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Lujian Zhou Yu Ye Qian Zhao Xiaoxia Du Shamsu Ado Zakari Da Su Gang Pan Fangmin Cheng 《Plant Growth Regulation》2018,85(3):411-424
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Bruno Campion Francesca Sparvoli Enrico Doria Giovanni Tagliabue Incoronata Galasso Marzia Fileppi Roberto Bollini Erik Nielsen 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,118(6):1211-1221
Phytic acid is considered as one of the major antinutritional compounds in cereal and legume seeds. The development of lpa (low phytic acid) grains, resulting in increased mineral cation availability, is considered a major goal in the improvement
of the nutritional quality of seed crops, especially those largely consumed in developing countries. From a mutagenised population
of common bean we isolated a homozygous lpa mutant line (lpa-280-10) showing, compared to wild type, a 90% reduction of phytic acid, a 25% reduction of raffinosaccharides and a much
higher amount of free or weakly bound iron cations in the seed. Genetic analysis showed that the lpa character is due to a recessive mutation that segregates in a monogenic, Mendelian fashion. Germination tests performed using
varying ageing or stress conditions, clearly showed that the bean line lpa-280-10 has a better germination response than the wild type. These data, together with those obtained from 2 years of agronomic
trials showing that the mutant seed yield is close to that of its parents and other evidence, indicate that the new lpa-280-10 mutation might be the first devoid of visible macroscopic negative effects in plants, pods and seeds.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
5.
Feng-Jie Yuan Dan-Hua Zhu Yuan-Yuan Tan De-Kun Dong Xu-Jun Fu Shen-Long Zhu Bai-Quan Li Qing-Yao Shu 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2012,125(7):1413-1423
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 (InsP5) 2-kinase (IPK1), which transforms InsP5 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 F2 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. 相似文献
6.
Dynamic Changes in the Distribution of Minerals in Relation to Phytic Acid Accumulation during Rice Seed Development 总被引:1,自引:0,他引:1
Toru Iwai Michiko Takahashi Koshiro Oda Yasuko Terada Kaoru T. Yoshida 《Plant physiology》2012,160(4):2007-2014
Phytic acid (inositol hexakisphosphate [InsP6]) is the storage compound of phosphorus in seeds. As phytic acid binds strongly to metallic cations, it also acts as a storage compound of metals. To understand the mechanisms underlying metal accumulation and localization in relation to phytic acid storage, we applied synchrotron-based x-ray microfluorescence imaging analysis to characterize the simultaneous subcellular distribution of some mineral elements (phosphorus, calcium, potassium, iron, zinc, and copper) in immature and mature rice (Oryza sativa) seeds. This fine-imaging method can reveal whether these elements colocalize. We also determined their accumulation patterns and the changes in phosphate and InsP6 contents during seed development. While the InsP6 content in the outer parts of seeds rapidly increased during seed development, the phosphate contents of both the outer and inner parts of seeds remained low. Phosphorus, calcium, potassium, and iron were most abundant in the aleurone layer, and they colocalized throughout seed development. Zinc was broadly distributed from the aleurone layer to the inner endosperm. Copper localized outside the aleurone layer and did not colocalize with phosphorus. From these results, we suggest that phosphorus translocated from source organs was immediately converted to InsP6 and accumulated in aleurone layer cells and that calcium, potassium, and iron accumulated as phytic acid salt (phytate) in the aleurone layer, whereas zinc bound loosely to InsP6 and accumulated not only in phytate but also in another storage form. Copper accumulated in the endosperm and may exhibit a storage form other than phytate.The transport of nutrients into developing seeds has received considerable attention. During the grain-filling stage, plants remobilize and transport nutrients distributed throughout the vegetative source organs into seeds. Plant seeds contain large amounts of phosphorus (P) in organic form, which supports growth during the early stages of seedling development. Most of the P in seeds is stored in the form of phytic acid (inositol hexakisphosphate [InsP6]). Seeds also accumulate mineral nutrients such as potassium (K), magnesium (Mg), calcium (Ca), iron (Fe), zinc (Zn), copper (Cu), and manganese (Mn), which are used in seedling growth. Phytic acid acts as a strong chelator of metal cations and binds them to form phytate, a salt of InsP6 (Lott et al., 2002; Raboy, 2009). During germination, phytate is decationized and hydrolyzed by phytases, and then inorganic phosphates, inositol, and various minerals are released from the phytate (Loewus and Murthy, 2000). Phytate accumulates within protein bodies, generally of vacuolar origin, in seed storage cells and is usually concentrated in spherical inclusions called globoids. Many studies of the elemental composition of phytate in seeds have been published. Energy-dispersive x-ray microanalyses of many plant species have revealed that, other than P, globoids contain mainly K and Mg as well as low levels of Ca, Mn, Fe, and Zn (Lott, 1984; Lott et al., 1995; Wada and Lott, 1997). This indicates that phytate is a mixed salt of these cations.Whether all storage metal elements can bind equally to InsP6 is not known, although most elements are thought to exist in seeds in the form of phytate (Raboy, 2009). To form phytate, P and the other elements must be present in the same place. Therefore, determination of the precise locations of P and other elements in seed tissues makes it possible to judge whether an element exists in the form of phytate. Differences in metal distribution with P might suggest a storage form other than phytate. For determining distributions, synchrotron-based x-ray microfluorescence (µ-XRF) imaging utilizing an x-ray microbeam is a powerful tool. The microbeam excites the elements, thereby revealing the details of their spatial distribution. The development of focusing optics for high-energy x-rays using a Kirkpatrick-Baez mirror raises the imaging resolution of elements in µ-XRF analysis. A focal spot size smaller than 1 µm with x-ray energy as high as 100 keV enables detection of the subcellular distribution of elements in plant tissues (Fukuda et al., 2008; Takahashi et al., 2009).Whether there is an order in the affinity of elements for phytic acid in plant cells remains unknown. The stability of InsP6-metal complexes has been estimated by in vitro titration (Maddaiah et al., 1964; Vohra et al., 1965; Persson et al., 1998). The binding strength of InsP6 with metal is stronger for Zn and Cu than for Fe, Mn, and Ca. We also do not know if the mineral composition of phytate in seeds is determined by the relative abundance of these elements in the seed or by their biochemical characteristics. As a first step to address these issues, we examined the simultaneous changes in the distribution of P and metal elements during seed development using µ-XRF imaging analysis.Our objective in this study was to observe the dynamic changes in the distribution of some nutritionally important minerals (P, Ca, K, Fe, Zn, and Cu) in relation to the accumulation of phytic acid during rice (Oryza sativa) seed development. 相似文献
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Vicky Roslinsky Peter E. Eckstein Victor Raboy Brian G. Rossnagel Graham J. Scoles 《Molecular breeding : new strategies in plant improvement》2007,20(4):323-330
Phytate is the primary form of phosphorus found in mature cereal grain. This form of phosphorus is not available to monogastric
animals due to a lack of the enzyme phytase in their digestive tract. Several barley low
phytic
acid (lpa) mutants have been identified that contain substantial decreases in seed phytate accompanied by concomitant increases in
inorganic phosphorus. Seed homozygous for low phytic acid
1-1 (lpa1-1) or low phytic acid
2-1 (lpa2-1) has a 50% and 70% decrease in seed phytate respectively. These mutations were previously mapped to chromosomes 2HL and 7HL
respectively. The RFLP marker ABC153 located in the same region of 2H was converted to a sequence-characterized-amplified-region
(SCAR) marker. Segregation analysis of the CDC McGwire × Lp422 doubled haploid population confirmed linkage between the SCAR
marker and the lpa1-1 locus with 15% recombination. A third low phytic acid mutant, M635, has a 75% decrease in phytate. This mutation was located
to chromosome 1HL by linkage with an inter-simple sequence repeat (ISSR) based marker (LP75) identified through bulked-segregant
analysis, and has been designated lpa3-1. Based on analysis of recombination between marker LP75 and low phytic acid in an additional mutant line M955 (95% phytate
decrease), lpa3-1 and the mutation in M955 are in the same region on chromosome 1HL, and may be allelic. 相似文献
8.
