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Goyal S, Chatterjee V, Kulkarni VM, Bhat V. Plant regeneration through somatic embryogenesis in cell suspensions of Cenchrus ciliaris L. PLANT METHODS 2023; 19:110. [PMID: 37853411 PMCID: PMC10585800 DOI: 10.1186/s13007-023-01081-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 09/25/2023] [Indexed: 10/20/2023]
Abstract
BACKGROUND This study aims to establish cell suspension culture, its maintenance and induction of somatic embryogenesis, and in vitro plant regeneration in Cenchrus ciliaris L. Suspension cultures are relatively homogenous cell lines facilitating uniform access to nutrition. These are ideal sources of competent cells for genetic transformation. RESULTS Callus was initiated by culturing immature inflorescences of Cenchrus ciliaris cv. IGFRI-3108 on Murashige and Skoog (MS) medium containing 3 mg l-1 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.5 mg l-1 6-benzylaminopurine (BAP) with 30 g l-1 sucrose. Cell suspension cultures were established in liquid MS medium using an inoculum size of 10 g l-1. These were maintained to achieve embryogenic cell/regeneration competent cultures. Growth curve analysis and a subculture interval of 20 days were determined to harvest cells at the end of the exponential phase. The cell doubling time was found to be 11 days. Somatic embryogenesis was accomplished in MS medium containing 1 mg l-1 2,4-D, 1 mg l-1 BAP along with growth adjuvants, 300 mg l-1 casein hydrolysate, 400 mg l-1 glutamine and 300 mg l-1 proline. The highest number (16 ± 3.78/per inoculum) of shoots regenerated on this medium. The elongation and rooting of shoots were recorded on basal MS and ½ MS media, respectively. Rooted plants were successfully transferred to pots containing a Soilrite and cocopeat mixture in a 3:1 proportion for 3-4 weeks and later successfully acclimatized in the greenhouse with a 60% survival rate. The genetic fidelity of 12 regenerated plants was analysed using RAPD primers that were genetically identical to the mother plant. CONCLUSION Cell suspension culture-based in vitro plant regeneration of C. ciliaris involved the establishment, maintenance and progression of somatic embryogenesis during shoot and root development. The inherent limitation of callus-mediated in vitro plant regeneration reducing the regeneration potential due to the aging of the calli has been overcome.
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Affiliation(s)
- Shipra Goyal
- Plant Developmental Biology, Department of Botany, University of Delhi, Delhi, 110007, India
| | - Vijaya Chatterjee
- Department of Biotechnology, St. Aloysius College, Jabalpur, 482001, India
| | - Vishvas M Kulkarni
- Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai, 400085, India.
| | - Vishnu Bhat
- Plant Developmental Biology, Department of Botany, University of Delhi, Delhi, 110007, India.
