diversity on a global scale will positively affect the rubber trade while reducing price volatility and ensuring supply security [9].