Liu QL Xu XH Ren XL Fu HW Wu DX Shu QY 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2007,114(5):803-814
Phytic acid (PA, myo-inositol 1,2,3,4,5,6-hexakisphosphate), or its salt form, phytate, is commonly regarded as the major anti-nutritional component in cereal and legume grains.
Breeding of low phytic acid (lpa) crops has recently been considered as a potential way to increase nutritional quality of crop products. In this study, eight
independent lpa rice mutant lines from both indica and japonica subspecies were developed through physical and chemical mutagenesis. Among them, five are non-lethal while the other three
are homozygous lethal. None of the lethal lines could produce homozygous lpa plants through seed germination and growth under field conditions, but two of them could be rescued through in vitro culture
of mature embryos. The non-lethal lpa mutants had lower PA content ranging from 34 to 64% that of their corresponding parent and four of them had an unchanged
total P level. All the lpa mutations were inherited in a single recessive gene model and at least four lpa mutations were identified mutually non-allelic, while the other two remain to be verified. One mutation was mapped on chromosome
2 between microsatellite locus RM3542 and RM482, falling in the same region as the previously mapped lpa1-1 locus did; another lpa mutation was mapped on chromosome 3, tightly linked to RM3199 with a genetic distance of 1.198 cM. The latter mutation was
very likely to have happened to the LOC_Os03g52760, a homolog of the maize myo-inositol kinase (EC 2.7.1.64) gene. The present work greatly expands the number of loci that could influence the biosynthesis
of PA in rice, making rice an excellent model system for research in this area. 相似文献
9.
Mintu Desai Padma Rangarajan Janet L. Donahue Sarah P. Williams Eric S. Land Mihir K. Mandal Brian Q. Phillippy Imara Y. Perera Victor Raboy Glenda E. Gillaspy 《The Plant journal : for cell and molecular biology》2014,80(4):642-653
Inositol pyrophosphates are unique cellular signaling molecules with recently discovered roles in energy sensing and metabolism. Studies in eukaryotes have revealed that these compounds have a rapid turnover, and thus only small amounts accumulate. Inositol pyrophosphates have not been the subject of investigation in plants even though seeds produce large amounts of their precursor, myo‐inositol hexakisphosphate (InsP6). Here, we report that Arabidopsis and maize InsP6 transporter mutants have elevated levels of inositol pyrophosphates in their seed, providing unequivocal identification of their presence in plant tissues. We also show that plant seeds store a little over 1% of their inositol phosphate pool as InsP7 and InsP8. Many tissues, including, seed, seedlings, roots and leaves accumulate InsP7 and InsP8, thus synthesis is not confined to tissues with high InsP6. We have identified two highly similar Arabidopsis genes, AtVip1 and AtVip2, which are orthologous to the yeast and mammalian VIP kinases. Both AtVip1 and AtVip2 encode proteins capable of restoring InsP7 synthesis in yeast mutants, thus AtVip1 and AtVip2 can function as bonafide InsP6 kinases. AtVip1 and AtVip2 are differentially expressed in plant tissues, suggesting non‐redundant or non‐overlapping functions in plants. These results contribute to our knowledge of inositol phosphate metabolism and will lay a foundation for understanding the role of InsP7 and InsP8 in plants. 相似文献
10.
Isolation and characterization of a low phytic acid rice mutant reveals a mutation in the rice orthologue of maize MIK 总被引:2,自引:0,他引:2
Kim SI Andaya CB Newman JW Goyal SS Tai TH 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2008,117(8):1291-1301
Using a forward genetics approach, we isolated two independent low phytic acid (lpa) rice mutants, N15-186 and N15-375. Both mutants are caused by single gene, recessive non-lethal mutations, which result
in approximately 75% (N15-186) and 43% (N15-375) reductions in seed phytic acid (inositol hexakisphosphate). High-performance liquid chromatography and GC–MS analysis of seed extracts from N15-186 indicated that, in addition
to phytic acid, inositol monophosphate was significantly reduced whereas inorganic phosphorus and myo-inositol were greatly increased when compared with wild-type. The changes observed in N15-186 resemble those previously described
for the maize lpa3 mutant. Analysis of N15-375 revealed changes similar to those observed in previously characterized rice lpa1 mutants (i.e. significant reduction in phytic acid and corresponding increase in inorganic phosphorus with little or no
change in inositol phosphate intermediates or myo-inositol). Further genetic analysis of the N15-186 mutant indicated that the mutation, designated lpa N15-186, was located in a region on chromosome 3 between the microsatellite markers RM15875 and RM15907. The rice orthologue
of maize lpa3, which encodes a myo-inositol kinase, is in this interval. Sequence analysis of the N15-186 allele of this orthologue (Os03g52760) revealed a
single base pair change (C/G to T/A) in the first exon of the gene, which results in a nonsense mutation. Our results indicate
that lpa N15-186 is a mutant allele of the rice myo-inositol kinase (OsMIK) gene. Identification and characterization of lpa mutants, such as N15-186, will facilitate studies on the regulation of phytic acid biosynthesis and accumulation and help
address questions concerning the contribution of the inositol lipid-dependent and independent biosynthetic pathways to the
production of seed phytic acid.
