scholarly journals Identification and Analysis of the FAD Gene Family in Walnuts (Juglans regia L.) Based on Transcriptome Data

2019 ◽  
Author(s):  
Kai Liu ◽  
Shugang Zhao ◽  
Shuang Wang ◽  
Hongxia Wang ◽  
Zhihua Zhang

Abstract Background Walnut fatty acids, the main component of walnut kernels, contain a large amount of unsaturated fatty acids, such as linoleic acid and linolenic acid, which are essential fatty acids in humans and have important effects on human growth and health. Fatty acid desaturase (FAD) is widely distributed throughout the biological world. Its main function is to remove hydrogen from carbon chains in the biosynthesis of unsaturated fatty acids to synthesize C=C double bonds.Results In the current research, 25 members of the JrFAD gene family were identified by bioinformatics analysis; the expression of fatty acid synthesis genes in walnut kernels at different developmental stages was analysed by transcriptome sequencing, and the expression of JrFAD3-1 , an enzyme gene for linolenic acid synthesis, was particularly prominent. The results showed that the relative expression level of FAD3-1 changed dramatically with the kernel development stage, and the expression changes showed a "bell shape". There was a significant positive correlation between the expression of JrFAD3-1 from 90-100 days after anthesis and the content of alpha-linolenic acid from 100-130 days after anthesis, with a correlation coefficient of 0.991. JrFAD3-1 can be considered closely related to Betula pendula and Corylus heterophylla .Conclusion 25 walnut kernels FAD genes were identified and comprehensive analyzed for the first time. The function of a walnut kernels FAD3-1 gene was also characterized from its location in the phylogeny. This work lays a theoretical foundation for the regulation of unsaturated fatty acid synthesis and provide techniques and methods for the creation of new germplasm.

2020 ◽  
Author(s):  
Kai Liu ◽  
Shugang Zhao ◽  
Shuang Wang ◽  
Hongxia Wang ◽  
Zhihua Zhang

Abstract Background: Walnut kernels contain a large amount of unsaturated fatty acids, such as linoleic acid and linolenic acid, which are essential fatty acids for humans and have important effects on growth and health. The main function of fatty acid desaturase (FAD), which is widely distributed in organisms, is to remove hydrogen from carbon chains in the biosynthesis of unsaturated fatty acids to generate C=C bonds. Results: By performing a series of bioinformatics analysis, 24 members of the JrFAD gene family were identified from the genome database of walnut, and then compared with the homologous genes from Arabidopsis. Phylogenetic analysis showed that JrFADs were classified into four subfamilies: the SAD desaturase subfamily, Δ7/Δ9 desaturase subfamily, Δ12/ω-3 desaturase subfamily and "front-end" desaturase subfamily. Meanwhile, the expression of fatty acid synthesis genes in walnut kernels at different developmental stages was analysed by transcriptome sequencing, with expression of JrFAD3-1, which encodes an enzyme involved in linolenic acid synthesis, being particularly prominent. The relative expression level of JrFAD3-1 changed dramatically with the kernel development stages and exhibited a Bell-Shaped Curve. A significant positive correlation was observed between the expression of JrFAD3-1 during 70-100 DAF (Days after flowering) and the content of alpha-linolenic acid during 100-130 DAF, with a correlation coefficient of 0.991. Additionally, JrFAD3-1 was proved closely related to homologous genes in Betula pendula and Corylus heterophylla, indicating that the conserved structure of FADs is consistent with classical plant taxonomy. Conclusion: Twenty-four members JrFADs in walnut were identified and classified into four subfamilies. JrFAD3-1 may play significant roles in the biosynthesis of polyunsaturated fatty acids in walnut.


2020 ◽  
Author(s):  
Kai Liu ◽  
Shugang Zhao ◽  
Shuang Wang ◽  
Hongxia Wang ◽  
Zhihua Zhang

