1
|
Han J, Guo Z, Wang M, Liu S, Hao Z, Zhang D, Yong H, Weng J, Zhou Z, Li M, Li X. Using the dominant mutation gene Ae1-5180 ( amylose extender) to develop high-amylose maize. MOLECULAR BREEDING : NEW STRATEGIES IN PLANT IMPROVEMENT 2022; 42:57. [PMID: 37313014 PMCID: PMC10248602 DOI: 10.1007/s11032-022-01323-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 08/18/2022] [Indexed: 06/15/2023]
Abstract
Maize amylose is a type of high value-added starch used for medical, food, and chemical applications. Mutations in the starch branching enzyme (SBEIIb), with recessive ae (amylose extender) and dominant Ae1-5180 alleles, are the primary way to improve maize endosperm amylose content (AC). However, studies on Ae1-5180 mutation are scarce, and its roles in starch synthesis and breeding potential are unclear. We found that the AC of the Ae1-5180 mutant was 47.23%, and its kernels were tarnished and glassy and are easily distinguished from those of the wild type (WT), indicating that the dominant mutant has the classical characteristics of the ae mutant. Starch granules of Ae1-5180 became smaller, and higher in amount with irregular shape. The degree of amylopectin polymerisation changed to induce an increase in starch thermal stability. Compared with WT, the activity of granule-bound starch synthase and starch synthase was higher in early stages and lower in later stages, and other starch synthesis enzymes decreased during kernel development in the Ae1-5180 mutant. We successfully developed a marker (mu406) for the assisted selection of 17 Ae1-5180 near isogenic lines (NILs) according to the position of insertion of the Mu1 transposon in the SBEIIb promoter of Ae1-5180. JH214/Ae1-5180, CANS-1/Ae1-5180, CA240/Ae1-5180, and Z1698/Ae1-5180 have high breeding application potential with their higher AC (> 40%) and their 100-kernel weight decreased to < 25% compared to respective recurrent parents. Therefore, using the dominant Ae1-5180 mutant as a donor can detect the kernel phenotype and AC of Ae1-5180-NILs in advance, thereby accelerating the high-amylose breeding process. Supplementary Information The online version contains supplementary material available at 10.1007/s11032-022-01323-7.
Collapse
Affiliation(s)
- Jienan Han
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, No. 12 Zhongguancun South Street, Haidian District, Beijing, 100081 China
| | - Zenghui Guo
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, No. 12 Zhongguancun South Street, Haidian District, Beijing, 100081 China
- College of Agriculture, Heilongjiang Bayi Agricultural University, Daqing, 163319 Heilongjiang China
| | - Meijuan Wang
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, No. 12 Zhongguancun South Street, Haidian District, Beijing, 100081 China
| | - Shiyuan Liu
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, No. 12 Zhongguancun South Street, Haidian District, Beijing, 100081 China
- College of Agriculture, Heilongjiang Bayi Agricultural University, Daqing, 163319 Heilongjiang China
| | - Zhuanfang Hao
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, No. 12 Zhongguancun South Street, Haidian District, Beijing, 100081 China
| | - Degui Zhang
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, No. 12 Zhongguancun South Street, Haidian District, Beijing, 100081 China
| | - Hongjun Yong
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, No. 12 Zhongguancun South Street, Haidian District, Beijing, 100081 China
| | - Jianfeng Weng
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, No. 12 Zhongguancun South Street, Haidian District, Beijing, 100081 China
| | - Zhiqiang Zhou
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, No. 12 Zhongguancun South Street, Haidian District, Beijing, 100081 China
| | - Mingshun Li
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, No. 12 Zhongguancun South Street, Haidian District, Beijing, 100081 China
| | - Xinhai Li
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, No. 12 Zhongguancun South Street, Haidian District, Beijing, 100081 China
| |
Collapse
|
2
|
Sapkota S, Boatwright JL, Jordan K, Boyles R, Kresovich S. Identification of Novel Genomic Associations and Gene Candidates for Grain Starch Content in Sorghum. Genes (Basel) 2020; 11:E1448. [PMID: 33276449 PMCID: PMC7760202 DOI: 10.3390/genes11121448] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 11/10/2020] [Accepted: 11/27/2020] [Indexed: 01/15/2023] Open
Abstract
Starch accumulated in the endosperm of cereal grains as reserve energy for germination serves as a staple in human and animal nutrition. Unraveling genetic control for starch metabolism is important for breeding grains with high starch content. In this study, we used a sorghum association panel with 389 individuals and 141,557 single nucleotide polymorphisms (SNPs) to fit linear mixed models (LMM) for identifying genomic regions and potential candidate genes associated with starch content. Three associated genomic regions, one in chromosome (chr) 1 and two novel associations in chr-8, were identified using combination of LMM and Bayesian sparse LMM. All significant SNPs were located within protein coding genes, with SNPs ∼ 52 Mb of chr-8 encoding a Casperian strip membrane protein (CASP)-like protein (Sobic.008G111500) and a heat shock protein (HSP) 90 (Sobic.008G111600) that were highly expressed in reproductive tissues including within the embryo and endosperm. The HSP90 is a potential hub gene with gene network of 75 high-confidence first interactors that is enriched for five biochemical pathways including protein processing. The first interactors of HSP90 also showed high transcript abundance in reproductive tissues. The candidates of this study are likely involved in intricate metabolic pathways and represent candidate gene targets for source-sink activities and drought and heat stress tolerance during grain filling.