The mention of trade names or commercial products in this publication is solely for the purpose of providing specific information
and does not imply recommendation or endorsement by the U.S. Department of Agriculture. 相似文献
11.
Generation and characterization of two novel low phytate mutations in soybean (<Emphasis Type="Italic">Glycine max</Emphasis> L. Merr.) 总被引:1,自引:0,他引:1
Yuan FJ Zhao HJ Ren XL Zhu SL Fu XJ Shu QY 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2007,115(7):945-957
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 ∼4.63 and
∼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. 相似文献
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13.
Yuan-Yuan Tan Hao-Wei Fu Hai-Jun Zhao Sha Lu Jun-Jie Fu You-Fa Li Hai-Rui Cui Qing-Yao Shu 《Molecular breeding : new strategies in plant improvement》2013,31(3):517-528
Phytic acid (PA, myo-inositol-1,2,3,4,5,6-hexakis-phosphate) and its salt form (phytate) are the principal storage forms of phosphorus in cereal grains. Since PA and phytates cannot be efficiently digested by monogastric animals, the abundance of PA in cereal and legume grains causes nutritional and environmental problems. The present study aimed at developing breeder-friendly functional molecular markers of five low phytic acid (LPA) mutant alleles of three rice (Oryza sativa L.) genes: viz., XQZ-lpa (a 1,475-bp deletion) and KBNT-lpa (a C→T single nucleotide polymorphism [SNP]) of LOC_Os02g57400, Z9B-lpa (a 6-bp deletion) and MH-lpa (a 1-bp deletion) of LOC_Os04g55800, and XS-lpa (a C→T SNP) of LOC_Os03g04920. First, markers for gel-based length polymorphism analysis were developed: viz., two insertion–deletion markers for XQZ-lpa and Z9B-lpa, two cleaved amplified polymorphic sequence (CAPS) markers for KBNT-lpa and XS-lpa, and one derived CAPS marker for MH-lpa. Second, the high-resolution melting (HRM) curve analysis method was explored for distinguishing plants with wild-type (WT) and LPA alleles (except XQZ-lpa). Plants of genotypes with homozygous mutant allele and WT, and with heterozygous alleles, could be directly differentiated by HRM for KBNT-lpa, XS-lpa and MH-lpa; only heterozygous individuals could be directly distinguished from homozygous WT and mutant plants for Z9B-lpa. However, by adding 15 % WT DNA templates to test samples before PCR, amplicons of three genotypes of the Z9B-lpa allele could also be differentiated by HRM analysis. Third, it was demonstrated that these markers could be effectively used for marker-assisted selection of LPA rice, and breeding lines with two non-allelic LPA mutations were developed with PA contents significantly lower than their respective parental LPA lines. Taken together, the present study developed functional molecular markers for efficient selection of LPA plants and demonstrated that double mutant LPA lines with significantly lower PA levels than primary LPA mutants (with single mutations) could be developed by pyramiding two non-allelic LPA mutations. 相似文献
14.
