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Zein El Din AFM, Darwesh RSS, Ibrahim MFM, Salama GMY, Shams El-Din IM, Abdelaal WB, Ali GA, Elsayed MS, Ismail IA, Dessoky ES, Abdellatif YMR. Antioxidants Application Enhances Regeneration and Conversion of Date Palm (Phoenix dactylifera L.) Somatic Embryos. PLANTS 2022; 11:plants11152023. [PMID: 35956500 PMCID: PMC9370564 DOI: 10.3390/plants11152023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 07/30/2022] [Accepted: 07/31/2022] [Indexed: 11/16/2022]
Abstract
Many embryogenic systems have been designed to generate somatic embryos (SEs) with the morphology, biochemistry, and vigor uniformity of zygotic embryos (ZEs). During the current investigation, several antioxidants were added to the maturation media of the developing somatic embryos of date palm. Explant material was a friable embryogenic callus that was placed in maturation media containing ABA at 0.5 mg L−1, 5 g L−1 polyethylene glycol, and 10 g L−1 phytagel. Furthermore, α-tocopherol or reduced glutathione (GSH) were used separately at (25 and 50 mg L−1). These treatments were compared to a widely used date palm combination of reduced ascorbic acid (ASC) and citric acid at 150 and 100 mg L−1, respectively, and to the medium free from any antioxidants. The relative growth percentage of embryogenic callus (EC), globularization degree, differentiation%, and SEs number were significantly increased with GSH (50 mg L−1). Additionally, the latter treatment significantly enhanced the conversion% of SEs and the number of secondary somatic embryos (SSEs). ASC and citric acid treatment increased leaf length, while α-tochopherol (50 mg L−1) elevated the number of leaves plantlet−1. GSH at 50 mg L−1 catalyzed the activities of polyphenol oxidase (PPO) and peroxidase (POD) in EC and enhanced the accumulation of proteins in SEs.
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Affiliation(s)
- Amal F. M. Zein El Din
- The Central Laboratory for Date Palm Researches and Development, Agricultural Research Center, Giza 12619, Egypt; (A.F.M.Z.E.D.); (R.S.S.D.); (I.M.S.E.-D.); (W.B.A.); (G.A.A.); (M.S.E.)
| | - Rasmia S. S. Darwesh
- The Central Laboratory for Date Palm Researches and Development, Agricultural Research Center, Giza 12619, Egypt; (A.F.M.Z.E.D.); (R.S.S.D.); (I.M.S.E.-D.); (W.B.A.); (G.A.A.); (M.S.E.)
| | - Mohamed F. M. Ibrahim
- Department of Agricultural Botany, Faculty of Agriculture, Ain Shams University, Cairo 11566, Egypt;
- Correspondence: ; Tel.: +2-011-23403173
| | - Gehan M. Y. Salama
- Botanical Garden Research Department, Horticulture Research institute (HRI). Agricultural ResearchCenter (ARC), Giza 12619, Egypt;
| | - Ibrahim M. Shams El-Din
- The Central Laboratory for Date Palm Researches and Development, Agricultural Research Center, Giza 12619, Egypt; (A.F.M.Z.E.D.); (R.S.S.D.); (I.M.S.E.-D.); (W.B.A.); (G.A.A.); (M.S.E.)
| | - Walid B. Abdelaal
- The Central Laboratory for Date Palm Researches and Development, Agricultural Research Center, Giza 12619, Egypt; (A.F.M.Z.E.D.); (R.S.S.D.); (I.M.S.E.-D.); (W.B.A.); (G.A.A.); (M.S.E.)
| | - Ghada A. Ali
- The Central Laboratory for Date Palm Researches and Development, Agricultural Research Center, Giza 12619, Egypt; (A.F.M.Z.E.D.); (R.S.S.D.); (I.M.S.E.-D.); (W.B.A.); (G.A.A.); (M.S.E.)
| | - Maha S. Elsayed
- The Central Laboratory for Date Palm Researches and Development, Agricultural Research Center, Giza 12619, Egypt; (A.F.M.Z.E.D.); (R.S.S.D.); (I.M.S.E.-D.); (W.B.A.); (G.A.A.); (M.S.E.)
