Influence of Bna.FAD2 Alleles on the Erucic Acid and Polyunsaturates Content in Brassica napus Oil

Brassica napus L. (rapeseed) is an economically important oilseed crop worldwide, having uses in both food and non-food sectors. Its industrial applications are linked to the natural occurrence of erucic acid (EA, C22:1), together with other fatty acids in its seeds. EA is a valuable fatty acid that could be derived into products such as erucamide, brassylic acid and pelargonic acid having a wide range of industrial applications such as plasticizers, slip additives, lubricants, pharmaceuticals, biodiesel and many more. EA biosynthesis is controlled by Bna.FAE1s (FATTY ACID ELONGASES 1) in B. napus. In addition, low levels of polyunsaturated fatty acids (PUFAs) are desirable in the oil for the industry as it increases the thermal stability of the oil. PUFAs biosynthesis is controlled by Bna.FADs (FATTY ACID DESATURASES) in B. napus. The present study was aimed to underpin the new loci affecting the EA biosynthesis by using the associative transcriptomics approach and to study the influence of Bna.FAD2 family on the erucic acid (or very long chain fatty acids, VLCFAs) and polyunsaturated fatty acids levels. Although new loci influencing the erucic acid levels were not found from the present study but a unique specification – high erucic acid rapeseed in the low polyunsaturates (HELP) background was developed by introducing partially functional Bna.FAD2 family from EMS mutagenized mutants to the high erucic acid rapeseed background. HELP lines showed the influence of partially functional Bna.FAD2 alleles in the fatty acid compositions, ~8% increase in the erucic acid (60%) and VLCFAs (66%) levels as compared to the parental high erucic parents having functional Bna.FAD2 family. Polyunsaturates content of less than 7% was found in these HELP lines. HELP oil is anticipated to be a valuable industrial oil that could contribute significantly to reduce the processing costs and serve as a renewable environment-friendly industrial resource with no toxicity.