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Jogam P, Sandhya D, Alok A, Shekhawat MS, Peddaboina V, Singh K, Allini VR. A grobacterium-mediated genetic transformation and cloning of candidate reference genes in suspension cells of Artemisia pallens Wall. ex DC. 3 Biotech 2022; 12:194. [PMID: 35910289 PMCID: PMC9334505 DOI: 10.1007/s13205-022-03251-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 07/05/2022] [Indexed: 11/01/2022] Open
Abstract
A reliable and stable Agrobacterium-mediated genetic transformation system for Artemisia pallens has been developed using cell suspension cultures derived from cotyledon explants. Cotyledon, attached cotyledon, and compound leaves were found to be suitable for the induction of callus among five different types of explants tested. The yellow friable callus derived from attached cotyledon was used to initiate suspension cultures in Suspension Culture Medium (SCM) which was supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D) at 2.0 mg L-1 and in combination with different concentrations of Zeatin (ZEA) at 0.25 mg L-1. Two different shock treatments, cold shock (at 4 ℃) for 20 min and heat shock (at 45 ℃) treatment for 5 min, heat shock treatment increased the transformation efficiency. The supplementation of Pluronic F-68 (0.05%) significantly enhanced the transformation efficiency of suspension cultures, whereas Silwet L-77 (0.05%) leads to more browning of the cells and reduced the transformation efficiency. The maximum GUS intensity was recorded with an optimal intensity of blue spots in the transformed cells. The highest GUS fluorometric activity measured was 879.4 ± 113.7 nmol 4MU/mg/min in transformed cell suspension cultures. The hygromycin-resistant calli showed intense blue color in GUS histochemical assay. The transgene integration into the plant genome was confirmed by polymerase chain reaction (PCR) using uidA specific primers in six hygromycin-resistant cell lines. The partial coding sequence of three candidate reference genes, i.e., ADP-ribosylation factor (Arf), β-actin (Act), and ubiquitin (Ubi), and carotenoid biosynthesis pathway gene, i.e., Phytoene desaturase (Pds) were cloned, sequenced, and submitted to NCBI for the first time. The quantitative mRNA expression of the transgene (uidA) and internal ApPds gene were evaluated in transgenic callus lines. The present Agrobacterium-mediated genetic transformation protocol could help in better understanding of the metabolic pathways of this medicinally important plant and its genetic improvement. Supplementary Information The online version contains supplementary material available at 10.1007/s13205-022-03251-x.
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Affiliation(s)
- Phanikanth Jogam
- Department of Biotechnology, Kakatiya University, Warangal, Telangana 506009 India
| | - Dulam Sandhya
- Department of Biotechnology, Kakatiya University, Warangal, Telangana 506009 India
| | - Anshu Alok
- Department of Biotechnology, Punjab University, Chandigarh, 160014 India
| | - Mahipal S. Shekhawat
- Biotechnology Unit, Kanchi Mamunivar Government Institute for Postgraduate Studies and Research, Puducherry, 605008 India
| | | | - Kashmir Singh
- Department of Biotechnology, Punjab University, Chandigarh, 160014 India
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Ondzighi‐Assoume CA, Bhusal B, Traore AM, Ouma WK, Mmbaga MT, Swiggart EM. Efficient fluorescence-based localization technique for real-time tracking endophytes route in host-plants colonization. PLANT DIRECT 2022; 6:e427. [PMID: 35959216 PMCID: PMC9360559 DOI: 10.1002/pld3.427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 06/01/2022] [Accepted: 06/28/2022] [Indexed: 06/15/2023]
Abstract
Bacterial isolates that enhance plant growth and suppress plant pathogens growth are essential tools for reducing pesticide applications in plant production systems. The objectives of this study were to develop a reliable fluorescence-based technique for labeling bacterial isolates selected as biological control agents (BCAs) to allow their direct tracking in the host-plant interactions, understand the BCA localization within their host plants, and the route of plant colonization. Objectives were achieved by developing competent BCAs transformed with two plasmids, pBSU101 and pANIC-10A, containing reporter genes eGFP and pporRFP, respectively. Our results revealed that the plasmid-mediated transformation efficiencies of antibiotic-resistant competent BCAs identified as PSL, IMC8, and PS were up 84%. Fluorescent BCA-tagged reporter genes were associated with roots and hypocotyls but not with leaves or stems and were confirmed by fluoresence microscopy and PCR analyses in colonized Arabidopsis and sorghum. This fluorescence-based technique's high resolution and reproducibility make it a platform-independent system that allows tracking of BCAs spatially within plant tissues, enabling assessment of the movement and niches of BCAs within colonized plants. Steps for producing and transforming competent fluorescent BCAs, as well as the inoculation of plants with transformed BCAs, localization, and confirmation of fluorescent BCAs through fluorescence imaging and PCR, are provided in this manuscript. This study features host-plant interactions and subsequently biological and physiological mechanisms implicated in these interactions. The maximum time to complete all the steps of this protocol is approximately 3 months.
