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Barrera M, Olmedo B, Zúñiga C, Cepeda M, Olivares F, Vergara R, Cordero-Lara K, Prieto H. Somatic Embryogenesis and Agrobacterium-Mediated Gene Transfer Procedures in Chilean Temperate Japonica Rice Varieties for Precision Breeding. PLANTS (BASEL, SWITZERLAND) 2024; 13:416. [PMID: 38337949 PMCID: PMC10857379 DOI: 10.3390/plants13030416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 01/08/2024] [Accepted: 01/18/2024] [Indexed: 02/12/2024]
Abstract
Rice (Oryza sativa) varieties are generated through breeding programs focused on local requirements. In Chile, the southernmost rice producer, rice productivity relies on the use and generation of temperate japonica germplasms, which need to be adapted to the intensifying effects of climate change. Advanced biotechnological tools can contribute to these breeding programs; new technologies associated with precision breeding, including gene editing, rely on procedures such as regeneration and gene transfer. In this study, the local rice varieties Platino, Cuarzo, Esmeralda, and Zafiro were evaluated for somatic embryogenesis potential using a process that involved the combined use of auxins and cytokinins. An auxin-based (2,4-D) general medium (2N6) allowed for the induction of embryogenic masses in all the genotypes. After induction, masses required culturing either in N6R (kinetin; Platino) or N6RN (BAP, kinetin, IBA, and 2,4-D; Cuarzo, Esmeralda, and Zafiro) to yield whole plants using regeneration medium (N6F, no hormone). The sprouting rates indicated Platino as the most responsive genotype; for this reason, this variety was evaluated for gene transfer. Fifteen-day-old embryo masses were assayed for Agrobacterium-mediated transformation using the bacterial strain EHA105 harboring pFLC-Myb/HPT/GFP, a modified T-DNA vector harboring a geminivirus-derived replicon. The vector included the green fluorescent protein reporter gene, allowing for continuous traceability. Reporter mRNA was produced as early as 3 d after agroinfiltration, and stable expression of the protein was observed along the complete process. These achievements enable further biotechnological steps in these and other genotypes from our breeding program.
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Affiliation(s)
- Marion Barrera
- Natural Sciences, Mathematics, and Environment Faculty, Metropolitan Technological University, Santiago 8330526, Chile;
- Biotechnology Laboratory, La Platina Research Station, INIA-Chile, Santiago 8831314, Chile; (B.O.); (C.Z.); (M.C.); (F.O.); (R.V.)
| | - Blanca Olmedo
- Biotechnology Laboratory, La Platina Research Station, INIA-Chile, Santiago 8831314, Chile; (B.O.); (C.Z.); (M.C.); (F.O.); (R.V.)
| | - Carolina Zúñiga
- Biotechnology Laboratory, La Platina Research Station, INIA-Chile, Santiago 8831314, Chile; (B.O.); (C.Z.); (M.C.); (F.O.); (R.V.)
| | - Mario Cepeda
- Biotechnology Laboratory, La Platina Research Station, INIA-Chile, Santiago 8831314, Chile; (B.O.); (C.Z.); (M.C.); (F.O.); (R.V.)
| | - Felipe Olivares
- Biotechnology Laboratory, La Platina Research Station, INIA-Chile, Santiago 8831314, Chile; (B.O.); (C.Z.); (M.C.); (F.O.); (R.V.)
| | - Ricardo Vergara
- Biotechnology Laboratory, La Platina Research Station, INIA-Chile, Santiago 8831314, Chile; (B.O.); (C.Z.); (M.C.); (F.O.); (R.V.)
| | - Karla Cordero-Lara
- Rice Breeding Program, Quilamapu Research Station, INIA-Chile, Chillán 3780000, Chile;
| | - Humberto Prieto
- Biotechnology Laboratory, La Platina Research Station, INIA-Chile, Santiago 8831314, Chile; (B.O.); (C.Z.); (M.C.); (F.O.); (R.V.)
