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Khan N, Zhang J, Islam S, Appels R, Dell B. Wheat Water-Soluble Carbohydrate Remobilisation under Water Deficit by 1-FEH w3. Curr Issues Mol Biol 2023; 45:6634-6650. [PMID: 37623238 PMCID: PMC10453044 DOI: 10.3390/cimb45080419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 08/03/2023] [Accepted: 08/08/2023] [Indexed: 08/26/2023] Open
Abstract
Fructan 1-exohydrolase (1-FEH) is one of the major enzymes in water-soluble carbohydrate (WSC) remobilisation for grains in wheat. We investigated the functional role of 1-FEH w1, w2, and w3 isoforms in WSC remobilisation under post-anthesis water deficit using mutation lines derived from the Australian wheat variety Chara. F1 seeds, developed by backcrossing the 1-FEH w1, w2, and w3 mutation lines with Chara, were genotyped using the Infinium 90K SNP iSelect platform to characterise the mutated region. Putative deletions were identified in FEH mutation lines encompassing the FEH genomic regions. Mapping analysis demonstrated that mutations affected significantly longer regions than the target FEH gene regions. Functional roles of the non-target genes were carried out utilising bioinformatics and confirmed that the non-target genes were unlikely to confound the effects considered to be due to the influence of 1-FEH gene functions. Glasshouse experiments revealed that the 1-FEH w3 mutation line had a slower degradation and remobilisation of fructans than the 1-FEH w2 and w1 mutation lines and Chara, which reduced grain filling and grain yield. Thus, 1-FEH w3 plays a vital role in reducing yield loss under drought. This insight into the distinct role of the 1-FEH isoforms provides new gene targets for water-deficit-tolerant wheat breeding.
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Affiliation(s)
- Nusrat Khan
- Centre for Crop and Food Innovation, Food Futures Institute, Murdoch University, 90 South Street, Murdoch, WA 6163, Australia; (N.K.); (J.Z.); (S.I.)
- Department of Plant Sciences, North Dakota State University, Fargo, ND 58102, USA
| | - Jingjuan Zhang
- Centre for Crop and Food Innovation, Food Futures Institute, Murdoch University, 90 South Street, Murdoch, WA 6163, Australia; (N.K.); (J.Z.); (S.I.)
| | - Shahidul Islam
- Centre for Crop and Food Innovation, Food Futures Institute, Murdoch University, 90 South Street, Murdoch, WA 6163, Australia; (N.K.); (J.Z.); (S.I.)
- Department of Plant Sciences, North Dakota State University, Fargo, ND 58102, USA
| | - Rudi Appels
- Faculty of Science, University of Melbourne, Parkville, VIC 3010, Australia;
| | - Bernard Dell
- Centre for Crop and Food Innovation, Food Futures Institute, Murdoch University, 90 South Street, Murdoch, WA 6163, Australia; (N.K.); (J.Z.); (S.I.)
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Jiang Y, Wang Z, Liu Y, Han Y, Wang Y, Wang Q, Liu T. Nematodes and their bacterial prey improve phosphorus acquisition by wheat. THE NEW PHYTOLOGIST 2023; 237:974-986. [PMID: 36285379 DOI: 10.1111/nph.18569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 10/18/2022] [Indexed: 06/16/2023]
Abstract
Plant growth is greatly influenced by the rhizosphere microbiome, which has been traditionally investigated from a bottom-up perspective assessing how resources such as root exudates stimulate microbial growth and drive microbiome assembly. However, the importance of predation as top-down force on the soil microbiome remains largely underestimated. Here, we planted wheat both in natural and in sterilized soils inoculated with the key microbiome predators - bacterivorous nematodes - to assess how plant performance responds to top-down predation of the soil microbiome and specific plant growth-promoting bacteria, namely phosphate-solubilizing bacteria. We found that nematodes enriched certain groups (e.g. Actinobacteria, Chloroflexi, and Firmicutes) and strengthened microbial connectance (e.g. Actinobacteria and Proteobacteria). These changes in microbiome structure were associated with phosphate-solubilizing bacteria that facilitated phosphorus (P) cycling, leading to greater P uptake and biomass of wheat in both soils. However, the enhancement varied between nematode species, which may be attributed to the divergence of feeding behavior, as nematodes with weaker grazing intensity supported greater abundance of phosphate-solubilizing bacteria and better plant performance compared with nematodes with greater grazing intensity. These results confirmed the ecological importance of soil nematodes for ecosystem functions via microbial co-occurrence networks and suggested that the predation strength of nematodes determines the soil bacteria contribution to P biogeochemical cycling and plant growth.
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Affiliation(s)
- Ying Jiang
- College of Resources and Environment, Henan Agricultural University, Zhengzhou, 450002, China
| | - Zhonghua Wang
- College of Resources and Environment, Henan Agricultural University, Zhengzhou, 450002, China
| | - Ye Liu
- College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
| | - Yanlai Han
- College of Resources and Environment, Henan Agricultural University, Zhengzhou, 450002, China
| | - Yi Wang
- College of Resources and Environment, Henan Agricultural University, Zhengzhou, 450002, China
| | - Qiang Wang
- College of Resources and Environment, Henan Agricultural University, Zhengzhou, 450002, China
| | - Ting Liu
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
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3
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Fei M, Jin Y, Hu J, Dotsenko G, Ruan Y, Liu C, Seisenbaeva G, Andersson AAM, Andersson R, Sun C. Achieving of high-diet-fiber barley via managing fructan hydrolysis. Sci Rep 2022; 12:19151. [PMID: 36351972 PMCID: PMC9646770 DOI: 10.1038/s41598-022-21955-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 10/06/2022] [Indexed: 11/11/2022] Open
Abstract
High fructan content in the grain of cereals is an important trait in agriculture such as environmental resilience and dietary fiber food production. To understand the mechanism in determining final grain fructan content and achieve high fructan cereal, a cross breeding strategy based on fructan synthesis and hydrolysis activities was set up and have achieved barley lines with 11.8% storage fructan in the harvested grain. Our study discovered that high activity of fructan hydrolysis at later grain developmental stage leads to the low fructan content in mature seeds, simultaneously increasing fructan synthesis at early stage and decreasing fructan hydrolysis at later stage through crossing breeding is an efficient way to elevate grain diet-fiber content. A good correlation between fructan and beta glucans was also discovered with obvious interest. Field trials showed that the achieved high fructan barley produced over seven folds higher fructan content than control barley and pull carbon-flux to fructan through decreasing fructan hydrolysis without disruption starch synthesis will probably not bring yield deficiency.
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Affiliation(s)
- Mingliang Fei
- grid.257160.70000 0004 1761 0331Key Laboratory of Crop Epigenetic Regulation and Development in Hunan Province, Hunan Agricultural University, Changsha, 410128 China ,grid.6341.00000 0000 8578 2742Department of Plant Biology, Uppsala BioCenter, Linnean Centre for Plant Biology, Swedish University of Agricultural Sciences (SLU), P.O. Box 7080, 750 07 Uppsala, Sweden ,grid.257160.70000 0004 1761 0331Key Laboratory of Education Department of Hunan Province On Plant Genetics and Molecular Biology, College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, 410128 China
| | - Yunkai Jin
- grid.6341.00000 0000 8578 2742Department of Plant Biology, Uppsala BioCenter, Linnean Centre for Plant Biology, Swedish University of Agricultural Sciences (SLU), P.O. Box 7080, 750 07 Uppsala, Sweden
| | - Jia Hu
- grid.6341.00000 0000 8578 2742Department of Plant Biology, Uppsala BioCenter, Linnean Centre for Plant Biology, Swedish University of Agricultural Sciences (SLU), P.O. Box 7080, 750 07 Uppsala, Sweden
| | - Gleb Dotsenko
- grid.6341.00000 0000 8578 2742Department of Molecular Sciences, Uppsala BioCenter, Swedish University of Agricultural Sciences, P.O. Box 7015, 750 07 Uppsala, Sweden
| | - Ying Ruan
- grid.257160.70000 0004 1761 0331Key Laboratory of Crop Epigenetic Regulation and Development in Hunan Province, Hunan Agricultural University, Changsha, 410128 China ,grid.257160.70000 0004 1761 0331Key Laboratory of Education Department of Hunan Province On Plant Genetics and Molecular Biology, College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, 410128 China
| | - Chunlin Liu
- grid.257160.70000 0004 1761 0331Key Laboratory of Education Department of Hunan Province On Plant Genetics and Molecular Biology, College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, 410128 China ,grid.257160.70000 0004 1761 0331College of Agronomy, Hunan Agricultural University, Changsha, 410128 China
| | - Gulaim Seisenbaeva
- grid.6341.00000 0000 8578 2742Department of Molecular Sciences, Uppsala BioCenter, Swedish University of Agricultural Sciences, P.O. Box 7015, 750 07 Uppsala, Sweden
| | - Annica A. M. Andersson
- grid.6341.00000 0000 8578 2742Department of Molecular Sciences, Uppsala BioCenter, Swedish University of Agricultural Sciences, P.O. Box 7015, 750 07 Uppsala, Sweden
| | - Roger Andersson
- grid.6341.00000 0000 8578 2742Department of Molecular Sciences, Uppsala BioCenter, Swedish University of Agricultural Sciences, P.O. Box 7015, 750 07 Uppsala, Sweden
| | - Chuanxin Sun
- grid.6341.00000 0000 8578 2742Department of Plant Biology, Uppsala BioCenter, Linnean Centre for Plant Biology, Swedish University of Agricultural Sciences (SLU), P.O. Box 7080, 750 07 Uppsala, Sweden
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Versluys M, Toksoy Öner E, Van den Ende W. Fructan oligosaccharide priming alters apoplastic sugar dynamics and improves resistance against Botrytis cinerea in chicory. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:4214-4235. [PMID: 35383363 DOI: 10.1093/jxb/erac140] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Accepted: 04/01/2022] [Indexed: 06/14/2023]
Abstract
Carbohydrates such as fructans can be involved in priming or defence stimulation, and hence potentially provide new strategies for crop protection against biotic stress. Chicory (Cichorium intybus) is a model plant for fructan research and is a crop with many known health benefits. Using the chicory-Botrytis cinerea pathosystem, we tested the effectiveness of fructan-induced immunity, focussing on different plant and microbial fructans. Sugar dynamics were followed after priming and subsequent pathogen infection. Our results indicated that many higher plants might detect extracellular levan oligosaccharides (LOS) of microbial origin, while chicory also detects extracellular small inulin-type fructooligosaccharides (FOS) of endogenous origin, thus differing from the findings of previous fructan priming studies. No clear positive effects were observed for inulin or mixed-type fructans. An elicitor-specific burst of reactive oxygen species was observed for sulfated LOS, while FOS and LOS both behaved as genuine priming agents. In addition, a direct antifungal effect was observed for sulfated LOS. Intriguingly, LOS priming led to a temporary increase in apoplastic sugar concentrations, mainly glucose, which could trigger downstream responses. Total sugar and starch contents in total extracts of LOS-primed leaves were higher after leaf detachment, indicating they could maintain their metabolic activity. Our results indicate the importance of balancing intra- and extracellular sugar levels (osmotic balance) in the context of 'sweet immunity' pathways.
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Affiliation(s)
- Maxime Versluys
- Laboratory of Molecular Plant Biology and KU Leuven Plant Institute, KU Leuven, Kasteelpark Arenberg 31, 3001 Leuven, Belgium
| | - Ebru Toksoy Öner
- IBSB-Industrial Biotechnology and Systems Biology Research Group, Department of Bioengineering, Marmara University, Istanbul, Turkey
| | - Wim Van den Ende
- Laboratory of Molecular Plant Biology and KU Leuven Plant Institute, KU Leuven, Kasteelpark Arenberg 31, 3001 Leuven, Belgium
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5
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Gaur A, Jindal Y, Singh V, Tiwari R, Kumar D, Kaushik D, Singh J, Narwal S, Jaiswal S, Iquebal MA, Angadi UB, Singh G, Rai A, Singh GP, Sheoran S. GWAS to Identify Novel QTNs for WSCs Accumulation in Wheat Peduncle Under Different Water Regimes. FRONTIERS IN PLANT SCIENCE 2022; 13:825687. [PMID: 35310635 PMCID: PMC8928439 DOI: 10.3389/fpls.2022.825687] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 01/27/2022] [Indexed: 05/27/2023]
Abstract
Water-soluble carbohydrates (WSCs) play a vital role in water stress avoidance and buffering wheat grain yield. However, the genetic architecture of stem WSCs' accumulation is partially understood, and few candidate genes are known. This study utilizes the compressed mixed linear model-based genome wide association study (GWAS) and heuristic post GWAS analyses to identify causative quantitative trait nucleotides (QTNs) and candidate genes for stem WSCs' content at 15 days after anthesis under different water regimes (irrigated, rainfed, and drought). Glucose, fructose, sucrose, fructans, total non-structural carbohydrates (the sum of individual sugars), total WSCs (anthrone based) quantified in the peduncle of 301 bread wheat genotypes under multiple environments (E01-E08) pertaining different water regimes, and 14,571 SNPs from "35K Axiom Wheat Breeders" Array were used for analysis. As a result, 570 significant nucleotide trait associations were identified on all chromosomes except for 4D, of which 163 were considered stable. A total of 112 quantitative trait nucleotide regions (QNRs) were identified of which 47 were presumable novel. QNRs qWSC-3B.2 and qWSC-7A.2 were identified as the hotspots. Post GWAS integration of multiple data resources prioritized 208 putative candidate genes delimited into 64 QNRs, which can be critical in understanding the genetic architecture of stem WSCs accumulation in wheat under optimum and water-stressed environments. At least 19 stable QTNs were found associated with 24 prioritized candidate genes. Clusters of fructans metabolic genes reported in the QNRs qWSC-4A.2 and qWSC-7A.2. These genes can be utilized to bring an optimum combination of various fructans metabolic genes to improve the accumulation and remobilization of stem WSCs and water stress tolerance. These results will further strengthen wheat breeding programs targeting sustainable wheat production under limited water conditions.