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Affiliation(s)
- Christine A. Ondzighi‐Assoume
- College of Agriculture, Department of Agricultural and Environmental SciencesTennessee State UniversityNashvilleTennesseeUSA
| | - Bandana Bhusal
- College of Agriculture, Department of Agricultural and Environmental SciencesTennessee State UniversityNashvilleTennesseeUSA
| | - Adam M. Traore
- College of Agriculture, Department of Agricultural and Environmental SciencesTennessee State UniversityNashvilleTennesseeUSA
| | - Wilson K. Ouma
- Department of Entomology and Plant PathologyThe University of TennesseeKnoxvilleTennesseeUSA
| | - Margaret T. Mmbaga
- College of Agriculture, Department of Agricultural and Environmental SciencesTennessee State UniversityNashvilleTennesseeUSA
| | - Ethan M. Swiggart
- College of Agriculture, Department of Agricultural and Environmental SciencesTennessee State UniversityNashvilleTennesseeUSA
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Tiedge K, Destremps J, Solano-Sanchez J, Arce-Rodriguez ML, Zerbe P. Foxtail mosaic virus-induced gene silencing (VIGS) in switchgrass (Panicum virgatum L.). PLANT METHODS 2022; 18:71. [PMID: 35644680 PMCID: PMC9150325 DOI: 10.1186/s13007-022-00903-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 05/07/2022] [Indexed: 05/08/2023]
Abstract
BACKGROUND Although the genome for the allotetraploid bioenergy crop switchgrass (Panicum virgatum) has been established, limitations in mutant resources have hampered in planta gene function studies toward crop optimization. Virus-induced gene silencing (VIGS) is a versatile technique for transient genetic studies. Here we report the implementation of foxtail mosaic virus (FoMV)-mediated gene silencing in switchgrass in above- and below-ground tissues and at different developmental stages. RESULTS The study demonstrated that leaf rub-inoculation is a suitable method for systemic gene silencing in switchgrass. For all three visual marker genes, Magnesium chelatase subunit D (ChlD) and I (ChlI) as well as phytoene desaturase (PDS), phenotypic changes were observed in leaves, albeit at different intensities. Gene silencing efficiency was verified by RT-PCR for all tested genes. Notably, systemic gene silencing was also observed in roots, although silencing efficiency was stronger in leaves (~ 63-94%) as compared to roots (~ 48-78%). Plants at a later developmental stage were moderately less amenable to VIGS than younger plants, but also less perturbed by the viral infection. CONCLUSIONS Using FoMV-mediated VIGS could be achieved in switchgrass leaves and roots, providing an alternative approach for studying gene functions and physiological traits in this important bioenergy crop.
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Affiliation(s)
- Kira Tiedge
- Department of Plant Biology, University of California, Davis, USA.
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands.
| | | | | | | | - Philipp Zerbe
- Department of Plant Biology, University of California, Davis, USA
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Muguerza MB, Gondo T, Ishigaki G, Shimamoto Y, Umami N, Nitthaisong P, Rahman MM, Akashi R. Tissue Culture and Somatic Embryogenesis in Warm-Season Grasses—Current Status and Its Applications: A Review. PLANTS 2022; 11:plants11091263. [PMID: 35567264 PMCID: PMC9101205 DOI: 10.3390/plants11091263] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 05/02/2022] [Accepted: 05/04/2022] [Indexed: 11/16/2022]
Abstract
Warm-season grasses are C4 plants and have a high capacity for biomass productivity. These grasses are utilized in many agricultural production systems with their greatest value as feeds for livestock, bioethanol, and turf. However, many important warm-season perennial grasses multiply either by vegetative propagation or form their seeds by an asexual mode of reproduction called apomixis. Therefore, the improvement of these grasses by conventional breeding is difficult and is dependent on the availability of natural genetic variation and its manipulation through breeding and selection. Recent studies have indicated that plant tissue culture system through somatic embryogenesis complements and could further develop conventional breeding programs by micropropagation, somaclonal variation, somatic hybridization, genetic transformation, and genome editing. This review summarizes the tissue culture and somatic embryogenesis in warm-season grasses and focus on current status and above applications including the author’s progress.