| | - Ismail A. Ismail
- Department of Biology, College of Science, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia; (I.A.I.); (E.S.D.)
| | - Eldessoky S. Dessoky
- Department of Biology, College of Science, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia; (I.A.I.); (E.S.D.)
| | - Yasmin M. R. Abdellatif
- Department of Agricultural Botany, Faculty of Agriculture, Ain Shams University, Cairo 11566, Egypt;
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Żur I, Kopeć P, Surówka E, Dubas E, Krzewska M, Nowicka A, Janowiak F, Juzoń K, Janas A, Barna B, Fodor J. Impact of Ascorbate-Glutathione Cycle Components on the Effectiveness of Embryogenesis Induction in Isolated Microspore Cultures of Barley and Triticale. Antioxidants (Basel) 2021; 10:1254. [PMID: 34439502 PMCID: PMC8389252 DOI: 10.3390/antiox10081254] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 07/30/2021] [Accepted: 08/03/2021] [Indexed: 12/12/2022] Open
Abstract
Enhanced antioxidant defence plays an essential role in plant survival under stress conditions. However, excessive antioxidant activity sometimes suppresses the signal necessary for the initiation of the desired biological reactions. One such example is microspore embryogenesis (ME)-a process of embryo-like structure formation triggered by stress in immature male gametophytes. The study focused on the role of reactive oxygen species and antioxidant defence in triticale (×Triticosecale Wittm.) and barley (Hordeum vulgare L.) microspore reprogramming. ME was induced through various stress treatments of tillers and its effectiveness was analysed in terms of ascorbate and glutathione contents, total activity of low molecular weight antioxidants and activities of glutathione-ascorbate cycle enzymes. The most effective treatment for both species was a combination of low temperature and exogenous application of 0.3 M mannitol, with or without 0.3 mM reduced glutathione. The applied treatments induced genotype-specific defence responses. In triticale, both ascorbate and glutathione were associated with ME induction, though the role of glutathione did not seem to be related to its function as a reducing agent. In barley, effective ME was accompanied by an accumulation of ascorbate and high activity of enzymes regulating its redox status, without direct relation to glutathione content.
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Affiliation(s)
- Iwona Żur
- The Franciszek Górski Institute of Plant Physiology Polish Academy of Sciences, Niezapominajek 21, 30-239 Kraków, Poland; (P.K.); (E.S.); (E.D.); (M.K.); (A.N.); (F.J.); (K.J.); (A.J.)
| | - Przemysław Kopeć
- The Franciszek Górski Institute of Plant Physiology Polish Academy of Sciences, Niezapominajek 21, 30-239 Kraków, Poland; (P.K.); (E.S.); (E.D.); (M.K.); (A.N.); (F.J.); (K.J.); (A.J.)
| | - Ewa Surówka
- The Franciszek Górski Institute of Plant Physiology Polish Academy of Sciences, Niezapominajek 21, 30-239 Kraków, Poland; (P.K.); (E.S.); (E.D.); (M.K.); (A.N.); (F.J.); (K.J.); (A.J.)
| | - Ewa Dubas
- The Franciszek Górski Institute of Plant Physiology Polish Academy of Sciences, Niezapominajek 21, 30-239 Kraków, Poland; (P.K.); (E.S.); (E.D.); (M.K.); (A.N.); (F.J.); (K.J.); (A.J.)
| | - Monika Krzewska
- The Franciszek Górski Institute of Plant Physiology Polish Academy of Sciences, Niezapominajek 21, 30-239 Kraków, Poland; (P.K.); (E.S.); (E.D.); (M.K.); (A.N.); (F.J.); (K.J.); (A.J.)
| | - Anna Nowicka
- The Franciszek Górski Institute of Plant Physiology Polish Academy of Sciences, Niezapominajek 21, 30-239 Kraków, Poland; (P.K.); (E.S.); (E.D.); (M.K.); (A.N.); (F.J.); (K.J.); (A.J.)