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Affiliation(s)
- Arpit Gaur
- Department of Genetics and Plant Breeding, CCS Haryana Agricultural University, Hisar, India
- ICAR-Indian Institute of Wheat and Barley Research, Karnal, India
| | - Yogesh Jindal
- Department of Genetics and Plant Breeding, CCS Haryana Agricultural University, Hisar, India
| | - Vikram Singh
- Department of Genetics and Plant Breeding, CCS Haryana Agricultural University, Hisar, India
| | - Ratan Tiwari
- ICAR-Indian Institute of Wheat and Barley Research, Karnal, India
| | - Dinesh Kumar
- ICAR-Indian Agricultural Statistics Research Institute, New Delhi, India
| | - Deepak Kaushik
- Department of Genetics and Plant Breeding, CCS Haryana Agricultural University, Hisar, India
| | - Jogendra Singh
- ICAR-Central Soil Salinity Research Institute, Karnal, India
| | - Sneh Narwal
- ICAR-Indian Agricultural Research Institute, New Delhi, India
| | - Sarika Jaiswal
- ICAR-Indian Agricultural Statistics Research Institute, New Delhi, India
| | - Mir Asif Iquebal
- ICAR-Indian Agricultural Statistics Research Institute, New Delhi, India
| | - Ulavapp B. Angadi
- ICAR-Indian Agricultural Statistics Research Institute, New Delhi, India
| | - Gyanendra Singh
- ICAR-Indian Institute of Wheat and Barley Research, Karnal, India
| | - Anil Rai
- ICAR-Indian Agricultural Statistics Research Institute, New Delhi, India
| | | | - Sonia Sheoran
- ICAR-Indian Institute of Wheat and Barley Research, Karnal, India
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6
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Yoshida M. Fructan Structure and Metabolism in Overwintering Plants. PLANTS 2021; 10:plants10050933. [PMID: 34067059 PMCID: PMC8151721 DOI: 10.3390/plants10050933] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/27/2021] [Accepted: 04/27/2021] [Indexed: 12/27/2022]
Abstract
In northern regions, annual and perennial overwintering plants such as wheat and temperate grasses accumulate fructan in vegetative tissues as an energy source. This is necessary for the survival of wintering tissues and degrading fructan for regeneration in spring. Other types of wintering plants, including chicory and asparagus, store fructan as a reserve carbohydrate in their roots during winter for shoot- and spear-sprouting in spring. In this review, fructan metabolism in plants during winter is discussed, with a focus on the fructan-degrading enzyme, fructan exohydrolase (FEH). Plant fructan synthase genes were isolated in the 2000s, and FEH genes have been isolated since the cloning of synthase genes. There are many types of FEH in plants with complex-structured fructan, and these FEHs control various kinds of fructan metabolism in growth and survival by different physiological responses. The results of recent studies on the fructan metabolism of plants in winter have shown that changes in fructan contents in wintering plants that are involved in freezing tolerance and snow mold resistance might be largely controlled by regulation of the expressions of genes for fructan synthesis, whereas fructan degradation by FEHs is related to constant energy consumption for survival during winter and rapid sugar supply for regeneration or sprouting of tissues in spring.
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Affiliation(s)
- Midori Yoshida
- NARO Hokkaido National Agricultural Research Center, Sapporo 062-8555, Japan
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7
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Mohammadi F, Naghavi MR, Peighambari SA, Dehaghi NK, Nasiri J, Khaldari I, Bravi E, Sileoni V, Marconi O, Perretti G. Comparison of carbohydrate partitioning and expression patterns of some genes involved in carbohydrate biosynthesis pathways in annual and biennial species of Cichorium spp. PHYTOCHEMISTRY 2021; 183:112620. [PMID: 33360645 DOI: 10.1016/j.phytochem.2020.112620] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 12/04/2020] [Accepted: 12/05/2020] [Indexed: 06/12/2023]
Abstract
Variation in metabolism and partitioning of carbohydrates, particularly fructans, between annual and perennial Cichorium species remains a challenging topic. To address this problem, an annual (endive, Cichorium endive L. var. Crispum; Asteraceae) and a biennial species (chicory, Cichorium intybus L. var. Witloof; Asteraceae) were compared with in terms of variability in carbohydrate accumulation and expression patterns of fructan-active enzyme genes, as well as sucrose metabolism at various growth and developmental stages. In general, constituents such as 1-kestose, nystose, and inulin were detected only in the root of chicory and were not present in any of the endive tissues. For both species, flower tissue contained maximum levels of both fructose and glucose, while for sucrose, more fluctuations were observed. On the other hand, all the genes under study exhibited variation, not only between the two species but also among different tissues at different sampling times. In endive root compared to endive leaf, the expression of cell wall invertase genes and sucrose accumulation decreased simultaneously, indicating the limited capacity of its roots to absorb sucrose, a precursor to inulin production. In addition, low expression of fructan: fructan fructosyltransferase in endive root compared to chicory root confirmed the inability of endive to inulin synthesis. Overall, annual and biennial species were different in the production of inulin, transport, remobilization, and unloading of sucrose.
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Affiliation(s)
- Fatemeh Mohammadi
- Division of Biotechnology, Agronomy and Plant Breeding Dept, Agricultural and Natural Resources College, University of Tehran, Karaj, Iran
| | - Mohammad Reza Naghavi
- Division of Biotechnology, Agronomy and Plant Breeding Dept, Agricultural and Natural Resources College, University of Tehran, Karaj, Iran.
| | - Seyed Ali Peighambari
- Division of Biotechnology, Agronomy and Plant Breeding Dept, Agricultural and Natural Resources College, University of Tehran, Karaj, Iran
| | - Nafiseh Khosravi Dehaghi
- Evidence-based Phytotherapy & Complementary Medicine Research Center, Alborz University of Medical Sciences, Karaj, Iran; Department of Pharmacognosy, School of Pharmacy, Alborz University of Medical Sciences, Karaj, Iran
| | - Jaber Nasiri
- Division of Biotechnology, Agronomy and Plant Breeding Dept, Agricultural and Natural Resources College, University of Tehran, Karaj, Iran
| | - Iman Khaldari
- Division of Biotechnology, Agronomy and Plant Breeding Dept, Agricultural and Natural Resources College, University of Tehran, Karaj, Iran
| | - Elisabetta Bravi
- University of Perugia, Department of Agricultural, Food and Environmental Science, via San Costanzo s.n.c., 06126, Perugia, Italy.
| | - Valeria Sileoni
- University of Perugia, Department of Agricultural, Food and Environmental Science, via San Costanzo s.n.c., 06126, Perugia, Italy
| | - Ombretta Marconi
- University of Perugia, Department of Agricultural, Food and Environmental Science, via San Costanzo s.n.c., 06126, Perugia, Italy
| | - Giuseppe Perretti
- University of Perugia, Department of Agricultural, Food and Environmental Science, via San Costanzo s.n.c., 06126, Perugia, Italy
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Dhanagond S, Liu G, Zhao Y, Chen D, Grieco M, Reif J, Kilian B, Graner A, Neumann K. Non-Invasive Phenotyping Reveals Genomic Regions Involved in Pre-Anthesis Drought Tolerance and Recovery in Spring Barley. FRONTIERS IN PLANT SCIENCE 2019; 10:1307. [PMID: 31708943 PMCID: PMC6823269 DOI: 10.3389/fpls.2019.01307] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 09/19/2019] [Indexed: 05/07/2023]
Abstract
With ongoing climate change, drought events are becoming more frequent and will affect biomass formation when occurring during pre-flowering stages. We explored growth over time under such a drought scenario, via non-invasive imaging and revealed the underlying key genetic factors in spring barley. By comparing with well-watered conditions investigated in an earlier study and including information on timing, QTL could be classified as constitutive, drought or recovery-adaptive. Drought-adaptive QTL were found in the vicinity of genes involved in dehydration tolerance such as dehydrins (Dhn4, Dhn7, Dhn8, and Dhn9) and aquaporins (e.g. HvPIP1;5, HvPIP2;7, and HvTIP2;1). The influence of phenology on biomass formation increased under drought. Accordingly, the main QTL during recovery was the region of HvPPD-H1. The most important constitutive QTL for late biomass was located in the vicinity of HvDIM, while the main locus for seedling biomass was the HvWAXY region. The disappearance of QTL marked the genetic architecture of tiller number. The most important constitutive QTL was located on 6HS in the region of 1-FEH. Stage and tolerance specific QTL might provide opportunities for genetic manipulation to stabilize biomass and tiller number under drought conditions and thereby also grain yield.
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Affiliation(s)
- Sidram Dhanagond
- Department of Genebank, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Seeland, Germany
| | - Guozheng Liu
- Department of Breeding Research, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Seeland, Germany
- BBCC – Innovation Center Gent, Gent Zwijnaarde, Belgium
| | - Yusheng Zhao
- Department of Breeding Research, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Seeland, Germany
| | - Dijun Chen
- Institute for Biology, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Michele Grieco
- Department of Genebank, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Seeland, Germany
| | - Jochen Reif
- Department of Breeding Research, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Seeland, Germany
- Plant Breeding Department, Martin-Luther-University Halle-Wittenberg, Halle, Germany
| | - Benjamin Kilian
- Department of Genebank, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Seeland, Germany
- Global Crop Diversity Trust (GCDT), Bonn, Germany
| | - Andreas Graner
- Department of Genebank, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Seeland, Germany
- Plant Breeding Department, Martin-Luther-University Halle-Wittenberg, Halle, Germany
| | - Kerstin Neumann
- Department of Genebank, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Seeland, Germany
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9
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Ueno K, Sonoda T, Yoshida M, Shiomi N, Onodera S. Purification, characterization, and functional analysis of a novel 6G&1-FEH mainly hydrolyzing neokestose from asparagus. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:4295-4308. [PMID: 29931209 DOI: 10.1093/jxb/ery234] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2018] [Accepted: 06/14/2018] [Indexed: 06/08/2023]
Abstract
Asparagus (Asparagus officinalis L.) accumulates inulin- and inulin neoseries-type fructans. Fructose released by the hydrolysis of fructans is an energy source for emerging asparagus spears. Plant fructans are hydrolyzed by fructan exohydrolases (FEHs), whose presence in asparagus has not yet been fully characterized. Here, we describe for the first time the purification and characterization of an FEH from asparagus, and the functional analysis of its gene. The purified enzyme was predicted to exist as a dimer (approximately 130 kDa) consisting of two polypeptides with a molecular mass of approximately 68 kDa. N-terminal sequences of the purified enzyme were matched with the amino acid sequences of aoeh4a and aoeh4b cDNAs isolated from asparagus (cv. Gijnlim and Taihouwase). Native enzymes obtained from asparagus roots and recombinant enzymes produced by Pichia pastoris showed fructan 1-exohydrolase (1-FEH) activity via the hydrolysis of inulin-type fructan. Unlike other 1-FEHs, these enzymes showed minimal hydrolysis of 1-kestose but efficiently hydrolyzed neokestose. Therefore, the enzyme was termed 6G&1-FEH. Gene expression studies in asparagus roots showed that aoeh4 increased during root storage at 2 °C and spear harvesting. These findings suggest that 6G&1-FEH may be involved in fructan hydrolysis in asparagus roots to provide an energy source for emerging asparagus spears.
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Affiliation(s)
- Keiji Ueno
- Department of Food Sciences, Faculty of Dairy Science, Rakuno Gakuen University, Ebetsu, Japan
| | - Takahiro Sonoda
- Department of Sustainable Agricultures, College of Agriculture, Food and Environment Sciences, Rakuno Gakuen University, Ebetsu, Japan
- Department of Food Sciences, Faculty of Dairy Science, Rakuno Gakuen University, Ebetsu, Japan
| | - Midori Yoshida
- NARO Hokkaido Agricultural Research Center, Hitsujigaoka, Sapporo, Japan
| | - Norio Shiomi
- Department of Food Sciences, Faculty of Dairy Science, Rakuno Gakuen University, Ebetsu, Japan
| | - Shuichi Onodera
- Department of Food Science and Human Wellness, College of Agriculture, Food and Environment Sciences, Rakuno Gakuen University, Ebetsu, Japan
- Department of Food Sciences, Faculty of Dairy Science, Rakuno Gakuen University, Ebetsu, Japan
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10
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Singh R, Gupta P, Khan F, Singh SK, Mishra T, Kumar A, Dhawan SS, Shirke PA. Modulations in primary and secondary metabolic pathways and adjustment in physiological behaviour of Withania somnifera under drought stress. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2018; 272:42-54. [PMID: 29807605 DOI: 10.1016/j.plantsci.2018.03.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 03/16/2018] [Accepted: 03/28/2018] [Indexed: 05/20/2023]
Abstract
In general medicinal plants grown under water limiting conditions show much higher concentrations of secondary metabolites in comparison to control plants. In the present study, Withania somnifera plants were subjected to water stress and data related to drought tolerance phenomenon was collected and a putative mechanistic concept considering growth responses, physiological behaviour, and metabolite content and gene expression aspects is presented. Drought induced metabolic and physiological responses as well as drastic decrease in CO2 uptake due to stomatal limitations. As a result, the consumption of reduction equivalents (NADPH2+) for CO2 assimilation via the calvin cycle declines significantly resulting in the generation of a large oxidative stress and an oversupply of antioxidant enzymes. Drought also results in the shifting of metabolic processes towards biosynthetic activities that consume reduction equivalents. Thus, biosynthesis of reduced compounds (isoprenoids, phenols and alkaloids) is enhanced. The dynamics of various metabolites have been discussed in the light of gene expression analysis of control and drought treated leaves. Gene encoding enzymes of pathways leading to glucose, fructose and fructan production, conversion of triose phosphates to hexoses and hexose phosphorylation were up-regulated in the drought stressed leaves. The down-regulated Calvin cycle genes were co-ordinately regulated with the down-regulation of chloroplast triosephosphate/phosphate translocator, cytoplasmic fructose-1,6-bisphosphate aldolase and fructose bisphosphatase. Expression of gene encoding Squalene Synthase (SQS) was highly upregulated under drought stress which is responsible for the diversion of carbon flux towards withanolides biosynthesis from isoprenoid pathway.