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Affiliation(s)
- Melody Ballitoc Muguerza
- Faculty of Agriculture, University of Miyazaki, 1-1 Gakuenkibanadai-Nishi, Miyazaki 889-2192, Japan; (M.B.M.); (G.I.); (Y.S.); (R.A.)
| | - Takahiro Gondo
- Frontier Science Research Center, University of Miyazaki, 1-1 Gakuenkibanadai-Nishi, Miyazaki 889-2192, Japan
- Correspondence:
| | - Genki Ishigaki
- Faculty of Agriculture, University of Miyazaki, 1-1 Gakuenkibanadai-Nishi, Miyazaki 889-2192, Japan; (M.B.M.); (G.I.); (Y.S.); (R.A.)
| | - Yasuyo Shimamoto
- Faculty of Agriculture, University of Miyazaki, 1-1 Gakuenkibanadai-Nishi, Miyazaki 889-2192, Japan; (M.B.M.); (G.I.); (Y.S.); (R.A.)
| | - Nafiatul Umami
- Faculty of Animal Science, Universitas Gadjah Mada, Jl Fauna 3, Yogyakarta 55281, Indonesia;
| | - Pattama Nitthaisong
- Faculty of Agricultural Technology, King Mongkut’s Institute of Technology Ladkrabang, Bangkok 10520, Thailand;
| | - Mohammad Mijanur Rahman
- Faculty of Agro-Based Industry, Jeli Campus, Universiti Malaysia Kelantan, Jeli 17600, Kelantan, Malaysia;
| | - Ryo Akashi
- Faculty of Agriculture, University of Miyazaki, 1-1 Gakuenkibanadai-Nishi, Miyazaki 889-2192, Japan; (M.B.M.); (G.I.); (Y.S.); (R.A.)
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Maren NA, Duan H, Da K, Yencho GC, Ranney TG, Liu W. Genotype-independent plant transformation. HORTICULTURE RESEARCH 2022; 9:uhac047. [PMID: 35531314 PMCID: PMC9070643 DOI: 10.1093/hr/uhac047] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 02/11/2022] [Indexed: 05/26/2023]
Abstract
Plant transformation and regeneration remain highly species- and genotype-dependent. Conventional hormone-based plant regeneration via somatic embryogenesis or organogenesis is tedious, time-consuming, and requires specialized skills and experience. Over the last 40 years, significant advances have been made to elucidate the molecular mechanisms underlying embryogenesis and organogenesis. These pioneering studies have led to a better understanding of the key steps and factors involved in plant regeneration, resulting in the identification of crucial growth and developmental regulatory genes that can dramatically improve regeneration efficiency, shorten transformation time, and make transformation of recalcitrant genotypes possible. Co-opting these regulatory genes offers great potential to develop innovative genotype-independent genetic transformation methods for various plant species, including specialty crops. Further developing these approaches has the potential to result in plant transformation without the use of hormones, antibiotics, selectable marker genes, or tissue culture. As an enabling technology, the use of these regulatory genes has great potential to enable the application of advanced breeding technologies such as genetic engineering and gene editing for crop improvement in transformation-recalcitrant crops and cultivars. This review will discuss the recent advances in the use of regulatory genes in plant transformation and regeneration, and their potential to facilitate genotype-independent plant transformation and regeneration.