Collapse
Affiliation(s)
- Sirjan Sapkota
- Advanced Plant Technology Program, Clemson University, Clemson, SC 29634, USA; (J.L.B.); (K.J.); (S.K.)
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC 29634, USA;
| | - J. Lucas Boatwright
- Advanced Plant Technology Program, Clemson University, Clemson, SC 29634, USA; (J.L.B.); (K.J.); (S.K.)
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC 29634, USA;
| | - Kathleen Jordan
- Advanced Plant Technology Program, Clemson University, Clemson, SC 29634, USA; (J.L.B.); (K.J.); (S.K.)
| | - Richard Boyles
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC 29634, USA;
- Pee Dee Research and Education Center, Clemson University, Florence, SC 29506, USA
| | - Stephen Kresovich
- Advanced Plant Technology Program, Clemson University, Clemson, SC 29634, USA; (J.L.B.); (K.J.); (S.K.)
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC 29634, USA;
| |
Collapse
|
3
|
Luo J, Butardo VM, Yang Q, Konik-Rose C, Colgrave ML, Millar A, Jobling SA, Li Z. The impact of the indica rice SSIIa allele on the apparent high amylose starch from rice grain with downregulated japonica SBEIIb. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2020; 133:2961-2974. [PMID: 32651668 DOI: 10.1007/s00122-020-03649-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 07/01/2020] [Indexed: 05/24/2023]
Abstract
Catalytically active indica SSIIa allele in high amylose rice with down-regulated japonica SBEIIb can increase starch content and modify the starch structure and properties without changing its amylose content. Rice (Oryza sativa) genotypes with inactive starch synthase IIa (SSIIa) with recessive variants of starch branching enzyme IIb (SBEIIb) exhibit a range of alterations in grain phenotype, starch granule morphology, starch granule bound proteins, starch structure, and functional properties. However, the interactions between the two enzymes have not been thoroughly investigated yet. We analysed recombinant rice lines having down-regulated SBEIIb expression (SBEIIbDR) with either indica or japonica type SSIIa (SSIIaind or SSIIajap). In SBEIIbDR rice starch granules, the increased abundance of two protein bands (SSI and SSIIa) was found with eight additional protein bands not generally associated with starch granules. The amount of SSIIa was higher in SSIIaindSBEIIbDR than SSIIajapSBEIIbDR, which indicated that indica type SSIIa, possibly in the monomer form, was extensively involved in starch biosynthesis in the SBEIIbDR endosperm. Furthermore, SSIIaindSBEIIbDR grains had higher total starch content and higher starch swelling power than SSIIajapSBEIIbDR lines, but the amylopectin gelatinization temperatures and enthalpy and the apparent amylose content remained similar. In summary, this work suggests that SSIIaind can partly compensate for the alteration of starch synthesis resulting from the SBEIIb down-regulation in japonica background without reducing its amylose content. The study provides insight into the starch structural and textural improvements of high amylose starch.
Collapse
Affiliation(s)
- Jixun Luo
- CSIRO Agriculture and Food, GPO Box 1700, Canberra, ACT, 2601, Australia
- Research School of Biology, Australian National University, Canberra, ACT, 0200, Australia
| | - Vito M Butardo
- CSIRO Agriculture and Food, GPO Box 1700, Canberra, ACT, 2601, Australia
- Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, VIC, 3122, Australia
| | - Qiang Yang
- CSIRO Agriculture and Food, GPO Box 1700, Canberra, ACT, 2601, Australia
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China
- Triticeae Research Institute, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China
| | | | | | - Anthony Millar
- Research School of Biology, Australian National University, Canberra, ACT, 0200, Australia
| | - Stephen A Jobling
- CSIRO Agriculture and Food, GPO Box 1700, Canberra, ACT, 2601, Australia
| | - Zhongyi Li
- CSIRO Agriculture and Food, GPO Box 1700, Canberra, ACT, 2601, Australia.
