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Miyahara T, Ohkubo H, Umeyama Y, Oguchi T, Ogawa T, Ohta D, Mochizuki T, Kodama H. Discontinuous Translocation of a Luciferase Protein beyond Graft Junction in Tobacco. Food Saf (Tokyo) 2024; 12:1-16. [PMID: 38532775 PMCID: PMC10961615 DOI: 10.14252/foodsafetyfscj.d-23-00010] [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: 09/25/2023] [Accepted: 01/29/2024] [Indexed: 03/28/2024] Open
Abstract
Transgrafting, a grafting technique that uses both genetically modified (GM) and non-GM plants, is a novel plant breeding technology that can be used to improve the efficiency of crop cultivation without introducing foreign genes into the edible parts of non-GM plants. This technique can facilitate the acquisition of disease resistance and/or increased yield. However, the translocation of low-molecular-weight compounds, ribonucleic acid (RNA), and proteins through graft junctions raises a potential safety risk for food crops. Here, we used a transgenic tobacco plant expressing a firefly luciferase gene (LUC) to examine the translocation of the LUC protein beyond the graft junction in grafted plants. We observed the bi-directional translocation of LUC proteins in transgrafted tobacco plants, i.e., from the rootstock to scion and vice versa. Transcriptomic analysis revealed that transcripts of the LUC gene were undetectable in non-GM plant bodies, indicating that the LUC protein itself was translocated. Moreover, the movement of the LUC protein is an episodic (i.e., non-continuous) event, since non-GM samples showing high LUC activity were flanked by non-GM samples showing no apparent LUC activity. Translocation from the GM to non-GM part depends on the characteristics of GM plant bodies; here, the enhanced translocation of the LUC protein into the non-GM scion was observed when LUC-expressing rootstocks with hairy roots were used. Moreover, the quantity of translocated LUC protein was far below the level that is generally required to induce an allergenic response. Finally, since the LUC protein levels of plants used for transgrafting are moderate and the LUC protein itself is relatively unstable, further investigation is necessary regarding whether the newly expressed protein in GM plants is highly stable, easily translocated, and/or highly expressed.
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Affiliation(s)
- Taira Miyahara
- Graduate School of Horticulture, Chiba University, 1-33
Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
| | - Hitomi Ohkubo
- Graduate School of Horticulture, Chiba University, 1-33
Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
| | - Yukiko Umeyama
- Graduate School of Horticulture, Chiba University, 1-33
Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
| | - Taichi Oguchi
- Institute of Life and Environmental Sciences, University of
Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
- Tsukuba Plant Innovation Research Center, University of Tsukuba,
1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
| | - Takumi Ogawa
- Graduate School of Agriculture, Osaka Metropolitan University,
1-1 Gakuen-cho, Naka-ku, Sakai,Osaka 599-8531, Japan
- Graduate School of Life and Environmental Sciences, Osaka
Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Daisaku Ohta
- Graduate School of Agriculture, Osaka Metropolitan University,
1-1 Gakuen-cho, Naka-ku, Sakai,Osaka 599-8531, Japan
- Graduate School of Life and Environmental Sciences, Osaka
Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Tomofumi Mochizuki
- Graduate School of Agriculture, Osaka Metropolitan University,
1-1 Gakuen-cho, Naka-ku, Sakai,Osaka 599-8531, Japan
- Graduate School of Life and Environmental Sciences, Osaka
Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Hiroaki Kodama
- Graduate School of Horticulture, Chiba University, 1-33
Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
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Xiao R, Zou Y, Guo X, Li H, Lu H. Fatty acid desaturases (FADs) modulate multiple lipid metabolism pathways to improve plant resistance. Mol Biol Rep 2022; 49:9997-10011. [PMID: 35819557 DOI: 10.1007/s11033-022-07568-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Accepted: 03/28/2022] [Indexed: 01/03/2023]
Abstract
BACKGROUND Biological and abiotic stresses such as salt, extreme temperatures, and pests and diseases place major constraints on plant growth and crop yields. Fatty acids (FAs) and FA- derivatives are unique biologically active substance that show a wide range of functions in biological systems. They are not only participated in the regulation of energy storage substances and cell membrane plasm composition, but also extensively participate in the regulation of plant basic immunity, effector induced resistance and systemic resistance and other defense pathways, thereby improving plant resistance to adversity stress. Fatty acid desaturases (FADs) is involved in the desaturation of fatty acids, where desaturated fatty acids can be used as substrates for FA-derivatives. OBJECTIVE In this paper, the role of omega-FADs (ω-3 FADs and ω-6 FADs) in the prokaryotic and eukaryotic pathways of fatty acid biosynthesis in plant defense against stress (biological and abiotic stress) and the latest research progress were summarized. Moreover' the existing problems in related research and future research directions were also discussed. RESULTS Fatty acid desaturases are involved in various responses of plants during biotic and abiotic stress. For example, it is involved in regulating the stability and fluidity of cell membranes, reactive oxygen species signaling pathways, etc. In this review, we have collected several experimental studies to represent the differential effects of fatty acid desaturases on biotic and abiotic species. CONCLUSION Fatty acid desaturases play an important role in regulating biotic and abiotic stresses.
