共查询到20条相似文献,搜索用时 15 毫秒
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Qing Liu Shijiang Cao Xue-Rong Zhou Craig Wood Allan Green Surinder Singh 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2013,126(9):2219-2231
There are two types of safflower oil, high oleic (HO) with 70–75 % oleic acid and high linoleic (HL) with about 70 % linoleic acid. The original HO trait in safflower, found in an introduction from India, is controlled by a partially recessive allele ol at a single locus (Knowles and Bill 1964). In the lipid biosynthesis pathway of developing safflower seeds, microsomal oleoyl phosphatidylcholine desaturase (FAD2) is largely responsible for the conversion of oleic acid to linoleic acid. In vitro microsomal assays indicated drastically reduced FAD2 enzyme activity in the HO genotype compared to conventional HL safflower. A previous study indicated that a single-nucleotide deletion was found in the coding region of CtFAD2-1 that causes premature termination of translation in the HO genotypes, and the expression of the mutant CtFAD2-1Δ was attenuated in the HO genotypes compared to conventional HL safflower (Guan et al. 2012). In this study, we hypothesise that down-regulation of CtFAD2-1 expression in the HO genotype may be explained by nonsense-mediated RNA decay (NMD). NMD phenomenon, indicated by gene-specific RNA degradation of defective CtFAD2-1Δ, was subsequently confirmed in Arabidopsis thaliana seed as well as in the transient expression system in Nicotiana benthamiana leaves. We have developed a perfect molecular marker corresponding to the olol mutation that can facilitate a rapid screening and early detection of genotypes carrying the olol mutation for use in marker-assisted selection for the management of the HO trait in safflower breeding programmes. 相似文献
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Van Cam Nguyen Yuki Nakamura Kazue Kanehara 《The Plant journal : for cell and molecular biology》2019,99(3):478-493
Unsaturation of membrane glycerolipid classes at their hydrophobic fatty acid tails critically affects the physical nature of the lipid molecule. In Arabidopsis thaliana, 7 fatty acid desaturases (FADs) differently desaturate each glycerolipid class in plastids and the endoplasmic reticulum (ER). Here, we showed that polyunsaturation of ER glycerolipids is required for the ER stress response. Through systematic screening of FAD mutants, we found that a mutant of FAD2 resulted in a hypersensitive response to tunicamycin, a chemical inducer of ER stress. FAD2 converts oleic acid to linoleic acid of the fatty acyl groups of ER‐synthesized phospholipids. Our functional in vivo reporter assay revealed the ER localization and distinct tissue‐specific expression patterns of FAD2. Moreover, glycerolipid profiling of both mutants and overexpressors of FAD2 under tunicamycin‐induced ER stress conditions, along with phenotypic screening of the mutants of the FAD family, suggested that the ratio of monounsaturated fatty acids to polyunsaturated fatty acids, particularly 18:1 to 18:2 species, may be an important factor in allowing the ER membrane to cope with ER stress. Therefore, our results suggest that membrane lipid polyunsaturation mediated by FAD2 is involved in ER stress tolerance in Arabidopsis. 相似文献
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Kyeong-Ryeol Lee Sun Hee Kim Young-Sam Go Sung Min Jung Kyung Hee Roh Jong-Bum Kim Mi-Chung Suh Sukchan Lee Hyun Uk Kim 《Gene》2012
The synthesis of polyunsaturated fatty acids (PUFAs), the most abundant fatty acids in plants, begins with a reaction catalyzed by fatty acid desaturase 2 (FAD2; EC 1.3.1.35), also called microsomal oleate Δ12-desaturase. Since the FAD2 gene was first identified in Arabidopsis thaliana, FAD2 research has gained wide interest as the essential enzyme for synthesizing PUFA. Grapes are one of the most frequently cultivated fruits in the world, with most commercial growers cultivating Vitis vinifera and V. labrusca. Grapeseed oil contains a high proportion, 60–70% of linoleic acid (18:2). We cloned two putative FAD2 genes from V. labrusca cv. Campbell Early based on V. vinifera genome sequences. Deduced amino acid sequences of two putative genes showed that VlFAD2s show high similarity to Arabidopsis FAD2 and commonly contain six transmembrane domain, three histidine boxes and endoplasmic reticulum (ER) retrieval motif representing the characteristics of fatty acid desaturase. Phylogenetic analyses of various plant FAD2s showed that VlFAD2-1 and VlFAD2-2 are separately grouped with constitutive and seed-type FAD2s, respectively. Southern blot showed that one or two bands are found in each lane. Because Campbell Early is a hybrid cultivar, FAD2-1 and FAD2-2 genes may exist as one copy in V. labrusca. Expression analysis in different tissues indicated that VlFAD2-1 is a constitutive gene but VlFAD2-2 is a seed-type gene. Complementation experiments of fad2-1 mutant Arabidopsis with VlFAD2-1 or VlFAD2-2 demonstrated that VlFAD2-1 and VlFAD2-2 can restore low PUFA proportion of fad2 to normal PUFA proportion. 相似文献
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Xiaoyuan Chi Qingli Yang Yandu Lu Jinyan Wang Qingfen Zhang Lijuan Pan Mingna Chen Yanan He Shanlin Yu 《Plant Molecular Biology Reporter》2011,29(4):769-783
Fatty acid desaturases can introduce double bonds into the hydrocarbon chains of fatty acids to produce unsaturated fatty
acids. In the present study, 29 full-length desaturase genes were identified from soybean genome by a thorough annotation
exercise. A comprehensive analysis was performed to characterize phylogeny, chromosomal locations, structures, conserved motifs,
and expression patterns of those genes. The soybean genes were phylogenetically clustered into nine subfamilies with the Arabidopsis counterparts, FAB2, FAD2, FAD3, FAD5, FAD6, FAD7, FAD8, SLD1, and DES1. Twenty-nine desaturase genes were found to be distributed on at least 15 of the 20 soybean chromosomes. The gene structures
and motif compositions were considerably conserved among the subfamilies. The majority of desaturase genes showed specific
temporal and spatial expression patterns across different tissues and developmental stages based on microarray data analyses.
