title: Identification of candidate genes from the SAD gene family in cotton for determination of cottonseed oil composition.
abstract: Cotton is an economically important crop grown for natural fiber and seed oil production. Cottonseed oil ranks third after soybean oil and colza oil in terms of edible oilseed tonnage worldwide. The fatty acid composition of cottonseed oil determines its industrial application and nutritional values. However, little progress has been made in understanding cottonseed oil biogenesis. Stearoyl-acyl carrier protein desaturase (SAD), the only known enzyme to convert saturated fatty acids into unsaturated fatty acids in plants, plays key roles in determining the fatty acid composition of cottonseed oil. In this study, we identified 9, 9, 18 and 19 SAD genes in the genomes of four sequenced cotton species: diploid Gossypium raimondii (D5), G. arboreum (A2), tetraploid G. hirsutum acc. TM-1 (AD1) and G. barbadense cv. Xinhai21 (AD2), respectively. Bioinformatic and phylogenetic analyses revealed that cotton SADs can be classified into two classes. Expression patterns showed developmental and spatial regulation of SADs in cotton. GhSAD2 and GhSAD4 were preferentially expressed in developing ovules 20-35 days post-anthesis, and significantly different expression patterns were found between high-oil and low-oil cotton cultivars, implying these two genes could be involved in cottonseed oil biogenesis. Association analysis further confirmed that GhSAD4-At expression was closely related to the oleic acid (O) content, linoleic acid (L) content and O/L value in cottonseed, implying GhSAD4 plays an important role in cottonseed oil composition. This study brings new perspectives for integrated genome-wide identification of SADs in cotton and provides references for the genetic improvement of cottonseed oil.
authors: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Hybrid Cotton R&D Engineering Research Center, Ministry of Education, Nanjing Agricultural University, Nanjing, 210095, China.
authors: Xiaoguang
authors: X
authors: Shang
authors: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Hybrid Cotton R&D Engineering Research Center, Ministry of Education, Nanjing Agricultural University, Nanjing, 210095, China.
authors: Chaoze
authors: C
authors: Cheng
authors: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Hybrid Cotton R&D Engineering Research Center, Ministry of Education, Nanjing Agricultural University, Nanjing, 210095, China.
authors: Jian
authors: J
authors: Ding
authors: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Hybrid Cotton R&D Engineering Research Center, Ministry of Education, Nanjing Agricultural University, Nanjing, 210095, China. moelab@njau.edu.cn.
authors: Wangzhen
authors: W
authors: Guo
mesh_terms: D003369:Cottonseed Oil / Q000737:chemistry*; D005227:Fatty Acids / Q000032:analysis*; D003368:Gossypium / Q000201:enzymology* / Q000235:genetics*; D006899:Mixed Function Oxygenases / Q000235:genetics*; D005810:Multigene Family; D010802:Phylogeny
chemical_list: D003369:Cottonseed Oil; D005227:Fatty Acids; D006899:Mixed Function Oxygenases; C018747:acyl-(acyl-carrier-protein)desaturase
keywords: Fatty acid biosynthesis; Genome-wide identification; Gossypium; SAD gene