| |
Collapse
|
4
|
Niu L, Ding H, Zhang J, Wang W. Proteomic Analysis of Starch Biosynthesis in Maize Seeds. STARCH-STARKE 2019. [DOI: 10.1002/star.201800294] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Liangjie Niu
- State Key Laboratory of Wheat & Maize Crop ScienceCollege of Life SciencesHenan Agricultural UniversityZhengzhouP. R. China
| | - Huiying Ding
- State Key Laboratory of Wheat & Maize Crop ScienceCollege of Life SciencesHenan Agricultural UniversityZhengzhouP. R. China
| | - Jinghua Zhang
- State Key Laboratory of Wheat & Maize Crop ScienceCollege of Life SciencesHenan Agricultural UniversityZhengzhouP. R. China
| | - Wei Wang
- State Key Laboratory of Wheat & Maize Crop ScienceCollege of Life SciencesHenan Agricultural UniversityZhengzhouP. R. China
| |
Collapse
|
5
|
Xing S, Meng X, Zhou L, Mujahid H, Zhao C, Zhang Y, Wang C, Peng Z. Proteome Profile of Starch Granules Purified from Rice (Oryza sativa) Endosperm. PLoS One 2016; 11:e0168467. [PMID: 27992503 PMCID: PMC5167393 DOI: 10.1371/journal.pone.0168467] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Accepted: 12/01/2016] [Indexed: 01/16/2023] Open
Abstract
Starch is the most important food energy source in cereals. Many of the known enzymes involved in starch biosynthesis are partially or entirely granule-associated in the endosperm. Studying the proteome of rice starch granules is critical for us to further understand the mechanisms underlying starch biosynthesis and packaging of starch granules in rice amyloplasts, consequently for the improvement of rice grain quality. In this article, we developed a protocol to purify starch granules from mature rice endosperm and verified the quality of purified starch granules by microscopy observations, I2 staining, and Western blot analyses. In addition, we found the phenol extraction method was superior to Tris-HCl buffer extraction method with respect to the efficiency in recovery of starch granule associated proteins. LC-MS/MS analysis showed identification of already known starch granule associated proteins with high confidence. Several proteins reported to be involved in starch synthesis in prior genetic studies in plants were also shown to be enriched with starch granules, either directly or indirectly, in our studies. In addition, our results suggested that a few additional candidate proteins may also be involved in starch synthesis. Furthermore, our results indicated that some starch synthesis pathway proteins are subject to protein acetylation modification. GO analysis and KEGG pathway enrichment analysis showed that the identified proteins were mainly located in plastids and involved in carbohydrate metabolism. This study substantially advances the understanding of the starch granule associated proteome in rice and post translational regulation of some starch granule associated proteins.
Collapse
Affiliation(s)
- Shihai Xing
- Institute of Food Crops, Jiangsu Academy of Agricultural Sciences, Jiangsu High Quality Rice Research and Development Center, Nanjing Branch of China National Center for Rice Improvement, Nanjing, Jiangsu, China
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Starkville, Mississippi, United States of America
| | - Xiaoxi Meng
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Starkville, Mississippi, United States of America
| | - Lihui Zhou
- Institute of Food Crops, Jiangsu Academy of Agricultural Sciences, Jiangsu High Quality Rice Research and Development Center, Nanjing Branch of China National Center for Rice Improvement, Nanjing, Jiangsu, China
| | - Hana Mujahid
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Starkville, Mississippi, United States of America
| | - Chunfang Zhao
- Institute of Food Crops, Jiangsu Academy of Agricultural Sciences, Jiangsu High Quality Rice Research and Development Center, Nanjing Branch of China National Center for Rice Improvement, Nanjing, Jiangsu, China
| | - Yadong Zhang
- Institute of Food Crops, Jiangsu Academy of Agricultural Sciences, Jiangsu High Quality Rice Research and Development Center, Nanjing Branch of China National Center for Rice Improvement, Nanjing, Jiangsu, China
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Starkville, Mississippi, United States of America
| | - Cailin Wang
- Institute of Food Crops, Jiangsu Academy of Agricultural Sciences, Jiangsu High Quality Rice Research and Development Center, Nanjing Branch of China National Center for Rice Improvement, Nanjing, Jiangsu, China
| | - Zhaohua Peng
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Starkville, Mississippi, United States of America
| |
Collapse
|
6
|
Kawagoe Y. The Characteristic Polyhedral, Sharp-edged Shape of Compound-type Starch Granules in Rice Endosperm is Achieved via the Septum-like Structure of the Amyloplast. J Appl Glycosci (1999) 2013. [DOI: 10.5458/jag.jag.jag-2012_013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
|
7
|
Fu X, Deng J, Yang H, Masuda T, Goto F, Yoshihara T, Zhao G. A novel EP-involved pathway for iron release from soya bean seed ferritin. Biochem J 2010; 427:313-21. [PMID: 20146668 DOI: 10.1042/bj20100015] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023]
Abstract
Iron in phytoferritin from legume seeds is required for seedling germination and early growth. However, the mechanism by which phytoferritin regulates its iron complement to these physiological processes remains unknown. In the present study, protein degradation is found to occur in purified SSF (soya bean seed ferritin) (consisting of H-1 and H-2 subunits) during storage, consistent with previous results that such degradation also occurs during seedling germination. In contrast, no degradation is observed with animal ferritin under identical conditions, suggesting that SSF autodegradation might be due to the EP (extension peptide) on the exterior surface of the protein, a specific domain found only in phytoferritin. Indeed, EP-deleted SSF becomes stable, confirming the above hypothesis. Further support comes from a protease activity assay showing that EP-1 (corresponding to the EP of the H-1 subunit) exhibits significant serine protease-like activity, whereas the activity of EP-2 (corresponding to the EP of the H-2 subunit) is much weaker. Consistent with the observation above, rH-1 (recombinant H-1 ferritin) is prone to degradation, whereas its analogue, rH-2, becomes very stable under identical conditions. This demonstrates that SSF degradation mainly originates from the serine protease-like activity of EP-1. Associated with EP degradation is a considerable increase in the rate of iron release from SSF induced by ascorbate in the amyloplast (pH range, 5.8-6.1). Thus phytoferritin may have facilitated the evolution of the specific domain to control its iron complement in response to cell iron need in the seedling stage.
