Russian dandelion (<i>Taraxacum kok-saghyz</i> Rodin): rubber extraction methods and prospects for biotechnological methods application

Natural rubber is a strategic natural raw material, which is used in the production of tires and military equipment, in medicine and other industries. An alternative to Hevea brasiliensis (Willd. ex A. Juss.) Müll. Arg. and the most promising rubber plant is the Russian dandelion (Taraxacum kok-saghyz Rodin). The rubber that accumulates in the roots of this dandelion is not inferior in quality to the natural rubber from H. brasiliensis, and its content reaches 27% of the dry weight of roots. The purpose of this paper is to describe the economically important components of T. kok-saghyz roots, the main methods for extracting natural rubber from the roots, as well as the approaches to micropropagation and genetic transformation of kok-saghyz and related species. In the middle of the 20th century, the industrial method of isolating rubber from Russian dandelion in the USSR was based on preliminary treatment of the roots with a 2% solution of alkali, which could negatively affect rubber quality. Therefore, it is important to develop new, rapid, but at the same time, inexpensive methods of rubber extraction from T. koksaghyz. Some of them are considered in this paper. The breeding of Russian dandelion should be aimed at both increasing the root size and the content of rubber. In this regard, the development of laboratory express methods for rubber extraction is also important. The authors have developed and optimized a method for extracting rubber from dry plant tissue using polar solvents (water and acetone), with the final extraction with a non‑polar solvent (hexane). The developed rubber extraction protocol showed results comparable to the literature data. In order to create more productive plant forms, experiments are also being conducted on T. kok-saghyz micropropagation and genetic transformation. However, the number of such works is still very small, probably due to the low regenerative abilities of this dandelion species.