| | - Franciszek Janowiak
- The Franciszek Górski Institute of Plant Physiology Polish Academy of Sciences, Niezapominajek 21, 30-239 Kraków, Poland; (P.K.); (E.S.); (E.D.); (M.K.); (A.N.); (F.J.); (K.J.); (A.J.)
| | - Katarzyna Juzoń
- The Franciszek Górski Institute of Plant Physiology Polish Academy of Sciences, Niezapominajek 21, 30-239 Kraków, Poland; (P.K.); (E.S.); (E.D.); (M.K.); (A.N.); (F.J.); (K.J.); (A.J.)
| | - Agnieszka Janas
- The Franciszek Górski Institute of Plant Physiology Polish Academy of Sciences, Niezapominajek 21, 30-239 Kraków, Poland; (P.K.); (E.S.); (E.D.); (M.K.); (A.N.); (F.J.); (K.J.); (A.J.)
| | - Balázs Barna
- Plant Protection Institute, Centre for Agricultural Research, Herman Ottó út 15, 1022 Budapest, Hungary; (B.B.); (J.F.)
| | - József Fodor
- Plant Protection Institute, Centre for Agricultural Research, Herman Ottó út 15, 1022 Budapest, Hungary; (B.B.); (J.F.)
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Hazubska-Przybył T, Ratajczak E, Obarska A, Pers-Kamczyc E. Different Roles of Auxins in Somatic Embryogenesis Efficiency in Two Picea Species. Int J Mol Sci 2020; 21:E3394. [PMID: 32403374 PMCID: PMC7246981 DOI: 10.3390/ijms21093394] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 05/01/2020] [Accepted: 05/09/2020] [Indexed: 12/18/2022] Open
Abstract
The effects of auxins 2,4-D (2,4-dichlorophenoxyacetic acid), NAA (1-naphthaleneacetic acid) or picloram (4-amino-3,5,6-trichloropicolinic acid; 9 µM) and cytokinin BA (benzyloadenine; 4.5 µM) applied in the early stages of somatic embryogenesis (SE) on specific stages of SE in Picea abies and P. omorika were investigated. The highest SE initiation frequency was obtained after 2,4-D application in P. omorika (22.00%) and picloram application in P. abies (10.48%). NAA treatment significantly promoted embryogenic tissue (ET) proliferation in P. abies, while 2,4-D treatment reduced it. This reduction was related to the oxidative stress level, which was lower with the presence of NAA in the proliferation medium and higher with the presence of 2,4-D. The reduced oxidative stress level after NAA treatment suggests that hydrogen peroxide (H2O2) acts as a signalling molecule and promotes ET proliferation. NAA and picloram in the proliferation medium decreased the further production and maturation of P. omorika somatic embryos compared with that under 2,4-D. The quality of the germinated P. abies embryos and their development into plantlets depended on the auxin type and were the highest in NAA-originated embryos. These results show that different auxin types can generate different physiological responses in plant materials during SE in both spruce species.
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Affiliation(s)
- Teresa Hazubska-Przybył
- Institute of Dendrology, Polish Academy of Sciences, 62-035 Kórnik, Poland; (E.R.); (A.O.); (E.P.-K.)
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Żur I, Dubas E, Krzewska M, Zieliński K, Fodor J, Janowiak F. Glutathione provides antioxidative defence and promotes microspore-derived embryo development in isolated microspore cultures of triticale (× Triticosecale Wittm.). PLANT CELL REPORTS 2019; 38:195-209. [PMID: 30499031 PMCID: PMC6349815 DOI: 10.1007/s00299-018-2362-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 11/24/2018] [Indexed: 05/05/2023]
Abstract
Depending on the capability for stress adaptation, the role played by glutathione in microspore embryogenesis consists of both antioxidative activity and stimulation of embryo-like structure development. The efficiency of microspore embryogenesis (ME) is determined by the complex network of internal and environmental factors. Among them, the efficient defence against oxidative stress seems to be one of the most important. The present study confirms this hypothesis showing the positive effect of glutathione-the most abundant cellular antioxidant-on ME in isolated microspore cultures of triticale (× Triticosecale Wittm.). For the first time, low temperature (LT) pre-treatment of tillers was combined with the exogenous application of glutathione and associated with the total activity of low-molecular weight antioxidants, the endogenous content and redox status of glutathione, and the effectiveness of ME. The results indicate that efficient antioxidative defence is the first, although not the only, prerequisite for effective ME. In responsive genotypes, LT alone stimulated antioxidative defence and decreased cell redox status, which was associated with increased cell viability and high frequency (ca. 20%) of microspore reprogramming. Application of glutathione had no effect either on the microspore viability or on the initial number of embryogenic microspores. However, it increased the number of embryo-like structures, probably by stimulating the next phases of its development. In recalcitrant genotypes, the main role of glutathione seems to be its participation in cell protection from oxidative stress. However, even enhanced antioxidative activity, which sustained cell viability and increased the number of embryogenic microspores, was insufficient for efficient haploid/doubled haploid plant production. Evidently, there are still other defective elements in the complex network of factors that regulate the process of ME.
