In various aspects, the invention provides Brassica juncea plants, seeds, cells, nucleic acid sequences and oils. Edible oil derived from plants of the invention may have significantly higher oleic acid content than other B. juncea plants. In one embodiment, the B. juncea line MJ02-086-3 contains a mutant allele MJ02-086-3/BjFAD2-a at the BjFAD2-a gene locus, having a premature stop codon, so that there are no functional copies of the FAD2 gene in MJ02-086-3 plants. Seeds from MJ02-086-3 plants may for example yield an oil having oleic acid content of greater than about 70% by weight.