Collapse
Affiliation(s)
- Xiaoping Fu
- China Agricultural University, Beijing, China
| | | | | | | | | | | | | |
Collapse
|
8
|
Stensballe A, Hald S, Bauw G, Blennow A, Welinder KG. The amyloplast proteome of potato tuber. FEBS J 2008; 275:1723-41. [DOI: 10.1111/j.1742-4658.2008.06332.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
9
|
|
10
|
Hussain H, Mant A, Seale R, Zeeman S, Hinchliffe E, Edwards A, Hylton C, Bornemann S, Smith AM, Martin C, Bustos R. Three isoforms of isoamylase contribute different catalytic properties for the debranching of potato glucans. THE PLANT CELL 2003; 15:133-49. [PMID: 12509527 PMCID: PMC143484 DOI: 10.1105/tpc.006635] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2002] [Accepted: 10/24/2002] [Indexed: 05/17/2023]
Abstract
Isoamylases are debranching enzymes that hydrolyze alpha-1,6 linkages in alpha-1,4/alpha-1,6-linked glucan polymers. In plants, they have been shown to be required for the normal synthesis of amylopectin, although the precise manner in which they influence starch synthesis is still debated. cDNA clones encoding three distinct isoamylase isoforms (Stisa1, Stisa2, and Stisa3) have been identified from potato. The expression patterns of the genes are consistent with the possibility that they all play roles in starch synthesis. Analysis of the predicted sequences of the proteins suggested that only Stisa1 and Stisa3 are likely to have hydrolytic activity and that there probably are differences in substrate specificity between these two isoforms. This was confirmed by the expression of each isoamylase in Escherichia coli and characterization of its activity. Partial purification of isoamylase activity from potato tubers showed that Stisa1 and Stisa2 are associated as a multimeric enzyme but that Stisa3 is not associated with this enzyme complex. Our data suggest that Stisa1 and Stisa2 act together to debranch soluble glucan during starch synthesis. The catalytic specificity of Stisa3 is distinct from that of the multimeric enzyme, indicating that it may play a different role in starch metabolism.
Collapse
Affiliation(s)
- Hasnain Hussain
- Department of Cell and Developmental Biology, John Innes Centre, Colney, Norwich NR4 7UH, United Kingdom
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Hussain H, Mant A, Seale R, Zeeman S, Hinchliffe E, Edwards A, Hylton C, Bornemann S, Smith AM, Martin C, Bustos R. Three isoforms of isoamylase contribute different catalytic properties for the debranching of potato glucans. THE PLANT CELL 2003. [PMID: 12509527 DOI: 10.1105/tpc.006635.1901] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Isoamylases are debranching enzymes that hydrolyze alpha-1,6 linkages in alpha-1,4/alpha-1,6-linked glucan polymers. In plants, they have been shown to be required for the normal synthesis of amylopectin, although the precise manner in which they influence starch synthesis is still debated. cDNA clones encoding three distinct isoamylase isoforms (Stisa1, Stisa2, and Stisa3) have been identified from potato. The expression patterns of the genes are consistent with the possibility that they all play roles in starch synthesis. Analysis of the predicted sequences of the proteins suggested that only Stisa1 and Stisa3 are likely to have hydrolytic activity and that there probably are differences in substrate specificity between these two isoforms. This was confirmed by the expression of each isoamylase in Escherichia coli and characterization of its activity. Partial purification of isoamylase activity from potato tubers showed that Stisa1 and Stisa2 are associated as a multimeric enzyme but that Stisa3 is not associated with this enzyme complex. Our data suggest that Stisa1 and Stisa2 act together to debranch soluble glucan during starch synthesis. The catalytic specificity of Stisa3 is distinct from that of the multimeric enzyme, indicating that it may play a different role in starch metabolism.
