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Silva VM, Putti FF, White PJ, Reis ARD. Phytic acid accumulation in plants: Biosynthesis pathway regulation and role in human diet. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2021; 164:132-146. [PMID: 33991859 DOI: 10.1016/j.plaphy.2021.04.035] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 04/28/2021] [Indexed: 06/12/2023]
Abstract
Phytate or phytic acid (PA), is a phosphorus (P) containing compound generated by the stepwise phosphorylation of myo-inositol. It forms complexes with some nutrient cations, such as Ca, Fe and Zn, compromising their absorption and thus acting as an anti-nutrient in the digestive tract of humans and monogastric animals. Conversely, PAs are an important form of P storage in seeds, making up to 90% of total seed P. Phytates also play a role in germination and are related to the synthesis of abscisic acid and gibberellins, the hormones involved in seed germination. Decreasing PA content in plants is desirable for human dietary. Therefore, low phytic acid (lpa) mutants might present some negative pleiotropic effects, which could impair germination and seed viability. In the present study, we review current knowledge of the genes encoding enzymes that function in different stages of PA synthesis, from the first phosphorylation of myo-inositol to PA transport into seed reserve tissues, and the application of this knowledge to reduce PA concentrations in edible crops to enhance human diet. Finally, phylogenetic data for PA concentrations in different plant families and distributed across several countries under different environmental conditions are compiled. The results of the present study help explain the importance of PA accumulation in different plant families and the distribution of PA accumulation in different foods.
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Affiliation(s)
| | | | - Philip J White
- The James Hutton Institute, Invergowrie, Dundee, DD2 5DA, UK
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Sashidhar N, Harloff HJ, Jung C. Identification of phytic acid mutants in oilseed rape (Brassica napus) by large-scale screening of mutant populations through amplicon sequencing. THE NEW PHYTOLOGIST 2020; 225:2022-2034. [PMID: 31651044 DOI: 10.1111/nph.16281] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 10/11/2019] [Indexed: 05/18/2023]
Abstract
Brassica napus (oilseed rape) is an important oil crop in temperate regions, which originated from hybridization of Brassica oleracea and Brassica rapa. Owing to its polyploidy, the functional study of single genes is cumbersome. Phytic acid is considered as an antinutritive compound, and we aimed to knock out the underlying synthesis and transporter genes to identify low phytic acid mutants. We implemented a high-throughput next-generation sequencing screening protocol for an ethylmethane sulfonate population of 7680 plants in six gene families (BnMIPS, BnMIK, Bn2-PGK, BnIPK1, BnIPK2, and BnMRP5) with two paralogues for each gene. A total of 1487 mutations were revealed, and the vast majority (96%) were confirmed by Sanger sequencing. Furthermore, the characterization of double mutants of Bn.2-PGK2 showed a significant reduction of phytic acid contents. We propose to use three-dimensional pooling combined with amplicon stacking and next-generation sequencing to identify mutations in polyploid oilseed rape in a fast and cost-effective manner for complex metabolic pathways. Furthermore, the mutants identified in Bn2-PGK2 might be a very valuable resource for industrial production of oilseed rape protein for human consumption.
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Affiliation(s)
- Niharika Sashidhar
- Plant Breeding Institute, Christian-Albrechts-University of Kiel, Olshausenstr. 40, D-24118, Kiel, Germany
| | - Hans-Joachim Harloff
- Plant Breeding Institute, Christian-Albrechts-University of Kiel, Olshausenstr. 40, D-24118, Kiel, Germany
| | - Christian Jung
- Plant Breeding Institute, Christian-Albrechts-University of Kiel, Olshausenstr. 40, D-24118, Kiel, Germany
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3
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Freed C, Adepoju O, Gillaspy G. Can Inositol Pyrophosphates Inform Strategies for Developing Low Phytate Crops? PLANTS (BASEL, SWITZERLAND) 2020; 9:E115. [PMID: 31963418 PMCID: PMC7020182 DOI: 10.3390/plants9010115] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Revised: 01/14/2020] [Accepted: 01/15/2020] [Indexed: 01/01/2023]
Abstract
Inositol pyrophosphates (PP-InsPs) are an emerging class of "high-energy" intracellular signaling molecules, containing one or two diphosphate groups attached to an inositol ring, that are connected with phosphate sensing, jasmonate signaling, and inositol hexakisphosphate (InsP6) storage in plants. While information regarding this new class of signaling molecules in plants is scarce, the enzymes responsible for their synthesis have recently been elucidated. This review focuses on InsP6 synthesis and its conversion into PP-InsPs, containing seven and eight phosphate groups (InsP7 and InsP8). These steps involve two types of enzymes: the ITPKs that phosphorylate InsP6 to InsP7, and the PPIP5Ks that phosphorylate InsP7 to InsP8. This review also considers the potential roles of PP-InsPs in plant hormone and inorganic phosphate (Pi) signaling, along with an emerging role in bioenergetic homeostasis. PP-InsP synthesis and signaling are important for plant breeders to consider when developing strategies that reduce InsP6 in plants, as this will likely also reduce PP-InsPs. Thus, this review is primarily intended to bridge the gap between the basic science aspects of PP-InsP synthesis/signaling and breeding/engineering strategies to fortify foods by reducing InsP6.
