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1.
BMC Plant Biol ; 19(1): 569, 2019 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-31856712

RESUMO

BACKGROUND: Seed germination is essential to crop growth and development, and ultimately affects its harvest. It is difficult to breed soybeans low in phytic acid with a higher seed field emergence. Although additional management and selection could overcome the phytate reduction, the mechanisms of seed germination remain unknown. RESULTS: A comparative proteomic analysis was conducted between two low phytic acid (LPA) soybean mutants (TW-1-M and TW-1), both of which had a deletion of 2 bp in the GmMIPS1 gene. However, the TW-1 seeds showed a significantly lower field emergence compared to the TW-1-M. There were 282 differentially accumulated proteins (DAPs) identified between two mutants at the three stages. Among these DAPs, 80 were down-accumulated and 202 were up-accumulated. Bioinformatic analysis showed that the identified proteins were related to functional categories of oxidation reduction, response to stimulus and stress, dormancy and germination processes and catalytic activity. KEGG analysis showed that these DAPs were mainly involved in energy metabolism and anti-stress pathways. Based upon the conjoint analysis of DAPs with the differentially expressed genes (DEGs) previously published among three germination stages in two LPA mutants, 30 shared DAPs/DEGs were identified with different patterns, including plant seed protein, beta-amylase, protein disulfide-isomerase, disease resistance protein, pyrophosphate-fructose 6-phosphate 1-phosphotransferase, cysteine proteinase inhibitor, non-specific lipid-transfer protein, phosphoenolpyruvate carboxylase and acyl-coenzyme A oxidase. CONCLUSIONS: Seed germination is a very complex process in LPA soybean mutants. The TW-1-M and TW-1 showed many DAPs involved in seed germination. The differential accumulation of these proteins could result in the difference of seed field emergence between the two mutants. The high germination rate in the TW-1-M might be strongly attributed to reactive oxygen species-related and plant hormone-related genes. All these findings would help us further explore the germination mechanisms in LPA crops.


Assuntos
Genes de Plantas , Germinação/genética , Ácido Fítico/metabolismo , Proteínas de Plantas/metabolismo , Proteoma/metabolismo , Soja/genética , Sementes/fisiologia , Soja/metabolismo
2.
Nucleic Acids Res ; 47(15): 8096-8110, 2019 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-31291454

RESUMO

The spindle assembly checkpoint (SAC) ensures the fidelity of chromosome segregation during mitosis. Here, we show that ULK1, a serine/threonine kinase that plays a key role in initiation of autophagy, also has an important function in the activation of SAC. ULK1 phosphorylates the SAC protein Mad1 at Ser546 to recruit Mad1 to kinetochores. Furthermore, Rod/ZW10/Zwilch (RZZ) complex may serve as a receptor for phos-Ser546-Mad1 at kinetochore, since phosphorylation of Mad1 by ULK1 strengthens the interaction between Mad1 and RZZ complex. In addition, deletion of ULK1 increases chromosome instability and cytotoxicity of paclitaxel, resulting in significant impairment of cancer cell growth. These findings highlight the role of ULK1 as a protein kinase controlling the fidelity of chromosome segregation and cell-cycle progression.


Assuntos
Proteína Homóloga à Proteína-1 Relacionada à Autofagia/metabolismo , Pontos de Checagem do Ciclo Celular , Proteínas de Ciclo Celular/metabolismo , Fuso Acromático/metabolismo , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/genética , Proteínas de Ciclo Celular/genética , Linhagem Celular Tumoral , Proteínas Cromossômicas não Histona/genética , Proteínas Cromossômicas não Histona/metabolismo , Segregação de Cromossomos , Células HCT116 , Células HeLa , Humanos , Cinetocoros/metabolismo , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Fosforilação , Fuso Acromático/genética
3.
J Agric Food Chem ; 67(17): 5043-5052, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30977368

RESUMO

The low phytic acid ( lpa) soybean ( Glycine max L. Merr.) mutant Gm-lpa-TW-1-M, resulting from a 2 bp deletion in GmMIPS1, was crossed with a commercial cultivar. F3 and F5 progenies were subjected to nontargeted GC-based metabolite profiling, allowing analysis of a broad array of low molecular weight constituents. In the homozygous lpa mutant progenies the intended phytic acid reduction was accompanied by remarkable metabolic changes of nutritionally relevant constituents such as reduced contents of raffinose oligosaccharides and galactosyl cyclitols as well as increased concentrations in sucrose and various free amino acids. The mutation-induced metabolite signature was nearly unaffected by the cross-breeding and consistently expressed over generations and in different growing seasons. Therefore, not only the primary MIPS1 lpa mutant but also its progenies might be valuable genetic resources for commercial breeding programs to produce soybean seeds stably exhibiting improved phytate-related and nutritional properties.