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Affiliation(s)
- Ruchi Singh
- CSIR - Central Institute of Medicinal and Aromatic Plants, Lucknow, 226015, India.
| | - Pankhuri Gupta
- CSIR - Central Institute of Medicinal and Aromatic Plants, Lucknow, 226015, India
| | - Furqan Khan
- CSIR - National Botanical Research Institute, Lucknow, 226001, India
| | - Susheel Kumar Singh
- CSIR - Central Institute of Medicinal and Aromatic Plants, Lucknow, 226015, India
| | - Tripti Mishra
- CSIR - National Botanical Research Institute, Lucknow, 226001, India
| | - Anil Kumar
- CSIR - National Botanical Research Institute, Lucknow, 226001, India
| | - Sunita Singh Dhawan
- CSIR - Central Institute of Medicinal and Aromatic Plants, Lucknow, 226015, India
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11
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Milner MJ, Howells RM, Craze M, Bowden S, Graham N, Wallington EJ. A PSTOL-like gene, TaPSTOL, controls a number of agronomically important traits in wheat. BMC PLANT BIOLOGY 2018; 18:115. [PMID: 29884124 PMCID: PMC5994007 DOI: 10.1186/s12870-018-1331-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 05/24/2018] [Indexed: 05/18/2023]
Abstract
BACKGROUND Phosphorus (P) is an essential macronutrient for plant growth, and is required in large quantities by elite varieties of crops to maintain yields. Approximately 70% of global cultivated land suffers from P deficiency, and it has recently been estimated that worldwide P resources will be exhausted by the end of this century, increasing the demand for crops more efficient in their P usage. A greater understanding of how plants are able to maintain yield with lower P inputs is, therefore, highly desirable to both breeders and farmers. Here, we clone the wheat (Triticum aestivum L.) homologue of the rice PSTOL gene (OsPSTOL), and characterize its role in phosphate nutrition plus other agronomically important traits. RESULTS TaPSTOL is a single copy gene located on the short arm of chromosome 5A, encoding a putative kinase protein, and shares a high level of sequence similarity to OsPSTOL. We re-sequenced TaPSTOL from 24 different wheat accessions and (3) three T. durum varieties. No sequence differences were detected in 26 of the accessions, whereas two indels were identified in the promoter region of one of the durum wheats. We characterised the expression of TaPSTOL under different P concentrations and demonstrated that the promoter was induced in root tips and hairs under P limiting conditions. Overexpression and RNAi silencing of TaPSTOL in transgenic wheat lines showed that there was a significant effect upon root biomass, flowering time independent of P treatment, tiller number and seed yield, correlating with the expression of TaPSTOL. However this did not increase PUE as elevated P concentration in the grain did not correspond to increased yields. CONCLUSIONS Manipulation of TaPSTOL expression in wheat shows it is responsible for many of the previously described phenotypic advantages as OsPSTOL except yield. Furthermore, we show TaPSTOL contributes to additional agronomically important traits including flowering time and grain size. Analysis of TaPSTOL sequences from a broad selection of wheat varieties, encompassing 91% of the genetic diversity in UK bread wheat, showed that there is very little genetic variation in this gene, which would suggest that this locus may have been under high selection pressure.
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Affiliation(s)
- Matthew J. Milner
- The John Bingham Laboratory, NIAB, Huntingdon Road, Cambridge, CB3 0LE UK
| | - Rhian M. Howells
- The John Bingham Laboratory, NIAB, Huntingdon Road, Cambridge, CB3 0LE UK
| | - Melanie Craze
- The John Bingham Laboratory, NIAB, Huntingdon Road, Cambridge, CB3 0LE UK
| | - Sarah Bowden
- The John Bingham Laboratory, NIAB, Huntingdon Road, Cambridge, CB3 0LE UK
| | - Neil Graham
- Plant and Crop Sciences Division, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD UK
| | - Emma J. Wallington
- The John Bingham Laboratory, NIAB, Huntingdon Road, Cambridge, CB3 0LE UK
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12
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Vinje MA, Duke SH, Henson CA. Comparison of Factors Involved in Starch Degradation in Barley Germination under Laboratory and Malting Conditions,. JOURNAL OF THE AMERICAN SOCIETY OF BREWING CHEMISTS 2018. [DOI: 10.1094/asbcj-2015-0318-01] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
| | - Stanley H. Duke
- University of Wisconsin-Madison, Department of Agronomy, Madison, WI
| | - Cynthia A. Henson
- University of Wisconsin-Madison, Department of Agronomy, Madison, WI
- USDA-ARS, CCRU
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13
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Yáñez A, Tapia G, Guerra F, del Pozo A. Stem carbohydrate dynamics and expression of genes involved in fructan accumulation and remobilization during grain growth in wheat (Triticum aestivum L.) genotypes with contrasting tolerance to water stress. PLoS One 2017; 12:e0177667. [PMID: 28552955 PMCID: PMC5446126 DOI: 10.1371/journal.pone.0177667] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 05/01/2017] [Indexed: 11/18/2022] Open
Abstract
The genetic and physiological mechanisms underlying the relationship between water-soluble carbohydrates (WSC) and water stress tolerance are scarcely known. This study aimed to evaluate the main WSC in stems, and the expression of genes involved in fructan metabolism in wheat genotypes growing in a glasshouse with water stress (WS; 50% field capacity from heading) and full irrigation (FI; 100% field capacity). Eight wheat genotypes (five tolerant and three susceptible to water stress) were evaluated initially (experiment 1) and the two most contrasting genotypes in terms of WSC accumulation were evaluated in a subsequent experiment (experiment 2). Maximum accumulation of WSC occurred 10-20 days after anthesis. Under WS, the stress-tolerant genotype exhibited higher concentrations of WSC, glucose, fructose and fructan in the stems, compared to FI. In addition, the stress-tolerant genotype exhibited higher up-regulation of the fructan 1-fructosyltransferase B (1-FFTB) and fructan 1-exohydrolase w2 (1-FEHw2) genes, whereas the susceptible cultivar presented an up-regulation of the fructan 6-fructosyltransferase (6-SFT) and fructan 1-exohydrolase w3 (1-FEHw3) genes. Our results indicated clear differences in the pattern of WSC accumulation and the expression of genes regulating fructan metabolism between the tolerant and susceptible genotypes under WS.
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Affiliation(s)
- Alejandra Yáñez
- Centro de Mejoramiento Genético y Fenómica Vegetal, Facultad de Ciencias Agrarias, PIEI Adaptación de la Agricultura al Cambio Climático (A2C2), Universidad de Talca, Talca, Chile
| | - Gerardo Tapia
- CRI-Quilamapu, Instituto de Investigaciones Agropecuarias, Chillán, Chile
| | - Fernando Guerra
- Instituto de Ciencias Biológicas, Universidad de Talca, Talca, Chile
| | - Alejandro del Pozo
- Centro de Mejoramiento Genético y Fenómica Vegetal, Facultad de Ciencias Agrarias, PIEI Adaptación de la Agricultura al Cambio Climático (A2C2), Universidad de Talca, Talca, Chile
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14
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Mellado-Mojica E, González de la Vara LE, López MG. Fructan active enzymes (FAZY) activities and biosynthesis of fructooligosaccharides in the vacuoles of Agave tequilana Weber Blue variety plants of different age. PLANTA 2017; 245:265-281. [PMID: 27730409 DOI: 10.1007/s00425-016-2602-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 09/29/2016] [Indexed: 05/28/2023]
Abstract
Biosynthesis of agave fructans occurs in mesontle vacuoles which showed fluctuations in FAZY activities and synthesized a diverse spectrum of fructooligosaccharide isomers. Agave tequilana Weber Blue variety is an important agronomic crop in Mexico. Fructan metabolism in A. tequilana exhibits changes in fructan content, type, degree of polymerization (DP), and molecular structure. Specific activities of vacuolar fructan active enzymes (FAZY) in A. tequilana plants of different age and the biosynthesis of fructooligosaccharides (FOSs) were analyzed in this work. Vacuoles from mesontle (stem) protoplasts were isolated and collected from 2- to 7-year-old plants. For the first time, agave fructans were identified in the vacuolar content by HPAEC-PAD. Several FAZY activities (1-SST, 6-SFT, 6G-FFT, 1-FFT, and FEH) with fluctuations according to the plant age were found in protein vacuolar extracts. Among vacuolar FAZY, 1-SST activities appeared in all plant developmental stages, as well as 1-FFT and FEH activities. The enzymes 6G-FFT and 6-SST showed only minimal activities. Lowest and highest FAZY activities were found in 2- and 6-year-old plants, respectively. Synthesized products (FOS) were analyzed by TLC and HPAEC-PAD. Vacuolar FAZYs yielded large FOS isomers diversity, being 7-year-old plants the ones that synthesized a greater variety of fructans with different DP, linkages, and molecular structures. Based on the above, we are proposing a model for the FAZY activities constituting the FOS biosynthetic pathways in Agave tequilana Weber Blue variety.
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Affiliation(s)
- Erika Mellado-Mojica
- Departamento de Biotecnología y Bioquímica, Centro de Investigación y de Estudios Avanzados del IPN, Unidad Irapuato. Km. 9.6 Lib. Norte Carretera Irapuato-León, Apartado Postal 629, 36821, Irapuato, Gto, Mexico
| | - Luis E González de la Vara
- Departamento de Biotecnología y Bioquímica, Centro de Investigación y de Estudios Avanzados del IPN, Unidad Irapuato. Km. 9.6 Lib. Norte Carretera Irapuato-León, Apartado Postal 629, 36821, Irapuato, Gto, Mexico
| | - Mercedes G López
- Departamento de Biotecnología y Bioquímica, Centro de Investigación y de Estudios Avanzados del IPN, Unidad Irapuato. Km. 9.6 Lib. Norte Carretera Irapuato-León, Apartado Postal 629, 36821, Irapuato, Gto, Mexico.
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15
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Zhang J, Dell B, Ma W, Vergauwen R, Zhang X, Oteri T, Foreman A, Laird D, Van den Ende W. Contributions of Root WSC during Grain Filling in Wheat under Drought. FRONTIERS IN PLANT SCIENCE 2016; 7:904. [PMID: 27446134 PMCID: PMC4917532 DOI: 10.3389/fpls.2016.00904] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 06/08/2016] [Indexed: 05/26/2023]
Abstract
As the first organ in plants to sense water-deficit in the soil, roots have important roles for improving crop adaption to water limited environments. Stem water soluble carbohydrates (WSC) are a major carbon source for grain filling under drought conditions. The contributions of root WSC during grain filling under drought has not been revealed. Wheat parental lines of Westonia, Kauz and their derived four double haploid (DH) lines, namely, DH 125, DH 139, DH 307, and DH 338 were used in a field drought experiment with four replications. Through measurements of the root and stem WSC components, and the associated enzyme activities during grain filling, we identified that the levels of root WSC and fructan were one third of the levels in stems. In particular, root glucose and 6-kestose levels were one third of the stem, while the root fructose and bifurcose level were almost half of the stem and sucrose level was two third of the stem. The accumulation and the degradation patterns of root fructan levels were similar to that in the stem, especially under drought. Correlations between root fructan levels and grain assimilation were highly significant, indicating that under terminal drought, root WSC represents a redistributed carbon source for grain filling rather than deep rooting. The significantly higher root sucrose levels under drought suggest that sucrose may act as a signal under drought stress. As compared with stem fructose levels, the earlier increased root fructose levels in DH 307, DH 139, and DH 338 provided agile response to drought stress. Our root results further confirmed that β-(2-6) linkages predominate in wheat with patterns of 6-kestose being closely correlated with overall fructan patterns. Further research will focus on the roles of 6-FEH during fructan remobilization in stems.
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Affiliation(s)
- Jingjuan Zhang
- School of Veterinary and Life Sciences, Murdoch University, MurdochWA, Australia
| | - Bernard Dell
- School of Veterinary and Life Sciences, Murdoch University, MurdochWA, Australia
| | - Wujun Ma
- School of Veterinary and Life Sciences, Murdoch University, MurdochWA, Australia
| | - Rudy Vergauwen
- Laboratory of Molecular Plant Biology, KU LeuvenLeuven, Belgium
| | - Xinmin Zhang
- School of Veterinary and Life Sciences, Murdoch University, MurdochWA, Australia
| | - Tina Oteri
- School of Engineering and Information Technology, Murdoch University, MurdochWA, Australia
| | - Andrew Foreman
- School of Engineering and Information Technology, Murdoch University, MurdochWA, Australia
| | - Damian Laird
- School of Engineering and Information Technology, Murdoch University, MurdochWA, Australia
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16
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Meguro-Maoka A, Yoshida M. Analysis of seasonal expression levels of wheat fructan exohydrolase (FEH) genes regulating fructan metabolism involved in wintering ability. JOURNAL OF PLANT PHYSIOLOGY 2016; 191:54-62. [PMID: 26717012 DOI: 10.1016/j.jplph.2015.12.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 11/25/2015] [Accepted: 12/01/2015] [Indexed: 05/20/2023]
Abstract
In northern regions, winter wheat (Triticum aestivum L.) accumulates fructan during cold-acclimation in autumn and freeze-acclimation in early winter. The content of fructan in wheat crown tissues is associated with both freezing tolerance and snow mold resistance, and expression levels of fructan synthesis genes in leaf and crown tissue are correlated with both changes and varietal differences in fructan accumulation levels of wheat during cold- and freeze-acclimation. Fructan hydrolysis activity has also been thought be involved in wintering ability of wheat. Since several kinds of gene homologs encoding fructan exohydrolase (FEH: EC. 3.2.1.153, 154) with different substrate specificities have recently been cloned from wheat, changes in transcript levels of wheat FEH genes in field-grown wheat cultivars from autumn to spring were analyzed to investigate regulation of seasonal changes in fructan content. The seasonal expression patterns of five genes encoding 1-FEH, 6-FEH (and Wfh-sm3), 6&1-FEH and 6-KEH (kestose exohydrolase) varied. Among the five genes, only seasonal changes in the expression of wfh-sm3, which codes an enzyme that is able to hydrolyze almost all components of fructan that has accumulated in hardened wheat tissues, were correlated with those changes in fructan contents. Moreover, the transcript levels of wfh-sm3 were low in snow mold-resistant cultivars that accumulate high levels of fructan. The transcript levels of 6-FEH increased with decrease in ambient temperatures and the levels decreased under snow. The analysis indicated that cooperative expression of 6-FEH and 1-FEH genes might be related to the seasonal changes and varietal difference in mono- and disaccharide contents. This study showed that the coordinated expression of FEH genes in wheat was related to the regulation of water-soluble carbohydrate accumulation from autumn to early winter and fructan consumption under snow cover as well as energy supply and that wheat FEHs also play an important role in the varietal difference in freezing tolerance and snow mold resistance. In particular, the expression of wfh-sm3 may regulate fructan metabolism associated with tolerance for wintering stresses.
