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United States Department of Agriculture

Agricultural Research Service

Title: Characterization and Expression of the Gene Encoding Beta-Ketoacyl-Acyl Carrier Protein Synthase (Kas)

Authors
item Ko, T -S. - UOFI URBANA
item Strauss, E - UOFI URBANA
item Nelson, Randall
item Korban, S - UOFI URBANA

Submitted to: Cellular and Molecular Biology of Soybean Biennial Conference
Publication Type: Proceedings
Publication Acceptance Date: August 31, 2002
Publication Date: August 20, 2002
Citation: KO, T., STRAUSS, E., NELSON, R.L., KORBAN, S.S. CHARACTERIZATION AND EXPRESSION OF THE GENE ENCODING BETA-KETOACYL-ACYL CARRIER PROTEIN SYNTHASE (KAS). CELLULAR AND MOLECULAR BIOLOGY OF SOYBEAN BIENNIAL CONFERENCE. 2002. v. Aug. p. 11-14.

Technical Abstract: A cDNA clone, encoding soybean [Glycine max (L.) Merr.] Beta-ketoacyl-acyl carrier synthase (KAS III), was previously isolated using a soybean KAS III partial sequence obtained from RT-PCR using degenerate primers. This gene is thought to be involved in the regulation of fatty acid synthesis. The expression of this KAS III in different tissues of a soybean plant and during embryo development was investigated. A 1.9 kb transcript was detected by Northern analysis using this cDNA clone as a probe. The expression level of KAS III was highest when developing embryos were between 100 and 200 mg in size. Multiple sequence alignment of the deduced amino acid sequence from the soybean cDNA clone revealed a high degree of sequence similarity with other previously reported KAS IIIs. A KAS III genomic clone was also isolated, and its sequence was used for structural analysis of the KAS III gene. The genomic clone contained 8 exons separated by 7 intervening sequences varying from 78 to 931 bp in length. This clone encoded a 397 amino acid polypeptide, including a putative signal peptide at the N-terminus. Southern analysis of total genomic DNA indicated that there were at least two KAS III genes present in soybean. Northern blot analysis revealed that the mRNA level for the KAS III gene in high-oil soybean lines was lower than that in low-oil soybean lines, suggesting that the KAS III gene expression appeared to be regulated by feedback inhibition of one of the end products through fatty acid synthesis. Expression profiles and sequence analysis of the KAS III gene with other genes involved in fatty acid synthesis is presented.

Last Modified: 8/1/2014