Assuntos
Proteínas de Arabidopsis/genética , Mio-Inositol-1-Fosfato Sintase/genética , Ácido Fítico/análise , Proteínas de Plantas/genética , Soja/enzimologia , Proteínas de Arabidopsis/metabolismo , Homozigoto , Hibridização Genética , Mutação , Mio-Inositol-1-Fosfato Sintase/metabolismo , Oligossacarídeos/análise , Oligossacarídeos/metabolismo , Ácido Fítico/metabolismo , Melhoramento Vegetal , Proteínas de Plantas/metabolismo , Rafinose/análise , Rafinose/metabolismo , Soja/química , Soja/genética , Soja/metabolismo , Sacarose/análise , Sacarose/metabolismo
4.
Int J Mol Sci ; 20(4)2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30781405

RESUMO

Unsaturated fatty acids are the main components of vegetable oils. Fatty acid desaturase 2 (FAD2) catalyzes oleic acid (OA) into linoleic acid (LA) transformations, which are essential to the profile of FAs in seeds. To further understand the roles of FAD2s in the synthesis of oil, the evolution and biocatalysis of FAD2s were comprehensively analyzed. The evolution history of the FAD2 gene family showed that most of the FAD2 genes formed monophyletic clades except in eudicots. The FAD2 genes in some eudicots diverged into constitutive and seed-specific expression clades. Notably, the biocatalysis of seed-specific or -abundant expression FAD2s in soybean, perilla, rice, and spruce revealed that their catalytic activity was strongly correlated with the total oil content of their seeds in nature. Additionally, it was found that I and Y in site 143 of GmaFAD2-1 were strictly conserved in the seed-specific and constitutive expression clades of Fabaceae, respectively. Furthermore, the site-directed mutation demonstrated that I and Y are vital to improving and reducing the activity of GmaFAD2s. Therefore, the results indicate that the activity of FAD2s in seeds might be a reference to the total oil content of seeds, and site 143 might have been specifically evolved to be required for the activity of FAD2s in some expression-diverged eudicots, especially in legumes.


Assuntos
Biocatálise , Evolução Molecular , Ácidos Graxos Dessaturases/genética , Óleos Vegetais/metabolismo , Sementes/metabolismo , Sequência de Aminoácidos , Fabaceae/metabolismo , Ácidos Graxos Dessaturases/metabolismo , Ácidos Graxos/química , Ácidos Graxos/metabolismo , Família Multigênica , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Saccharomyces cerevisiae/metabolismo
5.
J Agric Food Chem ; 67(1): 247-257, 2019 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-30541281

RESUMO

The knowledge on consequences of cross-breeding of induced low phytic acid ( lpa) soybean ( Glycine max L. Merr.) mutants on the contents of phytic acid (InsP6) and lower inositol phosphate isomers (InsP2-InsP5) in the resulting progenies is limited. Therefore, MIPS1 and IPK1 lpa soybean mutants were crossed with wild-type (WT) cultivars or among themselves to generate homozygous lpa and WT progenies and double lpa mutants. The lpa trait of the MIPS1 mutant was not altered by cross-breeding with a WT cultivar; lpa progenies had InsP6 reductions of about 44% compared to WT progenies. IPK1 progenies showed pronounced accumulations of specific InsP3-InsP5 isomers (up to 12.4 mg/g) compared to the progenitor lpa mutant (4.7 mg/g); the extent of InsP6 reduction (43-71%) was depending on the WT crossing parent. Double mutants exhibited the most pronounced InsP6 reductions (up to 87%), accompanied by moderate accumulations of InsP3-InsP5 (2.5 mg/g). Cross-breeding offers the potential to modulate the amounts of both InsP6 and InsP3-InsP5 contents in lpa soybean mutants and thus to improve their nutritional quality.