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Olivares F, Loyola R, Olmedo B, Miccono MDLÁ, Aguirre C, Vergara R, Riquelme D, Madrid G, Plantat P, Mora R, Espinoza D, Prieto H. CRISPR/Cas9 Targeted Editing of Genes Associated With Fungal Susceptibility in Vitis vinifera L. cv. Thompson Seedless Using Geminivirus-Derived Replicons. FRONTIERS IN PLANT SCIENCE 2021; 12:791030. [PMID: 35003180 PMCID: PMC8733719 DOI: 10.3389/fpls.2021.791030] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 11/29/2021] [Indexed: 05/14/2023]
Abstract
The woody nature of grapevine (Vitis vinifera L.) has hindered the development of efficient gene editing strategies to improve this species. The lack of highly efficient gene transfer techniques, which, furthermore, are applied in multicellular explants such as somatic embryos, are additional technical handicaps to gene editing in the vine. The inclusion of geminivirus-based replicons in regular T-DNA vectors can enhance the expression of clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9) elements, thus enabling the use of these multicellular explants as starting materials. In this study, we used Bean yellow dwarf virus (BeYDV)-derived replicon vectors to express the key components of CRISPR/Cas9 system in vivo and evaluate their editing capability in individuals derived from Agrobacterium-mediated gene transfer experiments of 'Thompson Seedless' somatic embryos. Preliminary assays using a BeYDV-derived vector for green fluorescent protein reporter gene expression demonstrated marker visualization in embryos for up to 33 days post-infiltration. A universal BeYDV-based vector (pGMV-U) was assembled to produce all CRISPR/Cas9 components with up to four independent guide RNA (gRNA) expression cassettes. With a focus on fungal tolerance, we used gRNA pairs to address considerably large deletions of putative grape susceptibility genes, including AUXIN INDUCED IN ROOT CULTURE 12 (VviAIR12), SUGARS WILL EVENTUALLY BE EXPORTED TRANSPORTER 4 (VviSWEET4), LESION INITIATION 2 (VviLIN2), and DIMERIZATION PARTNER-E2F-LIKE 1 (VviDEL1). The editing functionality of gRNA pairs in pGMV-U was evaluated by grapevine leaf agroinfiltration assays, thus enabling longer-term embryo transformations. These experiments allowed for the establishment of greenhouse individuals exhibiting a double-cut edited status for all targeted genes under different allele-editing conditions. After approximately 18 months, the edited grapevine plants were preliminary evaluated regarding its resistance to Erysiphe necator and Botrytis cinerea. Assays have shown that a transgene-free VviDEL1 double-cut edited line exhibits over 90% reduction in symptoms triggered by powdery mildew infection. These results point to the use of geminivirus-based replicons for gene editing in grapevine and other relevant fruit species.
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Affiliation(s)
- Felipe Olivares
- Biotechnology Laboratory, La Platina Research Station, National Institute of Agriculture Research, Santiago, Chile
| | - Rodrigo Loyola
- Biotechnology Laboratory, La Platina Research Station, National Institute of Agriculture Research, Santiago, Chile
| | - Blanca Olmedo
- Biotechnology Laboratory, La Platina Research Station, National Institute of Agriculture Research, Santiago, Chile
| | - María de los Ángeles Miccono
- Biotechnology Laboratory, La Platina Research Station, National Institute of Agriculture Research, Santiago, Chile
| | - Carlos Aguirre
- Biotechnology Laboratory, La Platina Research Station, National Institute of Agriculture Research, Santiago, Chile
| | - Ricardo Vergara
- Biotechnology Laboratory, La Platina Research Station, National Institute of Agriculture Research, Santiago, Chile
| | - Danae Riquelme
- Phytopathology Laboratory, La Platina Research Station, National Institute of Agriculture Research, Santiago, Chile
| | - Gabriela Madrid
- Biotechnology Laboratory, La Platina Research Station, National Institute of Agriculture Research, Santiago, Chile
| | - Philippe Plantat
- Biotechnology Laboratory, La Platina Research Station, National Institute of Agriculture Research, Santiago, Chile
| | - Roxana Mora
- Biotechnology Laboratory, La Platina Research Station, National Institute of Agriculture Research, Santiago, Chile
| | - Daniel Espinoza
- Biotechnology Laboratory, La Platina Research Station, National Institute of Agriculture Research, Santiago, Chile
| | - Humberto Prieto
- Biotechnology Laboratory, La Platina Research Station, National Institute of Agriculture Research, Santiago, Chile
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