Collapse
Affiliation(s)
- Hasnain Hussain
- Department of Cell and Developmental Biology, John Innes Centre, Colney, Norwich NR4 7UH, United Kingdom
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Wu C, Colleoni C, Myers AM, James MG. Enzymatic properties and regulation of ZPU1, the maize pullulanase-type starch debranching enzyme. Arch Biochem Biophys 2002; 406:21-32. [PMID: 12234486 DOI: 10.1016/s0003-9861(02)00412-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Starch debranching enzymes (DBE) are required for mobilization of carbohydrate reserves and for the normal structural organization of storage glucan polymers. Two isoforms, the pullulanase-type DBEs and the isoamylase-type DBEs, are both highly conserved in plants. To address DBE functions in starch assembly and breakdown, this study characterized the biochemical activity of ZPU1, a pullulanase-type DBE that is the product of the maize Zpu1 gene. Assays showed directly that recombinant ZPU1 (ZPU1r) expressed in Escherichia coli functions as a pullulanase-type enzyme, and 1H-NMR spectroscopy demonstrated that ZPU1r specifically hydrolyzes alpha(1-->6) branch linkages. Preferred substrates for ZPU1r hydrolytic activity were determined, as were pH, temperature, and thermal stability optima. Kinetic properties of ZPU1r with respect to two substrates, beta-limit dextrin and pullulan, were determined. ZPU1 activity was increased by incubation with thioredoxin h, and native activity was decreased in mutants that accumulate soluble sugars, suggesting potential regulatory mechanisms.
Collapse
Affiliation(s)
- Chunyuan Wu
- Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, 2152 Molecular Biology Building, Ames, Iowa 50011, USA
| | | | | | | |
Collapse
|
13
|
Identification and Transformation of Campestanol in Cultured Cells of Phaseolus vulgaris. B KOREAN CHEM SOC 2002. [DOI: 10.5012/bkcs.2002.23.7.1035] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
14
|
Mu HH, Yu Y, Wasserman BP, Carman GM. Purification and characterization of the maize amyloplast stromal 112-kDa starch phosphorylase. Arch Biochem Biophys 2001; 388:155-64. [PMID: 11361132 DOI: 10.1006/abbi.2000.2267] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A plastidic 112-kDa starch phosphorylase (SP) has been identified in the amyloplast stromal fraction of maize. This starch phosphorylase was purified 310-fold from maize endosperm and characterized with respect to its enzymological and kinetic properties. The purification procedure included ammonium sulfate fractionation, Sephacryl 300 HR chromatography, affinity starch adsorption, Q-Sepharose, and Mono Q chromatography. The procedure resulted in a nearly homogeneous enzyme preparation as determined by native and SDS-polyacrylamide gel electrophoresis. Anti-SP antibodies recognized the purified 112-kDa SP enzyme and N-terminal amino acid sequence analysis confirmed that the purified enzyme is the amyloplast stromal 112-kDa SP. Analysis of the purified enzyme by Superose 6 gel filtration chromatography indicated that the native enzyme consisted of two identical subunits. The pH optimum for the enzyme was 6.0 in the synthetic direction and 5.5 in the phosphorolytic direction. SP activity was inhibited by thioreactive agents, diethyl pyrocarbonate, phenylglyoxal, and ADP-glucose. The activation energies for the synthetic and phosphorolytic reactions were 11.1 and 16.9 kcal/mol, respectively, and the enzyme was thermally labile above 50 degrees C. Results of kinetic experiments indicated that the enzyme catalyzes its reaction via a sequential Bi Bi mechanism. The Km value for amylopectin was eight-fold lower than that of glycogen. A kinetic analysis indicated that the phosphorolytic reaction was favored over the synthetic reaction when malto-oligosaccharides (4 to 7 units) were used as substrates. The specificity constants (Vmax/Km) of the enzyme measured in either the synthetic or the phosphorolytic directions increased with increasing chain length.