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Affiliation(s)
- Ayano Meguro-Maoka
- NARO Hokkaido Agricultural Research Center, Hitsujigaoka, Sapporo, Hokkaido 062-8555, Japan
| | - Midori Yoshida
- NARO Hokkaido Agricultural Research Center, Hitsujigaoka, Sapporo, Hokkaido 062-8555, Japan.
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17
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Martínez-Noël GMA, Dosio GAA, Puebla AF, Insani EM, Tognetti JA. Sunflower: a potential fructan-bearing crop? FRONTIERS IN PLANT SCIENCE 2015; 6:798. [PMID: 26528295 PMCID: PMC4600902 DOI: 10.3389/fpls.2015.00798] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 09/14/2015] [Indexed: 06/05/2023]
Abstract
Grain filling in sunflower (Helianthus annuus L.) mainly depends on actual photosynthesis, being the contribution of stored reserves in stems (sucrose, hexoses, and starch) rather low. Drought periods during grain filling often reduce yield. Increasing the capacity of stem to store reserves could help to increase grain filling and yield stability in dry years. Fructans improve water uptake in soils at low water potential, and allow the storage of large amount of assimilates per unit tissue volume that can be readily remobilized to grains. Sunflower is a close relative to Jerusalem artichoke (H. tuberosus L.), which accumulates large amounts of fructan (inulin) in tubers and true stems. The reason why sunflower does not accumulate fructans is obscure. Through a bioinformatics analysis of a sunflower transcriptome database, we found sequences that are homologous to dicotyledon and monocotyledon fructan synthesis genes. A HPLC analysis of stem sugar composition revealed the presence of low amounts of 1-kestose, while a drastic enhancement of endogenous sucrose levels by capitulum removal did not promote 1-kestose accumulation. This suggests that the regulation of fructan synthesis in this species may differ from the currently best known model, mainly derived from research on Poaceae, where sucrose acts as both a signaling molecule and substrate, in the induction of fructan synthesis. Thus, sunflower might potentially constitute a fructan-bearing species, which could result in an improvement of its performance as a grain crop. However, a large effort is needed to elucidate how this up to now unsuspected potential could be effectively expressed.
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Affiliation(s)
- Giselle M. A. Martínez-Noël
- Instituto de Investigaciones en Biodiversidad y Biotecnología-Consejo Nacional de Investigaciones Científicas y TécnicasMar del Plata, Argentina
| | - Guillermo A. A. Dosio
- Laboratorio de Fisiología Vegetal, Facultad de Ciencias Agrarias, Universidad Nacional de Mar del PlataBalcarce, Argentina
| | - Andrea F. Puebla
- Instituto de Biotecnología, CICVyA-CNIA-INTAHurlingham, Argentina
| | - Ester M. Insani
- Instituto de Biotecnología, CICVyA-CNIA-INTAHurlingham, Argentina
| | - Jorge A. Tognetti
- Laboratorio de Fisiología Vegetal, Facultad de Ciencias Agrarias, Universidad Nacional de Mar del PlataBalcarce, Argentina
- Comisión de Investigaciones Científicas de la Provincia de Buenos AiresLa Plata, Argentina
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18
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Zhang J, Chen W, Dell B, Vergauwen R, Zhang X, Mayer JE, Van den Ende W. Wheat genotypic variation in dynamic fluxes of WSC components in different stem segments under drought during grain filling. FRONTIERS IN PLANT SCIENCE 2015; 6:624. [PMID: 26322065 PMCID: PMC4531436 DOI: 10.3389/fpls.2015.00624] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Accepted: 07/27/2015] [Indexed: 05/13/2023]
Abstract
In wheat, stem water soluble carbohydrates (WSC), composed mainly of fructans, are the major carbon sources for grain filling during periods of decreasing photosynthesis or under drought stress after anthesis. Here, in a field drought experiment, WSC levels and associated enzyme activities were followed in different stem segments (peduncle, penultimate internode, lower parts of stem, and sheath) during grain filling. The focus was on two double haploid (DH) lines, DH 307 and DH 338, derived from a Westonia/Kauz cross, two drought-tolerant wheat varieties that follow different drought adaptation strategies during grain filling. The results showed that in irrigated plants, in the period between 20 and 30 days after anthesis (DAA), 70-80% of WSC were fructans. Before and after this period, the fructan proportion varied from 10 to 60%, depending on the location along the stem. Under drought, the fructan proportion changed, depending on genotype, and developmental stages. After anthesis, stem fructans accumulation occurred mainly in the peduncle and penultimate internode until 14 DAA in both DH lines, with clear genotypic variation in subsequent fructan degradation under drought. In DH 307 a significant reduction of fructans with a concomitant increase in fructose levels occurred earlier in the lower parts of the stem and the sheath, as compared to DH 338 or other stem segments in both lines. This was associated with an earlier increase of grain weight and thousand grain weight in DH 307. Spatiotemporal analysis of fructan dynamics and enzymatic activities in fructan metabolism revealed that several types of FEHs are involved in fructan remobilization to the grain under drought.
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Affiliation(s)
- Jingjuan Zhang
- Agricultural Sciences, School of Veterinary and Life Sciences, Murdoch UniversityMurdoch, WA, Australia
| | - Wei Chen
- State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water ResourcesYangling, Shaanxi, China
| | - Bernard Dell
- Agricultural Sciences, School of Veterinary and Life Sciences, Murdoch UniversityMurdoch, WA, Australia
| | - Rudy Vergauwen
- Lab of Molecular Plant Biology, Institute of Botany and Microbiology, KU LeuvenLeuven, Belgium
| | - Xinmin Zhang
- Agricultural Sciences, School of Veterinary and Life Sciences, Murdoch UniversityMurdoch, WA, Australia
| | - Jorge E. Mayer
- Grains Research and Development CorporationBarton, ACT, Australia
| | - Wim Van den Ende
- Lab of Molecular Plant Biology, Institute of Botany and Microbiology, KU LeuvenLeuven, Belgium
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19
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Cimini S, Locato V, Vergauwen R, Paradiso A, Cecchini C, Vandenpoel L, Verspreet J, Courtin CM, D'Egidio MG, Van den Ende W, De Gara L. Fructan biosynthesis and degradation as part of plant metabolism controlling sugar fluxes during durum wheat kernel maturation. FRONTIERS IN PLANT SCIENCE 2015; 6:89. [PMID: 25750648 PMCID: PMC4335405 DOI: 10.3389/fpls.2015.00089] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 02/03/2015] [Indexed: 05/15/2023]
Abstract
Wheat kernels contain fructans, fructose based oligosaccharides with prebiotic properties, in levels between 2 and 35 weight % depending on the developmental stage of the kernel. To improve knowledge on the metabolic pathways leading to fructan storage and degradation, carbohydrate fluxes occurring during durum wheat kernel development were analyzed. Kernels were collected at various developmental stages and quali-quantitative analysis of carbohydrates (mono- and di-saccharides, fructans, starch) was performed, alongside analysis of the activities and gene expression of the enzymes involved in their biosynthesis and hydrolysis. High resolution HPAEC-PAD of fructan contained in durum wheat kernels revealed that fructan content is higher at the beginning of kernel development, when fructans with higher DP, such as bifurcose and 1,1-nystose, were mainly found. The changes in fructan pool observed during kernel maturation might be part of the signaling pathways influencing carbohydrate metabolism and storage in wheat kernels during development. During the first developmental stages fructan accumulation may contribute to make kernels more effective Suc sinks and to participate in osmotic regulation while the observed decrease in their content may mark the transition to later developmental stages, transition that is also orchestrated by changes in redox balance.
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Affiliation(s)
- Sara Cimini
- Laboratory of Plant Biochemistry and Food Sciences, Campus Bio-Medico UniversityRome, Italy
| | - Vittoria Locato
- Laboratory of Plant Biochemistry and Food Sciences, Campus Bio-Medico UniversityRome, Italy
| | - Rudy Vergauwen
- Laboratory for Molecular Plant Biology and Leuven Food Science and Nutrition Research Centre (LFoRCe), KU LeuvenLeuven, Belgium
| | | | - Cristina Cecchini
- Consiglio per la Ricerca e la Sperimentazione in Agricoltura, Unità di ricerca per la Valorizzazione Qualitativa dei CerealiRome, Italy
| | - Liesbeth Vandenpoel
- Laboratory of Plant Biochemistry and Food Sciences, Campus Bio-Medico UniversityRome, Italy
- Laboratory for Molecular Plant Biology and Leuven Food Science and Nutrition Research Centre (LFoRCe), KU LeuvenLeuven, Belgium
| | - Joran Verspreet
- Laboratory of Food Chemistry and Biochemistry, KU LeuvenLeuven, Belgium
| | | | - Maria Grazia D'Egidio
- Consiglio per la Ricerca e la Sperimentazione in Agricoltura, Unità di ricerca per la Valorizzazione Qualitativa dei CerealiRome, Italy
| | - Wim Van den Ende
- Laboratory for Molecular Plant Biology and Leuven Food Science and Nutrition Research Centre (LFoRCe), KU LeuvenLeuven, Belgium
| | - Laura De Gara
- Laboratory of Plant Biochemistry and Food Sciences, Campus Bio-Medico UniversityRome, Italy
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20
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Zhang J, Xu Y, Chen W, Dell B, Vergauwen R, Biddulph B, Khan N, Luo H, Appels R, Van den Ende W. A wheat 1-FEH w3 variant underlies enzyme activity for stem WSC remobilization to grain under drought. THE NEW PHYTOLOGIST 2015; 205:293-305. [PMID: 25250511 DOI: 10.1111/nph.13030] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 07/27/2014] [Indexed: 05/18/2023]
Abstract
In wheat stems, the levels of fructan-dominated water-soluble carbohydrates (WSC) do not always correlate well with grain yield. Field drought experiments were carried out to further explain this lack of correlation. Wheat (Triticum aestivum) varieties, Westonia, Kauz and c. 20 genetically diverse double haploid (DH) lines derived from them were investigated. Substantial genotypic differences in fructan remobilization were found and the 1-FEH w3 gene was shown to be the major contributor in the stem fructan remobilization process based on enzyme activity and gene expression results. A single nucleotide polymorphism (SNP) was detected in an auxin response element in the 1-FEH w3 promoter region, therefore we speculated that the mutated Westonia allele might affect gene expression and enzyme activity levels. A cleaved amplified polymorphic (CAP) marker was generated from the SNP. The harvested results showed that the mutated Westonia 1-FEH w3 allele was associated with a higher thousand grain weight (TGW) under drought conditions in 2011 and 2012. These results indicated that higher gene expression of 1-FEH w3 and 1-FEH w3 mediated enzyme activities that favoured stem WSC remobilization to the grains. The CAP marker residing in the 1-FEH w3 promoter region may facilitate wheat breeding by selecting lines with high stem fructan remobilization capacity under terminal drought.
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Affiliation(s)
- Jingjuan Zhang
- School of Veterinary and Life Sciences, Murdoch University, South Street, Murdoch, WA, 6150, Australia
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Casassola A, Brammer SP, Chaves MS, Martinelli JA, Stefanato F, Boyd LA. Changes in gene expression profiles as they relate to the adult plant leaf rust resistance in the wheat cv. Toropi. PHYSIOLOGICAL AND MOLECULAR PLANT PATHOLOGY 2015; 89:49-54. [PMID: 25892845 PMCID: PMC4394150 DOI: 10.1016/j.pmpp.2014.12.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 12/19/2014] [Indexed: 05/08/2023]
Abstract
Leaf rust, caused by the foliar pathogen Puccinia triticina is a major disease of wheat in the southern region of Brazil and invariably impacts on production, being responsible for high yield losses. The Brazilian wheat cultivar Toropi has proven, durable adult plant resistance (APR) to leaf rust, which uniquely shows a pre-haustorial resistance phenotype. In this study we aimed to understand the interaction between P. triticina and the pre-haustorial APR in Toropi by quantitatively evaluating the temporal transcription profiles of selected genes known to be related to infection and defense in wheat. The expression profiles of 15 selected genes varied over time, grouping into six expression profile groups. The expression profiles indicated the induction of classical defence pathways in response to pathogen development, but also the potential modification of Toropi's cellular status for the benefit of the pathogen. Classical defence genes, including peroxidases, β-1,3-glucanases and an endochitinase were expressed both early (pre-haustorial) and late (post-haustorial) over the 72 h infection time course, while induction of transcription of other infection-related genes with a potential role in defence, although variable was maintained through-out. These genes directly or indirectly had a role in plant lignification, oxidative stress, the regulation of energy supply, water and lipid transport, and cell cycle regulation. The early induction of transcription of defence-related genes supports the pre-haustorial resistance phenotype in Toropi, providing a valuable source of genes controlling leaf rust resistance for wheat breeding.
