Drought stress alters rubber molecular weight and relative expression levels of key genes -involved in natural rubber production in rubber dandelion, Taraxacum kok-saghyz

Abstract

Abstract Natural rubber (NR) is a vital raw material for many industries, but its main source, Hevea brasiliensis, is vulnerable to diseases and climate change. Taraxacum kok-saghyz (rubber dandelion, TKS) is an alternative source of NR that can grow in temperate regions. This study investigated the effect of drought stress on NR biosynthesis and quality in TKS roots. Drought stress didn’t affect the total rubber content, but increased the molecular weight (Mw) of the rubber significantly. The highest Mw was observed under severe drought stress, which also induced the highest expression of CPT and SRPP genes, which are involved in NR production. The rubber from TKS roots (TNR) had a high Mw of 994,000 g/mol under normal irrigation and a low glass transition temperature (Tg) of below − 60°C, indicating its industrial potential. Drought stress also increased the levels of proline, H2O2, MDA, and antioxidant enzymes (CAT, APX, GPX) in TKS roots, indicating a drought response mechanism. These results suggest that TKS can produce good quality NR under drought stress conditions and can be cultivated in regions with water scarcity.