Arabidopsis inositol phosphate kinases IPK1 and ITPK1 constitute a metabolic pathway in maintaining phosphate homeostasis
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Hui‐Fen Kuo Yu‐Ying Hsu Wei‐Chi Lin Kai‐Yu Chen Teun Munnik Charles A. Brearley Tzyy‐Jen Chiou 《The Plant journal : for cell and molecular biology》2018,95(4):613-630
Emerging studies have suggested that there is a close link between inositol phosphate (InsP) metabolism and cellular phosphate (Pi) homeostasis in eukaryotes; however, whether a common InsP species is deployed as an evolutionarily conserved metabolic messenger to mediate Pi signaling remains unknown. Here, using genetics and InsP profiling combined with Pi‐starvation response (PSR) analysis in Arabidopsis thaliana, we showed that the kinase activity of inositol pentakisphosphate 2‐kinase (IPK1), an enzyme required for phytate (inositol hexakisphosphate; InsP6) synthesis, is indispensable for maintaining Pi homeostasis under Pi‐replete conditions, and inositol 1,3,4‐trisphosphate 5/6‐kinase 1 (ITPK1) plays an equivalent role. Although both ipk1‐1 and itpk1 mutants exhibited decreased levels of InsP6 and diphosphoinositol pentakisphosphate (PP‐InsP5; InsP7), disruption of another ITPK family enzyme, ITPK4, which correspondingly caused depletion of InsP6 and InsP7, did not display similar Pi‐related phenotypes, which precludes these InsP species from being effectors. Notably, the level of d /l ‐Ins(3,4,5,6)P4 was concurrently elevated in both ipk1‐1 and itpk1 mutants, which showed a specific correlation with the misregulated Pi phenotypes. However, the level of d /l ‐Ins(3,4,5,6)P4 is not responsive to Pi starvation that instead manifests a shoot‐specific increase in the InsP7 level. This study demonstrates a more nuanced picture of the intersection of InsP metabolism and Pi homeostasis and PSRs than has previously been elaborated, and additionally establishes intermediate steps to phytate biosynthesis in plant vegetative tissues. 相似文献
15.
Ho-Seok Lee Du-Hwa Lee Hui Kyung Cho Song Hee Kim Joong Hyuck Auh Hyun-Sook Pai 《The Plant cell》2015,27(2):417-431
Myo-inositol-1,2,3,4,5,6-hexakisphosphate (InsP6), also known as phytic acid, accumulates in large quantities in plant seeds, serving as a phosphorus reservoir, but is an animal antinutrient and an important source of water pollution. Here, we report that Gle1 (GLFG lethal 1) in conjunction with InsP6 functions as an activator of the ATPase/RNA helicase LOS4 (low expression of osmotically responsive genes 4), which is involved in mRNA export in plants, supporting the Gle1-InsP6-Dbp5 (LOS4 homolog) paradigm proposed in yeast. Interestingly, plant Gle1 proteins have modifications in several key residues of the InsP6 binding pocket, which reduce the basicity of the surface charge. Arabidopsis thaliana Gle1 variants containing mutations that increase the basic charge of the InsP6 binding surface show increased sensitivity to InsP6 concentrations for the stimulation of LOS4 ATPase activity in vitro. Expression of the Gle1 variants with enhanced InsP6 sensitivity rescues the mRNA export defect of the ipk1 (inositol 1,3,4,5,6-pentakisphosphate 2-kinase) InsP6-deficient mutant and, furthermore, significantly improves vegetative growth, seed yield, and seed performance of the mutant. These results suggest that Gle1 is an important factor responsible for mediating InsP6 functions in plant growth and reproduction and that Gle1 variants with increased InsP6 sensitivity may be useful for engineering high-yielding low-phytate crops. 相似文献
16.
Miranda S. C. Wilson Simon J. Bulley Francesca Pisani Robin F. Irvine Adolfo Saiardi 《Open biology》2015,5(3)
Inositol phosphates are a large and diverse family of signalling molecules. While
genetic studies have discovered important functions for them, the biochemistry
behind these roles is often not fully characterized. A key obstacle in inositol
phosphate research in mammalian cells has been the lack of straightforward
techniques for their purification and analysis. Here we describe the ability of
titanium dioxide (TiO2) beads to bind inositol phosphates. This
discovery allowed the development of a new purification protocol that, coupled
with gel analysis, permitted easy identification and quantification of
InsP6 (phytate), its pyrophosphate derivatives InsP7
and InsP8, and the nucleotides ATP and GTP from cell or tissue
extracts. Using this approach, InsP6, InsP7 and
InsP8 were visualized in Dictyostelium extracts
and a variety of mammalian cell lines and tissues, and the effects of metabolic
perturbation on these were explored. TiO2 bead purification also
enabled us to quantify InsP6 in human plasma and urine, which led to
two distinct but related observations. Firstly, there is an active
InsP6 phosphatase in human plasma, and secondly, InsP6
is undetectable in either fluid. These observations seriously question reports
that InsP6 is present in human biofluids and the advisability of
using InsP6 as a dietary supplement. 相似文献
17.