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Key Words
- APR, adult plant resistance
- AQP1, aquaporin
- COMT1, caffeic acid O-methyltransferase
- ETI, Effector-Triggered-Immunity
- FREX, fructan exohydrolase
- G6DPH, glucose-6-phosphate dehydrogenase
- GAPDH, glyceraldehyde 3-phosphate dehydrogenase
- HSP80, heat shock protein 80
- LHC, light-harvesting complex
- LTP, type 1 non-specific lipid transfer protein precursor
- MIP, major intrinsic proteins
- NADPH, nicotinamide adenine dinucleotide phosphate
- PAL, phenylalanine ammonia-lyase
- PR, pathogenesis-related
- PRA2, class III peroxidase
- PTI, PAMP-Triggered-Immunity
- Pre-haustorial
- Puccinia triticina
- Quantitative PCR
- RBR1, retinoblastoma related protein 1
- ROS, reactive oxygen species
- Triticum aestivum (L.) thell
- WCAB, chlorophyll a/b-binding protein WCAB precursor
- Wheat breeding
- ZIP5, putative zinc transporter
- hai, hours after inoculation
- qPCR, quantitative PCR
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Affiliation(s)
- Alice Casassola
- Agronomy Post-Graduate Program, University of Passo Fundo, BR285, Passo Fundo, Rio Grande do Sul 99052900, Brazil
| | - Sandra P. Brammer
- Department of Biotechnology and Phytophatology, Brazilian Agricultural Research Corporation, BR285, Km294, Passo Fundo, Rio Grande do Sul 99001970, Brazil
| | - Márcia S. Chaves
- Department of Biotechnology and Phytophatology, Brazilian Agricultural Research Corporation, BR285, Km294, Passo Fundo, Rio Grande do Sul 99001970, Brazil
| | - José A. Martinelli
- Department of Fitossanidade, Federal University of Rio Grande do Sul, Avenida Bento Gonçalves 7712, Porto Alegre, Rio Grande do Sul 91540000, Brazil
| | - Francesca Stefanato
- Department of Genetics and Pre-Breeding, National Institute of Agricultural Botany, Huntington Road, Cambridge, Cambridgeshire CB3 0LE, UK
| | - Lesley A. Boyd
- Department of Genetics and Pre-Breeding, National Institute of Agricultural Botany, Huntington Road, Cambridge, Cambridgeshire CB3 0LE, UK
- Department of Life and Medical Sciences, University of Hertfordshire, Hatfield, Hertfordshire AL10 9AB, UK
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22
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Nie Z, Hu C, Liu H, Tan Q, Sun X. Differential expression of molybdenum transport and assimilation genes between two winter wheat cultivars (Triticum aestivum). PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2014; 82:27-33. [PMID: 24880579 DOI: 10.1016/j.plaphy.2014.05.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Accepted: 05/09/2014] [Indexed: 05/12/2023]
Abstract
Molybdenum (Mo) is an essential trace element for higher plants. Winter wheat cultivar 97003 has a higher Mo efficiency than 97014 under Mo-deficiency stress. Mo efficiency is related to Mo uptake, transfer and assimilation in plants. Several genes are involved in regulating Mo uptake, transfer and assimilation in plants. To obtain a better understanding of the aforementioned difference in Mo uptake, we have conducted a hydroponic trail to investigate the expression of genes related to Mo uptake, transfer and assimilation in the above two cultivars. The results indicate a closed relationship between Mo uptake and TaSultr5.1, TaSultr5.2 and TaCnx1 expression, according to a stepwise regression analysis of the time course of Mo uptake in the two cultivars. Meanwhile, expression of TaSultr5.2 in roots also showed a positive relationship with Mo uptake rates. 97003 had stronger Mo uptake than 97014 at low Mo-application rates (less than 1 μmol Mo L(-1)) due to the higher expression of TaSultr5.2, TaSultr5.1 and TaCnx1 in roots. On the contrary, Mo uptake of 97003 was weaker than 97014 at high Mo application rates (ranging from 5 to 20 μmol Mo L(-1)), which was related to significant down-regulation of TaSultr5.2 and TaCnx1 genes in roots of 97003 compared to 97014. Therefore, we speculated that the differential-expression intensities of TaSultr5.2, TaSultr5.1 and TaCnx1 could be the cause of the difference in Mo uptake between the two winter wheat cultivars at low and high Mo application levels.
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Affiliation(s)
- Zhaojun Nie
- Micro-element Research Center, Huazhong Agricultural University, Wuhan 430070, China
| | - Chengxiao Hu
- Micro-element Research Center, Huazhong Agricultural University, Wuhan 430070, China
| | - Hongen Liu
- Micro-element Research Center, Huazhong Agricultural University, Wuhan 430070, China; College of Resources and Environment, Henan Agricultural University, Zhengzhou 450002, China
| | - Qiling Tan
- Micro-element Research Center, Huazhong Agricultural University, Wuhan 430070, China
| | - Xuecheng Sun
- Micro-element Research Center, Huazhong Agricultural University, Wuhan 430070, China.
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Lothier J, Van Laere A, Prud'homme MP, Van den Ende W, Morvan-Bertrand A. Cloning and characterization of a novel fructan 6-exohydrolase strongly inhibited by sucrose in Lolium perenne. PLANTA 2014; 240:629-43. [PMID: 25023629 DOI: 10.1007/s00425-014-2110-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Accepted: 06/17/2014] [Indexed: 05/22/2023]
Abstract
The first 6-fructan exohydrolase (6-FEH) cDNA from Lolium perenne was cloned and characterized. Following defoliation, Lp6 - FEHa transcript level unexpectedly decreased together with an increase in total FEH activity. Lolium perenne is a major forage grass species that accumulates fructans, mainly composed of β(2,6)-linked fructose units. Fructans are mobilized through strongly increased activities of fructan exohydrolases (FEHs), sustaining regrowth following defoliation. To understand the complex regulation of fructan breakdown in defoliated grassland species, the objective was to clone and characterize new FEH genes in L. perenne. To find FEH genes related to refoliation, a defoliated tiller base cDNA library was screened. Characterization of the recombinant protein was performed in Pichia pastoris. In this report, the cloning and enzymatic characterization of the first 6-FEH from L. perenne is described. Following defoliation, during fructan breakdown, Lp6-FEHa transcript level unexpectedly decreased in elongating leaf bases (ELB) and in mature leaf sheaths (tiller base) in parallel to increased total FEH activities. In comparison, transcript levels of genes coding for fructosyltransferases (FTs) involved in fructan biosynthesis also decreased after defoliation but much faster than FEH transcript levels. Since Lp6-FEHa was strongly inhibited by sucrose, mechanisms modulating FEH activities are discussed. It is proposed that differences in the regulation of FEH activity among forage grasses influence their tolerance to defoliation.
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Affiliation(s)
- Jérémy Lothier
- Institut de Recherche en Horticulture et Semences (INRA, Agrocampus-Ouest, Université d'Angers), Université d'Angers, SFR 149 QUASAV, 49045, Angers, France
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24
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Suárez-González EM, López MG, Délano-Frier JP, Gómez-Leyva JF. Expression of the 1-SST and 1-FFT genes and consequent fructan accumulation in Agave tequilana and A. inaequidens is differentially induced by diverse (a)biotic-stress related elicitors. JOURNAL OF PLANT PHYSIOLOGY 2014; 171:359-72. [PMID: 23988562 DOI: 10.1016/j.jplph.2013.08.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Revised: 08/02/2013] [Accepted: 08/03/2013] [Indexed: 05/20/2023]
Abstract
The expression of genes coding for sucrose:sucrose 1-fructosyltransferase (1-SST; EC 2.4.1.99) and fructan:fructan 1-fructosyltransferase (1-FFT; EC 2.4.1.100), both fructan biosynthesizing enzymes, characterization by TLC and HPAEC-PAD, as well as the quantification of the fructo-oligosaccharides (FOS) accumulating in response to the exogenous application of sucrose, kinetin (cytokinin) or other plant hormones associated with (a)biotic stress responses were determined in two Agave species grown in vitro, domesticated Agave tequilana var. azul and wild A. inaequidens. It was found that elicitors such as salicylic acid (SA), and jasmonic acid methyl ester (MeJA) had the strongest effect on fructo-oligosaccharide (FOS) accumulation. The exogenous application of 1mM SA induced a 36-fold accumulation of FOS of various degrees of polymerization (DP) in stems of A. tequilana. Other treatments, such as 50mM abscisic acid (ABA), 8% Sucrose (Suc), and 1.0 mg L(-1) kinetin (KIN) also led to a significant accumulation of low and high DP FOS in this species. Conversely, treatment with 200 μM MeJA, which was toxic to A. tequilana, induced an 85-fold accumulation of FOS in the stems of A. inaequidens. Significant FOS accumulation in this species also occurred in response to treatments with 1mM SA, 8% Suc, and 10% polyethylene glycol (PEG). Maximum yields of 13.6 and 8.9 mg FOS per g FW were obtained in stems of A. tequilana and A. inaequidens, respectively. FOS accumulation in the above treatments was tightly associated with increased expression levels of either the 1-FFT or the 1-SST gene in tissues of both Agave species.
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Affiliation(s)
- Edgar Martín Suárez-González
- Laboratorio de Biología Molecular, Instituto Tecnológico de Tlajomulco, Jalisco (ITTJ), km 10 Carretera a San Miguel Cuyutlán, CP 45640 Tlajomulco de Zúñiga, Jalisco, Mexico
| | - Mercedes G López
- Unidad de Biotecnología e Ingeniería Genética de Plantas, Cinvestav-Unidad Irapuato, km 9.6, Libramiento Norte Carretera Irapuato-León, CP 36821 Irapuato, Guanajuato, Mexico
| | - John P Délano-Frier
- Unidad de Biotecnología e Ingeniería Genética de Plantas, Cinvestav-Unidad Irapuato, km 9.6, Libramiento Norte Carretera Irapuato-León, CP 36821 Irapuato, Guanajuato, Mexico
| | - Juan Florencio Gómez-Leyva
- Laboratorio de Biología Molecular, Instituto Tecnológico de Tlajomulco, Jalisco (ITTJ), km 10 Carretera a San Miguel Cuyutlán, CP 45640 Tlajomulco de Zúñiga, Jalisco, Mexico.
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25
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Rohozková J, Šebela M, Navrátil M. P1 peptidase of Pea seed-borne mosaic virus contains non-canonical C2H2 zinc finger and may act in a truncated form. ACTA ACUST UNITED AC 2014. [DOI: 10.7243/2050-2389-3-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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26
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Verspreet J, Cimini S, Vergauwen R, Dornez E, Locato V, Le Roy K, De Gara L, Van den Ende W, Delcour JA, Courtin CM. Fructan Metabolism in Developing Wheat (Triticum aestivum L.) Kernels. ACTA ACUST UNITED AC 2013; 54:2047-57. [DOI: 10.1093/pcp/pct144] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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27
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Kawakami A, Yoshida M. Graminan breakdown by fructan exohydrolase induced in winter wheat inoculated with snow mold. JOURNAL OF PLANT PHYSIOLOGY 2012; 169:294-302. [PMID: 21983139 DOI: 10.1016/j.jplph.2011.09.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2011] [Revised: 09/14/2011] [Accepted: 09/14/2011] [Indexed: 05/28/2023]
Abstract
Fructan structures vary widely among plant species. Graminan-type fructans, extensions of sucrose through β-(2,6)-linked fructosyl units with branches of β-(2,1)-linked fructosyl units, accumulate in tissues of winter wheat (Triticum aestivum) during cold hardening and are metabolized under persistent snow cover. Snow molds such as Typhula ishikariensis and Microdochium nivale opportunistically infect wheat under snow cover. Snow mold-resistant wheat cultivars tend to heavily accumulate and slowly metabolize water-soluble carbohydrates including graminans in comparison with snow mold-susceptible cultivars. We observed time-dependent changes in the amounts of water-soluble carbohydrates in snow mold-inoculated wheat tissues, and accumulated fructan levels significantly decreased as a result of snow mold inoculation and incubation under snow cover, especially in a snow mold-susceptible wheat cultivar. Three candidates for fructan exohydrolase (FEH) cDNAs with high homology to cell wall invertases were isolated from wheat leaf tissues inoculated with snow mold and incubated under snow cover. The substrate specificity of enzymes encoded by the isolated clones was analyzed by recombinant proteins expressed in Pichia pastoris. The recombinant protein (Wfh-sm3m) encoded by one (Wfh-sm3) of the isolated clones preferentially degraded 6-kestotriose and possessed minor hydrolase activity to 1-kestotriose and 1,1-kestotetraose. Moreover, Wfh-sm3m hydrolyzed almost all graminans that accumulated in hardened wheat tissues. Wfh-sm3 transcripts increased in wheat leaf tissues inoculated with snow mold and incubated under snow cover. These results suggest that Wfh-sm3 encodes a 6-FEH with minor 1-FEH activity and is associated with degradation of fructans in wheat leaf tissues during inoculation and incubation under snow cover.
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Affiliation(s)
- Akira Kawakami
- NARO Hokkaido Agricultural Research Center, Hitsujigaoka 1, Toyohira, Sapporo 062-8555, Japan.
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28
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Joudi M, Ahmadi A, Mohamadi V, Abbasi A, Vergauwen R, Mohammadi H, Van den Ende W. Comparison of fructan dynamics in two wheat cultivars with different capacities of accumulation and remobilization under drought stress. PHYSIOLOGIA PLANTARUM 2012; 144:1-12. [PMID: 21895669 DOI: 10.1111/j.1399-3054.2011.01517.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Remobilization of stored carbohydrates in the stem of wheat plants is an important contributor to grain filling under drought stress (DS) conditions. A massive screening on Iranian wheat cultivars was performed based on stem dry weight changes under well-watered and DS conditions. Two cultivars, Shole and Crossed Falat Hamun (CFH), with different fructan accumulation and remobilization behavior were selected for further studies. Water-soluble carbohydrates (WSCs) and fructan metabolizing enzymes were studied both in the stem penultimate and in sucrose (Suc) treated, excised leaves. Under drought, CFH produced higher grain yields than Shole (412 vs 220 g m(-2)). Also, grain yield loss under drought was more limited in CFH than in Shole (17 vs 54%). Under drought, CFH accumulated more graminan-type fructo-oligosaccharides than Shole. After anthesis, fructan 6-exohydrolase (6-FEH; EC 3.2.1.154) activities increased more prominently than fructan 1-exohydrolase (EC 3.2.1.153) activities during carbon remobilization. Interestingly, CFH showed higher 6-FEH activities in the penultimate than Shole. The field experiment results suggest that the combined higher remobilization efficiency and high 6-FEH activities in stems of wheat could contribute to grain yield under terminal drought. Similar to the penultimate, fructan metabolism differed strongly in Suc-treated detached leaves of selected cultivars. This suggests that variation in the stem fructan among wheat cultivars grown in the field could be traced by leaf blade induction experiments.