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Affiliation(s)
- Iwona Żur
- The Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Niezapominajek 21, 30-239, Kraków, Poland.
| | - Ewa Dubas
- The Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Niezapominajek 21, 30-239, Kraków, Poland
| | - Monika Krzewska
- The Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Niezapominajek 21, 30-239, Kraków, Poland
| | - Kamil Zieliński
- The Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Niezapominajek 21, 30-239, Kraków, Poland
| | - Jozsef Fodor
- Plant Protection Institute, Hungarian Academy of Sciences, Herman Ottó út 15, Budapest, 1022, Hungary
| | - Franciszek Janowiak
- The Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Niezapominajek 21, 30-239, Kraków, Poland
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CHAGAS KRISTHIANO, CIPRIANO JAMILEL, LOPES JOSÉCARLOS, SCHMILDT EDILSONR, OTONI WAGNERC, ALEXANDRE RODRIGOS. The effects of an osmoregulator, carbohydrates and polyol on maturation and germination of ‘Golden THB’ papaya somatic embryos. AN ACAD BRAS CIENC 2018; 90:3433-3447. [DOI: 10.1590/0001-3765201820171035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Accepted: 03/02/2018] [Indexed: 11/21/2022] Open
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Hudec L, Konrádová H, Hašková A, Lipavská H. Norway spruce embryogenesis: changes in carbohydrate profile, structural development and response to polyethylene glycol. TREE PHYSIOLOGY 2016; 36:548-61. [PMID: 27052433 PMCID: PMC4886291 DOI: 10.1093/treephys/tpw016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 02/14/2016] [Indexed: 05/25/2023]
Abstract
Two unrelated, geographically distinct, highly embryogenic lines of Norway spruce (Picea abies (L.) Karst.) were analysed to identify metabolic traits characteristic for lines with good yields of high-quality embryos. The results were compared with corresponding characteristics of a poorly productive line (low embryo yield, scarce high-quality embryos). The following carbohydrate profiles and spectra during maturation, desiccation and germination were identified as promising characteristics for line evaluation: a gradual decrease in total soluble carbohydrates with an increasing sucrose : hexose ratio during maturation; accumulation of raffinose family oligosaccharides resulting from desiccation and their rapid degradation at the start of germination; and a decrease in sucrose, increase in hexoses and the appearance of pinitol with proceeding germination. We propose that any deviation from this profile in an embryonic line is a symptom of inferior somatic embryo development. We further propose that a fatty acid spectrum dominated by linoleic acid (18 : 2) was a common feature of healthy spruce somatic embryos, although it was quite different from zygotic embryos mainly containing oleic acid (18 : 1). The responses of the lines to osmotic stress were evaluated based on comparison of control (without osmoticum) and polyethylene glycol (PEG)-exposed (PEG 4000) variants. Although genetically distinct, both highly embryogenic lines responded in a very similar manner, with the only difference being sensitivity to high concentrations of PEG. At an optimum PEG concentration (3.75 and 5%), which was line specific, negative effects of PEG on embryo germination were compensated for by a higher maturation efficiency so that the application of PEG at an appropriate concentration improved the yield of healthy germinants per gram of initial embryonal mass and accelerated the process. Polyethylene glycol application, however, resulted in no improvement of the poorly productive line.
