Down-regulation of LACS8A03 gene in Brassica napus L. decrease the content of glucosinolates

Long-chain acyl-CoA synthetase (LACS), belonging to the AMP-bound superfamily, catalyzes the activation of long-chain fatty acids to their coenzyme A esters. Candidate Gene Association analysis showed that LACS8 was not only related to the content of fatty acid, but also, surprisingly, to the content of glucosinolates. Here, we cloned BnaLACS8A03 from rapeseed, and demonstrated its association with the glucosinolates content. We found that BnaLACS8A03 was widely expressed in all tissues and organs, and significantly highly expressed in leaf and flower, which are the sites of glucosinolate synthesis. Bioinformatics predicted that it was located in peroxisome, where the β-oxidation of fatty acids mainly occurred, indicating that BnaLACS8A03 was involved in the metabolism of fatty acids. Phenotypic studies of RNA interference (RNAi) lines revealed that down-regulation of BnaLACS8A03 in rapeseed significantly reduced the glucosinolates content. In addition, the expression of glucosinolates biosynthesis-related genes and transport-related genes is altered in BnaLACS8A03 -RNAi plants, suggesting that a possible crosstalk regulation mechanism exists in the regulation network of glucosinolate mechanism. Our results demonstrate that glucosinolates content can be manipulated by altering the expression of long chain acyl-Coenzyme A synthase gene BnaLACS8A03 , which provide an available genetic resource for low glucosinolate breeding practice in rapeseed.