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Affiliation(s)
| | | | - Glenda Gillaspy
- Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061, USA (O.A.)
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Kishor DS, Lee C, Lee D, Venkatesh J, Seo J, Chin JH, Jin Z, Hong SK, Ham JK, Koh HJ. Novel allelic variant of Lpa1 gene associated with a significant reduction in seed phytic acid content in rice (Oryza sativa L.). PLoS One 2019; 14:e0209636. [PMID: 30870429 PMCID: PMC6417671 DOI: 10.1371/journal.pone.0209636] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 02/19/2019] [Indexed: 01/26/2023] Open
Abstract
In plants, myo-inositol-1,2,3,4,5,6-hexakisphosphate (InsP6), also known as phytic acid (PA), is a major component of organic phosphorus (P), and accounts for up to 85% of the total P in seeds. In rice (Oryza sativa L.), PA mainly accumulates in rice bran, and chelates mineral cations, resulting in mineral deficiencies among brown rice consumers. Therefore, considerable efforts have been focused on the development of low PA (LPA) rice cultivars. In this study, we performed genetic and molecular analyses of OsLpa1, a major PA biosynthesis gene, in Sanggol, a low PA mutant variety developed via chemical mutagenesis of Ilpum rice cultivar. Genetic segregation and sequencing analyses revealed that a recessive allele, lpa1-3, at the OsLpa1 locus (Os02g0819400) was responsible for a significant reduction in seed PA content in Sanggol. The lpa1-3 gene harboured a point mutation (C623T) in the fourth exon of the predicted coding region, resulting in threonine (Thr) to isoleucine (Ile) amino acidsubstitution at position 208 (Thr208Ile). Three-dimensional analysis of Lpa1 protein structure indicated that myo-inositol 3-monophosphate [Ins(3)P1] could bind to the active site of Lpa1, with ATP as a cofactor for catalysis. Furthermore, the presence of Thr208 in the loop adjacent to the entry site of the binding pocket suggests that Thr208Ile substitution is involved in regulating enzyme activity via phosphorylation. Therefore, we propose that Thr208Ile substitution in lpa1-3 reduces Lpa1 enzyme activity in Sanggol, resulting in reduced PA biosynthesis.
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Affiliation(s)
- D. S. Kishor
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute of Agriculture and Life Science, Seoul National University, Seoul, Republic of Korea
| | - Choonseok Lee
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute of Agriculture and Life Science, Seoul National University, Seoul, Republic of Korea
| | - Dongryung Lee
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute of Agriculture and Life Science, Seoul National University, Seoul, Republic of Korea
| | - Jelli Venkatesh
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute of Agriculture and Life Science, Seoul National University, Seoul, Republic of Korea
| | - Jeonghwan Seo
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute of Agriculture and Life Science, Seoul National University, Seoul, Republic of Korea
| | - Joong Hyoun Chin
- Graduate School of Integrated Bioindustry, Sejong University, Seoul, Republic of Korea
| | - Zhuo Jin
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute of Agriculture and Life Science, Seoul National University, Seoul, Republic of Korea
| | - Soon-Kwan Hong
- Division of Biotechnology, Kangwon National University, Chuncheon, Gangwon-do, Republic of Korea
| | - Jin-Kwan Ham
- Gangwon provincial Agricultural Research & Extension Services, Chuncheon, Gangwon-do, Republic of Korea
| | - Hee Jong Koh
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute of Agriculture and Life Science, Seoul National University, Seoul, Republic of Korea
- * E-mail:
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Cominelli E, Orozco-Arroyo G, Sparvoli F. Phytic Acid Biosynthesis and Transport in Phaseolus vulgaris: Exploitation of New Genomic Resources. ACTA ACUST UNITED AC 2017. [DOI: 10.1007/978-3-319-63526-2_8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
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Zhang S, Yang W, Zhao Q, Zhou X, Fan Y, Chen R. Rapid Method for Simultaneous Determination of Inositol Phosphates by IPC-ESI–MS/MS and Its Application in Nutrition and Genetic Research. Chromatographia 2017. [DOI: 10.1007/s10337-017-3238-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Zhang S, Yang W, Zhao Q, Zhou X, Jiang L, Ma S, Liu X, Li Y, Zhang C, Fan Y, Chen R. Analysis of weighted co-regulatory networks in maize provides insights into new genes and regulatory mechanisms related to inositol phosphate metabolism. BMC Genomics 2016; 17:129. [PMID: 26911482 PMCID: PMC4765147 DOI: 10.1186/s12864-016-2476-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 02/16/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND D-myo-inositol phosphates (IPs) are a series of phosphate esters. Myo-inositol hexakisphosphate (phytic acid, IP6) is the most abundant IP and has negative effects on animal and human nutrition. IPs play important roles in plant development, stress responses, and signal transduction. However, the metabolic pathways and possible regulatory mechanisms of IPs in maize are unclear. In this study, the B73 (high in phytic acid) and Qi319 (low in phytic acid) lines were selected for RNA-Seq analysis from 427 inbred lines based on a screening of IP levels. By integrating