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Affiliation(s)
- Lukáš Hudec
- Faculty of Science, Department of Experimental Plant Biology, Charles University in Prague, Viničná 5, 128 44 Praha 2, Czech Republic
| | - Hana Konrádová
- Faculty of Science, Department of Experimental Plant Biology, Charles University in Prague, Viničná 5, 128 44 Praha 2, Czech Republic
| | - Anna Hašková
- Faculty of Science, Department of Experimental Plant Biology, Charles University in Prague, Viničná 5, 128 44 Praha 2, Czech Republic
| | - Helena Lipavská
- Faculty of Science, Department of Experimental Plant Biology, Charles University in Prague, Viničná 5, 128 44 Praha 2, Czech Republic
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Klimaszewska K, Hargreaves C, Lelu-Walter MA, Trontin JF. Advances in Conifer Somatic Embryogenesis Since Year 2000. Methods Mol Biol 2016; 1359:131-66. [PMID: 26619862 DOI: 10.1007/978-1-4939-3061-6_7] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
This review compiles research results published over the last 14 years on conifer somatic embryogenesis (SE). Emphasis is placed on the newest findings that affect the response of seed embryos (typical explants) and shoot primordia (rare explants) to the induction of SE and long-term culture of early somatic embryos. Much research in recent years has focused on maturation of somatic embryos, with respect to both yield and quality, as an important stage for the production of a large number of vigorous somatic seedlings. Attempts to scale up somatic embryo production numbers and handling have resulted in a few bioreactor designs, the utility of which may prove beneficial for an industrial application. A few simplified cryopreservation methods for embryonal masses (EM) were developed as a means to ensure cost-efficient long-term storage of genotypes during clonal field testing. Finally, recent long-term studies on the growth of somatic trees in the field, including seed production yield and comparison of seed parameters produced by somatic versus seed-derived trees, are described.
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Affiliation(s)
- Krystyna Klimaszewska
- Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, 1055 du P.E.P.S., 10380, Stn. Sainte-Foy, QC, Canada, G1V 4C7.
| | | | - Marie-Anne Lelu-Walter
- INRA, UR 0588 Unité Amélioration, Génétique et Physiologie Forestières, 2163 Avenue de la Pomme de Pin, CS 4001, Ardon, Orléans Cedex 2, 45075, France
| | - Jean-François Trontin
- FCBA, Pôle Biotechnologie et Sylviculture Avancée, Équipe Génétique et Biotechnologie, Campus Forêt-Bois de Pierroton, 71 Route d'Arcachon, Cestas, 33610, France
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Pullman GS, Zeng X, Copeland-Kamp B, Crockett J, Lucrezi J, May SW, Bucalo K. Conifer somatic embryogenesis: improvements by supplementation of medium with oxidation-reduction agents. TREE PHYSIOLOGY 2015; 35:209-24. [PMID: 25716878 DOI: 10.1093/treephys/tpu117] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A major barrier to the commercialization of somatic embryogenesis technology in loblolly pine (Pinus taeda L.) is recalcitrance of some high-value crosses to initiate embryogenic tissue (ET) and continue early-stage somatic embryo growth. Developing initiation and multiplication media that resemble the seed environment has been shown to decrease this recalcitrance. Glutathione (GSH), glutathione disulfide (GSSG), ascorbic acid and dehydroascorbate analyses were performed weekly throughout the sequence of seed development for female gametophyte and zygotic embryo tissues to determine physiological concentrations. Major differences in stage-specific oxidation-reduction (redox) agents were observed. A simple bioassay was used to evaluate potential growth-promotion of natural and inorganic redox agents added to early-stage somatic embryo growth medium. Compounds showing statistically significant increases in early-stage embryo growth were then tested for the ability to increase initiation of loblolly pine. Low-cost reducing agents sodium dithionite and sodium thiosulfate increased ET initiation for loblolly pine and Douglas fir (Mirb) Franco. Germination medium supplementation with GSSG increased somatic embryo germination. Early-stage somatic embryos grown on medium with or without sodium thiosulfate did not differ in GSH or GSSG content, suggesting that sodium thiosulfate-mediated growth stimulation does not involve GSH or GSSG. We have developed information demonstrating that alteration of the redox environment in vitro can improve ET initiation, early-stage embryo development and somatic embryo germination in loblolly pine.