Abstract Background: Walnut kernels contain a large amount of unsaturated fatty acids, such as linoleic acid and linolenic acid, which are essential fatty acids for humans and have important effects on growth and health. The main function of fatty acid desaturase (FAD), which is widely distributed in organisms, is to remove hydrogen from carbon chains in the biosynthesis of unsaturated fatty acids to generate C=C bonds. Results: By performing a series of bioinformatics analysis, 24 members of the JrFAD gene family were identified from the genome database of walnut, and then compared with the homologous genes from Arabidopsis. Phylogenetic analysis showed that JrFADs were classified into four subfamilies: the SAD desaturase subfamily, Δ7/Δ9 desaturase subfamily, Δ12/ω-3 desaturase subfamily and "front-end" desaturase subfamily. Meanwhile, the expression of fatty acid synthesis genes in walnut kernels at different developmental stages was analysed by transcriptome sequencing, with expression of JrFAD3-1, which encodes an enzyme involved in linolenic acid synthesis, being particularly prominent. The relative expression level of JrFAD3-1 changed dramatically with the kernel development stages and exhibited a Bell-Shaped Curve. A significant positive correlation was observed between the expression of JrFAD3-1 during 70-100 DAF (Days after flowering) and the content of alpha-linolenic acid during 100-130 DAF, with a correlation coefficient of 0.991. Additionally, JrFAD3-1 was proved closely related to homologous genes in Betula pendula and Corylus heterophylla, indicating that the conserved structure of FADs is consistent with classical plant taxonomy. Conclusion: Twenty-four members JrFADs in walnut were identified and classified into four subfamilies. JrFAD3-1 may play significant roles in the biosynthesis of polyunsaturated fatty acids in walnut.


2020 ◽  
Author(s):  
Kai Liu ◽  
Shugang Zhao ◽  
Shuang Wang ◽  
Hongxia Wang ◽  
Zhihua Zhang

Abstract Background: Walnut fatty acids, the main component of walnut kernels, contain a large amount of unsaturated fatty acids, such as linoleic acid and linolenic acid, which are essential fatty acids in humans and have important effects on human growth and health. Fatty acid desaturase (FAD) is widely distributed throughout the biological world. Its main function is to remove hydrogen from carbon chains in the biosynthesis of unsaturated fatty acids to synthesize C=C double bonds. Results: In the current research, 24 members of the JrFAD gene family were identified by bioinformatics analysis; the expression of fatty acid synthesis genes in walnut kernels at different developmental stages was analysed by transcriptome sequencing, and the expression of JrFAD3-1 , an enzyme gene for linolenic acid synthesis, was particularly prominent. The results showed that the relative expression level of FAD3-1 changed dramatically with the kernel development stage, and the expression changes showed a "bell shape". There was a significant positive correlation between the expression of JrFAD3-1 from 90-100 DAF (days after flower) and the content of alpha-linolenic acid from 100-130 DAF, with a correlation coefficient of 0.991. JrFAD3-1 can be considered closely related to Betula pendula and Corylus heterophylla . Conclusion: 24 members of the JrFAD gene family consist of four subfamilies: the SAD desaturase subfamily, Δ7/Δ9 desaturase subfamily, Δ12/ω-3 desaturase subfamily and "front-end" desaturase subfamily. A key gene Jr FAD3-1 was obtained based on transcriptome data and there was a significant positive correlation between the expression of JrFAD3-1 from 90-100 DAF and the content of alpha-linolenic acid from 100-130 DAF. JrFAD3-1 can be considered closely related to Betula pendula and Corylus heterophylla .


FEBS Letters ◽  
2005 ◽  
Vol 579 (23) ◽  
pp. 5157-5162 ◽  
Author(s):  
Chang Ji Zheng ◽  
Jung-Sung Yoo ◽  
Tae-Gyu Lee ◽  
Hee-Young Cho ◽  
Young-Ho Kim ◽  
...  

2019 ◽  
Vol 11 (12) ◽  
pp. 1718-1723 ◽  
Author(s):  
Li Chen ◽  
Hao Yu ◽  
Shengping Yang ◽  
Yunfang Qian ◽  
Jing Xie

In order to investigate the cold tolerance mechanism of Shewanella, the whole genome of strain Shewanella putrefaciens WS13 was used to study the comparative genome related to cold tolerance of Shewanella . By comparing and analyzing the key enzymes involved in the process of lipid synthesis with those of other psychrophilic and non-psychrophilic bacteria, the results showed that in S. putrefaciens WS13, the genes fabA, fabB, fabD, fabF, fabG, fabH and fabZ, as the key enzymes of fatty acid synthesis, were found in the target strain, but the gene fabI did not exist in the type II fatty acid synthesis pathway. However, due to the absence of the key enzyme fabI gene, the synthesis process of saturated fatty acids will be blocked, and the pathway of unsaturated fatty acid synthesis still exists, which leads to the bacteria Shewanella start to synthesize a large number of unsaturated fatty acids, thus increasing the synthesis of unsaturated fatty acids and reducing the synthesis of saturated fatty acids. It is precisely because unsaturated fatty acids have lower phase transition temperature than that saturated fatty acids have, which can increase the fluidity of biofilm, so that Shewanella has better cold adaptability than that other bacteria have. It is a complex biological process for microorganisms to adapt to the environment, and the biosynthesis of fatty acids is only one aspect. However, the mechanism of cold adaptation of Shewanella in other aspects remains to be further discussed.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Lihong Ma ◽  
Xinqi Cheng ◽  
Chuan Wang ◽  
Xinyu Zhang ◽  
Fei Xue ◽  
...  

