title: Cloning and functional characterization of SAD genes in potato.
abstract: Stearoyl-acyl carrier protein desaturase (SAD), locating in the plastid stroma, is an important fatty acid biosynthetic enzyme in higher plants. SAD catalyzes desaturation of stearoyl-ACP to oleyl-ACP and plays a key role in determining the homeostasis between saturated fatty acids and unsaturated fatty acids, which is an important player in cold acclimation in plants. Here, four new full-length cDNA of SADs (ScoSAD, SaSAD, ScaSAD and StSAD) were cloned from four Solanum species, Solanum commersonii, S. acaule, S. cardiophyllum and S. tuberosum, respectively. The ORF of the four SADs were 1182 bp in length, encoding 393 amino acids. A sequence alignment indicated 13 amino acids varied among the SADs of three wild species. Further analysis showed that the freezing tolerance and cold acclimation capacity of S. commersonii are similar to S. acaule and their SAD amino acid sequences were identical but differed from that of S. cardiophyllum, which is sensitive to freezing. Furthermore, the sequence alignments between StSAD and ScoSAD indicated that only 7 different amino acids at residues were found in SAD of S. tuberosum (Zhongshu8) against the protein sequence of ScoSAD. A phylogenetic analysis showed the three wild potato species had the closest genetic relationship with the SAD of S. lycopersicum and Nicotiana tomentosiformis but not S. tuberosum. The SAD gene from S. commersonii (ScoSAD) was cloned into multiple sites of the pBI121 plant binary vector and transformed into the cultivated potato variety Zhongshu 8. A freeze tolerance analysis showed overexpression of the ScoSAD gene in transgenic plants significantly enhanced freeze tolerance in cv. Zhongshu 8 and increased their linoleic acid content, suggesting that linoleic acid likely plays a key role in improving freeze tolerance in potato plants. This study provided some new insights into how SAD regulates in the freezing tolerance and cold acclimation in potato.
authors.affiliation: The Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China; Institute of Potato in Guizhou Province, Guiyang, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Li
authors.affiliation: The Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Chun Song
authors.initials: CS
authors.lastname: Bian
authors.affiliation: The Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Jian Fei
authors.initials: JF
authors.lastname: Xu
authors.affiliation: The Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Wan Fu
authors.initials: WF
authors.lastname: Pang
authors.affiliation: The Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
authors.affiliation: The Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Shao Guang
authors.initials: SG
authors.lastname: Duan
authors.affiliation: Institute of Potato in Guizhou Province, Guiyang, China.
authors.forename: Zun-Guo
authors.initials: ZG
authors.lastname: Lei
authors.affiliation: Department of Horticulture, University of Wisconsin, Madison, Wisconsin, United States of America.
authors.forename: Palta
authors.initials: P
authors.lastname: Jiwan
authors.affiliation: The Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Li-Ping
authors.initials: LP
authors.lastname: Jin
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics; D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D019143:Evolution, Molecular; D005615:Freezing; D017343:Genes, Plant; D006899:Mixed Function Oxygenases / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D030821:Plants, Genetically Modified; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D011198:Solanum tuberosum / Q000201:enzymology / Q000235:genetics* / Q000502:physiology
chemical_list: D018076:DNA, Complementary; D006899:Mixed Function Oxygenases; C018747:acyl-(acyl-carrier-protein)desaturase
references.citation: Plant Cell Physiol. 2003 Apr;44(4):447-50
references.pmid: 12721386
references.citation: Proc Natl Acad Sci U S A. 1993 Aug 15;90(16):7869-73
references.pmid: 11607422
references.citation: Plant Cell. 1995 Jul;7(7):957-70
references.pmid: 7640528
references.citation: Proc Natl Acad Sci U S A. 1992 Apr 1;89(7):2624-8
references.pmid: 1557366
references.citation: Proc Natl Acad Sci U S A. 1991 Mar 15;88(6):2578-82
references.pmid: 2006194
references.citation: Plant Physiol Biochem. 2004 Dec;42(10):811-22
references.pmid: 15596101
references.citation: Proc Natl Acad Sci U S A. 1991 Mar 15;88(6):2510-4
references.pmid: 2006187
references.citation: Biochim Biophys Acta. 1998 Oct 2;1394(1):3-15
references.pmid: 9767077
references.citation: Biotechnol Lett. 2008 Jun;30(6):967-77
references.pmid: 18227974
references.citation: Plant Physiol. 1994 Feb;104(2):445-52
references.pmid: 7909163
references.citation: Plant Physiol. 1992 Sep;100(1):533-4
references.pmid: 16652995
references.citation: Plant Physiol. 1993 Nov;103(3):793-803
references.pmid: 12231980
references.citation: EMBO J. 1987 Dec 20;6(13):3901-7
references.pmid: 3327686
references.citation: J Biol Chem. 1982 Oct 25;257(20):12141-7
references.pmid: 7118934
references.citation: Plant Physiol. 1995 Apr;107(4):1177-1185
references.pmid: 12228424
references.citation: Plant Mol Biol. 1992 Jul;19(4):711-3
references.pmid: 1627785
references.citation: Biotechnol Lett. 2009 Jul;31(7):1089-101
references.pmid: 19277477