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Affiliation(s)
| | - Hui Duan
- Corresponding authors: E-mail: ;
| | - Kedong Da
- Department of Horticultural Science, North Carolina State University, Raleigh, NC, 27607, USA
| | - G Craig Yencho
- Department of Horticultural Science, North Carolina State University, Raleigh, NC, 27607, USA
| | - Thomas G Ranney
- Mountain Crop Improvement Lab, Department of Horticultural Science, Mountain Horticultural Crops Research and Extension Center, North Carolina State University, Mills River, NC 28759, USA
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Silva TN, Thomas JB, Dahlberg J, Rhee SY, Mortimer JC. Progress and challenges in sorghum biotechnology, a multipurpose feedstock for the bioeconomy. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:646-664. [PMID: 34644381 PMCID: PMC8793871 DOI: 10.1093/jxb/erab450] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 10/10/2021] [Indexed: 05/09/2023]
Abstract
Sorghum [Sorghum bicolor (L.) Moench] is the fifth most important cereal crop globally by harvested area and production. Its drought and heat tolerance allow high yields with minimal input. It is a promising biomass crop for the production of biofuels and bioproducts. In addition, as an annual diploid with a relatively small genome compared with other C4 grasses, and excellent germplasm diversity, sorghum is an excellent research species for other C4 crops such as maize. As a result, an increasing number of researchers are looking to test the transferability of findings from other organisms such as Arabidopsis thaliana and Brachypodium distachyon to sorghum, as well as to engineer new biomass sorghum varieties. Here, we provide an overview of sorghum as a multipurpose feedstock crop which can support the growing bioeconomy, and as a monocot research model system. We review what makes sorghum such a successful crop and identify some key traits for future improvement. We assess recent progress in sorghum transformation and highlight how transformation limitations still restrict its widespread adoption. Finally, we summarize available sorghum genetic, genomic, and bioinformatics resources. This review is intended for researchers new to sorghum research, as well as those wishing to include non-food and forage applications in their research.
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Affiliation(s)
- Tallyta N Silva
- Joint BioEnergy Institute, Emeryville, CA, USA
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Jason B Thomas
- Carnegie Institution for Science, Department of Plant Biology, Stanford, CA, USA
| | - Jeff Dahlberg
- Joint BioEnergy Institute, Emeryville, CA, USA
- UC-ANR-KARE, 9240 S. Riverbend Ave, Parlier, CA, USA
| | - Seung Y Rhee
- Carnegie Institution for Science, Department of Plant Biology, Stanford, CA, USA
- Correspondence: or
| | - Jenny C Mortimer
- Joint BioEnergy Institute, Emeryville, CA, USA
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- School of Agriculture, Food and Wine, Waite Research Institute, University of Adelaide, SA, Australia
- Correspondence: or
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Li Q, Jia E, Yan Y, Ma R, Dong J, Ma P. Using the Strategy of Inducing and Genetically Transforming Plant Suspension Cells to Produce High Value-Added Bioactive Substances. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:699-710. [PMID: 35018771 DOI: 10.1021/acs.jafc.1c05712] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Plants can produce many functional bioactive substances. The suspension cell system of plants can be constructed based on its characteristics to realize the large-scale production of valuable products. In this review, we mainly talk about the main strategies, elicitation, and genetic transformation to improve the yield of active substances by using this system. Meanwhile, we focus on the challenges hiding in the practical application and the future prospects and provide new ideas and the theoretical basis for obtaining numerous bioactive substances from plants.