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Affiliation(s)
- Ruixue Xiao
- National Engineering Laboratory for Tree Breeding, Beijing Forestry University, Beijing, 100083, China
- Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, Beijing Forestry University, Beijing, 100083, China
- The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of National Forestry and Grassland Administration, College of Biological Sciences and Biotechnology, Beijing Forestry University, Tsinghua East Road 35, Haidian District, Beijing, 100083, China
| | - Yirong Zou
- The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of National Forestry and Grassland Administration, College of Biological Sciences and Biotechnology, Beijing Forestry University, Tsinghua East Road 35, Haidian District, Beijing, 100083, China
| | - Xiaorui Guo
- The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of National Forestry and Grassland Administration, College of Biological Sciences and Biotechnology, Beijing Forestry University, Tsinghua East Road 35, Haidian District, Beijing, 100083, China
| | - Hui Li
- National Engineering Laboratory for Tree Breeding, Beijing Forestry University, Beijing, 100083, China
- Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, Beijing Forestry University, Beijing, 100083, China
- The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of National Forestry and Grassland Administration, College of Biological Sciences and Biotechnology, Beijing Forestry University, Tsinghua East Road 35, Haidian District, Beijing, 100083, China
| | - Hai Lu
- National Engineering Laboratory for Tree Breeding, Beijing Forestry University, Beijing, 100083, China.
- Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, Beijing Forestry University, Beijing, 100083, China.
- The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of National Forestry and Grassland Administration, College of Biological Sciences and Biotechnology, Beijing Forestry University, Tsinghua East Road 35, Haidian District, Beijing, 100083, China.
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Omics Profiles of Non-transgenic Scion Grafted on Transgenic RdDM Rootstock. Food Saf (Tokyo) 2022; 10:13-31. [PMID: 35510071 PMCID: PMC9008877 DOI: 10.14252/foodsafetyfscj.d-21-00012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 12/16/2021] [Indexed: 11/21/2022] Open
Abstract
Grafting of commercial varieties onto transgenic stress-tolerant rootstocks is attractive
approach, because fruit from the non-transgenic plant body does not contain foreign genes.
RNA silencing can modulate gene expression and protect host plants from viruses and
insects, and small RNAs (sRNAs), key molecules of RNA silencing, can move systemically.
Here, to evaluate the safety of foods obtained from sRNA-recipient plant bodies, we
investigated the effects of rootstock-derived sRNAs involved in mediating RNA-directed DNA
methylation (RdDM) on non-transgenic scions. We used tobacco rootstocks showing RdDM
against the cauliflower mosaic virus (CaMV) 35S promoter. When scions harboring CaMV 35S
promoter sequence were grafted onto RdDM-inducing rootstocks, we found that RdDM-inducing
sRNAs were only weakly transported from the rootstocks to the scion, and we observed a low
level of DNA methylation of the CaMV 35S promoter in the scion. Next, wild-type (WT)
tobacco scions were grafted onto RdDM-inducing rootstocks (designated NT) or WT rootstocks
(designated NN), and scion leaves were subjected to multi-omics analyses. Our
transcriptomic analysis detected 55 differentially expressed genes between the NT and NN
samples. A principal component analysis of proteome profiles showed no significant
differences. In the positive and negative modes of LC-ESI-MS and GC-EI-MS analyses, we
found a large overlap between the metabolomic clusters of the NT and NN samples. In
contrast, the negative mode of a LC-ESI-MS analysis showed separation of clusters of NT
and NN metabolites, and we detected 6 peak groups that significantly differed. In
conclusion, we found that grafting onto RdDM-inducing rootstocks caused a low-level
transmission of sRNAs, resulting in limited DNA methylation in the scion. However, the
causal relationships between sRNA transmission and the very slight changes in the
transcriptomic and metabolomic profiles of the scions remains unclear. The safety
assessment points for grafting with RdDM rootstocks are discussed.