the metabolite data with the RNA-Seq data at three different kernel developmental stages (12, 21 and 30 days after pollination), co-regulatory networks were constructed to explore IP metabolism and its interactions with other pathways. RESULTS Differentially expressed gene analyses showed that the expression of MIPS and ITPK was related to differences in IP metabolism in Qi319 and B73. Moreover, WRKY and ethylene-responsive transcription factors (TFs) were common among the differentially expressed TFs, and are likely to be involved in the regulation of IP metabolism. Six co-regulatory networks were constructed, and three were chosen for further analysis. Based on network analyses, we proposed that the GA pathway interacts with the IP pathway through the ubiquitination pathway, and that Ca(2+) signaling functions as a bridge between IPs and other pathways. IP pools were found to be transported by specific ATP-binding cassette (ABC) transporters. Finally, three candidate genes (Mf3, DH2 and CB5) were identified and validated using Arabidopsis lines with mutations in orthologous genes or RNA interference (RNAi)-transgenic maize lines. Some mutant or RNAi lines exhibited seeds with a low-phytic-acid phenotype, indicating perturbation of IP metabolism. Mf3 likely encodes an enzyme involved in IP synthesis, DH2 encodes a transporter responsible for IP transport across organs and CB5 encodes a transporter involved in IP co-transport into vesicles. CONCLUSIONS This study provides new insights into IP metabolism and regulation, and facilitates our development of a better understanding of the functions of IPs and how they interact with other pathways involved in plant development and stress responses. Three new genes were discovered and preliminarily validated, thereby increasing our knowledge of IP metabolism.
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Affiliation(s)
- Shaojun Zhang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, 100081, Beijing, China.
- National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI), 100081, Beijing, China.
| | - Wenzhu Yang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, 100081, Beijing, China.
- National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI), 100081, Beijing, China.
| | - Qianqian Zhao
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, 100081, Beijing, China.
- National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI), 100081, Beijing, China.
| | - Xiaojin Zhou
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, 100081, Beijing, China.
- National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI), 100081, Beijing, China.
| | - Ling Jiang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, 100081, Beijing, China.
- National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI), 100081, Beijing, China.
| | - Shuai Ma
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, 100081, Beijing, China.
| | - Xiaoqing Liu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, 100081, Beijing, China.
- National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI), 100081, Beijing, China.
| | - Ye Li
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, 100081, Beijing, China.
- National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI), 100081, Beijing, China.
| | - Chunyi Zhang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, 100081, Beijing, China.
- National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI), 100081, Beijing, China.
| | - Yunliu Fan
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, 100081, Beijing, China.
- National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI), 100081, Beijing, China.
| | - Rumei Chen
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, 100081, Beijing, China.
- National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI), 100081, Beijing, China.
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Sparvoli F, Cominelli E. Seed Biofortification and Phytic Acid Reduction: A Conflict of Interest for the Plant? PLANTS 2015; 4:728-55. [PMID: 27135349 PMCID: PMC4844270 DOI: 10.3390/plants4040728] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 11/13/2015] [Indexed: 02/03/2023]
Abstract
Most of the phosphorus in seeds is accumulated in the form of phytic acid (myo-inositol-1,2,3,4,5,6-hexakisphosphate, InsP6). This molecule is a strong chelator of cations important for nutrition, such as iron, zinc, magnesium, and calcium. For this reason, InsP6 is considered an antinutritional factor. In recent years, efforts to biofortify seeds through the generation of low phytic acid (lpa) mutants have been noteworthy. Moreover, genes involved in the biosynthesis and accumulation of this molecule have been isolated and characterized in different species. Beyond its role in phosphorus storage, phytic acid is a very important signaling molecule involved in different regulatory processes during plant development and responses to different stimuli. Consequently, many lpa mutants show different negative pleitotropic effects. The strength of these pleiotropic effects depends on the specific mutated gene, possible functional redundancy, the nature of the mutation, and the spatio-temporal expression of the gene. Breeding programs or transgenic approaches aimed at development of new lpa mutants must take into consideration these different aspects in order to maximize the utility of these mutants.
