scholarly journals Genome-Wide Analysis of the Fatty Acid Desaturase Gene Family Reveals the Key Role of PfFAD3 in α-Linolenic Acid Biosynthesis in Perilla Seeds

2021 ◽  
Vol 12 ◽  
Author(s):  
Wu Duan ◽  
Yang Shi-Mei ◽  
Shang Zhi-Wei ◽  
Xu Jing ◽  
Zhao De-Gang ◽  
...  

Perilla (Perilla frutescens), a traditional medicinal and oilseed crop in Asia, contains extremely high levels of polyunsaturated α-linolenic acid (ALA) (up to 60.9%) in its seeds. ALA biosynthesis is a multistep process catalyzed by fatty acid desaturases (FADs), but the FAD gene family in perilla has not been systematically characterized. Here, we identified 42 PfFADs in the perilla genome and classified them into five subfamilies. Subfamily members of PfFADs had similar exon/intron structures, conserved domain sequences, subcellular localizations, and cis-regulatory elements in their promoter regions. PfFADs also possessed various expression patterns. PfFAD3.1 was highly expressed in the middle stage of seed development, whereas PfFAD7/8.3 and PfFAD7/8.5 were highly expressed in leaf and later stages of seed development, respectively. Phylogenetic analysis revealed that the evolutionary features coincided with the functionalization of different subfamilies of PUFA desaturase. Heterologous overexpression of PfFAD3.1 in Arabidopsis thaliana seeds increased ALA content by 17.68%–37.03%. These findings provided insights into the characteristics and functions of PfFAD genes in perilla.

Genome ◽  
2011 ◽  
Vol 54 (6) ◽  
pp. 471-483 ◽  
Author(s):  
Mitali Banik ◽  
Scott Duguid ◽  
Sylvie Cloutier

Three genes encoding fatty acid desaturase 3 (fad3a, fad3b, and a novel fad3c) were cloned from four flax genotypes varying in linolenic acid content. Real-time PCR was used to quantify expression levels of the three fad3 genes during seed development. High amounts of both fad3a and fad3b transcripts were observed and reached their peak levels at 20 days after anthesis, except for fad3a from SP2047 where only low level expression was observed throughout seed development. Transcript accumulation of the novel fad3c gene was at similar background levels. The fatty acid composition was analysed for all genotypes and stages of development and compared with the fad3 gene expression patterns. α-Linolenic acid gradually accumulated during seed development, while linoleic acid was transient and decreased in M5791, UGG5-5, and AC McDuff. In contrast, the linolenic acid present in the early stages of development nearly completely disappeared in SP2047, while linoleic acid steadily accumulated. fad3a of the low linolenic acid line SP2047 encoded a truncated protein caused by a premature stop codon resulting from a single point mutation, and the low level of transcript accumulation in this genotype is likely due to nonsense-mediated mRNA decay caused by the premature termination of translation as a result of this early stop codon. Although substantial amounts of transcript accumulation occurred with fad3b of SP2047 genotype, cloning of the gene revealed a mutation in the first histidine box causing an amino acid change. Heterologous expression in yeast of the SP2047 and UGG5-5 fad3b genes showed that the mutation in the histidine box in SP2047 caused the enzyme inactivity. Taken together, these results showed that fad3a and fad3b are responsible for linolenic acid accumulation in flax seeds but did not support a major role for the novel fad3c. These observations were further supported by phenotypic and genotypic assessment of a doubled haploid population. Expression patterns of fad3a and fad3b were highly correlated with linolenic acid accumulation during seed development, with the exception of fad3b in SP2047 whose lack of activity was caused by the histidine box mutation despite its transcript accumulation being similar to that of the fad3b of the other genotypes.


Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1456
Author(s):  
Xin Jin ◽  
Can Baysal ◽  
Margit Drapal ◽  
Yanmin Sheng ◽  
Xin Huang ◽  
...  