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Affiliation(s)
- Qian Li
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, People's Republic of China
| | - Entong Jia
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, People's Republic of China
| | - Yurong Yan
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, People's Republic of China
| | - Rui Ma
- Jilin Provincial Key Laboratory of Agricultural Biotechnology, Jilin Academy of Agricultural Sciences, Changchun, Jilin 130033, People's Republic of China
| | - Juane Dong
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, People's Republic of China
| | - Pengda Ma
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, People's Republic of China
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Prías-Blanco M, Chappell TM, Freed EF, Illa-Berenguer E, Eckert CA, Parrott WA. An Agrobacterium strain auxotrophic for methionine is useful for switchgrass transformation. Transgenic Res 2022; 31:661-676. [PMID: 36239844 PMCID: PMC9747830 DOI: 10.1007/s11248-022-00328-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Accepted: 09/26/2022] [Indexed: 01/20/2023]
Abstract
Auxotrophic strains of Agrobacterium tumefaciens can contribute to the development of more efficient transformation systems, especially for crops historically considered recalcitrant. Homologous recombination was used to derive methionine auxotrophs of two common A. tumefaciens strains, LBA4404 and EHA105. The EHA105 strains were more efficient for switchgrass transformation, while both the EHA105 and LBA4404 strains worked equally well for the rice control. Event quality, as measured by transgene copy number, was not affected by auxotrophy, but was higher for the LBA4404 strains than the EHA105 strains. Ultimately, the use of auxotrophs reduced bacterial overgrowth during co-cultivation and decreased the need for antibiotics.
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Affiliation(s)
- Mónica Prías-Blanco
- Institute of Plant Breeding, Genetics and Genomics, University of Georgia, Athens, GA, USA
| | - Timothy M Chappell
- Institute of Plant Breeding, Genetics and Genomics, University of Georgia, Athens, GA, USA
| | - Emily F Freed
- Renewable and Sustainable Energy Institute (RASEI), University of Colorado Boulder, Boulder, CO, USA
| | | | - Carrie A Eckert
- Renewable and Sustainable Energy Institute (RASEI), University of Colorado Boulder, Boulder, CO, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Wayne A Parrott
- Institute of Plant Breeding, Genetics and Genomics, University of Georgia, Athens, GA, USA.
- Center for Applied Genetic Technologies, University of Georgia, Athens, GA, USA.
- Department of Crop and Soil Sciences, University of Georgia, Athens, GA, USA.
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10
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Bellido AM, Souza Canadá ED, Permingeat HR, Echenique V. Genetic Transformation of Apomictic Grasses: Progress and Constraints. FRONTIERS IN PLANT SCIENCE 2021; 12:768393. [PMID: 34804102 PMCID: PMC8602796 DOI: 10.3389/fpls.2021.768393] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 10/05/2021] [Indexed: 05/17/2023]
Abstract
The available methods for plant transformation and expansion beyond its limits remain especially critical for crop improvement. For grass species, this is even more critical, mainly due to drawbacks in in vitro regeneration. Despite the existence of many protocols in grasses to achieve genetic transformation through Agrobacterium or biolistic gene delivery, their efficiencies are genotype-dependent and still very low due to the recalcitrance of these species to in vitro regeneration. Many plant transformation facilities for cereals and other important crops may be found around the world in universities and enterprises, but this is not the case for apomictic species, many of which are C4 grasses. Moreover, apomixis (asexual reproduction by seeds) represents an additional constraint for breeding. However, the transformation of an apomictic clone is an attractive strategy, as the transgene is immediately fixed in a highly adapted genetic background, capable of large-scale clonal propagation. With the exception of some species like Brachiaria brizantha which is planted in approximately 100 M ha in Brazil, apomixis is almost non-present in economically important crops. However, as it is sometimes present in their wild relatives, the main goal is to transfer this trait to crops to fix heterosis. Until now this has been a difficult task, mainly because many aspects of apomixis are unknown. Over the last few years, many candidate genes have been identified and attempts have been made to characterize them functionally in Arabidopsis and rice. However, functional analysis in true apomictic species lags far behind, mainly due to the complexity of its genomes, of the trait itself, and the lack of efficient genetic transformation protocols. In this study, we review the current status of the in vitro culture and genetic transformation methods focusing on apomictic grasses, and the prospects for the application of new tools assayed in other related species, with two aims: to pave the way for discovering the molecular pathways involved in apomixis and to develop new capacities for breeding purposes because many of these grasses are important forage or biofuel resources.
