Somatic embryogenesis and plant regeneration of turf-type bermudagrass: Effect of 6-benzyladenine in callus induction medium
01 Feb 2000-Plant Cell Tissue and Organ Culture (Kluwer Academic Publishers)-Vol. 60, Iss: 2, pp 113-120
TL;DR: Tissue culture responses of young inflorescences of a hybrid bermudagrass cultivar `Tifgreen' (Cynodon dactylon×Cynodocus transvaalensis) and a common bermUDagrasses cultivar`Savannah' (cynodondactylon) were investigated and formed a compact, nodular embryogenic structure which was highly regenerable and morphologically normal.
Abstract: In order to optimize tissue culture conditions for bermudagrass, an important warm-season turfgrass species, tissue culture responses of young inflorescences of a hybrid bermudagrass cultivar `Tifgreen' (Cynodon dactylon×Cynodon transvaalensis) and a common bermudagrass cultivar `Savannah' (Cynodon dactylon) were investigated. When cultured on Murashige and Skoog medium with 4.52 to 13.57 μM (1–3 mg l-1) 2,4-D, young inflorescence segments yielded non-embryogenic calli which were unorganized and had loosely associated, long tubular cells on the surface. However, inclusion of 6-benzyladenine (BA) in callus induction medium at a level of 0.044 μM (0.01 mg l-1) induced formation of a compact, nodular embryogenic structure on approximately 20% of the calli. Calli with such a compact embryogenic structure were highly regenerable. When young inflorescences smaller than 0.75 cm were cultured, the embryogenic structure yielded green plantlets with regeneration rates of 79.5% and 83.3%, respectively for the two cultivars. All 96 plants regenerated from calli induced in the BA-containing medium were green and morphologically normal. The embryogenic nature of the compact structure was confirmed by scanning electron microscopy.
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TL;DR: Using this efficient regeneration system, plantlets were regenerated from seven elite maize inbred lines and provided a solid basis for genetic transformation of maize.
Abstract: An efficient maize regeneration system was developed using mature embryos. Embryos were removed from surface-sterilized mature seeds and sliced into halves. They were used as explants to initiate callus on induction medium supplemented with 4.0 mg l(-1) 2,4-dichlorophenoxyacetic acid (2,4-D). The induction frequency of primary calli was over 90% for all inbred lines tested. The primary calli were then transferred onto subculture medium supplemented with 2.0 mg l(-1) 2,4-D. Following two biweekly subcultures, embryogenic calli were formed. Inclusion of a low concentration (0.2 mg l(-1)) of 6-benzylaminopurine (BA) in the subculture medium significantly promoted the formation of embryogenic callus. The addition of silver nitrate (10 mg l(-1)) also supported an increased frequency of embryogenesis. The embryogenic callus readily formed plantlets on regeneration medium supplemented with 0.5 mg l(-1) BA. The regenerated plantlets were transferred to half-strength Murashige and Skoog medium supplemented with 0.6 mg l(-1) indole-3-butyric acid to develop healthy roots. The regenerated plantlets were successful on transfer to soil and set seed. Using this system, plantlets were regenerated from seven elite maize inbred lines. The frequency of forming green shoots ranged from 19.8% to 32.4%. This efficient regeneration system provides a solid basis for genetic transformation of maize.
101 citations
Cites background from "Somatic embryogenesis and plant reg..."
...Chaudhury and Qu (2000), in the turf-type Bermuda grass, reported that inclusion of a low concentration of cytokinin (0.044 mM BA) in the callus induction medium containing 2,4-...
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TL;DR: This study demonstrates an efficient tissue culture system for switchgrass Alamo 2, which yields increased viability of callus and the ability to maintain callus for a duration of over 6 months, which gives a greater useful callus lifetime than for published switchgrass MS-based media.
Abstract: The increased emphasis on research of dedicated biomass and biofuel crops begs for biotechnology method improvements. For switchgrass (Panicum virgatum L.), one limitation is inefficient tissue culture and transformation systems. The objectives of this study were to investigate the utility of a new medium described here, LP9, for the production and maintenance of switchgrass callus and its regeneration, which also enables genetic transformation. LP9 medium is not based on Murashige and Skoog (MS) medium, the basal medium that all published switchgrass transformation has been performed. We demonstrate an efficient tissue culture system for switchgrass Alamo 2, which yields increased viability of callus and the ability to maintain callus for a duration of over 6 months. This longevity gives a greater useful callus lifetime than for published switchgrass MS-based media. This increased longevity enables greater potential efficiency and throughput for a transformation pipeline. Callus produced on LP9 is categorized as type II callus, which is more friable and easier to multiply, maintain and transfer than type I callus obtained from previously described tissue culture systems.
87 citations
TL;DR: It is concluded that kinetin is crucial for plant regeneration from the induced embryoids of cumin, and both the callus proliferation and the subsequent differentiation of the embryoids on the PGR-free medium are enhanced.
Abstract: Callus was induced from hypocotyl and primary leaf explants of cumin (Cuminum cyminum L) seedlings on a medium with 4 μM 2,4-D alone or plus 2 or 4 μM kinetin An embryogenic callus developed within 2 weeks after transferring the callus to medium lacking plant growth regulators (PGR) The presence of kinetin in the callus induction medium with 2,4-D enhanced both the callus proliferation and the subsequent differentiation of the embryoids on the PGR-free medium Plumules with or without simultaneously developed roots were observed 3–4 weeks after subculturing the embryogenic callus on medium containing 05 or 10 μM kinetin Subsequently, they were transferred onto half-strength medium supplemented with 1 μM indole-3-butyric acid (IBA) and 2% polyethylene glycol (PEG, 6000) for root induction and/or proliferation, and in vitro hardening of the regenerated plants The survival rate ex vitro was 70% No plants developed from the embryogenic callus continuously incubated on medium lacking kinetin We concluded that kinetin is crucial for plant regeneration from the induced embryoids of cumin
69 citations
Cites background from "Somatic embryogenesis and plant reg..."