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Affiliation(s)
- Mehdi Joudi
- Moghan College of Agriculture, University of Mohaghegh Ardabili, Ardabil, Iran
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29
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Murgia I, Arosio P, Tarantino D, Soave C. Biofortification for combating 'hidden hunger' for iron. TRENDS IN PLANT SCIENCE 2012; 17:47-55. [PMID: 22093370 DOI: 10.1016/j.tplants.2011.10.003] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Revised: 09/14/2011] [Accepted: 10/07/2011] [Indexed: 05/20/2023]
Abstract
Micronutrient deficiencies are responsible for so-called 'hidden undernutrition'. In particular, iron (Fe) deficiency adversely affects growth, immune function and can cause anaemia. However, supplementation of iron can exacerbate infectious diseases and current policies of iron therapy carefully evaluate the risks and benefits of these interventions. Here we review the approaches of biofortification of valuable crops for reducing 'hidden undernutrition' of iron in the light of the latest nutritional and medical advances. The increase of iron and prebiotics in edible parts of plants is expected to improve health, whereas the reduction of phytic acid concentration, in crops valuable for human diet, might be less beneficial for the developed countries, or for the developing countries exposed to endemic infections.
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Affiliation(s)
- Irene Murgia
- Sezione di Fisiologia e Biochimica delle Piante, Dipartimento di Biologia, Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy.
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Xue GP, Kooiker M, Drenth J, McIntyre CL. TaMYB13 is a transcriptional activator of fructosyltransferase genes involved in β-2,6-linked fructan synthesis in wheat. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2011; 68:857-70. [PMID: 21838777 DOI: 10.1111/j.1365-313x.2011.04737.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Fructans are soluble fructosyl-oligosaccharides deposited in many cool-season grass species as a carbon reserve; they are synthesised by fructosyltransferases. In wheat and barley fructans can accumulate in mature stems at a very high level and serve as an important carbon source for grain filling. Fructan synthesis in temperate cereals is regulated by sucrose level and developmental signals, and functions as a metabolic adjustment for carbon balance between carbon supply and sink demand. In this study the expression levels of a highly homologous group of Triticum aestivumMYB genes (TaMYB13-1, TaMYB13-2 and TaMYB13-3) were found to be positively correlated with the mRNA levels of sucrose:sucrose 1-fructosyltransferase (1-SST) and sucrose:fructan 6-fructosyltransferase (6-SFT) in wheat stems among recombinant inbred lines with a wide range of fructan concentrations through Affymetrix array expression analysis. This expression correction extended to expression profiles during stem development. TaMYB13 contains an R2R3-type MYB domain. In vitro random DNA-binding site selection followed by base substitution mutagenesis revealed that TaMYB13 bound to a (A/G/T)TT(A/T/C)GGT core sequence, which was present in the promoters of wheat Ta1-SST and Ta6-SFT genes as well as a barley Hv6-SFT gene. Transactivation analysis showed that TaMYB13 was a transcriptional activator and could markedly enhance the expression of 1-SST and 6-SFT promoter-driven reporter genes in wheat. Elimination of TaMYB13-binding sites in Ta6-SFT and Ta1-SST promoters markedly reduced TaMYB13-mediated reporter gene transactivation. These data suggest that TaMYB13 and its orthologues are positive regulators for controlling the expression of major fructosyltransferases involved in the fructan synthetic pathway in temperate cereals.
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Affiliation(s)
- Gang-Ping Xue
- CSIRO Plant Industry, 306 Carmody Road, St Lucia, Qld 4067, Australia.
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Pearce S, Saville R, Vaughan SP, Chandler PM, Wilhelm EP, Sparks CA, Al-Kaff N, Korolev A, Boulton MI, Phillips AL, Hedden P, Nicholson P, Thomas SG. Molecular characterization of Rht-1 dwarfing genes in hexaploid wheat. PLANT PHYSIOLOGY 2011; 157:1820-31. [PMID: 22013218 PMCID: PMC3327217 DOI: 10.1104/pp.111.183657] [Citation(s) in RCA: 177] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2011] [Accepted: 10/19/2011] [Indexed: 05/18/2023]
Abstract
The introduction of the Reduced height (Rht)-B1b and Rht-D1b semidwarfing genes led to impressive increases in wheat (Triticum aestivum) yields during the Green Revolution. The reduction in stem elongation in varieties containing these alleles is caused by a limited response to the phytohormone gibberellin (GA), resulting in improved resistance to stem lodging and yield benefits through an increase in grain number. Rht-B1 and Rht-D1 encode DELLA proteins, which act to repress GA-responsive growth, and their mutant alleles Rht-B1b and Rht-D1b are thought to confer dwarfism by producing more active forms of these growth repressors. While no semidwarfing alleles of Rht-A1 have been identified, we show that this gene is expressed at comparable levels to the other homeologs and represents a potential target for producing novel dwarfing alleles. In this study, we have characterized additional dwarfing mutations in Rht-B1 and Rht-D1. We show that the severe dwarfism conferred by Rht-B1c is caused by an intragenic insertion, which results in an in-frame 90-bp insertion in the transcript and a predicted 30-amino acid insertion within the highly conserved amino-terminal DELLA domain. In contrast, the extreme dwarfism of Rht-D1c is due to overexpression of the semidwarfing Rht-D1b allele, caused by an increase in gene copy number. We show also that the semidwarfing alleles Rht-B1d and Rht-B1e introduce premature stop codons within the amino-terminal coding region. Yeast two-hybrid assays indicate that these newly characterized mutations in Rht-B1 and Rht-D1 confer "GA-insensitive" dwarfism by producing DELLA proteins that do not bind the GA receptor GA INSENSITIVE DWARF1, potentially compromising their targeted degradation.
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Tamura KI, Sanada Y, Tase K, Komatsu T, Yoshida M. Pp6-FEH1 encodes an enzyme for degradation of highly polymerized levan and is transcriptionally induced by defoliation in timothy (Phleum pratense L.). JOURNAL OF EXPERIMENTAL BOTANY 2011; 62:3421-31. [PMID: 21317211 PMCID: PMC3130170 DOI: 10.1093/jxb/err018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Revised: 01/07/2011] [Accepted: 01/17/2011] [Indexed: 05/07/2023]
Abstract
The ability of grasses to regrow after defoliation by cutting or grazing is a vital factor in their survival and an important trait when they are used as forage crops. In temperate grass species accumulating fructans, defoliation induces the activity of a fructan exohydrolase (FEH) that degrades fructans to serve as a carbon source for regrowth. Here, a cDNA from timothy was cloned, named Pp6-FEH1, that showed similarity to wheat fructan 6-exohydrolase (6-FEH). The recombinant enzyme expressed in Pichia pastoris completely degraded fructans that were composed mainly of β(2,6)-linked and linear fructans (levan) with a high degree of polymerization (DP) in the crown tissues of timothy. The substrate specificity of Pp6-FEH1 differed from previously characterized enzymes with 6-FEH activity in fructan-accumulating plants: (i) Pp6-FEH1 showed 6-FEH activity against levan (mean DP 20) that was 4-fold higher than against 6-kestotriose (DP 3), indicating that Pp6-FEH1 has a preference for β(2,6)-linked fructans with high DP; (ii) Pp6-FEH1 had significant activity against β(2,1)-linked fructans, but considerably less than against β(2,6)-linked fructans; (iii) Pp6-FEH1 had weak invertase activity, and its 6-FEH activity was inhibited slightly by sucrose. In the stubble of seedlings and in young haplocorms from adult timothy plants, transcripts of Pp6-FEH1 were significantly increased within 3 h of defoliation, followed by an increase in 6-FEH activity and in the degradation of fructans. These results suggest that Pp6-FEH1 plays a role in the degradation of fructans and the mobilization of carbon sources for regrowth after defoliation in timothy.
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Affiliation(s)
- Ken-ihi Tamura
- National Agricultural Research Center for Hokkaido Region, Hitsujigaoka 1, Toyohira, Sapporo 062-8555, Japan.
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Ueno K, Ishiguro Y, Yoshida M, Onodera S, Shiomi N. Cloning and functional characterization of a fructan 1-exohydrolase (1-FEH) in edible burdock (Arctium lappa L.). Chem Cent J 2011; 5:16. [PMID: 21463533 PMCID: PMC3080278 DOI: 10.1186/1752-153x-5-16] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2011] [Accepted: 04/05/2011] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND We have previously reported on the variation of total fructooligosaccharides (FOS), total inulooligosaccharides (IOS) and inulin in the roots of burdock stored at different temperatures. During storage at 0°C, an increase of FOS as a result of the hydrolysis of inulin was observed. Moreover, we suggested that an increase of IOS would likely be due to the synthesis of the IOS by fructosyltransfer from 1-kestose to accumulated fructose and elongated fructose oligomers which can act as acceptors for fructan:fructan 1-fructosyltransferase (1-FFT). However, enzymes such as inulinase or fructan 1-exohydorolase (1-FEH) involved in inulin degradation in burdock roots are still not known. Here, we report the isolation and functional analysis of a gene encoding burdock 1-FEH. RESULTS A cDNA, named aleh1, was obtained by the RACE method following PCR with degenerate primers designed based on amino-acid sequences of FEHs from other plants. The aleh1 encoded a polypeptide of 581 amino acids. The relative molecular mass and isoelectric point (pI) of the deduced polypeptide were calculated to be 65,666 and 4.86. A recombinant protein of aleh1 was produced in Pichia pastoris, and was purified by ion exchange chromatography with DEAE-Sepharose CL-6B, hydrophobic chromatography with Toyopearl HW55S and gel filtration chromatography with Toyopearl HW55S. Purified recombinant protein showed hydrolyzing activity against β-2, 1 type fructans such as 1-kestose, nystose, fructosylnystose and inulin. On the other hand, sucrose, neokestose, 6-kestose and high DP levan were poor substrates.The purified recombinant protein released fructose from sugars extracted from burdock roots. These results indicated that aleh1 encoded 1-FEH.
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Affiliation(s)
- Keiji Ueno
- Department of Food and Nutrition Sciences, Graduate School of Dairy Science Research, Rakuno Gakuen University, 582 Bunkyodai Midorimachi, Ebetsu, 069-8501, Japan.
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Van den Ende W, Coopman M, Clerens S, Vergauwen R, Le Roy K, Lammens W, Van Laere A. Unexpected presence of graminan- and levan-type fructans in the evergreen frost-hardy eudicot Pachysandra terminalis (Buxaceae): purification, cloning, and functional analysis of a 6-SST/6-SFT enzyme. PLANT PHYSIOLOGY 2011; 155:603-14. [PMID: 21037113 PMCID: PMC3075768 DOI: 10.1104/pp.110.162222] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2010] [Accepted: 10/29/2010] [Indexed: 05/04/2023]
Abstract
About 15% of flowering plants accumulate fructans. Inulin-type fructans with β(2,1) fructosyl linkages typically accumulate in the core eudicot families (e.g. Asteraceae), while levan-type fructans with β(2,6) linkages and branched, graminan-type fructans with mixed linkages predominate in monocot families. Here, we describe the unexpected finding that graminan- and levan-type fructans, as typically occurring in wheat (Triticum aestivum) and barley (Hordeum vulgare), also accumulate in Pachysandra terminalis, an evergreen, frost-hardy basal eudicot species. Part of the complex graminan- and levan-type fructans as accumulating in vivo can be produced in vitro by a sucrose:fructan 6-fructosyltransferase (6-SFT) enzyme with inherent sucrose:sucrose 1-fructosyltransferase (1-SST) and fructan 6-exohydrolase side activities. This enzyme produces a series of cereal-like graminan- and levan-type fructans from sucrose as a single substrate. The 6-SST/6-SFT enzyme was fully purified by classic column chromatography. In-gel trypsin digestion led to reverse transcription-polymerase chain reaction-based cDNA cloning. The functionality of the 6-SST/6-SFT cDNA was demonstrated after heterologous expression in Pichia pastoris. Both the recombinant and native enzymes showed rather similar substrate specificity characteristics, including peculiar temperature-dependent inherent 1-SST and fructan 6-exohydrolase side activities. The finding that cereal-type fructans accumulate in a basal eudicot species further confirms the polyphyletic origin of fructan biosynthesis in nature. Our data suggest that the fructan syndrome in P. terminalis can be considered as a recent evolutionary event. Putative connections between abiotic stress and fructans are discussed.
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Affiliation(s)
- Wim Van den Ende
- Laboratory of Molecular Plant Physiology, Institute of Botany and Microbiology, KU Leuven, B-3001 Leuven, Belgium.
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Szucs A, Jäger K, Jurca ME, Fábián A, Bottka S, Zvara A, Barnabás B, Fehér A. Histological and microarray analysis of the direct effect of water shortage alone or combined with heat on early grain development in wheat (Triticum aestivum). PHYSIOLOGIA PLANTARUM 2010; 140:174-88. [PMID: 20573045 DOI: 10.1111/j.1399-3054.2010.01394.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Based on the in silico analysis of the representation of expressed sequence tags (ESTs) in wheat grain-related cDNA libraries, a specific 15k oligonucleotide microarray has been developed in order to monitor environmental stress-dependent gene expression changes in the wheat caryopses. Using this array, the effect of water withdrawal, with and without additional heat stress, has been investigated during the first five days of kernel development on two wheat cultivars differing in their drought sensitivity. Water shortage affected (more than twofold change) the expression of only 0.5% of the investigated genes. A parallel heat treatment increased the ratio of responding genes to 5-7% because of the temperature stress and/or the increased water deficit because of enhanced evaporation. It could be established that the two cultivars, differing in their long-term adaptation capabilities to drought, responded to the short and direct stress treatments on the same way. In response to the combined drought and heat treatment, the coordinately altered expression of genes coding for storage proteins, enzymes involved in sugar/starch metabolism, histone proteins, heat shock proteins, proteases, tonoplast aquaporins as well as several transcription factors has been observed. These gene expression changes were in agreement with histological data that demonstrated the accelerated development of the embryo as well as the endosperm.