Assuntos
Fosfatos de Inositol/química , Ácido Fítico/metabolismo , Soja/química , Hibridização Genética , Fosfatos de Inositol/metabolismo , Isomerismo , Mutação , Valor Nutritivo , Ácido Fítico/análise , Melhoramento Vegetal , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Soja/genética
6.
PeerJ ; 6: e6023, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30533310

RESUMO

Methionine (Met) is an essential sulfur-containing amino acid in animals. Cereal and legume crops with limiting levels of Met represent the major food and feed sources for animals. In plants, cystathionine gamma-synthase (CGS), methionine methyltransferase (MMT) and homocysteine methyltransferase (HMT) are committing enzymes synergistically synthesizing Met through the aspartate (Asp) family pathway and the S-methylmethionine (SMM) cycle. The biological functions of CGS, MMT and HMT genes have been respectively studied, whereas their evolution patterns and their contribution to the evolution of Met biosynthetic pathway in plants are unknown. In the present study, to reveal their evolution patterns and contribution, the evolutionary relationship of CGS, MMT and HMT gene families were reconstructed. The results showed that MMTs began in the ancestor of the land plants and kept conserved during evolution, while the CGSs and HMTs had diverged. The CGS genes were divided into two branches in the angiosperms, Class 1 and Class 2, of which Class 2 only contained the grasses. However, the HMT genes diverged into Class 1 and Class 2 in all of the seed plants. Further, the gene structure analysis revealed that the CGSs, MMTs and HMTs were relatively conserved except for the CGSs in Class 2. According to the expression of CGS, HMT and MMT genes in soybeans, as well as in the database of soybean, rice and Arabidopsis, the expression patterns of the MMTs were shown to be consistently higher in leaves than in seeds. However, the expression of CGSs and HMTs had diverged, either expressed higher in leaves or seeds, or showing fluctuated expression. Additionally, the functions of HMT genes had diverged into the repair of S-adenosylmethionine and SMM catabolism during the evolution. The results indicated that the CGS and HMT genes have experienced partial subfunctionalization. Finally, given the evolution and expression of the CGS, HMT and MMT gene families, we built the evolutionary model of the Met biosynthetic pathways in plants. The model proposed that the Asp family pathway existed in all the plant lineages, while the SMM cycle began in the ancestor of land plants and then began to diverge in the ancestor of seed plants. The model suggested that the evolution of Met biosynthetic pathway is basically consistent with that of plants, which might be vital to the growth and development of different botanical lineages during evolution.

7.
Autophagy ; 14(9): 1652-1653, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29995581

RESUMO

Macroautophagy/autophagy is a unique protein degradation process by which intracellular materials are recycled for energy homeostasis. However, the metabolic status and energy source of autophagy-defective tumor cells is poorly understood. Here in this study, we found ATF4-dependent amino acid transporter (AAT) gene expression and amino acid uptake were increased in autophagy-deficient cells under conditions of Gln deprivation. Notably, inhibition of amino acid uptake reduced the viability of Gln-deprived autophagy-deficient cells, but not significantly in wild-type cells, suggesting the reliance of autophagy-deficient tumor cells on extracellular amino acid uptake.


Assuntos
Autofagia , Glutamina , Aminoácidos , Sobrevivência Celular , Homeostase
8.
Cell Rep ; 23(10): 3006-3020, 2018 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-29874586

RESUMO

Autophagy is a protein degradation process by which intracellular materials are recycled for energy homeostasis. However, the metabolic status and energy source of autophagy-defective tumor cells are poorly understood. Here, our data show that amino acid uptake from the extracellular environment is increased in autophagy-deficient cells upon glutamine deprivation. This elevated amino acid uptake results from activating transcription factor 4 (ATF4)-dependent upregulation of AAT (amino acid transporter) gene expression. Furthermore, we identify SIRT6, a NAD+-dependent histone deacetylase, as a corepressor of ATF4 transcriptional activity. In autophagy-deficient cells, activated NRF2 enhances ATF4 transcriptional activity by disrupting the interaction between SIRT6 and ATF4. In this way, autophagy-deficient cells exhibit increased AAT expression and show increased amino acid uptake. Notably, inhibition of amino acid uptake reduces the viability of glutamine-deprived autophagy-deficient cells, but not significantly in wild-type cells, suggesting reliance of autophagy-deficient tumor cells on extracellular amino acid uptake.


