FUNCTIONAL ANALYSIS OF OLEATE DESATURASE GENE EXPRESSION FROM BRASSICA JUNCEA
KrishiKosh
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Title |
FUNCTIONAL ANALYSIS OF OLEATE DESATURASE GENE EXPRESSION FROM BRASSICA JUNCEA
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Creator |
SURESHA, G.S.
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Contributor |
I. M. Santha
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Subject |
acidity, genes, unsaturated fatty acids, fatty acids, planting, sowing, genetic structures, genomes, enzymes, biological phenomena
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Description |
t-8043
Higher plants express one or more microsomal oleic acid desaturase (FAD2; EC1.3.1.35) isoforms which catalyze the insertion of a double bond between carbons 12 and 13 of oleic acid at both the sn-1 and sn-2 positions of phosphatidylcholine. In the present study, full length genomic and cDNA sequences of fad2 gene have been isolated by using PCR approach from Brassica juncea. Analysis of genomic structure of fad2 gene revealed that isolated genomic sequence (2526bp) contains 1238 bp 5’ untranslated region which is having a large single intron of 1081 bp, 143 bp 3’ untranslated region, and a CDS of 1155 bp. Analysis of cDNA sequence (1445 bp) corresponding to genomic sequence (2526bp) revealed that isolated cDNA sequence exactly corresponded with the genomic sequence containing 5’UTR of 147 bp, CDS of 1155 bp and 3’UTR of 143 bp. Southern blot analysis using partial fad 2 genomic sequence as probe confirmed that there are atleast 2 copies of fad2 gene present in the Brassica juncea genome. ClustalW alignment of deduced amino acid sequences of the BjFAD2 protein together with the other plant fatty acid desaturases showed that all these membrane-bound desaturases contained the three conserved histidine clusters [HXXXH,HXXHH and HXXHH] that have been shown essential for desaturase activity-acting as potential ligands for non-heme iron atoms. Phylogenetic analysis of deduced amino acid sequences of BjFAD2 with other plant microsomal (FAD2) and plastidial (FAD6) oleate desaturases showed that a BjFAD2 was positioned in a subgroup with FAD2 enzymes that exhibit a house keeping pattern of expression. Study of developmental expression of fad2 gene from developing seeds of Brassica juncea through RT-PCR revealed that expression of fad2 gene was induced in early stages of seed development (15 DAF), peaked in mid maturation stage (30 DAF) and declined as seeds matured (45 DAF). Study of temperature dependent expression of fad2 gene through RT-PCR revealed that expression of fad2 gene increased under lower temperature treatments with incubation time as compared to the higher |
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Date |
2017-01-03T13:41:51Z
2017-01-03T13:41:51Z 2008 |
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Type |
Thesis
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Identifier |
http://krishikosh.egranth.ac.in/handle/1/94143
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Format |
application/pdf
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