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Cloning and functional characterization of SAD genes in potato.

Li F, Bian CS, Xu JF, Pang WF, Liu J, Duan SG, Lei ZG, Jiwan P, Jin LP - PLoS ONE (2015)

Bottom Line: 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 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.

View Article: PubMed Central - PubMed

Affiliation: The Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China; Institute of Potato in Guizhou Province, Guiyang, China.

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.

No MeSH data available.


Related in: MedlinePlus

Chromatogram of fatty acid methyl ester products in potato leaves.
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pone.0122036.g006: Chromatogram of fatty acid methyl ester products in potato leaves.

Mentions: Total fatty acids were extracted from mature leaves and methyl esterified for GC analysis (Fig 6). The compositions are listed in Table 4. The T13 line showed a lower palmitic acid (C16:0) content but increased palmitoleic acid (C16:1) content compared to wild-type plants under growth conditions of 20°C day/18°C night (P < 0.01). The C16:0 content decreased gradually after 12 days of cold acclimation, whereas that of octadecanoic acid increased slightly. Among the tested lines, only T13 showed a significant change in C16:0 and octadecanoic acid contents after cold acclimation. The oleic acid content was significantly lower in both the T13 and T15 lines after cold acclimation (P < 0.05), as well as in T33 (P < 0.01). However, the C18:2 content increased highly significant in the three ScoSAD-overexpressing lines following cold acclimation, whereas the C18:2 content did not differ in the wild type. Moreover, the C18:3 contents of all three ScoSAD-overexpressing lines decreased significantly (P<0.01), whereas no difference was evident in the wild type. This indicates that there may be a causal relationship between C18:3 content and cold acclimation.


Cloning and functional characterization of SAD genes in potato.

Li F, Bian CS, Xu JF, Pang WF, Liu J, Duan SG, Lei ZG, Jiwan P, Jin LP - PLoS ONE (2015)

Chromatogram of fatty acid methyl ester products in potato leaves.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4380360&req=5

pone.0122036.g006: Chromatogram of fatty acid methyl ester products in potato leaves.
Mentions: Total fatty acids were extracted from mature leaves and methyl esterified for GC analysis (Fig 6). The compositions are listed in Table 4. The T13 line showed a lower palmitic acid (C16:0) content but increased palmitoleic acid (C16:1) content compared to wild-type plants under growth conditions of 20°C day/18°C night (P < 0.01). The C16:0 content decreased gradually after 12 days of cold acclimation, whereas that of octadecanoic acid increased slightly. Among the tested lines, only T13 showed a significant change in C16:0 and octadecanoic acid contents after cold acclimation. The oleic acid content was significantly lower in both the T13 and T15 lines after cold acclimation (P < 0.05), as well as in T33 (P < 0.01). However, the C18:2 content increased highly significant in the three ScoSAD-overexpressing lines following cold acclimation, whereas the C18:2 content did not differ in the wild type. Moreover, the C18:3 contents of all three ScoSAD-overexpressing lines decreased significantly (P<0.01), whereas no difference was evident in the wild type. This indicates that there may be a causal relationship between C18:3 content and cold acclimation.

Bottom Line: 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 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.

View Article: PubMed Central - PubMed

Affiliation: The Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China; Institute of Potato in Guizhou Province, Guiyang, China.

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.

No MeSH data available.


Related in: MedlinePlus