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Affiliation(s)
- Gerald S Pullman
- School of Biology, Georgia Institute of Technology, 500 10th Street N.W., Atlanta, GA 30332-0620, USA Renewable Bioproducts Institute (RBI), Georgia Institute of Technology, 500 10th Street N.W., Atlanta, GA 30332-0620, USA
| | - Xiaoyan Zeng
- Renewable Bioproducts Institute (RBI), Georgia Institute of Technology, 500 10th Street N.W., Atlanta, GA 30332-0620, USA
| | - Brandi Copeland-Kamp
- Renewable Bioproducts Institute (RBI), Georgia Institute of Technology, 500 10th Street N.W., Atlanta, GA 30332-0620, USA
| | - Jonathan Crockett
- Renewable Bioproducts Institute (RBI), Georgia Institute of Technology, 500 10th Street N.W., Atlanta, GA 30332-0620, USA
| | - Jacob Lucrezi
- School of Chemistry and Biochemistry, Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Sheldon W May
- School of Chemistry and Biochemistry, Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Kylie Bucalo
- Renewable Bioproducts Institute (RBI), Georgia Institute of Technology, 500 10th Street N.W., Atlanta, GA 30332-0620, USA
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Abstract
Somatic embryogenesis (SE) has the potential to be the lowest-cost method to rapidly produce large numbers of high-value somatic seedlings with desired characteristics for plantation forestry. At least 24 of the 115-120 known Pinus species can undergo SE. Initiation for most species works best with immature megagametophytes as starting material, although a few pines can initiate SE cultures from isolated mature seed embryos. Successful initiation depends heavily on explant type, embryo developmental stage, and medium salt base. Most first reports of initiation used 2,4-D and BAP or a combination of cytokinins. More recent reports have optimized initiation for many Pinus spp., but still use mostly the combinations of auxin and cytokinins. Initiation can be stimulated with medium supplements including abscisic acid (ABA), brassinosteroids, ethylene inhibitors, gibberellin inhibitors, organic acids, putrescine, specific sugar types (maltose, galactose, D-chiro-inositol, and D-xylose), triacontanol, vitamins (B12, biotin, vitamin E, and folic acid), or manipulation of environmental factors including pH, water potential, cone cold storage, gelling agent concentration, and liquid medium. Embryo development and maturation usually occur best on medium containing ABA along with water potential reduction (with sugars and polyethylene glycol) or water availability reduction (with raised gelling agent increasing gel-strength). Activated carbon and maltose may also improve embryo maturation. The main issues holding SE technology back are related to the high cost of producing a somatic seedling, incurred from low initiation percentages for recalcitrant species, culture loss, and decline after initiation and poor embryo maturation resulting in no or poor germination. Although vast progress has been made in pine SE technology over the past 24 years, fundamental studies on seed and embryo physiology, biochemistry, and gene expression are still needed to help improve the technology to a point where large-scale commercialization is economically viable for a broad range of pine species.
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Affiliation(s)
- Gerald S Pullman
- School of Biology and Institute of Paper Science and Technology, Georgia Institute of Technology, Atlanta, GA, USA.