Assuntos
Autofagia , Glutamina/deficiência , Fator 4 Ativador da Transcrição/metabolismo , Sistemas de Transporte de Aminoácidos/genética , Sistemas de Transporte de Aminoácidos/metabolismo , Animais , Autofagia/genética , Sobrevivência Celular/genética , Regulação da Expressão Gênica , Glutamina/metabolismo , Células HCT116 , Humanos , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , Fator 2 Relacionado a NF-E2/metabolismo , Regiões Promotoras Genéticas/genética , Ligação Proteica , Estabilidade Proteica , Sirtuínas/metabolismo
9.
Int J Mol Sci ; 19(4)2018 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-29677135

RESUMO

Homocysteine methyltransferase (HMT) converts homocysteine to methionine using S-methylmethionine (SMM) or S-adenosylmethionine (SAM) as methyl donors in organisms, playing an important role in supplying methionine for the growth and the development of plants. To better understand the functions of the HMT genes in plants, we conducted a wide evolution and expression analysis of these genes. Reconstruction of the phylogenetic relationship showed that the HMT gene family was divided into Class 1 and Class 2. In Class 1, HMTs were only found in seed plants, while Class 2 presented in all land plants, which hinted that the HMT genes might have diverged in seed plants. The analysis of gene structures and selection pressures showed that they were relatively conserved during evolution. However, type I functional divergence had been detected in the HMTs. Furthermore, the expression profiles of HMTs showed their distinct expression patterns in different tissues, in which some HMTs were widely expressed in various organs, whereas the others were highly expressed in some specific organs, such as seeds or leaves. Therefore, according to our results in the evolution, functional divergence, and expression, the HMT genes might have diverged during evolution. Further analysis in the expression patterns of AthHMTs with their methyl donors suggested that the diverged HMTs might be related to supply methionine for the development of plant seeds.


Assuntos
Evolução Molecular , Homocisteína S-Metiltransferase/metabolismo , Plantas/metabolismo , Animais , Homocisteína S-Metiltransferase/genética , Humanos , Filogenia , Plantas/genética , S-Adenosilmetionina/metabolismo , Vitamina U/metabolismo
10.
J Biol Chem ; 292(32): 13296-13311, 2017 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-28655758

RESUMO

Sirtuin 7 (SIRT7), a member of the NAD+-dependent class III histone deacetylases, is involved in the regulation of various cellular processes and in resisting various stresses, such as hypoxia, low glucose levels, and DNA damage. Interestingly, SIRT7 is linked to the control of glycolysis, suggesting a role in glucose metabolism. Given the important roles of SIRT7, it is critical to clarify how SIRT7 activity is potentially regulated. It has been reported that some transcriptional and post-transcriptional regulatory mechanisms are involved. However, little is known how SIRT7 is regulated by the post-translational modifications. Here, we identified ubiquitin-specific peptidase 7 (USP7), a deubiquitinase, as a negative regulator of SIRT7. We showed that USP7 interacts with SIRT7 both in vitro and in vivo, and we further demonstrated that SIRT7 undergoes endogenous Lys-63-linked polyubiquitination, which is removed by USP7. Although the USP7-mediated deubiquitination of SIRT7 had no effect on its stability, the deubiquitination repressed its enzymatic activity. We also showed that USP7 coordinates with SIRT7 to regulate the expression of glucose-6-phosphatase catalytic subunit (G6PC), a gluconeogenic gene. USP7 depletion by RNA interference increased both G6PC expression and SIRT7 enzymatic activity. Moreover, SIRT7 targeted the G6PC promoter through the transcription factor ELK4 but not through forkhead box O1 (FoxO1). In summary, SIRT7 is a USP7 substrate and has a novel role as a regulator of gluconeogenesis. Our study may provide the basis for new clinical approaches to treat metabolic disorders related to glucose metabolism.