The study may provide new insights into the origin and evolution of fatty acid biosynthesis pathways in higher plants. Additionally,
the characterization of desaturases from soybean will lead to the identification of additional genes for genetic modification
of plants to produce nutritionally important fatty acids. 相似文献
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Nitrogen accumulation and redistribution in soybean genotypes with variation in seed protein concentration 总被引:1,自引:0,他引:1
Breeding for high seed protein concentration in soybean [Glycine max (L.) Merrill] often results in lower yield, but the basis for this negative relationship is not well understood. To address
this question, we evaluated the N acquisition characteristics of three high protein and three normal soybean genotypes in
the field for 3 years. Plants were grown in 0.76 m rows following conventional cultural practices and water stress was minimized
with sprinkler irrigation. We determined the mass and N concentration of leaves, petioles and stems at the beginning of seed
filling (growth stage R5) and of stems at maturity. The N concentration of abscised leaves and petioles was also determined.
There was significant variation among genotypes in total seed N (g m−2) at maturity (range from 14.7 to 24.4 g N m−2) as a result of variation in seed N concentration and yield. There was no evidence that the larger amounts of mature seed
N were associated with a larger vegetative N reservoir at growth stage R5 as determined by vegetative mass at R5 or the concentration
of N in vegetative tissues. Increasing seed N at maturity did not lower the N concentration in abscised leaves and petioles,
or in the stems at maturity. The rate and timing of leaf senescence (loss of chlorophyll) was essentially the same for all
genotypes. With no increase in the contribution from redistributed N, increases in N uptake or fixation during seed filling
must have been responsible for the higher levels of seed N at maturity in high-protein genotypes. These data suggest that
increasing total seed N at maturity by selecting for higher seed protein concentration or higher yield in soybean does not
require, as some models suggest, a larger vegetative N reservoir at the beginning of seed filling or more rapid senescence. 相似文献
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Gunnar F. Schuppert Shunxue Tang Mary B. Slabaugh Steven J. Knapp 《Molecular breeding : new strategies in plant improvement》2006,17(3):241-256
Ol, a chemically induced, incompletely dominant mutation, greatly increases oleic acid and is correlated with greatly reduced
expression of a seed-specific oleoyl-phosphatidyl choline desaturase (FAD2-1) in developing seeds of sunflower (Helianthus annuus L.). FAD2-1 is duplicated in high-oleic (mutant) strains and cosegregates with Ol. Codominant RFLP markers have been developed for FAD2-1 and are diagnositic for the Ol mutation; however, the structure of the mutant FAD2-1 locus is unknown and polymorphic sequence-tagged-site (STS) DNA markers have not been developed for FAD2-1. The mutant was discovered to carry tandem repeats of FAD2-1 separated by a 2.67 kb intergenic region. The upstream repeat (FAD2-1U) carries a 1.69 kb intron in the 5′UTR, whereas the downstream repeat (FAD2-1D) is missing the first 1.54 kb of the 5′UTR and intron. Other than the deletion in FAD2-1D, no DNA polymorphisms were identified between wildtype and mutant FAD2-1 alleles among elite oilseed inbred lines. We developed dominant INDEL markers diagnostic for presence or absence of the Ol mutation (tandem FAD2-1 repeats) by targeting DNA sequences upstream of FAD2-1D, identified 49 SNPs and five INDELs (two haplotypes) in DNA sequences downstream of FAD2-1 in the wildtype and FAD2-1U in the mutant, identified polymorphic [AT]n and [GT]n repeats in the 3′UTR of FAD2-1, and developed codominant SSR and INDEL markers for FAD2-1. Novel FAD2-1 alleles found in exotic low-oleic genotypes could be introgressed into elite low-oleic genotypes to facilitate marker-assisted
selection of Ol in mid- and high-oleic sunflower breeding programs. 相似文献