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Affiliation(s)
- Attila Szucs
- Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, Szeged, Hungary
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Bozkurt TO, McGrann GRD, MacCormack R, Boyd LA, Akkaya MS. Cellular and transcriptional responses of wheat during compatible and incompatible race-specific interactions with Puccinia striiformis f. sp. tritici. MOLECULAR PLANT PATHOLOGY 2010; 11:625-40. [PMID: 20696001 PMCID: PMC6640440 DOI: 10.1111/j.1364-3703.2010.00633.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The initial stages of Puccinia striiformis f. sp. tritici (the causal agent of yellow rust in wheat) infection triggered a hypersensitive cell death (HCD) response in both compatible and Yr1-mediated incompatible interactions, although the response was earlier and more extensive in the incompatible interaction. Later stages of fungal development were only associated with an HCD response in the incompatible interaction, the HCD response being effectively suppressed in the compatible interaction. Cell autofluorescence was seen in mesophyll cells in direct contact with fungal infection hyphae (primary HCD) and in adjacent mesophyll cells (secondary HCD), indicating the activation of cell-to-cell signalling. Microarray analysis identified a number of defence-related transcripts implicated in Yr1-mediated resistance, including classical pathogenesis-related (PR) transcripts and genes involved in plant cell defence responses, such as the oxidative burst and cell wall fortification. A quantitative reverse transcriptase-polymerase chain reaction time course analysis identified a number of defence-related genes, including PR2, PR4, PR9, PR10 and WIR1 transcripts, associated with the latter stages of Yr1-mediated resistance. A meta-analysis comparison of the Yr1-regulated transcriptome with the resistance transcriptomes of the race-specific resistance gene Yr5 and the race-nonspecific adult plant resistance gene Yr39 indicated limited transcript commonality. Common transcripts were largely confined to classic PR and defence-related genes.
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Affiliation(s)
- Tolga O Bozkurt
- Middle East Technical University, Department of Chemistry, Biochemistry and Biotechnology Programs, Ankara, Turkey
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Yıldız S. The Metabolism of Fructooligosaccharides and Fructooligosaccharide-Related Compounds in Plants. FOOD REVIEWS INTERNATIONAL 2010. [DOI: 10.1080/87559129.2010.518295] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- S. Yıldız
- a Süleyman Demirel University, Chemical Engineering Department , Çünür , Isparta , Turkey
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Engelke T, Hirsche J, Roitsch T. Anther-specific carbohydrate supply and restoration of metabolically engineered male sterility. JOURNAL OF EXPERIMENTAL BOTANY 2010; 61:2693-706. [PMID: 20427415 PMCID: PMC2882265 DOI: 10.1093/jxb/erq105] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2010] [Revised: 03/29/2010] [Accepted: 03/29/2010] [Indexed: 05/18/2023]
Abstract
Male-sterile plants are used in hybrid breeding as well as for gene confinement for genetically modified plants in field trials and agricultural production. Apart from naturally occurring mutations leading to male sterility, biotechnology has added new possibilities for obtaining male-sterile plants, although so far only one system is used in practical breeding due to limitations in propagating male-sterile plants without segregations in the next generation or insufficient restoration of fertility when fruits or seeds are to be harvested from the hybrid varieties. Here a novel mechanism of restoration for male sterility is presented that has been achieved by interference with extracellular invertase activity, which is normally specifically expressed in the anthers to supply the developing microspores with carbohydrates. Microspores are symplastically isolated in the locular space of the anthers, and thus an unloading pathway of assimilates via the apoplasmic space is mandatory for proper development of pollen. Antisense repression of the anther-specific cell wall invertase or interference with invertase activity by expressing a proteinacious inhibitor under the control of the anther-specific invertase promoter results in a block during early stages of pollen development, thus causing male sterility without having any pleiotropic effects. Restoration of fertility was successfully achieved by substituting the down-regulated endogenous plant invertase activity by a yeast invertase fused to the N-terminal portion of potato-derived vacuolar protein proteinase II (PiII-ScSuc2), under control of the orthologous anther-specific invertase promoter Nin88 from tobacco. The chimeric fusion PiII-ScSuc2 is known to be N-glycosylated and efficiently secreted from plant cells, leading to its apoplastic location. Furthermore, the Nin88::PiII-ScSuc2 fusion does not show effects on pollen development in the wild-type background. Thus, such plants can be used as paternal parents of a hybrid variety, thereby the introgression of Nin88::PiII-ScSuc2 to the hybrid is obtained and fertility is restored. In order to broaden the applicability of this male sterility/restoration system to other plant species, a phylogenic analysis of plant invertases(beta-fructofuranosidases) and related genes of different species was carried out. This reveals a specific clustering of the cell wall invertases with anther-specific expression for dicotyl species and another cluster for monocotyl plants. Thus, in both groups of plants, there seems to be a kind of co-evolution, but no recent common ancestor of these members of the gene family. These findings provide a helpful orientation to classify corresponding candidate genes in further plant species, in addition to the species analysed so far (Arabidopsis, tobacco, tomato, potato, carrots, rice, and wheat).
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Affiliation(s)
- T Engelke
- Lehrstuhl für Pharmazeutische Biologie, Julius von Sachs Institut, Universität Würzburg, Julius von Sachs Platz 2, Würzburg, Germany.
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Ganeshan S, Drinkwater JM, Repellin A, Chibbar RN. Selected carbohydrate metabolism genes show coincident expression peaks in grains of in vitro-cultured immature spikes of wheat (Triticum aestivum L.). JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2010; 58:4193-4201. [PMID: 20235533 DOI: 10.1021/jf903861q] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
An in vitro culture system is useful to study grain development under defined conditions to minimize confounding effects associated with whole plant studies and metabolite movement into the developing grains. The objective of this study was to monitor the expression patterns of carbohydrate metabolism genes during grain development in an in vitro wheat spike culture system. Immature spikes were cultured prior to anthesis, and grains were collected at various days postanthesis (DPA). Grains from cultured spikes showed maximum expression of starch metabolic genes by 10 DPA, with a rapid decline thereafter. The rapid increase and decrease in expression rate in the in vitro system was thought to be due to fructan exohydrolase (1-FEH and 6-FEH) or sucrose transporter 1 (SUT1) and sucrose synthase (SuSy) genes being highly expressed. SUT1 reached peak expression at 8 DPA, two days earlier than the other genes, and may account for the rapid early stage trigger in expression of the other genes. However, expression of 1-FEH and 6-FEH genes in in vitro-cultured spikes peaked at 12 DPA, two days later than the other genes, and could indicate that fructan catabolism was not a factor in the rapid accumulation of starch in the in vitro-cultured spikes. Accumulation of GBSSI polypeptides generally showed similar patterns in both systems, with the maximum amount in the in vitro system observed four days later than in the in planta spikes, reflecting different turnover controls of GBSSI transcripts. The in vitro system offers opportunities for further refinement and detailed grain development studies.
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Affiliation(s)
- Seedhabadee Ganeshan
- Department of Plant Sciences, College of Agriculture and Bioresources, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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del Viso F, Puebla AF, Hopp HE, Heinz RA. Cloning and functional characterization of a fructan 1-exohydrolase (1-FEH) in the cold tolerant Patagonian species Bromus pictus. PLANTA 2009; 231:13-25. [PMID: 19789892 DOI: 10.1007/s00425-009-1020-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2009] [Accepted: 09/04/2009] [Indexed: 05/28/2023]
Abstract
Fructans are fructose polymers synthesized in a wide range of species such as bacteria, fungi and plants. Fructans are synthesized by fructosyltransferases (FTs) and depolymerized by fructan exohydrolases (FEHs). Bromus pictus is a graminean decaploid species from the Patagonian region of Argentina, which accumulates large amounts of fructans even at temperate temperatures. The first gene isolated from B. pictus fructan metabolism was a putative sucrose:fructan 6-fructosyltransferase (6-SFT). Here, a complete cDNA of the first fructan exohydrolase (FEH) from B. pictus (Bp1-FEHa) was isolated using RT-PCR strategies. The Bp1-FEHa encoding gene is present as a single copy in B. pictus genome. Functional characterization in Pichia pastoris confirmed Bp1-FEHa is a fructan exohydrolase with predominant activity towards beta-(2-1) linkages. Its expression was analyzed in different leaf sections, showing the highest expression levels in the second section of the sheath and the tip of the blade. Bp1-FEHa expression was studied along with FEH and FT activities and fructan accumulation profile in response to chilling conditions during a 7-day time course experiment. Bp1-FEHa expression and FEH activity followed a similar pattern in response to low temperatures, especially in basal sections of the sheaths. In these sections the FEH and FT activities were particularly high and they were significantly correlated to fructan accumulation profile, along with cold treatment.
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Affiliation(s)
- Florencia del Viso
- Instituto de Biotecnología, CICVyA, Instituto Nacional de Tecnología Agropecuaria, INTA, Hurlingham, 1686, Buenos Aires, Argentina
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Tufan HA, McGrann GRD, Magusin A, Morel JB, Miché L, Boyd LA. Wheat blast: histopathology and transcriptome reprogramming in response to adapted and nonadapted Magnaporthe isolates. THE NEW PHYTOLOGIST 2009; 184:473-484. [PMID: 19645735 DOI: 10.1111/j.1469-8137.2009.02970.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
* Blast disease (causal agent Magnaporthe oryzae) has presented as a new and serious field disease of wheat in South America. Here, we investigated the responses of wheat to both adapted and nonadapted isolates of the blast fungus Magnaporthe, examining cellular defence and transcriptional changes. * Resistance towards the nonadapted isolate was associated with the formation of appositions, here termed halos, beneath attempted Magnaporthe grisea penetration sites that wheat-adapted, M. oryzae isolates were able to breach. * Transcriptome analysis indicated extensive transcriptional reprogramming following inoculation with both wheat-adapted and nonadapted isolates of Magnaporthe. Functional annotation of many of the differentially expressed transcripts classified into the categories: cell rescue and defence, plant metabolism, cellular transport and regulation of transcription (although a significant number of transcripts remain unclassified). * Defence-related transcripts induced in common by adapted and nonadapted isolates were differentially regulated in response to M. oryzae and M. grisea isolates over time. Differential expression of genes involved in cellular transport indicated the importance of this process in plant defence. Functional characterisation of these transcripts and their role in defence may eventually lead to the identification of broad-spectrum resistance mechanisms in wheat towards Magnaporthe.
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Affiliation(s)
- Hale A Tufan
- Department of Disease and Stress Biology, John Innes Centre, Norwich Research Park, Colney Lane, Colney, Norwich, Norfolk, NR4 7UH, UK
| | - Graham R D McGrann
- Department of Disease and Stress Biology, John Innes Centre, Norwich Research Park, Colney Lane, Colney, Norwich, Norfolk, NR4 7UH, UK
| | - Andreas Magusin
- Department of Computational and Systems Biology, John Innes Centre, Norwich Research Park, Colney Lane, Colney, Norwich, Norfolk, NR4 7UH, UK
| | - Jean-Benoit Morel
- UMR BGPI INRA/CIRAD/SupAgro, Campus International de Baillarguet, T41/K34398 Montpellier, France
| | - Lucie Miché
- UMR BGPI INRA/CIRAD/SupAgro, Campus International de Baillarguet, T41/K34398 Montpellier, France
| | - Lesley A Boyd
- Department of Disease and Stress Biology, John Innes Centre, Norwich Research Park, Colney Lane, Colney, Norwich, Norfolk, NR4 7UH, UK
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Sun X, Hu C, Tan Q, Liu J, Liu H. Effects of molybdenum on expression of cold-responsive genes in abscisic acid (ABA)-dependent and ABA-independent pathways in winter wheat under low-temperature stress. ANNALS OF BOTANY 2009; 104:345-56. [PMID: 19491090 PMCID: PMC2710908 DOI: 10.1093/aob/mcp133] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2009] [Revised: 02/24/2009] [Accepted: 04/21/2009] [Indexed: 05/18/2023]
Abstract
BACKGROUND AND AIMS Molybdenum (Mo) is an essential trace element for higher plants. It has been shown that application of Mo enhances the cold resistance of winter wheat. In order to improve our understanding of the molecular mechanisms of cold resistance arising from application of Mo in winter wheat, investigations were made regarding the transcription of cold-responsive (COR) genes in abscisic acid (ABA)-dependent and ABA-independent pathways in winter wheat regulated by Mo application under low-temperature stress. METHODS Two cultivars of winter wheat (Triticum aestivum), Mo-efficient cultivar '97003' and Mo-inefficient cultivar '97014', were grown in control (-Mo) and Mo fertilizer (+Mo) treatments for 40 d at 15/12 degrees C (day/night), and the temperature was then reduced to 5/2 degrees C (day/night) to create low-temperature stress. Aldehyde oxidase (AO) activities, ABA contents, the transcripts of basic leucine zipper (bZIP)-type transcription factor (TF) genes, ABA-dependent COR genes, CBF/DREB transcription factor genes and ABA-independent COR genes were investigated at 0, 3, 6 and 48 h post cold stress. KEY RESULTS Mo application significantly increased AO activity, ABA levels, and expression of bZIP-type TF genes (Wlip19 and Wabi5) and ABA-dependent COR genes (Wrab15, Wrab17, Wrab18 and Wrab19). Mo application increased expression levels of CBF/DREB transcription factor genes (TaCBF and Wcbf2-1) and ABA-independent COR genes (Wcs120, Wcs19, Wcor14 and Wcor15) after 3 and 6 h exposure to low temperature. CONCLUSIONS Mo might regulate the expression of ABA-dependent COR genes through the pathway: Mo --> AO --> ABA --> bZIP --> ABA-dependent COR genes in winter wheat. The response of the ABA-dependent pathway to Mo was prior to that of the ABA-independent pathway. Similarities and differences between the Mo-efficient and Mo-inefficient wheat cultivars in response to Mo under cold stress are discussed.