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Belmonte M, Elhiti M, Waldner B, Stasolla C. Depletion of cellular brassinolide decreases embryo production and disrupts the architecture of the apical meristems in Brassica napus microspore-derived embryos. JOURNAL OF EXPERIMENTAL BOTANY 2010; 61:2779-94. [PMID: 20435696 PMCID: PMC2882269 DOI: 10.1093/jxb/erq110] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2010] [Revised: 03/25/2010] [Accepted: 03/30/2010] [Indexed: 05/19/2023]
Abstract
Exogenous applications of brassinolide (BL) increased the number and quality of microspore-derived embryos (MDEs) whereas treatments with brassinazole (BrZ), a BL biosynthetic inhibitor, had the opposite effect. At the optimal concentration (4x10(-6) M) BrZ decreased both embryo yield and conversion to less than half the value of control embryos. Metabolic studies revealed that BL levels had profound effects on glutathione and ascorbate metabolism by altering the amounts of their reduced forms (ASC and GSH) and oxidized forms [dehydroascorbate (DHA), ascorbate free radicals (AFRs), and GSSG]. Applications of BL switched the glutathione and ascorbate pools towards the oxidized forms, thereby lowering the ASC/ASC+DHA+AFR and GSH/GSH+GSSG ratios. These changes were ascribed to the ability of BL to increase the activity of ascorbate peroxidase (APX) and decrease that of glutathione reductase (GR). This trend was reversed in a BL-depleted environment, effected by BrZ applications. These metabolic alterations were associated with changes in embryo structure and performance. BL-treated MDEs developed zygotic-like shoot apical meristems (SAMs) whereas embryos treated with BrZ developed abnormal meristems. In the presence of BrZ, embryos either lacked a visible SAM, or formed SAMs in which the meristematic cells showed signs of differentiation, such as vacuolation and storage product accumulation. These abnormalities were accompanied by the lack or misexpression of three meristem marker genes isolated from Brassica napus (denoted as BnSTM, BnCLV1, and BnZLL-1) homologous to the Arabidopsis SHOOTMERISTEMLESS (STM), CLAVATA 1 (CLV1), and ZWILLE (ZLL). The expression of BnSTM and BnCLV1 increased after a few days in cultures in embryos treated with BL whereas an opposite tendency was observed with applications of BrZ. Compared with control embryos where these two genes exhibited abnormal localization patterns, BnSTM and BnCLV1 always localized throughout the subapical domains of BL-treated embryos in a zygotic-like fashion. Expression of both genes was often lost in the SAM of BrZ-treated embryos. The results suggest that maintenance of cellular BL levels is required to modulate the ascorbate and glutathione redox status during embryogenesis to ensure proper development of the embryos and formation of functional apical meristems.
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Affiliation(s)
| | | | | | - Claudio Stasolla
- Department of Plant Science, University of Manitoba, Winnipeg, R3T 2N2, Manitoba, Canada
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Cistué L, Romagosa I, Batlle F, Echávarri B. Improvements in the production of doubled haploids in durum wheat (Triticum turgidum L.) through isolated microspore culture. PLANT CELL REPORTS 2009; 28:727-35. [PMID: 19288107 DOI: 10.1007/s00299-009-0690-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2008] [Revised: 01/30/2009] [Accepted: 02/19/2009] [Indexed: 05/21/2023]
Abstract
The objective of this study was to produce durum wheat doubled haploid (DH) plants through the induction of microspore embryogenesis. The microspore culture technique was improved to maximize production of green plants per spike using three commercial cultivars. Studies on factors such as induction media composition, induction media support and the stage and growth of donor plants were carried out in order to develop an efficient protocol to regenerate green and fertile DH plants. Microspores were plated on a C(17) induction culture medium with ovary co-culture and a supplement of glutathione plus glutamine; 300 g/l Ficoll Type-400 was incorporated to the induction medium support. Donor plants were fertilized with a combination of macro and microelements. With the cultivars 'Ciccio' and 'Claudio' an average of 36.5 and 148.5 fertile plants were produced, respectively, from 1,000 anthers inoculated. This technique was then used to produce fertile DH plants of potential agronomic interest from a collection of ten F(1) crosses involving cultivars of high breeding value. From these crosses 849 green plants were obtained and seed was harvested from 702 plants indicating that 83% of green plants were fertile and therefore were spontaneously DHs. No aneuploid plant was obtained. The 702 plants yielded enough seeds to be field tested. One of the DH lines obtained by microspore embryogenesis, named 'Lanuza', has been sent to the Spanish Plant Variety Office for Registration by the Batlle Seed Company. This protocol can be used instead of the labor-intensive inter-generic crossing with maize as an economically feasible method to obtain DHs for most crosses involving the durum wheat cultivars grown in Spain.
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Affiliation(s)
- Luis Cistué
- Departamento de Genética y Producción Vegetal, Estación Experimental de Aula Dei, Consejo Superior de Investigaciones Científicas, Zaragoza, Spain.
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