Light is an essential regulator of many developmental processes in higher plants. We investigated the effect of 4-hydroxy-3-methylbut-2-enyl diphosphate reductase 1/2 genes (OsHDR1/2) and isopentenyl diphosphate isomerase 1/2 genes (OsIPPI1/2) on the biosynthesis of chlorophylls, carotenoids, and phytosterols in 14-day-old etiolated rice (Oyza sativa L.) leaves during de-etiolation. However, little is known about the effect of isoprenoid biosynthesis genes on the corresponding metabolites during the de-etiolation of etiolated rice leaves. The results showed that the levels of α-tocopherol were significantly increased in de-etiolated rice leaves. Similar to 1-deoxy-D-xylulose-5-phosphate synthase 3 gene (OsDXS3), both OsDXS1 and OsDXS2 genes encode functional 1-deoxy-D-xylulose-5-phosphate synthase (DXS) activities. Their expression patterns and the synthesis of chlorophyll, carotenoid, and tocopherol metabolites suggested that OsDXS1 is responsible for the biosynthesis of plastidial isoprenoids in de-etiolated rice leaves. The expression analysis of isoprenoid biosynthesis genes revealed that the coordinated expression of the MEP (2-C-methyl-D-erythritol 4-phosphate) pathway, chlorophyll, carotenoid, and tocopherol pathway genes mirrored the changes in the levels of the corresponding metabolites during de-etiolation. The underpinning mechanistic basis of coordinated light-upregulated gene expression was elucidated during the de-etiolation process, specifically the role of light-responsive cis-regulatory motifs in the promoter region of these genes. In silico promoter analysis showed that the light-responsive cis-regulatory elements presented in all the promoter regions of each light-upregulated gene, providing an important link between observed phenotype during de-etiolation and the molecular machinery controlling expression of these genes.


2019 ◽  
Vol 20 (13) ◽  
pp. 3235 ◽  
Author(s):  
Yanguo Ke ◽  
Farhat Abbas ◽  
Yiwei Zhou ◽  
Rangcai Yu ◽  
Yuechong Yue ◽  
...  

Auxin plays a key role in different plant growth and development processes, including flower opening and development. The perception and signaling of auxin depend on the cooperative action of various components, among which auxin/indole-3-acetic acid (Aux/IAA) proteins play an imperative role. In a recent study, the entire Aux/IAA gene family was identified and comprehensively analyzed in Hedychium coronarium, a scented species used as an ornamental plant for cut flowers. Phylogenetic analysis showed that the Aux/IAA gene family in H. coronarium is slightly contracted compared to Arabidopsis, with low levels of non-canonical proteins. Sequence analysis of promoters showed numerous cis-regulatory elements related to various phytohormones. HcIAA genes showed distinct expression patterns in different tissues and flower developmental stages, and some HcIAA genes showed significant responses to auxin and ethylene, indicating that Aux/IAAs may play an important role in linking hormone signaling pathways. Based on the expression profiles, HcIAA2, HcIAA4, HcIAA6 and HcIAA12, were selected as candidate genes and HcIAA2 and HcIAA4 were screened for further characterization. Downregulation of HcIAA2 and HcIAA4 by virus-induced gene silencing in H. coronarium flowers modified the total volatile compound content, suggesting that HcIAA2 and HcIAA4 play important roles in H. coronarium floral scent formation. The results presented here will provide insights into the putative roles of HcIAA genes and will assist the elucidation of their precise roles during floral scent formation.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Zhixuan Du ◽  
Qitao Su ◽  
Zheng Wu ◽  
Zhou Huang ◽  
Jianzhong Bao ◽  
...  

AbstractMultidrug and toxic compound extrusion (MATE) proteins are involved in many physiological functions of plant growth and development. Although an increasing number of MATE proteins have been identified, the understanding of MATE proteins is still very limited in rice. In this study, 46 MATE proteins were identified from the rice (Oryza sativa) genome by homology searches and domain prediction. The rice MATE family was divided into four subfamilies based on the phylogenetic tree. Tandem repeats and fragment replication contribute to the expansion of the rice MATE gene family. Gene structure and cis-regulatory elements reveal the potential functions of MATE genes. Analysis of gene expression showed that most of MATE genes were constitutively expressed and the expression patterns of genes in different tissues were analyzed using RNA-seq. Furthermore, qRT-PCR-based analysis showed differential expression patterns in response to salt and drought stress. The analysis results of this study provide comprehensive information on the MATE gene family in rice and will aid in understanding the functional divergence of MATE genes.