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Affiliation(s)
- Xuecheng Sun
- Key Laboratory of Subtropical Agriculture and Environment, Ministry of Agriculture, Wuhan 430070, China
- Research Center of Trace Elements, Huazhong Agricultural University, Wuhan 430070, China
| | - Chengxiao Hu
- Key Laboratory of Subtropical Agriculture and Environment, Ministry of Agriculture, Wuhan 430070, China
- Research Center of Trace Elements, Huazhong Agricultural University, Wuhan 430070, China
- For correspondence. E-mail
| | - Qilin Tan
- Research Center of Trace Elements, Huazhong Agricultural University, Wuhan 430070, China
| | - Jinshan Liu
- Key Laboratory of Subtropical Agriculture and Environment, Ministry of Agriculture, Wuhan 430070, China
| | - Hongen Liu
- Key Laboratory of Subtropical Agriculture and Environment, Ministry of Agriculture, Wuhan 430070, China
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Livingston DP, Hincha DK, Heyer AG. Fructan and its relationship to abiotic stress tolerance in plants. Cell Mol Life Sci 2009; 66:2007-23. [PMID: 19290476 PMCID: PMC2705711 DOI: 10.1007/s00018-009-0002-x] [Citation(s) in RCA: 194] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2009] [Accepted: 02/04/2009] [Indexed: 01/24/2023]
Abstract
Numerous studies have been published that attempted to correlate fructan concentrations with freezing and drought tolerance. Studies investigating the effect of fructan on liposomes indicated that a direct interaction between membranes and fructan was possible. This new area of research began to move fructan and its association with stress beyond mere correlation by confirming that fructan has the capacity to stabilize membranes during drying by inserting at least part of the polysaccharide into the lipid headgroup region of the membrane. This helps prevent leakage when water is removed from the system either during freezing or drought. When plants were transformed with the ability to synthesize fructan, a concomitant increase in drought and/or freezing tolerance was confirmed. These experiments indicate that besides an indirect effect of supplying tissues with hexose sugars, fructan has a direct protective effect that can be demonstrated by both model systems and genetic transformation.
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Affiliation(s)
- David P Livingston
- USDA and North Carolina State University, 840 Method Road, Unit 3, Raleigh, NC 27695, USA.
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Avila-Fernández A, Rendón-Poujol X, Olvera C, González F, Capella S, Peña-Alvarez A, López-Munguía A. Enzymatic hydrolysis of fructans in the tequila production process. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2009; 57:5578-5585. [PMID: 19473003 DOI: 10.1021/jf900691r] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
In contrast to the hydrolysis of reserve carbohydrates in most plant-derived alcoholic beverage processes carried out with enzymes, agave fructans in tequila production have traditionally been transformed to fermentable sugars through acid thermal hydrolysis. Experiments at the bench scale demonstrated that the extraction and hydrolysis of agave fructans can be carried out continuously using commercial inulinases in a countercurrent extraction process with shredded agave fibers. Difficulties in the temperature control of large extraction diffusers did not allow the scaling up of this procedure. Nevertheless, batch enzymatic hydrolysis of agave extracts obtained in diffusers operating at 60 and 90 degrees C was studied at the laboratory and industrial levels. The effects of the enzymatic process on some tequila congeners were studied, demonstrating that although a short thermal treatment is essential for the development of tequila's organoleptic characteristics, the fructan hydrolysis can be performed with enzymes without major modifications in the flavor or aroma, as determined by a plant sensory panel and corroborated by the analysis of tequila congeners.
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Affiliation(s)
- Angela Avila-Fernández
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico
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Zhang J, Dell B, Conocono E, Waters I, Setter T, Appels R. Water deficits in wheat: fructan exohydrolase (1-FEH) mRNA expression and relationship to soluble carbohydrate concentrations in two varieties. THE NEW PHYTOLOGIST 2009; 181:843-850. [PMID: 19140945 DOI: 10.1111/j.1469-8137.2008.02713.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Terminal drought is a risk for wheat production in many parts of the world. Robust physiological traits for resilience would enhance the preselection of breeding lines in drought-prone areas. Three pot experiments were undertaken to characterize stem water-solublecarbohydrate (WSC), fructan exohydrolase expression, grain filling and leaf gas exchange in wheat (Triticum aestivum) varieties, Kauz and Westonia, which are considered to be drought-tolerant.Water deficit accelerated the remobilization of stem WSC in Westonia but not in Kauz. The profile of WSC accumulation and loss was negatively correlated with them RNA concentration of 1-FEH, especially 1-FEH w3 (1-FEH-6B). Under water deficit, Westonia showed lower concentrations of WSC than Kauz but did not show a corresponding drop in grain yield. The results from pot experiments suggest that stem WSC concentration is not, on its own, a reliable criterion to identify potential grain yield in wheat exposed to water deficits during grain filling. The expression of 1-FEH w3 may provide a better indicator when linked to osmotic potential and green leaf retention, and this requires validation in field-grown plants.
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Affiliation(s)
- Jingjuan Zhang
- Faculty of Sustainability, Environmental and Life Sciences, Murdoch University, South Street, WA, Australia, 6150
- Molecular Plant Breeding CRC, Murdoch University, South Street, WA, Australia, 6150
| | - Bernard Dell
- Faculty of Sustainability, Environmental and Life Sciences, Murdoch University, South Street, WA, Australia, 6150
| | - Elisabeth Conocono
- Department of Agriculture and Food Western Australia, 3 Baron Hay Court, South Perth, WA, Australia, 6151
| | - Irene Waters
- Department of Agriculture and Food Western Australia, 3 Baron Hay Court, South Perth, WA, Australia, 6151
| | - Tim Setter
- Department of Agriculture and Food Western Australia, 3 Baron Hay Court, South Perth, WA, Australia, 6151
| | - Rudi Appels
- Centre for Comparative Genomics, Murdoch University, South Street, WA, Australia, 6150
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Lammens W, Le Roy K, Schroeven L, Van Laere A, Rabijns A, Van den Ende W. Structural insights into glycoside hydrolase family 32 and 68 enzymes: functional implications. JOURNAL OF EXPERIMENTAL BOTANY 2009; 60:727-40. [PMID: 19129163 DOI: 10.1093/jxb/ern333] [Citation(s) in RCA: 150] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Glycoside hydrolases (GH) have been shown to play unique roles in various biological processes like the biosynthesis of glycans, cell wall metabolism, plant defence, signalling, and the mobilization of storage reserves. To date, GH are divided into more than 100 families based upon their overall structure. GH32 and GH68 are combined in clan GH-J, not only harbouring typical hydrolases but also non-Leloir type transferases (fructosyltransferases), involved in fructan biosynthesis. This review summarizes the recent structure-function research progress on plant GH32 enzymes, and highlights the similarities and differences compared with the microbial GH32 and GH68 enzymes. A profound analysis of ligand-bound structures and site-directed mutagenesis experiments identified key residues in substrate (or inhibitor) binding and recognition. In particular, sucrose can bind as inhibitor in Cichorium intybus 1-FEH IIa, whereas it binds as substrate in Bacillus subtilis levansucrase and Arabidopsis thaliana cell wall invertase (AtcwINV1). In plant GH32, a single residue, the equivalent of Asp239 in AtcwINV1, appears to be important for sucrose stabilization in the active site and essential in determining sucrose donor specificity.
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Affiliation(s)
- Willem Lammens
- Laboratorium voor Moleculaire Plantenfysiologie, Faculteit Wetenschappen, Departement Biologie, K. U. Leuven, Kasteelpark Arenberg 31, bus 2434, B-3001 Heverlee, Belgium
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Asega AF, do Nascimento JRO, Schroeven L, Van den Ende W, Carvalho MAM. Cloning, characterization and functional analysis of a 1-FEH cDNA from Vernonia herbacea (Vell.) Rusby. PLANT & CELL PHYSIOLOGY 2008; 49:1185-1195. [PMID: 18567893 DOI: 10.1093/pcp/pcn094] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Variations in the inulin contents have been detected in rhizophores of Vernonia herbacea during the phenological cycle. These variations indicate the occurrence of active inulin synthesis and depolymerization throughout the cycle and a role for this carbohydrate as a reserve compound. 1-Fructan exohydrolase (1-FEH) is the enzyme responsible for inulin depolymerization, and its activity has been detected in rhizophores of sprouting plants. Defoliation and low temperature are enhancer conditions of this 1-FEH activity. The aim of the present work was the cloning of this enzyme. Rhizophores were collected from plants induced to sprout, followed by storage at 5 degrees C. A full length 1-FEH cDNA sequence was obtained by PCR and inverse PCR techniques, and expressed in Pichia pastoris. Cold storage enhances FEH gene expression. Vh1-FEH was shown to be a functional 1-FEH, hydrolyzing predominantly beta-2,1 linkages, sharing high identity with chicory FEH sequences, and its activity was inhibited by 81% in the presence of 10 mM sucrose. In V. herbacea, low temperature and sucrose play a role in the control of fructan degradation. This is the first study concerning the cloning and functional analysis of a 1-FEH cDNA of a native species from the Brazilian Cerrado. Results will contribute to understanding the role of fructans in the establishment of a very successful fructan flora of the Brazilian Cerrado, subjected to water limitation and low temperature during winter.
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Affiliation(s)
- Amanda Francine Asega
- Seção de Fisiologia e Bioquímica de Plantas, Instituto de Botânica, CP 3005, 01061-970, São Paulo, SP, Brazil.
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Van Riet L, Altenbach D, Vergauwen R, Clerens S, Kawakami A, Yoshida M, Van den Ende W, Wiemken A, Van Laere A. Purification, cloning and functional differences of a third fructan 1-exohydrolase (1-FEHw3) from wheat (Triticum aestivum). PHYSIOLOGIA PLANTARUM 2008; 133:242-253. [PMID: 18346083 DOI: 10.1111/j.1399-3054.2008.01070.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A third fructan exohydrolase isoform (1-FEHw3) was purified from wheat stems by a combination of ammonium sulfate precipitation, ConA affinity and ion-exchange chromatography. Homogeneity of the preparation was indicated by the presence of a single band (70 kDa) after SDS-PAGE. The enzyme hydrolyzed mainly beta2-1 linkages in fructans and was inhibited by sucrose. A cDNA could be obtained after reverse transcriptase polymerase chain reaction (RT-PCR)-based strategies and screening of a cDNA library. Functionality tests of the cDNA performed after heterologous expression in the yeast Pichia pastoris showed that the encoded protein has essentially the same characteristics as the native enzyme. Homology with previously described 1-FEH isoforms from wheat was high (97% identity), and the enzyme showed minor differences to the previously published enzymes. The relative abundance of 1-FEH transcripts in different tissues was investigated by using quantitative RT-PCR.
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Affiliation(s)
- Liesbet Van Riet
- Laboratory of Molecular Plant Physiology, Department of Biology, Botanical Institute, K.U. Leuven, Kasteelpark Arenberg 31, B-3001 Leuven, Belgium.
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Xue GP, McIntyre CL, Glassop D, Shorter R. Use of expression analysis to dissect alterations in carbohydrate metabolism in wheat leaves during drought stress. PLANT MOLECULAR BIOLOGY 2008; 67:197-214. [PMID: 18299801 DOI: 10.1007/s11103-008-9311-y] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2007] [Accepted: 02/07/2008] [Indexed: 05/03/2023]
Abstract
Water deficit in plants causes a reduction in photosynthesis and high demands for osmolyte synthesis. To elucidate regulation of carbohydrate metabolic genes in wheat (Triticum aestivum) leaves during drought stress, we performed a systematic expression study using quantitative RT-PCR and cDNA microarray. These analyses revealed that expression levels of most genes encoding chloroplast enzymes involved in carbon fixation (Calvin cycle) were reduced in the leaves during prolonged drought stress. Transcript levels of highly expressed isoenzymes of hexokinase and fructokinase also decreased. Conversely, genes encoding cytoplasmic and vacuolar enzymes in the pathways leading to glucose, fructose and fructan production were up-regulated in the stressed leaves. Systematic expression analysis of an almost complete set of genes involved in conversion of triose phosphates to hexoses and hexose phosphorylation showed that isoenzymes of many enzymes were differentially regulated during drought stress. Correlation analysis indicated that the drought down-regulated Calvin cycle genes were coordinately regulated. This coordinated down-regulation extended to genes encoding major isoenzymes of chloroplast triosephosphate/phosphate translocator, cytoplasmic fructose-1,6-bisphosphate aldolase and fructose bisphosphatase. Highly correlated expression was also observed between drought up-regulated genes involved in sucrose synthesis and hydrolysis or fructan synthesis. These data dissect coordination in regulation of key enzyme genes involved in carbon fixation and accumulation of hexoses and fructans and provide an insight into molecular mechanisms at the transcript level underlying changes in carbohydrate metabolism in wheat adaptation to drought stress.
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Affiliation(s)
- Gang-Ping Xue
- CSIRO Plant Industry, St Lucia, QLD 4067, Australia.
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Le Roy K, Lammens W, Van Laere A, Van den Ende W. Influencing the binding configuration of sucrose in the active sites of chicory fructan 1-exohydrolase and sugar beet fructan 6-exohydrolase. THE NEW PHYTOLOGIST 2008; 178:572-80. [PMID: 18331426 DOI: 10.1111/j.1469-8137.2008.02386.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The hydrolytic plant enzymes of family 32 of glycoside hydrolases (GH32), including acid cell wall type invertases (EC 3.2.1.26), fructan 1-exohydrolases (1-FEH; EC 3.2.1.153) and fructan 6-exohydrolases (6-FEH; EC 3.2.1.154), are very similar at the molecular and structural levels, but are clearly functionally different. The work presented here aims at understanding the evolution of enzyme specificity and functional diversity in this family by means of site-directed mutagenesis. It is demonstrated for the first time that invertase activity can be introduced in an S101L mutant of chicory (Cichorium intybus) 1-FEH IIa by influencing the orientation of Trp 82. At high sucrose and enzyme concentrations, a shift is proposed from a stable inhibitor configuration to an unstable substrate configuration. In the same way, invertase activity was introduced in Beta vulgaris 6-FEH by introducing an acidic amino acid in the vicinity of the acid-base catalyst (F233D mutant), creating a beta-fructofuranosidase type of enzyme with dual activity against sucrose and levan. As single amino acid substitutions can influence the donor substrate specificity of FEHs, it is predicted that plant invertases and FEHs may have diversified by introduction of a very limited number of mutations in the common ancestor.
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Affiliation(s)
- Katrien Le Roy
- K. U. Leuven, Laboratory of Molecular Plant Physiology, Kasteelpark Arenberg 31, box 2434, B-3001 Leuven, Belgium
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