Assuntos
Regulação Enzimológica da Expressão Gênica , Glucose-6-Fosfatase/metabolismo , Regiões Promotoras Genéticas , Processamento de Proteína Pós-Traducional , Sirtuínas/metabolismo , Ubiquitina Tiolesterase/metabolismo , Proteínas Elk-4 do Domínio ets/metabolismo , Substituição de Aminoácidos , Linhagem Celular Tumoral , Deleção de Genes , Gluconeogênese , Glucose-6-Fosfatase/antagonistas & inibidores , Glucose-6-Fosfatase/genética , Células HEK293 , Humanos , Hidrólise , Lisina/metabolismo , Mutação , Fragmentos de Peptídeos/antagonistas & inibidores , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/metabolismo , Domínios e Motivos de Interação entre Proteínas , Subunidades Proteicas/genética , Subunidades Proteicas/metabolismo , Interferência de RNA , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/metabolismo , Sirtuínas/antagonistas & inibidores , Sirtuínas/genética , Especificidade por Substrato , Ubiquitina Tiolesterase/antagonistas & inibidores , Ubiquitina Tiolesterase/genética , Peptidase 7 Específica de Ubiquitina , Ubiquitinação , Proteínas Elk-4 do Domínio ets/genética
11.
BMC Plant Biol ; 17(1): 16, 2017 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-28100173

RESUMO

BACKGROUND: Seed germination is important to soybean (Glycine max) growth and development, ultimately affecting soybean yield. A lower seed field emergence has been the main hindrance for breeding soybeans low in phytate. Although this reduction could be overcome by additional breeding and selection, the mechanisms of seed germination in different low phytate mutants remain unknown. In this study, we performed a comparative transcript analysis of two low phytate soybean mutants (TW-1 and TW-1-M), which have the same mutation, a 2 bp deletion in GmMIPS1, but show a significant difference in seed field emergence, TW-1-M was higher than that of TW-1 . RESULTS: Numerous genes analyzed by RNA-Seq showed markedly different expression levels between TW-1-M and TW-1 mutants. Approximately 30,000-35,000 read-mapped genes and ~21000-25000 expressed genes were identified for each library. There were ~3900-9200 differentially expressed genes (DEGs) in each contrast library, the number of up-regulated genes was similar with down-regulated genes in the mutant TW-1and TW-1-M. Gene ontology functional categories of DEGs indicated that the ethylene-mediated signaling pathway, the abscisic acid-mediated signaling pathway, response to hormone, ethylene biosynthetic process, ethylene metabolic process, regulation of hormone levels, and oxidation-reduction process, regulation of flavonoid biosynthetic process and regulation of abscisic acid-activated signaling pathway had high correlations with seed germination. In total, 2457 DEGs involved in the above functional categories were identified. Twenty-two genes with 20 biological functions were the most highly up/down- regulated (absolute value Log2FC >5) in the high field emergence mutant TW-1-M and were related to metabolic or signaling pathways. Fifty-seven genes with 36 biological functions had the greatest expression abundance (FRPM >100) in germination-related pathways. CONCLUSIONS: Seed germination in the soybean low phytate mutants is a very complex process, which involves a series of physiological, morphological and transcriptional changes. Compared with TW-1, TW-1-M had a very different gene expression profile, which included genes related to plant hormones, antioxidation, anti-stress and energy metabolism processes. Our research provides a molecular basis for understanding germination mechanisms, and is also an important resource for the genetic analysis of germination in low phytate crops. Plant hormone- and antioxidation-related genes might strongly contribute to the high germination rate in the TW-1-M mutant.


Assuntos
Genoma de Planta , Ácido Fítico/metabolismo , Proteínas de Plantas/genética , Sementes/genética , Soja/genética , Soja/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Mutação , Ácido Fítico/análise , Proteínas de Plantas/metabolismo , Sementes/química , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Soja/química , Soja/crescimento & desenvolvimento
12.
J Biol Chem ; 292(7): 2830-2841, 2017 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-28073914

RESUMO

The serine/threonine kinase Unc-51-like kinase-1 (Ulk1) is thought to be essential for induction of autophagy, an intracellular bulk degradation process that is activated by various stresses. Although several proteins have been suggested as Ulk1 substrates during autophagic process, it still remains largely unknown about Ulk1's physiological substrates. Here, by performing in vitro and in vivo phosphorylation assay, we report that the co-chaperone cell division cycle protein 37 (Cdc37) is a Ulk1 substrate. Ulk1-mediated phosphorylation of Ser-339 in Cdc37 compromised the recruitment of client kinases to a complex comprising Cdc37 and heat shock protein 90 (Hsp90) but only modestly affected Cdc37 binding to Hsp90. Because the recruitment of protein kinase clients to the Hsp90 complex is essential for their stability and functions, Ser-339 phosphorylation of Cdc37 disrupts its ability as a co-chaperone to coordinate Hsp90. Hsp90 inhibitors are cancer chemotherapeutic agents by inducing depletion of clients, many of which are oncogenes. Upon treatment with an Hsp90 inhibitor in cancer cells, Ulk1 promoted the degradation of Hsp90-Cdc37 client kinases, resulting in increased cellular sensitivity to Hsp90 inhibitors. Thus, our study provides evidence for an anti-proliferative role of Ulk1 in response to Hsp90 inhibition in cancer cells.