Microbiology ◽  
2004 ◽  
Vol 150 (6) ◽  
pp. 1983-1990 ◽  
Author(s):  
Takahiro Oura ◽  
Susumu Kajiwara

Fungi, like plants, are capable of producing the 18-carbon polyunsaturated fatty acids linoleic acid and α-linolenic acid. These fatty acids are synthesized by catalytic reactions of Δ12 and ω3 fatty acid desaturases. This paper describes the first cloning and functional characterization of a yeast ω3 fatty acid desaturase gene. The deduced protein encoded by the Saccharomyces kluyveri FAD3 gene (Sk-FAD3) consists of 419 amino acids, and shows 30–60 % identity with Δ12 fatty acid desaturases of several eukaryotic organisms and 29–31 % identity with ω3 fatty acid desaturases of animals and plants. During Sk-FAD3 expression in Saccharomyces cerevisiae, α-linolenic acid accumulated only when linoleic acid was added to the culture medium. The disruption of Sk-FAD3 led to the disappearance of α-linolenic acid in S. kluyveri. These findings suggest that Sk-FAD3 is the only ω3 fatty acid desaturase gene in this yeast. Furthermore, transcriptional expression of Sk-FAD3 appears to be regulated by low-temperature stress in a manner different from the other fatty acid desaturase genes in S. kluyveri.


2019 ◽  
Vol 20 (22) ◽  
pp. 5796
Author(s):  
Qianqian Zhou ◽  
Qingchang Li ◽  
Peng Li ◽  
Songtao Zhang ◽  
Che Liu ◽  
...  

Carotenoid cleavage dioxygenases (CCDs) selectively catalyze carotenoids, forming smaller apocarotenoids that are essential for the synthesis of apocarotenoid flavor, aroma volatiles, and phytohormone ABA/SLs, as well as responses to abiotic stresses. Here, 19, 11, and 10 CCD genes were identified in Nicotiana tabacum, Nicotiana tomentosiformis, and Nicotiana sylvestris, respectively. For this family, we systematically analyzed phylogeny, gene structure, conserved motifs, gene duplications, cis-elements, subcellular and chromosomal localization, miRNA-target sites, expression patterns with different treatments, and molecular evolution. CCD genes were classified into two subfamilies and nine groups. Gene structures, motifs, and tertiary structures showed similarities within the same groups. Subcellular localization analysis predicted that CCD family genes are cytoplasmic and plastid-localized, which was confirmed experimentally. Evolutionary analysis showed that purifying selection dominated the evolution of these genes. Meanwhile, seven positive sites were identified on the ancestor branch of the tobacco CCD subfamily. Cis-regulatory elements of the CCD promoters were mainly involved in light-responsiveness, hormone treatment, and physiological stress. Different CCD family genes were predominantly expressed separately in roots, flowers, seeds, and leaves and exhibited divergent expression patterns with different hormones (ABA, MeJA, IAA, SA) and abiotic (drought, cold, heat) stresses. This study provides a comprehensive overview of the NtCCD gene family and a foundation for future functional characterization of individual genes.


Genome ◽  
2015 ◽  
Vol 58 (8) ◽  
pp. 375-383 ◽  
Author(s):  
Yun Wang ◽  
Xingguo Zhang ◽  
Yongli Zhao ◽  
C.S. Prakash ◽  
Guohao He ◽  
...  