Ectopic expression of a soybean phytase in developing seeds of <Emphasis Type="Italic">Glycine max</Emphasis> to improve phosphorus availability 总被引:3,自引:0,他引:3
A transgenic approach was used to alter soybean seed phytate content by expressing a soybean phytase gene (GmPhy) during seed development to degrade accumulating phytic acid (IP6). An expression vector containing the soybean phytase cDNA controlled by the seed-specific -conglycinin promoter (-subunit) was used to transform embryogenic soybean cultures. Plants from four independent transgenic lines were analyzed for transgene integration and seed IP6 levels. The reduction in IP6 levels in transgenic seeds compared to control Jack soybeans ranged from 12.6 to 24.8 as determined by HPLC. A low copy transformant was propagated to the T4 generation and examined in more detail for phytase expression and enzyme activity during seed development. Expression of phytase mRNA and phytase activity increased during seed development, consistent with the use of an embryo-specific promoter. Ectopic phytase expression during seed development offers potential as an effective strategy for reducing phytate content in soybean seed. 相似文献
18.
19.
Ragon M Aumelas A Chemardin P Galvez S Moulin G Boze H 《Applied microbiology and biotechnology》2008,78(1):47-53
Debaryomyces castellii phytase was purified to homogeneity in a single step by hydrophobic interaction chromatography. Its molecular mass is 74 kDa
with 28.8% glycosylation. Its activity was optimal at 60°C and pH 4.0. The K
m value for sodium phytate was 0.532 mM. The enzyme exhibited a low specificity and hydrolyzed many phosphate esters. The phytase
fully hydrolyzed myo-inositol hexakisphosphate (or phytic acid, Ins P6) to inositol and inorganic phosphate. The sequence of Ins P6 hydrolysis was determined by combining results from high-performance ionic chromatography and nuclear magnetic resonance.
D. castellii phytase is a 3-phytase that sequentially releases phosphate groups through Ins (1,2,4,5,6) P5, Ins (1,2,5,6) P4, Ins (1,2,6) P3, Ins (1,2) P2, Ins (1 or 2) P1, and inositol (notation 3/4/5/6/1 or 2). 相似文献
20.
磷是植物生长发育所必需的大量营养元素。在种子发育过程中,植酸是磷的贮存库,对维持植物体内磷平衡有重要的作用。在种子萌发过程中,植酸酶分解植酸盐,释放磷、矿质营养和肌醇供幼苗生长。本文综述了近年来植物(作物)种子中植酸的生物合成途径、种子植酸含量的遗传、低植酸作物的育种等研究进展。首先,植酸生物合成途径中最初的反应底物为葡萄糖-6-磷酸,形成肌醇后,以肌醇为底物合成植酸共有两条路径:依赖脂类与不依赖脂类,目前,已分离鉴定若干植酸合成所需的关键酶及其编码基因,包括肌醇-3-磷酸合成酶、肌醇激酶、肌醇多磷酸盐激酶,以及参与植酸运输的ATP结合盒转运子。其次,利用作图群体及关联分析群体,分别在水稻(Oryza sativa L.)、白菜(Brassica rapa L.)、菜豆(Phaseolus vulgaris L.)等植物中鉴定出多个与种子植酸磷含量相关的遗传位点。第三,筛选获得有价值的低植酸突变体是培育低植酸作物的主要途径。当把低植酸作为育种目标时,可能会忽略种子植酸含量的降低给植物带来的不利影响,如何消除低植酸造成的不利影响,成为科学家们亟需解决的问题。 相似文献