Assuntos
Proteína Homóloga à Proteína-1 Relacionada à Autofagia/fisiologia , Proteínas de Ciclo Celular/metabolismo , Divisão Celular/fisiologia , Chaperoninas/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/fisiologia , Linhagem Celular Tumoral , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Humanos , Fosforilação , Ligação Proteica , Estabilidade Proteica
13.
Food Chem ; 196: 776-82, 2016 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-26593554

RESUMO

Sugar and protein are important quality traits in soybean seeds for making soy-based food products. However, the investigations on both compositions and their relationship have rarely been reported. In this study, a total of 35 soybean germplasms collected from Zhejiang province of China, were evaluated for both water-soluble sugar and protein. The total water-soluble sugar (TWSS) content of the germplasms studied ranged from 84.70 to 140.91 mg/g and the water-soluble protein (WSP) content varied from 26.5% to 36.0%. The WSP content showed positive correlations with the TWSS and sucrose contents but negative correlations with the fructose and glucose contents. The clustering showed the 35 germplasms could be divided into four groups with specific contents of sugar and protein. The combination of water-soluble sugar and protein profiles provides useful information for future breeding and genetic research. This investigation will facilitate future work for seed quality improvement.


Assuntos
Carboidratos/química , Proteínas de Soja/química , Soja/química , Cruzamento , China , Sementes/química , Alimentos de Soja/análise , Soja/classificação
14.
Theor Appl Genet ; 125(7): 1413-23, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22733447

RESUMO

Phytic acid (myo-inositol 1, 2, 3, 4, 5, 6 hexakisphosphate) is an important constituent of soybean meal. Since phytic acid and its mineral salts (phytates) are almost indigestible for monogastrics, their abundance in grain food/feed causes nutritional and environmental problems; interest in breeding low phytic acid has therefore increased considerably. Based on gene mapping and the characteristics of inositol polyphosphates profile in the seeds of a soybean mutant line Gm-lpa-ZC-2, the soybean ortholog of inositol 1,3,4,5,6 pentakisphosphate (InsP(5)) 2-kinase (IPK1), which transforms InsP(5) into phytic acid, was first hypothesized as the candidate gene responsible for the low phytic acid alteration in Gm-lpa-ZC-2. One IPK1 ortholog (Glyma14g07880, GmIPK1) was then identified in the mapped region on chromosome 14. Sequencing revealed a G → A point mutation in the genomic DNA sequence and the exclusion of the entire fifth exon in the cDNA sequence of GmIPK1 in Gm-lpa-ZC-2 compared with its wild-type progenitor Zhechun No. 3. The excluded exon encodes 37 amino acids that spread across two conserved IPK1 motifs. Furthermore, complete co-segregation of low phytic acid phenotype with the G → A mutation was observed in the F(2) population of ZC-lpa x Zhexiandou No. 4 (a wild-type cultivar). Put together, the G → A point mutation affected the pre-mRNA splicing and resulted in the exclusion of the fifth exon of GmIPK1 which is expected to disrupt the GmIPK1 functionality, leading to low phytic acid level in Gm-lpa-ZC-2. Gm-lpa-ZC-2, would be a good germplasm source in low phytic acid soybean breeding.


Assuntos
Éxons/genética , Mutação/genética , Ácido Fítico/metabolismo , Sítios de Splice de RNA/genética , Homologia de Sequência de Aminoácidos , Soja/enzimologia , Soja/genética , Sequência de Bases , Cruzamentos Genéticos , DNA Complementar/genética , DNA de Plantas/genética , Regulação da Expressão Gênica de Plantas , Genes de Plantas/genética , Homozigoto , Dados de Sequência Molecular , Fenótipo , Fosfatos/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Mapeamento Físico do Cromossomo , Sementes/genética , Sementes/metabolismo , Soja/embriologia , Transcrição Genética
15.
J Agric Food Chem ; 57(9): 3632-8, 2009 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-19323582