The FAD2 gene family is functionally responsible for the conversion of oleic acid to linoleic acid in oilseed plants. Multiple members of the FAD gene are known to occur in several oilseed species. In this study, six novel full-length cDNA sequences (named as AhFAD2-1, -2, -3, -4, -5, and -6) were identified in peanut (Arachis hypogaea L.), an analysis of which revealed open reading frames of 379, 383, 394, or 442 amino acids. Sequence comparisons showed that AhFAD2-1 and AhFAD2-2 shared 76% identity, while AhFAD2-2, -3, and -4 displayed highly significant homology. There was only 27% identity overlap between the microsomal ω-6 fatty acid desaturase and the chloroplast ω-6 fatty acid desaturase encoded by AhFAD2-1, -2, -3, -4, and AhFAD2-5, -6, respectively. The phylogeny tree of FAD2 transcripts showed five major groups, and AhFAD2-1 was clearly separated from other groups. Analysis of AhFAD2-1 and AhFAD2-2 transcript distribution in different peanut tissues showed that the AhFAD2-1 gene showed upward of a 70-fold increase in expression of fatty acid than the AhFAD2-2 gene in peanut developing seeds, while the AhFAD2-2 gene expressed most abundantly in peanut flowers. Because the AhFAD2-1 gene played a major role in the conversion of oleic to linoleic acid during seed development, the identification of this novel member in this study would facilitate the further genetic manipulation of peanut oil quality. The implications of overall results also suggest that there may be more candidate genes controlling levels of oleate acid in developing seeds. Results also may be due to the presence of complex gene networks controlling the fluxes between the endoplasmic reticulum and the chloroplast within the peanut cells.


2020 ◽  
Author(s):  
Hengyou Zhang ◽  
Zhenbin Hu ◽  
Yuming Yang ◽  
Xiaoqian Liu ◽  
Haiyan Lv ◽  
...  

Abstract Background: Seeds are the economic basis of oilseed crops, especially for soybean, thus far the most widely cultivated oilseed crop worldwide. Seed development is accompanied with a multitude of diverse cellular processes and revealing the underlying regulatory activities is critical for seed improvement. Results: Here, we profiled transcriptomes of developing seeds (20, 25, 30, 40 days after flowering) representing key points of seed development from early to full development. We identified a set of highly-abundant genes and highlighted the importance of these genes to support nutrient accumulation and transcriptional regulation in developing seeds. We identified 8,925 differentially expressed genes that exhibited temporal expression patterns over the course and had expression specificities in distinct tissues including seeds and non-seed tissues (roots, stems, leaves). Genes with specificities to non-seed tissues have tissue-specialized roles while remain relatively low transcript abundance in developing seeds, exhibiting their supportive roles spatially for seed development. Co-expression network analysis identified several under-explored genes in soybean that bridge tissue-specific gene modules. Conclusions: Our study provides a global view of gene activities and biological processes critical for seed formation in soybean and prioritizes a set of genes for further study. The results shed insight into the mechanism controlling seed development and storage reserves.


2006 ◽  
Vol 131 (2) ◽  
pp. 284-289 ◽  
Author(s):  
Mauricio A. Cañoles ◽  
Randolph M. Beaudry ◽  
Chuanyou Li ◽  
Gregg Howe

Six-carbon aldehydes and alcohols formed by tomato (Lycopersicon esculentum Mill.) leaf and fruit tissue following disruption are believed to be derived from the degradation of lipids and free fatty acids. Collectively, these C-6 volatiles comprise some of the most important aroma impact compounds. If fatty acids are the primary source of tomato volatiles, then an alteration in the fatty acid composition such as that caused by a mutation in the chloroplastic omega-3-fatty acid desaturase (ω-3 FAD), referred to as LeFAD7, found in the mutant line of `Castlemart' termed Lefad7, would be reflected in the volatile profile of disrupted leaf and fruit tissue. Leaves and fruit of the Lefad7 mutant had ≈10% to 15% of the linolenic acid (18:3) levels and about 1.5- to 3-fold higher linoleic acid (18:2) levels found in the parent line. Production of unsaturated C-6 aldehydes Z-3-hexenal, Z-3-hexenol, and E-2-hexenal and the alcohol Z-3-hexenol derived from 18:3 was markedly reduced in disrupted leaf and fruit tissue of the Lefad7 mutant line. Conversely, the production of the saturated C-6 aldehyde hexanal and its alcohol, hexanol, were markedly higher in the mutant line. The shift in the volatile profile brought about by the loss of chloroplastic FAD activity in the Lefad7 line was detected by sensory panels at high significance levels (P < 0.0005) and detrimentally affected fruit sensory quality. The ratios and amounts of C-6 saturated and unsaturated aldehydes and alcohols produced by tomato were dependent on substrate levels, suggesting that practices that alter the content of linoleic and linolenic acids or change their ratios can influence tomato flavor.


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