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Thies JA. Grafting for managing vegetable crop pests. PEST MANAGEMENT SCIENCE 2021; 77:4825-4835. [PMID: 34148287 DOI: 10.1002/ps.6512] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 05/25/2021] [Accepted: 06/19/2021] [Indexed: 06/12/2023]
Abstract
Nematode and disease resistant rootstocks have been developed for many vegetable crops including tomato, eggplant, melon, watermelon, and cucumber and are being utilized by an increasing number of growers. Grafting commercially desirable vegetable scions on nematode and disease resistant rootstocks has been significantly stimulated by the need for an alternative to banned soil fumigation with methyl bromide, which had been the primary method for managing soil-borne nematodes, diseases, and weeds. Rootstocks resistant to root-knot nematodes (Meloidogyne spp.) and diseases including Fusarium wilt, Fusarium crown and root rot, Verticillium wilt, bacterial wilt, Southern blight, and sudden wilt have been developed and many are available commercially. New technologies such as transcriptomics, identification of differentially expressed genes, transgene rootstocks, and RNAi silencing are being used in the development of vegetable rootstocks which are resistant to pests, salt tolerant, and heat and cold tolerant. Overall, grafting has proven to be a successful and environmentally safe method for managing root-knot nematodes and soil-borne diseases by reducing infection, disease development, and inoculum build-up in the soil, which is especially important for growth of healthy subsequent crops. © 2021 Society of Chemical Industry.
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Affiliation(s)
- Judy A Thies
- Former employer: USDA, Agricultural Research Service, USVL, Charleston, SC, USA
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Almeida J, Perez-Fons L, Fraser PD. A transcriptomic, metabolomic and cellular approach to the physiological adaptation of tomato fruit to high temperature. PLANT, CELL & ENVIRONMENT 2021; 44:2211-2229. [PMID: 32691430 DOI: 10.1111/pce.13854] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 07/02/2020] [Accepted: 07/12/2020] [Indexed: 05/21/2023]
Abstract
High temperatures can negatively influence plant growth and development. Besides yield, the effects of heat stress on fruit quality traits remain poorly characterised. In tomato, insights into how fruits regulate cellular metabolism in response to heat stress could contribute to the development of heat-tolerant varieties, without detrimental effects on quality. In the present study, the changes occurring in wild type tomato fruits after exposure to transient heat stress have been elucidated at the transcriptome, cellular and metabolite level. An impact on fruit quality was evident as nutritional attributes changed in response to heat stress. Fruit carotenogenesis was affected, predominantly at the stage of phytoene formation, although altered desaturation/isomerisation arose during the transient exposure to high temperatures. Plastidial isoprenoid compounds showed subtle alterations in their distribution within chromoplast sub-compartments. Metabolite profiling suggests limited effects on primary/intermediary metabolism but lipid remodelling was evident. The heat-induced molecular signatures included the accumulation of sucrose and triacylglycerols, and a decrease in the degree of membrane lipid unsaturation, which influenced the volatile profile. Collectively, these data provide valuable insights into the underlying biochemical and molecular adaptation of fruit to heat stress and will impact on our ability to develop future climate resilient tomato varieties.
