Oxidosqualene Cyclase Knock-Down in Latex of Taraxacum koksaghyz Reduces Triterpenes in Roots and Separated Natural Rubber

Abstract

In addition to natural rubber (NR), several triterpenes are synthesized in laticifers of the Russian dandelion (Taraxacum koksaghyz). Detailed analysis of NR and resin contents revealed different concentrations of various pentacyclic triterpenes such as α-, β-amyrin and taraxasterol, which strongly affect the mechanical properties of the resulting rubber material. Therefore, the reduction of triterpene content would certainly improve the industrial applications of dandelion NR. We developed T. koksaghyz plants with reduced triterpene contents by tissue-specific downregulation of major laticifer-specific oxidosqualene cyclases (OSCs) by RNA interference, resulting in an almost 67% reduction in the triterpene content of NR. Plants of the T1 generation showed no obvious phenotypic changes and the rubber yield also remained unaffected. Hence, this study will provide a solid basis for subsequent modern breeding programs to develop Russian dandelion plants with low and stable triterpene levels.

Fabrication of Ag Nanosheet@TiO2 Antibacterial Membranes for Inulin Purification

“…These products are likely to become a substitute for three-leaf rubber and reduce our dependence on imported rubber. However, low rubber content and complicated extract production result in a high production cost that slows the large-scale application of dandelion rubber . Therefore, extracting other products from dandelion roots reduces the comprehensive cost of dandelion rubber and could effectively improve the competitiveness of dandelion rubber …”

“…However, low rubber content and complicated extract production result in a high production cost that slows the large-scale application of dandelion rubber. 2 Therefore, extracting other products from dandelion roots reduces the comprehensive cost of dandelion rubber and could effectively improve the competitiveness of dandelion rubber. 3 Inulin is of high commercial value as a kind of food additive that regulates the stomach, prevents dental caries, improves immunity, and promotes mineral absorption; 4,5 furthermore, its price is approximately 40,000 yuan/ton in China.…”

Latex Metabolome of Euphorbia Species: Geographical and Inter-Species Variation and its Proposed Role in Plant Defense against Herbivores and Pathogens

“…In addition to the fungicidal activity and function as a dispersion agent, triterpenes might have other functions. They could contribute to the polymeric structure of polyisoprene to strengthen the defensive barrier, as may be deduced from other related experiments (Mironenko et al 2016;van Deenen et al 2019). Further work is needed to understand the specificity of the synergy between latex and cycloartanol in particular, among many other available steroids and triterpenoids.…”

Natural rubber reduces herbivory and alters the microbiome below ground

“…As roots of rubber-depleted Tk CPTL1-RNAi plants accumulate about three fold higher pentacyclic triterpene levels compared to NIL plants (Niephaus et al ., 2019), we also investigated whether triterpenes alter T. koksaghyz performance under M. melolontha herbivory using two independent triterpene-reduced TkOSC -RNAi lines (oxidosqualene cyclase knock-down; TkOSC -RNAi-L2 and -L3) and their respective NILs (van Deenen et al ., 2019). The TkOSC -RNAi lines displayed 73-80% reduced pentacyclic triterpene content, but normal cis -1,4-polyisoprene levels (van Deenen et al ., 2019). In addition, we assessed whether lupeol, a T. koksaghyz triterpene, alters M. melolontha growth when added to artificial diet in physiologically relevant amounts (Unland et al ., 2018; Pütter et al ., 2019).…”

“…The copyright holder for this this version posted October 11, 2022. ; https://doi.org/10.1101/2022.10.10.511194 doi: bioRxiv preprint Natural rubber mediates plant-herbivore-microbe interactions 9 2019). The TkOSC-RNAi lines displayed 73-80% reduced pentacyclic triterpene content, but normal cis-1,4-polyisoprene levels (van Deenen et al, 2019). In addition, we assessed whether lupeol, a T. koksaghyz triterpene, alters M. melolontha growth when added to artificial diet in physiologically relevant amounts (Unland et al, 2018;Pütter et al, 2019).…”