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Affiliation(s)
- Francesca Sparvoli
- Institute of Agricultural Biology and Biotechnology, CNR, Via Bassini 15, 20133 Milan, Italy.
| | - Eleonora Cominelli
- Institute of Agricultural Biology and Biotechnology, CNR, Via Bassini 15, 20133 Milan, Italy.
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9
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Pignatta D, Erdmann RM, Scheer E, Picard CL, Bell GW, Gehring M. Natural epigenetic polymorphisms lead to intraspecific variation in Arabidopsis gene imprinting. eLife 2014; 3:e03198. [PMID: 24994762 PMCID: PMC4115658 DOI: 10.7554/elife.03198] [Citation(s) in RCA: 143] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Imprinted gene expression occurs during seed development in plants and is associated with differential DNA methylation of parental alleles, particularly at proximal transposable elements (TEs). Imprinting variability could contribute to observed parent-of-origin effects on seed development. We investigated intraspecific variation in imprinting, coupled with analysis of DNA methylation and small RNAs, among three Arabidopsis strains with diverse seed phenotypes. The majority of imprinted genes were parentally biased in the same manner among all strains. However, we identified several examples of allele-specific imprinting correlated with intraspecific epigenetic variation at a TE. We successfully predicted imprinting in additional strains based on methylation variability. We conclude that there is standing variation in imprinting even in recently diverged genotypes due to intraspecific epiallelic variation. Our data demonstrate that epiallelic variation and genomic imprinting intersect to produce novel gene expression patterns in seeds. DOI:http://dx.doi.org/10.7554/eLife.03198.001 When animals or plants reproduce sexually, the DNA in a sperm or pollen is combined with that in an egg cell to generate an offspring that inherits two copies of each gene, one from each parent. For a very small number of genes, the copy from one of the parents is consistently turned off. This process—called imprinting—means that the same gene can have different effects depending on if it is inherited from the mother or the father. In plants, imprinting is vital for the production of seeds and typically occurs in the endosperm: the tissue within a seed that provides nourishment to the plant embryo. One way genes can be imprinted is by adding small chemical marks—called methyl groups—on to the DNA that makes up the gene or nearby sequences. These marks can either switch on, or switch off, the expression of the gene. DNA methylation also immobilises stretches of DNA called transposable elements, stopping them from moving from one location to another in the genome. These stretches of DNA are identified and targeted for methylation by small molecules of RNA that match their DNA sequences. Genes that are imprinted in the endosperm of the model plant Arabidopsis are often associated with transposable elements, which can be methylated differently in the naturally occurring varieties, or strains, of Arabidopsis. However it is unclear how many genes are differently imprinted between these different strains. Pignatta et al. looked for differences in gene imprinting, DNA methylation and small RNA production in the seeds, embryos and endosperm tissue from three strains of Arabidopsis. They also examined seeds from crosses between these three strains. While most genes had the same imprinting pattern in all strains and crosses examined, 12 genes were imprinted differently depending on whether they were inherited from the male or female of a given strain. For example, for some genes the copy inherited from the male parent is always turned off, unless it is inherited via the pollen of one specific Arabidopsis strain. Half of this variation could be explained by a transposable element near to each gene that was methylated differently among the strains. By comparing the differentially methylated regions in the genomes of 140 Arabidopsis strains, Pignatta et al. found that differences in methylation may affect 11% of imprinted genes—and went on to confirm variable imprinting in some Arabidopsis strains based on the presence or absence of DNA methylation. Future work is needed to understand how variation in gene imprinting might affect the traits of hybrid seeds, and how it might affect the evolution of new traits in hybrid plants. DOI:http://dx.doi.org/10.7554/eLife.03198.002
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Affiliation(s)
- Daniela Pignatta
- Whitehead Institute for Biomedical Research, Cambridge, United States
| | - Robert M Erdmann
- Whitehead Institute for Biomedical Research, Cambridge, United States.,Department of Biology, Massachusetts Institute of Technology, Cambridge, United States
| | - Elias Scheer
- Whitehead Institute for Biomedical Research, Cambridge, United States
| | - Colette L Picard
- Whitehead Institute for Biomedical Research, Cambridge, United States.,Computational and Systems Biology Graduate Program, Massachusetts Institute of Technology, Cambridge, United States
| | - George W Bell
- Whitehead Institute for Biomedical Research, Cambridge, United States
| | - Mary Gehring
- Whitehead Institute for Biomedical Research, Cambridge, United States.,Department of Biology, Massachusetts Institute of Technology, Cambridge, United States.,Computational and Systems Biology Graduate Program, Massachusetts Institute of Technology, Cambridge, United States
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Yuan FJ, Zhu DH, Tan YY, Dong DK, Fu XJ, Zhu SL, Li BQ, Shu QY. Identification and characterization of the soybean IPK1 ortholog of a low phytic acid mutant reveals an exon-excluding splice-site mutation. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2012; 125:1413-23. [PMID: 22733447 DOI: 10.1007/s00122-012-1922-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2012] [Accepted: 06/11/2012] [Indexed: 05/07/2023]
Abstract
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.