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Affiliation(s)
- Juliana Almeida
- Department of Biological Sciences, Royal Holloway University of London, Egham, UK
| | - Laura Perez-Fons
- Department of Biological Sciences, Royal Holloway University of London, Egham, UK
| | - Paul D Fraser
- Department of Biological Sciences, Royal Holloway University of London, Egham, UK
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6
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Effect of Transgenic Rootstock Grafting on the Omics Profiles in Tomato. Food Saf (Tokyo) 2021; 9:32-47. [PMID: 34249588 PMCID: PMC8254850 DOI: 10.14252/foodsafetyfscj.d-20-00032] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 05/12/2021] [Indexed: 11/21/2022] Open
Abstract
Grafting of non-transgenic scion onto genetically modified (GM) rootstocks provides superior
agronomic traits in the GM rootstock, and excellent fruits can be produced for consumption. In
such grafted plants, the scion does not contain any foreign genes, but the fruit itself is
likely to be influenced directly or indirectly by the foreign genes in the rootstock. Before
market release of such fruit products, the effects of grafting onto GM rootstocks should be
determined from the perspective of safety use. Here, we evaluated the effects of a transgene
encoding β-glucuronidase (GUS) on the grafted tomato fruits as a model case. An edible tomato
cultivar, Stella Mini Tomato, was grafted onto GM Micro-Tom tomato plants that had been
transformed with the GUS gene. The grafted plants showed no difference in
their fruit development rate and fresh weight regardless of the presence or absence of the
GUS gene in the rootstock. The fruit samples were subjected to transcriptome
(NGS-illumina), proteome (shotgun LC-MS/MS), metabolome (LC-ESI-MS and GC-EI-MS), and general
food ingredient analyses. In addition, differentially detected items were identified between
the grafted plants onto rootstocks with or without transgenes (more than two-fold). The
transcriptome analysis detected approximately 18,500 expressed genes on average, and only 6
genes were identified as differentially expressed. Principal component analysis of 2,442 peaks
for peptides in proteome profiles showed no significant differences. In the LC-ESI-MS and
GC-EI-MS analyses, a total of 93 peak groups and 114 peak groups were identified, respectively,
and only 2 peak groups showed more than two-fold differences. The general food ingredient
analysis showed no significant differences in the fruits of Stella scions between GM and non-GM
Micro-Tom rootstocks. These multiple omics data showed that grafting on the rootstock harboring
the GUS transgene did not induce any genetic or metabolic variation in the
scion.
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Tsaballa A, Xanthopoulou A, Madesis P, Tsaftaris A, Nianiou-Obeidat I. Vegetable Grafting From a Molecular Point of View: The Involvement of Epigenetics in Rootstock-Scion Interactions. FRONTIERS IN PLANT SCIENCE 2021; 11:621999. [PMID: 33488662 PMCID: PMC7817540 DOI: 10.3389/fpls.2020.621999] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 12/07/2020] [Indexed: 05/25/2023]
Abstract
Vegetable grafting is extensively used today in agricultural production to control soil-borne pathogens, abiotic and biotic stresses and to improve phenotypic characteristics of the scion. Commercial vegetable grafting is currently practiced in tomato, watermelon, melon, eggplant, cucumber, and pepper. It is also regarded as a rapid alternative to the relatively slow approach of breeding for increased environmental-stress tolerance of fruit vegetables. However, even though grafting has been used for centuries, until today, there are still many issues that have not been elucidated. This review will emphasize on the important mechanisms taking place during grafting, especially the genomic interactions between grafting partners and the impact of rootstocks in scion's performance. Special emphasis will be drawn on the relation between vegetable grafting, epigenetics, and the changes in morphology and quality of the products. Recent advances in plant science such as next-generation sequencing provide new information regarding the molecular interactions between rootstock and scion. It is now evidenced that genetic exchange is happening across grafting junctions between rootstock and scion, potentially affecting grafting-mediated effects already recorded in grafted plants. Furthermore, significant changes in DNA methylation are recorded in grafted scions, suggesting that these epigenetic mechanisms could be implicated in grafting effects. In this aspect, we also discuss the process and the molecular aspects of rootstock scion communication. Finally, we provide with an extensive overview of gene expression changes recorded in grafted plants and how these are related to the phenotypic changes observed. Τhis review finally seeks to elucidate the dynamics of rootstock-scion interactions and thus stimulate more research on grafting in the future. In a future where sustainable agricultural production is the way forward, grafting could play an important role to develop products of higher yield and quality in a safe and "green" way.
