Genome‐wide identification of FAD gene family and functional analysis of MsFAD3.1 involved in the accumulation of α‐linolenic acid in alfalfa

Abstract

As an important forage legume in the world, alfalfa (Medicago sativa L.) has high adaptability to various unfavorable climatic conditions and high biomass, and have been playing critical roles in animal husbandry and industrial applications. As α‐linolenic acid cannot be synthesized by animals, and most must be obtained from plants, the increasing of α‐linolenic acid content in alfalfa will greatly contribute to improve quality of livestock. However, the molecular mechanisms for α‐linolenic acid synthesis and accumulation in alfalfa are still limited. In this study, the importance of ω‐3 fatty acid desaturase (FAD) was demonstrated by analyzing α‐linolenic acid metabolic pathways, combined with the dynamics of accumulation of unsaturated fatty acids in alfalfa. Moreover, the FAD3.1 identified in alfalfa was located in the endoplasmic reticulum, and its expression level was consistent with the accumulation patterns of α‐linolenic acid in leaves. Heterologous expression in yeast cells proves that MsFAD3.1 was involved in the synthesis of α‐linolenic acid, and the α‐linolenic acid content in MsFAD3.1‐overexpression transgenic alfalfa lines was significantly increased. These results indicate that new alfalfa germplasm with high α‐linolenic acid content can be successfully created through biotechnology, providing a theoretical basis for further improving the quality of alfalfa and the nutritional value of dairy products.

Genome-Wide Identification and Functional Differentiation of Fatty Acid Desaturase Genes in Olea europaea L.

“…FAD genes are essential factors which desaturate saturated fatty acids into unsaturated fatty acids for oil plants [ 6 ]. Until now, they have been identified and characterized in non-oil plants Arabidopsis (25) and rice (19) and oil plants soybean (41), rapeseed (84) and walnut (30) among others [ 12 , 13 , 14 , 15 , 16 , 17 ]. Olive is the only plant which extracts oil from its fresh fruits and is favored by consumers for redundant UFAs [ 38 , 39 ].…”

“…Among the genes related to fatty acid biosynthesis, fatty acid desaturase (FAD) is a significant enzyme that can desaturate SFAs into UFAs [ 6 ]. Until now, the whole genome of FAD genes had been studied and resulted in 25, 19, 41, 84, 57, 45, 46, 30 and 33 FAD genes in A. thaliana , O. sativa , G. max , B. napus , B. juncea , B. rapa , B. nigra , J. regia and M. sativa , respectively [ 12 , 13 , 14 , 15 , 16 , 17 ]. All the FAD genes are typed as soluble or membrane-bound.…”

“…FAD 4 group includes the Δ-3 FADs and catalyzes C16:0 to C16:1 [ 14 , 15 ]. ω-3 group introduces Δ-15 FADs and contain FAD3/FAD7/FAD8 genes, while ω-6 group introduces Δ-12 and contains FAD2/FAD6 genes [ 12 , 13 , 14 , 15 , 16 , 17 ].…”

Genome-Wide Analysis of the UDP-Glycosyltransferase Family Reveals Its Roles in Coumarin Biosynthesis and Abiotic Stress in Melilotus albus

“…Then, the yeast was collected and adjusted with SC-Ura including 2% galactose and cultivated up to A 600 = 1 for stress analysis. The same number of cells was resuspended in 30% PEG-6000 and 5 M NaCl [ 57 ]. The treated yeast liquid was diluted to 1:10 and cultured on SC-U/2% ( w / v ) glucose agar plates for 2–3 days to observe colony growth, and photos were taken to record the expression of the binding protein.…”

In Silico Analysis of Fatty Acid Desaturases Structures in Camelina sativa, and Functional Evaluation of Csafad7 and Csafad8 on Seed Oil Formation and Seed Morphology

“…Particularly, ω-3 fatty acid desaturases have been proven to use C18:2 as substrates to produce 18:3 in the plastid, where FAD7 and FAD8 are located, and in the ER where FAD3 are found [5]. In plants, the accumulation of 18:3 under the activity of ω-3 fatty acid desaturases, particularly FAD3 has been demonstrated in several studies, such as in soybean [108,109], in rice [110], in olive [111][112][113], in peanut [114], in flax [115], in walnuts [116], in cowpea [117], in alfalfa [118], in peach aphid [119] and now in C. sativa, according to the current study.…”