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Affiliation(s)
- Feng-Jie Yuan
- Institute of Crop Science and Nuclear Technology Utilization, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, China
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11
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Identification of genes necessary for wild-type levels of seed phytic acid in Arabidopsis thaliana using a reverse genetics approach. Mol Genet Genomics 2011. [PMID: 21698461 DOI: 10.1007/s00438‐011‐0631‐2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/29/2022]
Abstract
The majority of phosphorus (P) in seeds is found in phytic acid (InsP(6)) which accumulates as the mixed salt phytate. InsP(6) is generally considered to be an anti-nutrient and the development of low phytic acid (lpa) seed crops is of significant interest. We have employed a reverse genetics approach to examine the impact of disrupting genes involved in inositol phosphate metabolism on Arabidopsis seed InsP(6) levels. Our analysis revealed that knockout mutations in three genes (AtITPK1, AtITPK4, and AtMIK/At5g58730) reduced seed InsP(6) in addition to knockouts of four previously reported genes (AtIPK1, AtIPK2β, AtMRP5, and At5g60760). Seeds of these lpa mutants also exhibited reduced germination under various stress conditions. The greatest reduction in InsP(6) (>70%) was observed in atmrp5 seeds which were also among the least sensitive to the stresses examined. Expression analysis of the lpa genes revealed three distinct patterns in developing siliques consistent with their presumed roles. Disruption of each lpa gene resulted in changes in the expression in some of the other lpa genes indicating that transcription of lpa genes is modulated by other constituents of InsP(6) metabolism. While all the lpa genes represent possible targets for genetic engineering of low phytate seed crops, mutations in AtMRP5, AtMIK, and At5g60760 may be most successful for conventional approaches such as mutation breeding.
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12
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Kim SI, Tai TH. Identification of genes necessary for wild-type levels of seed phytic acid in Arabidopsis thaliana using a reverse genetics approach. Mol Genet Genomics 2011; 286:119-33. [PMID: 21698461 DOI: 10.1007/s00438-011-0631-2] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2010] [Accepted: 05/27/2011] [Indexed: 11/26/2022]
Abstract
The majority of phosphorus (P) in seeds is found in phytic acid (InsP(6)) which accumulates as the mixed salt phytate. InsP(6) is generally considered to be an anti-nutrient and the development of low phytic acid (lpa) seed crops is of significant interest. We have employed a reverse genetics approach to examine the impact of disrupting genes involved in inositol phosphate metabolism on Arabidopsis seed InsP(6) levels. Our analysis revealed that knockout mutations in three genes (AtITPK1, AtITPK4, and AtMIK/At5g58730) reduced seed InsP(6) in addition to knockouts of four previously reported genes (AtIPK1, AtIPK2β, AtMRP5, and At5g60760). Seeds of these lpa mutants also exhibited reduced germination under various stress conditions. The greatest reduction in InsP(6) (>70%) was observed in atmrp5 seeds which were also among the least sensitive to the stresses examined. Expression analysis of the lpa genes revealed three distinct patterns in developing siliques consistent with their presumed roles. Disruption of each lpa gene resulted in changes in the expression in some of the other lpa genes indicating that transcription of lpa genes is modulated by other constituents of InsP(6) metabolism. While all the lpa genes represent possible targets for genetic engineering of low phytate seed crops, mutations in AtMRP5, AtMIK, and At5g60760 may be most successful for conventional approaches such as mutation breeding.
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Affiliation(s)
- Sang-Ic Kim
- Crops Pathology and Genetics Research Unit, U.S. Department of Agriculture, Agricultural Research Service, Department of Plant Sciences - MS 1, University of California, Davis, CA 95616, USA
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