Reducing the carbon footprint of the lubricants industry by the substitution of mineral oil with rapeseed oil

Abstract

There are not many options to substitute for fossil-oil based lubricants and hydraulic fluids in industrial uses, such as engine oil or in a hydraulic ram on a digger arm. Rapeseed oil could present a low cost, low carbon, biodegradable alternative, if only there was a lower content of polyunsaturated fatty acids (PUFAs). These PUFAs breakdown under high temperatures and pressures, rendering the oil less than suitable. Commercial cultivars of oilseed rape (Brassica napus) with very low PUFA content have not yet been developed.

This project shows that a cultivar of oilseed rape with lower than usual PUFA content has non-functional alleles at three of the four orthologous FATTY ACID DESATURASE 2; (FAD2) loci. FAD2 is the principal locus controlling the proportion of PUFAs in seeds of Arabidopsis thaliana. Many important plant species have polyploidy in their recent ancestry, complicating inferences about the genetic bases of trait variation. To explore the genetic basis further, we developed an ethyl methanesulphonate (EMS) mutagenised population, JBnaCabE, and used it to identify lines that also carried mutations in the remaining functional copy. This confirmed the hypothesised basis of variation, resulting in an allelic series of mutant lines showing a spectrum of PUFA contents of seed oil. Several lines had PUFA content of ~6% and oleic acid content of ~84%, achieving a long-standing industry objective: very high oleic, very low PUFA rapeseed without the use of GM technology. The population contains a high rate of mutations and represents an important resource for research in Brassica napus.