Collapse
Affiliation(s)
- H H Mu
- Department of Food Science, Cook College, New Jersey Agricultural Experiment Station, Rutgers University, New Brunswick 08901, USA
| | | | | | | |
Collapse
|
15
|
Commuri PD, Keeling PL. Chain-length specificities of maize starch synthase I enzyme: studies of glucan affinity and catalytic properties. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2001; 25:475-86. [PMID: 11309138 DOI: 10.1046/j.1365-313x.2001.00955.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
It is widely known that some of the starch synthases and starch-branching enzymes are trapped inside the starch granule matrix during the course of starch deposition in amyloplasts. The objective of this study was to use maize SSI to further our understanding of the protein domains involved in starch granule entrapment and identify the chain-length specificities of the enzyme. Using affinity gel electrophoresis, we measured the dissociation constants of maize SSI and its truncated forms using various glucans. The enzyme has a high degree of specificity in terms of its substrate-enzyme dissociation constant, but has a greatly elevated affinity for increasing chain lengths of alpha-1, 4 glucans. Deletion of the N-terminal arm of SSI did not affect the Kd value. Further small deletions of either N- or C-terminal domains resulted in a complete loss of any measurable affinity for its substrate, suggesting that the starch-affinity domain of SSI is not discrete from the catalytic domain. Greater affinity was displayed for the amylopectin fraction of starch as compared to amylose, whereas glycogen revealed the lowest affinity. However, when the outer chain lengths (OCL) of glycogen were extended using the phosphorylase enzyme, we found an increase in affinity for SSI between an average OCL of 7 and 14, and then an apparently exponential increase to an average OCL of 21. On the other hand, the catalytic ability of SSI was reduced several-fold using these glucans with extended chain lengths as substrates, and most of the label from [14C]ADPG was incorporated into shorter chains of dp < 10. We conclude that the rate of catalysis of SSI enzyme decreases with the OCL of its glucan substrate, and it has a very high affinity for the longer glucan chains of dp approximately 20, rendering the enzyme catalytically incapable at longer chain lengths. Based on the observations in this study, we propose that during amylopectin synthesis shorter A and B1 chains are extended by SSI up to a critical chain length that soon becomes unsuitable for catalysis by SSI and hence cannot be elongated further by this enzyme. Instead, SSI is likely to become entrapped as a relatively inactive protein within the starch granule. Further glucan extension for continuation of amylopectin synthesis must require a handover to other SS enzymes which can extend the glucan chains further or for branching by branching enzymes. If this is correct, this proposal provides a biochemical basis to explain how the specificities of various SS enzymes determine and set the limitations on the length of A, B, C chains in the starch granule.
Collapse
Affiliation(s)
- P D Commuri
- ExSeed Genetics LLC, 2901 South Loop Dr Bldg #3, Suite 3360, ISU Research Park, Ames, IA 50010, USA
| | | |
Collapse
|
16
|
Yu Y, Mu HH, Wasserman BP, Carman GM. Identification of the maize amyloplast stromal 112-kD protein as a plastidic starch phosphorylase. PLANT PHYSIOLOGY 2001; 125:351-9. [PMID: 11154342 PMCID: PMC61015 DOI: 10.1104/pp.125.1.351] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2000] [Accepted: 08/31/2000] [Indexed: 05/18/2023]
Abstract
Amyloplast is the site of starch synthesis in the storage tissue of maize (Zea mays). The amyloplast stroma contains an enriched group of proteins when compared with the whole endosperm. Proteins with molecular masses of 76 and 85 kD have been identified as starch synthase I and starch branching enzyme IIb, respectively. A 112-kD protein was isolated from the stromal fraction by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and subjected to tryptic digestion and amino acid sequence analysis. Three peptide sequences showed high identity to plastidic forms of starch phosphorylase (SP) from sweet potato, potato, and spinach. SP activity was identified in the amyloplast stromal fraction and was enriched 4-fold when compared with the activity in the whole endosperm fraction. Native and sodium dodecyl sulfate-polyacrylamide gel electrophoresis analyses showed that SP activity was associated with the amyloplast stromal 112-kD protein. In addition, antibodies raised against the potato plastidic SP recognized the amyloplast stromal 112-kD protein. The amyloplast stromal 112-kD SP was expressed in whole endosperm isolated from maize harvested 9 to 24 d after pollination. Results of affinity electrophoresis and enzyme kinetic analyses showed that the amyloplast stromal 112-kD SP preferred amylopectin over glycogen as a substrate in the synthetic reaction. The maize shrunken-4 mutant had reduced SP activity due to a decrease of the amyloplast stromal 112-kD enzyme.