RESUMO

Reduction of phytic acid in soybean seeds has the potential to improve the nutritional value of soybean meal and lessen phosphorus pollution in large scale animal farming. The objective of this study was to assess the effect of two new low phytic acid (LPA) mutations on seed quality and nutritional traits. Multilocation/season comparative analyses showed that the two mutations did not affect the concentration of crude protein, any of the individual amino acids, crude oil, and individual saturated fatty acids. Among other traits, Gm-lpa-TW75-1 had consistently higher sucrose contents (+47.4-86.1%) and lower raffinose contents (-74.2 to -84.3%) than those of wild type (WT) parent Taiwan 75; Gm-lpa-ZC-2 had higher total isoflavone contents (3038.8-4305.4 microg/g) than its parent Zhechun # 3 (1583.6-2644.9 microg/g) in all environments. Further tests of homozygous F(3) progenies of the cross Gm-lpa-ZC-2 x Wuxing # 4 (WT variety) showed that LPA lines had a mean content of total isoflavone significantly higher than WT lines. This study demonstrated that two LPA mutant genes have no negative effects on seed quality and nutritional traits; they instead have the potential to improve a few other properties. Therefore, these two mutant genes are valuable genetic resources for breeding high quality soybean varieties.


Assuntos
Mutação , Valor Nutritivo , Ácido Fítico/análise , Sementes/genética , Soja/genética , Cruzamento , Ácidos Graxos/análise , Isoflavonas/análise , Oligossacarídeos/análise , Óleos Vegetais/análise , Proteínas de Plantas/análise , Rafinose/análise , Estações do Ano , Sementes/química , Soja/química , Sacarose/análise
16.
Theor Appl Genet ; 115(7): 945-57, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17701395

RESUMO

Phytic acid (PA, myo-inositol 1, 2, 3, 4, 5, 6 hexakisphosphate) is important to the nutritional quality of soybean meal. Organic phosphorus (P) in PA is indigestible in humans and non-ruminant animals, which affects nutrition and causes P pollution of ground water from animal wastes. Two novel soybean [(Glycine max L. (Merr.)] low phytic acid (lpa) mutations were isolated and characterized. Gm-lpa-TW-1 had a phytic acid P (PA-P) reduction of 66.6% and a sixfold increase in inorganic P (Pi), and Gm-lpa-ZC-2 had a PA-P reduction of 46.3% and a 1.4-fold increase in Pi, compared with their respective non-mutant progenitor lines. The reduction of PA-P and increase of Pi in Gm-lpa-TW-1 were molar equivalent; the decrease of PA-P in Gm-lpa-ZC-2, however, was accompanied by the increase of both Pi and lower inositol phosphates. In both mutant lines, the total P content remained similar to their wild type parents. The two lpa mutations were both inherited in a single recessive gene model but were non-allelic. Sequence data and progeny analysis indicate that Gm-lpa-TW-1 lpa mutation resulted from a 2 bp deletion in the soybean D: -myo-inositol 3-phosphate synthase (MIPS1 EC 5.5.1.4) gene 1 (MIPS1). The lpa mutation in Gm-lpa-ZC-2 was mapped on LG B2, closely linked with microsatellite loci Satt416 and Satt168, at genetic distances of approximately 4.63 and approximately 9.25 cM, respectively. Thus this mutation probably represents a novel soybean lpa locus. The seed emergence rate of Gm-lpa-ZC-2 was similar to its progenitor line and was not affected by seed source and its lpa mutation. However, Gm-lpa-TW-1 had a significantly reduced field emergence when seeds were produced in a subtropic environment. Field tests of the mutants and their progenies further demonstrated that the lpa mutation in Gm-lpa-ZC-2 does not negatively affect plant yield traits. These results will advance understanding of the genetic, biochemical and molecular control of PA synthesis in soybean. The novel lpa mutation in Gm-lpa-ZC-2, together with linked simple sequence repeat (SSR) markers, will be of value for breeding productive lpa soybeans, with meal high in digestible Pi eventually to improve animal nutrition and lessen environmental pollution.


Assuntos
Mutação , Ácido Fítico/metabolismo , Soja/genética , Ácido Fítico/química , Sementes/química , Sementes/genética , Sementes/metabolismo , Soja/química , Soja/metabolismo
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