Development of high oleic and low linoleic acid transgenics in a zero erucic acid Brassica juncea L. (Indian mustard) line by antisense suppression of the fad2 gene

• Published in: Molecular breeding 2004-05, Vol.13 (4), p.365-375
• Main Authors: Sivaraman, I, Arumugam, N, Sodhi, Y.S, Gupta, V, Mukhopadhyay, A, Pradhan, A.K, Burma, P.K, Pental, D
• Format: Article
• Language: English
• Subjects: Agronomy; Antisense DNA; Brassica; Brassica juncea; Brassica rapa; FAD2 gene; Fatty acid composition; gene silencing; Heterozygotes; Homozygotes; Linoleic acid; Linolenic acid; long chain fatty acids; Molecular biology; molecular sequence data; Mustard; mustard oil; nucleotide sequences; Oils & fats; oilseed crops; oleic acid; Plant biology; polyunsaturated fatty acids; Seeds; Segregation; stearoyl-CoA desaturase; structural genes; transcription (genetics); transgenic plants
• ISSN: 1380-3743; 1572-9788
• DOI: 10.1023/B:MOLB.0000034092.47934.d6

A zero erucic acid (C22:1) line of Brassica juncea (VH486), adapted to the agronomic conditions of Northern India, has been modified for its fatty acid composition in the seed oil with antisense constructs using the sequence of fad2 gene of B. rapa. The full-length B. rapa fad2 cDNA sequence was determined by 5' and 3' RACE of a partial sequence available in the EST database. Construct pASfad2.1 contained 315 to 1251 bp and construct pASfad2.2 contained 1 to 1251 bp fragment of the fad2 gene, both in antisense orientation, driven by a truncated napin promoter. Analysis of the levels of linoleic acid (C18:2) in the BC1 seeds of single-copy transgenics showed that the construct pASfad2.2 gave better suppression of the fad2 gene as compared to the construct pASfad2.1. The BC1 transgenic seeds containing the pASfad2.2 construct segregated into two distinct classes of C18:2>20% (putative null homozygotes) and C18:220%, C18:2 between 12% and 20%) and C18:2