Identification and functional analysis of soybean stearoyl-ACP Δ⁹ desaturase (GmSAD) gene family / 生物工程学报

Stearoyl-ACP Δ⁹ desaturase (SAD) catalyzes the synthesis of monounsaturated oleic acid or palmitoleic acid in plastids. SAD is the key enzyme to control the ratio of saturated fatty acids to unsaturated fatty acids in plant cells. In order to analyze the regulation mechanism of soybean oleic acid synthesis, soybean (Glycine max) GmSAD family members were genome-wide identified, and their conserved functional domains and physicochemical properties were also analyzed by bioinformatics tools. The spatiotemporal expression profile of each member of GmSADs was detected by qRT-PCR. The expression vectors of GmSAD5 were constructed. The enzyme activity and biological function of GmSAD5 were examined by Agrobacterium-mediated transient expression in Nicotiana tabacum leaves and genetic transformation of oleic acid-deficient yeast (Saccharomyces cerevisiae) mutant BY4389. Results show that the soybean genome contains five GmSAD family members, all encoding an enzyme protein with diiron center and two conservative histidine enrichment motifs (EENRHG and DEKRHE) specific to SAD enzymes. The active enzyme protein was predicted as a homodimer. Phylogenetic analysis indicated that five GmSADs were divided into two subgroups, which were closely related to AtSSI2 and AtSAD6, respectively. The expression profiles of GmSAD members were significantly different in soybean roots, stems, leaves, flowers, and seeds at different developmental stages. Among them, GmSAD5 expressed highly in the middle and late stages of developmental seeds, which coincided with the oil accumulation period. Transient expression of GmSAD5 in tobacco leaves increased the oleic acid and total oil content in leaf tissue by 5.56% and 2.73%, respectively, while stearic acid content was reduced by 2.46%. Functional complementation assay in defective yeast strain BY4389 demonstrated that overexpression of GmSAD5 was able to restore the synthesis of monounsaturated oleic acid, resulting in high oil accumulation. Taken together, soybean GmSAD5 has strong selectivity to stearic acid substrates and can efficiently catalyze the biosynthesis of monounsaturated oleic acid. It lays the foundation for the study of soybean seed oleic acid and total oil accumulation mechanism, providing an excellent target for genetic improvement of oil quality in soybean.

Oil Yield and Quality Different Varieties of Indian Mustard (Brassica juncea L.) as Influenced by Organic Manures and Biofertilisers

The study was conducted at the Central Research Field of Sam Higginbottom University of Agriculture, Technology and Sciences, Allahabad during 2016-17 and 2017-18. The experiments consisting of two factors viz., 5 varieties and 10 fertiliser treatments was laid out in a factorial randomized block design with replicated thrice. The results of the study revealed that the oil yield was significantly highest with Rani variety while the oil content did not vary significantly amongst different varieties. The fatty acid composition such as palmitic acid, stearic acid, oleic acid, linoleic & linolenic acid, and arachidic acid contents showed non-significant variations amongst varieties. The biochemical characters viz., total chlorophyll, total soluble sugars and proline content was recorded at 45, and 60 DAS were significantly higher in Rani variety. Both protein content and protein yields were also significantly highest in Rani variety. Application of 75% N through vermicompost produced significantly highest oil content and oil yield, protein content and protein yield, biochemical characters total chlorophyll, total soluble sugars and proline content recorded at 45 and 60 DAS, while palmitic acid, stearic acid and oleic acid were significantly highest with application of recommended dose of chemical fertilisers. Linoleic acid was significantly maximum with fertiliser treatment of 50% N through vermicompost + Azotobacter + Both linolenic and arachidic acid contents remained unaffected by the fertiliser treatments.

Performance of Different Levels of Nitrogen and Phosphorus on Oil Yield and Oil Qualities of Palmarosa (Cymbopogan Martini Var. Motia) A-review.

Cymbopogan martini var. Motia commonly known as Palmarosa or Rosha grass is a tall perennial tufted hedge native of most parts of sub-tropical India. Palmarosa oil has a sweet floral rose-like odour also has notes of rye bread, tea and clary sage. The oil is extensively used as perfumery raw material in soaps; floral rose-like perfumes; cosmetics preparations and in the manufacture of mosquito repellent products. It is used for flavoring tobacco products, foods and non-alcoholic beverages .The volatile oil is used as a remedy for lumbago, stiff joints, skin diseases and for bilious complaints ”Considering the importance of this crop every effort is made to increase the oil production of the crop by using improved nutrient management practices. The supply of inorganic fertilizers in appropriate quantity form and stage of crop growth could upgrade the quality and yields remarkably”.