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Affiliation(s)
- Andrés M. Bellido
- Departamento de Agronomía, Centro de Recursos Naturales Renovables de la Zona Semiárida (CERZOS – CCT – CONICET Bahía Blanca), Universidad Nacional del Sur (UNS), Bahía Blanca, Argentina
| | | | | | - Viviana Echenique
- Departamento de Agronomía, Centro de Recursos Naturales Renovables de la Zona Semiárida (CERZOS – CCT – CONICET Bahía Blanca), Universidad Nacional del Sur (UNS), Bahía Blanca, Argentina
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Tian D, Tang J, Luo L, Zhang Z, Du K, Larkin RM, Shi X, Zheng B. Influence of Switchgrass TDIF-like Genes on Arabidopsis Vascular Development. FRONTIERS IN PLANT SCIENCE 2021; 12:737219. [PMID: 34630487 PMCID: PMC8496505 DOI: 10.3389/fpls.2021.737219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 08/17/2021] [Indexed: 06/13/2023]
Abstract
As a member of the CLAVATA3 (CLV3)/EMBRYO SURROUNDING REGION (CLE) family, the dodecapeptide tracheary element differentiation inhibitory factor (TDIF) has a major impact on vascular development in plants. However, the influence of polymorphisms in the TDIF peptide motif on activity remains poorly understood. The model plant, Arabidopsis provides a fast and effective tool for assaying the activity of TDIF homologs. Five TDIF homologs from a group of 93 CLE genes in switchgrass (Panicum virgatum), a perennial biomass crop, named PvTDIF-like (PvTDIFL) genes were studied. The expression levels of PvTDIFL1, PvTDIFL3 MR3, and PvTDIFL3 MR2 were relatively high and all of them were expressed at the highest levels in the rachis of switchgrass. The precursor proteins for PvTDIFL1, PvTDIFL3MR3, and PvTDIFL3MR2 contained one, three, and two TDIFL motifs, respectively. Treatments with exogenous PvTDIFL peptides increased the number of stele cells in the hypocotyls of Arabidopsis seedlings, with the exception of PvTDIFL_4p. Heterologous expression of PvTDIFL1 in Arabidopsis strongly inhibited plant growth, increased cell division in the vascular tissue of the hypocotyl, and disrupted the cellular organization of the hypocotyl. Although heterologous expression of PvTDIFL3 MR3 and PvTDIFL3 MR2 also affected plant growth and vascular development, PvTDIFL activity was not enhanced by the multiple TDIFL motifs encoded by PvTDIFL3 MR3 and PvTDIFL3 MR2. These data indicate that in general, PvTDIFLs are functionally similar to Arabidopsis TDIF but that the processing and activities of the PvTDIFL peptides are more complex.
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Affiliation(s)
- Dongdong Tian
- Key Laboratory of Horticultural Plant Biology of Ministry of Education, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
- Tobacco Research Institute, Chinese Academy of Agricultural Science, Qingdao, China
| | - Jingwen Tang
- Key Laboratory of Horticultural Plant Biology of Ministry of Education, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
| | - Liwen Luo
- Key Laboratory of Horticultural Plant Biology of Ministry of Education, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
| | - Zhe Zhang
- Key Laboratory of Horticultural Plant Biology of Ministry of Education, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
| | - Kebing Du
- Key Laboratory of Horticultural Plant Biology of Ministry of Education, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
- Hubei Engineering Technology Research Center for Forestry Information, Huazhong Agricultural University, Wuhan, China
| | - Robert M. Larkin
- Key Laboratory of Horticultural Plant Biology of Ministry of Education, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
| | - Xueping Shi
- Key Laboratory of Horticultural Plant Biology of Ministry of Education, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
- Hubei Engineering Technology Research Center for Forestry Information, Huazhong Agricultural University, Wuhan, China
| | - Bo Zheng
- Key Laboratory of Horticultural Plant Biology of Ministry of Education, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
- Hubei Engineering Technology Research Center for Forestry Information, Huazhong Agricultural University, Wuhan, China
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