Collapse
Affiliation(s)
- Y Yu
- Department of Food Science, Cook College, New Jersey Agricultural Experiment Station, Rutgers University, 65 Dudley Road, New Brunswick, New Jersey 08901, USA
| | | | | | | |
Collapse
|
17
|
Metzler DE, Metzler CM, Sauke DJ. Some Pathways of Carbohydrate Metabolism. Biochemistry 2001. [DOI: 10.1016/b978-012492543-4/50023-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
18
|
Li Z, Mouille G, Kosar-Hashemi B, Rahman S, Clarke B, Gale KR, Appels R, Morell MK. The structure and expression of the wheat starch synthase III gene. Motifs in the expressed gene define the lineage of the starch synthase III gene family. PLANT PHYSIOLOGY 2000; 123:613-24. [PMID: 10859191 PMCID: PMC59029 DOI: 10.1104/pp.123.2.613] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/1999] [Accepted: 02/21/2000] [Indexed: 05/18/2023]
Abstract
The endosperm of hexaploid wheat (Triticum aestivum [L.]) was shown to contain a high molecular weight starch synthase (SS) analogous to the product of the maize du1 gene, starch synthase III (SSIII; DU1). cDNA and genomic DNA sequences encoding wheat SSIII were isolated and characterized. The wheat SSIII cDNA is 5,346 bp long and contains an open reading frame that encodes a 1,628-amino acid polypeptide. A putative N-terminal transit peptide, a 436-amino acid C-terminal catalytic domain, and a central 470-amino acid SSIII-specific domain containing three regions of repeated amino acid similarity were identified in the wheat gene. A fourth region between the transit peptide and the SSIII-specific domain contains repeat motifs that are variable with respect to motif sequence and repeat number between wheat and maize. In dicots, this N-terminal region does not contain repeat motifs and is truncated. The gene encoding wheat SSIII, designated ss3, consists of 16 exons extending over 10 kb, and is located on wheat chromosome I. Expression of ss3 mRNA in wheat was detected in leaves, pre-anthesis florets, and from very early to middle stage of endosperm development. The entire N-terminal variable repeat region and the majority of the SSIII-specific domain are encoded on a single 2,703-bp exon. A gene encoding a class III SS from the Arabidopsis genome sequencing project shows a strongly conserved exon structure to the wheat ss3 gene, with the exception of the N-terminal region. The evolutionary relationships of the genes encoding monocot and dicot class III SSs are discussed.
Collapse
Affiliation(s)
- Z Li
- Commonwealth Scientific and Industrial Research Organization, Division of Plant Industry, Canberra, Australian Capital Territory
| | | | | | | | | | | | | | | |
Collapse
|
19
|
Myers AM, Morell MK, James MG, Ball SG. Recent progress toward understanding biosynthesis of the amylopectin crystal. PLANT PHYSIOLOGY 2000; 122:989-97. [PMID: 10759494 PMCID: PMC1539245 DOI: 10.1104/pp.122.4.989] [Citation(s) in RCA: 202] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Affiliation(s)
- A M Myers
- Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa 50011, USA
| | | | | | | |
Collapse
|
20
|
Li Z, Chu X, Mouille G, Yan L, Kosar-Hashemi B, Hey S, Napier J, Shewry P, Clarke B, Appels R, Morell MK, Rahman S. The localization and expression of the class II starch synthases of wheat. PLANT PHYSIOLOGY 1999; 120:1147-56. [PMID: 10444098 PMCID: PMC59348 DOI: 10.1104/pp.120.4.1147] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/1999] [Accepted: 05/04/1999] [Indexed: 05/21/2023]
Abstract
The starch granules of hexaploid wheat (Triticum aestivum) contain a group of three proteins known as SGP-1 (starch granule protein-1) proteins, which have apparent molecular masses of 100, 108, and 115 kD. The nature and role of these proteins has not been defined previously. We demonstrate that these polypeptides are starch synthases that are present in both the starch granule and the soluble fraction at the early stages of wheat endosperm development, but that are exclusively granule bound at mid and late endosperm development. A partial cDNA clone encoding a fragment of the 100-kD protein was obtained by screening a wheat endosperm cDNA expression library using monoclonal antibodies. Three classes of cDNA were subsequently isolated from a wheat endosperm cDNA library by nucleic acid hybridization and were shown to encode the 100-, 108-, and 115-kD proteins. The cDNA sequences are highly homologous to class II starch synthases and have the highest homology with the maize SSIIa (starch synthase IIa) gene. mRNA for the SGP-1 proteins was detected in the leaf, pre-anthesis florets, and endosperm of wheat and is highly expressed in the leaf and in the grain during the early to mid stages of development. We discuss the roles of the SGP-1 proteins in starch biosynthesis in wheat.
Collapse
Affiliation(s)
- Z Li
- Commonwealth Scientific and Industrial Research Organization, Plant Industry, G.P.O. Box 1600, Canberra, Australian Capital Territory 2601, Australia
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Cao H, Imparl-Radosevich J, Guan H, Keeling PL, James MG, Myers AM. Identification of the soluble starch synthase activities of maize endosperm. PLANT PHYSIOLOGY 1999; 120:205-16. [PMID: 10318698 PMCID: PMC59252 DOI: 10.1104/pp.120.1.205] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/1998] [Accepted: 01/23/1999] [Indexed: 05/18/2023]
Abstract
This study identified the complement of soluble starch synthases (SSs) present in developing maize (Zea mays) endosperm. The product of the du1 gene, DU1, was shown to be one of the two major soluble SSs. The C-terminal 450 residues of DU1 comprise eight sequence blocks conserved in 28 known or predicted glucan synthases. This region of DU1 was expressed in Escherichia coli and shown to possess SS activity. DU1-specific antisera detected a soluble endosperm protein of more than 200 kD that was lacking in du1- mutants. These antisera eliminated 20% to 30% of the soluble SS activity from kernel extracts. Antiserum against the isozyme zSSI eliminated approximately 60% of the total soluble SS, and immunodepletion of du1- mutant extracts with this antiserum nearly eliminated SS activity. Two soluble SS activities were identified by electrophoretic fractionation, each of which correlated specifically with zSSI or DU1. Thus, DU1 and zSSI accounted for the great majority of soluble SS activity present in developing endosperm. The relative activity of the two isozymes did not change significantly during the starch biosynthetic period. DU1 and zSSI may be interdependent, because mutant extracts lacking DU1 exhibited a significant stimulation of the remaining SS activity.