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Affiliation(s)
- Aphrodite Tsaballa
- Institute of Plant Breeding and Genetic Resources, Hellenic Agricultural Organization (ELGO-Dimitra), Thessaloniki, Greece
| | - Aliki Xanthopoulou
- Institute of Plant Breeding and Genetic Resources, Hellenic Agricultural Organization (ELGO-Dimitra), Thessaloniki, Greece
| | - Panagiotis Madesis
- Laboratory of Molecular Biology of Plants, School of Agricultural Sciences, University of Thessaly, Volos, Greece
- Institute of Applied Biosciences, Centre for Research & Technology Hellas, Thessaloniki, Greece
| | - Athanasios Tsaftaris
- Perrotis College, American Farm School, Thessaloniki, Greece
- Laboratory of Genetics and Plant Breeding, School of Agriculture, Forestry and Natural Environment, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Irini Nianiou-Obeidat
- Laboratory of Genetics and Plant Breeding, School of Agriculture, Forestry and Natural Environment, Aristotle University of Thessaloniki, Thessaloniki, Greece
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8
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Zoong Lwe ZS, Welti R, Anco D, Naveed S, Rustgi S, Narayanan S. Heat stress elicits remodeling in the anther lipidome of peanut. Sci Rep 2020; 10:22163. [PMID: 33335149 PMCID: PMC7747596 DOI: 10.1038/s41598-020-78695-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 11/12/2020] [Indexed: 11/09/2022] Open
Abstract
Understanding the changes in peanut (Arachis hypogaea L.) anther lipidome under heat stress (HT) will aid in understanding the mechanisms of heat tolerance. We profiled the anther lipidome of seven genotypes exposed to ambient temperature (AT) or HT during flowering. Under AT and HT, the lipidome was dominated by phosphatidylcholine (PC), phosphatidylethanolamine (PE), and triacylglycerol (TAG) species (> 50% of total lipids). Of 89 lipid analytes specified by total acyl carbons:total carbon–carbon double bonds, 36:6, 36:5, and 34:3 PC and 34:3 PE (all contain 18:3 fatty acid and decreased under HT) were the most important lipids that differentiated HT from AT. Heat stress caused decreases in unsaturation indices of membrane lipids, primarily due to decreases in highly-unsaturated lipid species that contained 18:3 fatty acids. In parallel, the expression of Fatty Acid Desaturase 3-2 (FAD3-2; converts 18:2 fatty acids to 18:3) decreased under HT for the heat-tolerant genotype SPT 06-07 but not for the susceptible genotype Bailey. Our results suggested that decreasing lipid unsaturation levels by lowering 18:3 fatty-acid amount through reducing FAD3 expression is likely an acclimation mechanism to heat stress in peanut. Thus, genotypes that are more efficient in doing so will be relatively more tolerant to HT.
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Affiliation(s)
- Zolian S Zoong Lwe
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC, USA
| | - Ruth Welti
- Division of Biology, Kansas State University, Manhattan, KS, USA
| | - Daniel Anco
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC, USA.,Edisto Research & Education Center, Clemson University, Blackville, SC, USA
| | - Salman Naveed
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC, USA.,Pee Dee Research & Education Center, Clemson University, Florence, SC, USA
| | - Sachin Rustgi
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC, USA.,Pee Dee Research & Education Center, Clemson University, Florence, SC, USA
| | - Sruthi Narayanan
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC, USA.
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9
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Berestovoy MA, Pavlenko OS, Goldenkova-Pavlova IV. Plant Fatty Acid Desaturases: Role in the Life of Plants and Biotechnological Potential. ACTA ACUST UNITED AC 2020. [DOI: 10.1134/s2079086420020024] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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10
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Eckerstorfer MF, Dolezel M, Heissenberger A, Miklau M, Reichenbecher W, Steinbrecher RA, Waßmann F. An EU Perspective on Biosafety Considerations for Plants Developed by Genome Editing and Other New Genetic Modification Techniques (nGMs). Front Bioeng Biotechnol 2019; 7:31. [PMID: 30891445 PMCID: PMC6413072 DOI: 10.3389/fbioe.2019.00031] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 02/05/2019] [Indexed: 12/23/2022] Open
Abstract
The question whether new genetic modification techniques (nGM) in plant development might result in non-negligible negative effects for the environment and/or health is significant for the discussion concerning their regulation. However, current knowledge to address this issue is limited for most nGMs, particularly for recently developed nGMs, like genome editing, and their newly emerging variations, e.g., base editing. This leads to uncertainties regarding the risk/safety-status of plants which are developed with a broad range of different nGMs, especially genome editing, and other nGMs such as cisgenesis, transgrafting, haploid induction or reverse breeding. A literature survey was conducted to identify plants developed by nGMs which are relevant for future agricultural use. Such nGM plants were analyzed for hazards associated either (i) with their developed traits and their use or (ii) with unintended changes resulting from the nGMs or other methods applied during breeding. Several traits are likely to become particularly relevant in the future for nGM plants, namely herbicide resistance (HR), resistance to different plant pathogens as well as modified composition, morphology, fitness (e.g., increased resistance to cold/frost, drought, or salinity) or modified reproductive characteristics. Some traits such as resistance to certain herbicides are already known from existing GM crops and their previous assessments identified issues of concern and/or risks, such as the development of herbicide resistant weeds. Other traits in nGM plants are novel; meaning they are not present in agricultural plants currently cultivated with a history of safe use, and their underlying physiological mechanisms are not yet sufficiently elucidated. Characteristics of some genome editing applications, e.g., the small extent of genomic sequence change and their higher targeting efficiency, i.e., precision, cannot be considered an indication of safety per se, especially in relation to novel traits created by such modifications. All nGMs considered here can result in unintended changes of different types and frequencies. However, the rapid development of nGM plants can compromise the detection and elimination of unintended effects. Thus, a case-specific premarket risk assessment should be conducted for nGM plants, including an appropriate molecular characterization to identify unintended changes and/or confirm the absence of unwanted transgenic sequences.