Abstract Background Cottonseed is one of the major sources of vegetable oil. Analysis of the dynamic changes of fatty acid components and the genes regulating the composition of fatty acids of cottonseed oil is of great significance for understanding the biological processes underlying biosynthesis of fatty acids and for genetic improving the oil nutritional qualities. Results In this study, we investigated the dynamic relationship of 13 fatty acid components at 12 developmental time points of cottonseed (Gossypium hirsutum L.) and generated cottonseed transcriptome of the 12 time points. At 5–15 day post anthesis (DPA), the contents of polyunsaturated linolenic acid (C18:3n-3) and saturated stearic acid (C18:0) were higher, while linoleic acid (C18:2n-6) was mainly synthesized after 15 DPA. Using 5 DPA as a reference, 15,647 non-redundant differentially expressed genes were identified in 10–60 DPA cottonseed. Co-expression gene network analysis identified six modules containing 3275 genes significantly associated with middle-late seed developmental stages and enriched with genes related to the linoleic acid metabolic pathway and α-linolenic acid metabolism. Genes (Gh_D03G0588 and Gh_A02G1788) encoding stearoyl-ACP desaturase were identified as hub genes and significantly up-regulated at 25 DPA. They seemed to play a decisive role in determining the ratio of saturated fatty acids to unsaturated fatty acids. FAD2 genes (Gh_A13G1850 and Gh_D13G2238) were highly expressed at 25–50 DPA, eventually leading to the high content of C18:2n-6 in cottonseed. The content of C18:3n-3 was significantly decreased from 5 DPA (7.44%) to 25 DPA (0.11%) and correlated with the expression characteristics of Gh_A09G0848 and Gh_D09G0870. Conclusions These results contribute to our understanding on the relationship between the accumulation pattern of fatty acid components and the expression characteristics of key genes involved in fatty acid biosynthesis during the entire period of cottonseed development.


1972 ◽  
Vol 128 (5) ◽  
pp. 1057-1067 ◽  
Author(s):  
E. D Saggerson

1. 0.5mm-Palmitate stimulated incorporation of [U-14C]glucose into glyceride glycerol and fatty acids in normal fat cells in a manner dependent upon the glucose concentration. 2. In the presence of insulin the incorporation of 5mm-glucose into glyceride fatty acids was increased by concentrations of palmitate, adrenaline and 6-N-2′-O-dibutyryladenosine 3′:5′-cyclic monophosphate up to 0.5mm, 0.5μm and 0.5mm respectively. Higher concentrations of these agents produced progressive decreases in the rate of glucose incorporation into fatty acids. 3. The effects of palmitate and lipolytic agents upon the measured parameters of glucose utilization were similar, suggesting that the effects of lipolytic agents are mediated through increased concentrations of free fatty acids. 4. In fat cells from 24h-starved rats, maximal stimulation of glucose incorporation into fatty acids was achieved with 0.25mm-palmitate. Higher concentrations of palmitate were inhibitory. In fat cells from 72h-starved rats, palmitate only stimulated glucose incorporation into fatty acids at high concentrations of palmitate (1mm and above). 5. The ability of fat cells to incorporate glucose into glyceride glycerol in the presence of palmitate decreased with increasing periods of starvation. 6. It is suggested that low concentrations of free fatty acids stimulate fatty acid synthesis from glucose by increasing the utilization of ATP and cytoplasmic NADH for esterification of these free fatty acids. When esterification of free fatty acids does not keep pace with their provision, inhibition of fatty acid synthesis occurs. Provision of free fatty acids far in excess of the esterification capacity of the cells leads to uncoupling of oxidative phosphorylation and a secondary stimulation of fatty acid synthesis from glucose.


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