Collapse
Affiliation(s)
- H Cao
- Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa 50011, USA
| | | | | | | | | | | |
Collapse
|
22
|
Beatty MK, Rahman A, Cao H, Woodman W, Lee M, Myers AM, James MG. Purification and molecular genetic characterization of ZPU1, a pullulanase-type starch-debranching enzyme from maize. PLANT PHYSIOLOGY 1999; 119:255-66. [PMID: 9880368 PMCID: PMC32228 DOI: 10.1104/pp.119.1.255] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/1998] [Accepted: 10/12/1998] [Indexed: 05/20/2023]
Abstract
This study identified and purified specific isoamylase- and pullulanase-type starch-debranching enzymes (DBEs) present in developing maize (Zea mays L.) endosperm. The cDNA clone Zpu1 was isolated based on its homology with a rice (Oryza sativa L.) cDNA coding for a pullulanase-type DBE. Comparison of the protein product, ZPU1, with 18 other DBEs identified motifs common to both isoamylase- and pullulanase-type enzymes, as well as class-specific sequence blocks. Hybridization of Zpu1 to genomic DNA defined a single-copy gene, zpu1, located on chromosome 2. Zpu1 mRNA was abundant in endosperm throughout starch biosynthesis, but was not detected in the leaf or the root. Anti-ZPU1 antiserum specifically recognized the approximately 100-kD ZPU1 protein in developing endosperm, but not in leaves. Pullulanase- and isoamylase-type DBEs were purified from extracts of developing maize kernels. The pullulanase-type activity was identified as ZPU1 and the isoamylase-type activity as SU1. Mutations of the sugary1 (su1) gene are known to cause deficiencies of SU1 isoamylase and a pullulanase-type DBE. ZPU1 activity, protein level, and electrophoretic mobility were altered in su1-mutant kernels, indicating that it is the affected pullulanase-type DBE. The Zpu1 transcript levels were equivalent in nonmutant and su1-mutant kernels, suggesting that coordinated regulation of ZPU1 and SU1 occurs posttranscriptionally.
Collapse
MESH Headings
- Amino Acid Sequence
- Chromosome Mapping
- Conserved Sequence
- DNA, Complementary/genetics
- DNA, Plant/genetics
- Gene Expression Regulation, Developmental
- Gene Expression Regulation, Enzymologic
- Gene Expression Regulation, Plant
- Genes, Plant
- Glycoside Hydrolases/genetics
- Glycoside Hydrolases/isolation & purification
- Isoamylase/genetics
- Molecular Sequence Data
- Plant Proteins
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Plant/genetics
- RNA, Plant/metabolism
- Seeds/enzymology
- Sequence Homology, Amino Acid
- Tissue Distribution
- Zea mays/enzymology
- Zea mays/genetics
- Zea mays/growth & development
Collapse
Affiliation(s)
- M K Beatty
- Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames 50011, USA
| | | | | | | | | | | | | |
Collapse
|
23
|
Zhu ZP, Hylton CM, Rossner U, Smith AM. Characterization of starch-debranching enzymes in pea embryos. PLANT PHYSIOLOGY 1998; 118:581-90. [PMID: 9765544 PMCID: PMC34834 DOI: 10.1104/pp.118.2.581] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/1998] [Accepted: 06/26/1998] [Indexed: 05/17/2023]
Abstract
Two distinct types of debranching enzymes have been identified in developing pea (Pisum sativum L.) embryos using native gel analysis and tests of substrate preference on purified or partially purified activities. An isoamylase-like activity capable of hydrolyzing amylopectin and glycogen but not pullulan is present throughout development and is largely or entirely confined to the plastid. Activities capable of hydrolyzing pullulan are present both inside and outside of the plastid, and extraplastidial activity increases relative to the plastidial activity during development. Both types of debranching enzyme are also present in germinating embryos. We argue that debranching enzymes are likely to have a role in starch metabolism in the plastid of the developing embryo and in starch degradation during germination.
Collapse
Affiliation(s)
- ZP Zhu
- Shanghai Institute of Plant Physiology, 300 Fonglin Road, Shanghai, China 200032 (Z.-P.Z.)
| | | | | | | |
Collapse
|