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Affiliation(s)
| | - Marion Dolezel
- Department Landuse & Biosafety, Environment Agency Austria, Vienna, Austria
| | | | - Marianne Miklau
- Department Landuse & Biosafety, Environment Agency Austria, Vienna, Austria
| | - Wolfram Reichenbecher
- Department GMO Regulation, Biosafety, Federal Agency for Nature Conservation, Bonn, Germany
| | | | - Friedrich Waßmann
- Department GMO Regulation, Biosafety, Federal Agency for Nature Conservation, Bonn, Germany
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11
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Li W, Fang C, Krishnan S, Chen J, Yu H, Murphy AS, Merewitz E, Katin‐Grazzini L, McAvoy RJ, Deng Z, Zale J, Li Y. Elevated auxin and reduced cytokinin contents in rootstocks improve their performance and grafting success. PLANT BIOTECHNOLOGY JOURNAL 2017; 15:1556-1565. [PMID: 28376249 PMCID: PMC5698044 DOI: 10.1111/pbi.12738] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Revised: 03/27/2017] [Accepted: 03/28/2017] [Indexed: 05/21/2023]
Abstract
Plant grafting is an important technique for horticultural and silvicultural production. However, many rootstock plants suffer from undesirable lateral bud outgrowth, low grafting success rates or poor rooting. Here, we used a root-predominant gene promoter (SbUGT) to drive the expression of a tryptophan-2-monooxygenase gene (iaaM) from Agrobacterium tumefaciens to increase auxin levels in tobacco. The transgenic plants, when used as a rootstock, displayed inhibited lateral bud outgrowth, enhanced grafting success rate and improved root initiation. However, root elongation and biomass of SbUGT::iaaM transgenic plants were reduced compared to those of wild-type plants. In contrast, when we used this same promoter to drive CKX (a cytokinin degradation gene) expression, the transgenic tobacco plants displayed enhanced root elongation and biomass. We then made crosses between the SbUGT::CKX and SbUGT::iaaM transgenic plants. We observed that overexpression of the CKX gene neutralized the negative effects of auxin overproduction on root elongation. Also, the simultaneous expression of both the iaaM and CKX genes in rootstock did not disrupt normal growth and developmental patterns in wild-type scions. Our results demonstrate that expression of both the iaaM and CKX genes predominantly in roots of rootstock inhibits lateral bud release from rootstock, improves grafting success rates and enhances root initiation and biomass.
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Affiliation(s)
- Wei Li
- Department of Plant Science and Landscape ArchitectureUniversity of ConnecticutStorrsCTUSA
| | - Chu Fang
- Department of Plant Science and Landscape ArchitectureUniversity of ConnecticutStorrsCTUSA
| | | | - Junmei Chen
- Department of Plant Science and Landscape ArchitectureUniversity of ConnecticutStorrsCTUSA
| | - Hao Yu
- Department of Plant Science and Landscape ArchitectureUniversity of ConnecticutStorrsCTUSA
| | - Angus S. Murphy
- Department of Plant Science and Landscape ArchitectureUniversity of MarylandCollege ParkMDUSA
| | - Emily Merewitz
- Department of Crop ScienceMichigan State UniversityEast LansingMIUSA
| | - Lorenzo Katin‐Grazzini
- Department of Plant Science and Landscape ArchitectureUniversity of ConnecticutStorrsCTUSA
| | - Richard J. McAvoy
- Department of Plant Science and Landscape ArchitectureUniversity of ConnecticutStorrsCTUSA
| | - Ziniu Deng
- College of Horticulture, Hunan Agricultural UniversityChangshaHunanChina
| | - Janice Zale
- Plant Pathology Department, Institute of Food and Agricultural SciencesCitrus Research and Education CenterUniversity of FloridaLake AlfredFLUSA
| | - Yi Li
- Department of Plant Science and Landscape ArchitectureUniversity of ConnecticutStorrsCTUSA
- College of Horticulture, Hunan Agricultural UniversityChangshaHunanChina
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