...Chaudhury and Qu (2000), in the turf-type bermudagrass, reported that inclusion of a low concentration of cytokinin (0.044 µM 6-benzyladenine, BA) in the callus induction medium containing 2,4-...
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TL;DR: The incorporation of BAP at low levels in the medium was found to be most effective for embryogenesis and the maintenance of long-term morphogenic capacity and allowed the complete regeneration of plants in 16-20 weeks.
Abstract: A highly reproducible regeneration system through somatic embryogenesis from the excised mature embryos (MEs) of dry seeds of a range of European barley cultivars was developed. By minimizing the germination of plated MEs, primary callus could be obtained with high frequency which permitted efficient embryogenesis and regeneration of a large number of green plants. Different approaches were tested to reduce or prevent normal germination: (i) the use of a well defined balance of maltose and 2,4-D in the induction medium, (ii) soaking of seeds in water containing 2,4-D solution, (iii) direct culture of excised embryonic axes, (iv) longitudinally bisected MEs giving two halves, and (v) complete removal of the elongated main shoot including any roots within a week of culture initiation. Culturing of bisected MEs and whole embryonic axes gave the best responses with respect to large amounts of callus combined with minimal germination. The incorporation of BAP at low levels in the medium was found to be most effective for embryogenesis and the maintenance of long-term morphogenic capacity (more than 11 months up to now). This procedure allows the complete regeneration of plants in 16-20 weeks, from the initial isolation of MEs through all the steps to the development of plants ready to be transferred to the soil. The protocol was first developed for cv. Golden Promise and successfully applied to commercial cultivars. All cultivars tested formed embryogenic callus, with overall rates ranging from 22-55% and an average number of green plants per embryogenic callus from 1.5 to 7.5 across the genotypes.
57 citations
Cites result from "Somatic embryogenesis and plant reg..."
...…beneficial for improved callus quality and regeneration ability for MEs, in accordance with earlier reports for immature embryos of barley (Cho et al., 1998; Dahleen and Bregitzer, 2002) and was further demonstrated in other cereal and grass species (Chaudhury and Qu, 2000; Huang and Wei, 2004)....
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TL;DR: Three somaclonal variant lines showed higher relative growth and less injury than TifEagle under salt stress, indicating that they increased salt tolerance and drought tolerance, and different mechanisms for salt tolerance might exist in these three lines.
Abstract: A protocol was established for in vitro selection of salinity tolerant somaclonal variations from suspension cultured calli of triploid bermudagrass cv. TifEagle. To induce somaclonal variations the calli were subcultured for 18 months and were then subject to three-round selections for salt-tolerant calli by placing on solid medium containing 0.3 M NaCl for 10 days followed by a recovery for 2 weeks. The surviving calli were regenerated on regeneration medium containing 0.1 M NaCl. Three somaclonal variant lines (2, 71, and 77) were obtained and analyzed. The selected somaclonal lines showed higher relative growth and less injury than TifEagle under salt stress, indicating that they increased salt tolerance. In addition, they had higher relative water content and lower electrolyte leakage than TifEagle after withholding irrigation, indicating that they also increased drought tolerance. The three somaclonal variant lines had higher proline content than TifEagle under normal growth condition. The line 71 had a higher K+/Na+ ratio, whereas the lines 2 and 77 had higher CAT activity under control and salt stress conditions, indicating that different mechanisms for salt tolerance might exist in these three lines.
53 citations
Cites background from "Somatic embryogenesis and plant reg..."
...Embryogenic callus has been induced from vegetative tissues, such as nodal segments of the triploid bermudagrass cultivars, Tifgreen (Chaudhury and Qu 2000; Li and Qu 2002, 2004), Tifway Communicated by A. Altman....
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...Callus induction and plant regeneration from young influorescences of common and hybrid bermudagrass was investigated by several groups (Ahn et al. 1985, 1987; Artunduaga et al. 1988, 1989; Chaudhury and Qu 2000; Li and Qu 2002; Lu et al. 2003a, b)....
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...Embryogenic callus has been induced from vegetative tissues, such as nodal segments of the triploid bermudagrass cultivars, Tifgreen (Chaudhury and Qu 2000; Li and Qu 2002, 2004), Tifway Communicated by A....
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References
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TL;DR: In vivo redox biosensing resolves the spatiotemporal dynamics of compartmental responses to local ROS generation and provide a basis for understanding how compartment-specific redox dynamics may operate in retrograde signaling and stress 67 acclimation in plants.
Abstract: In experiments with tobacco tissue cultured on White's modified medium (basal meditmi hi Tnhles 1 and 2) supplemenk'd with kiticthi and hidoleacctic acid, a slrikin^' fourlo (ive-told intTease iu yield was ohtaitu-d within a three to Tour week j^rowth period on addition of an aqtteotis exlrarl of tobacco leaves (Fi^'ures 1 and 2). Subse(iueutly it was found Ihiit this jnoniotiou oi' f^rowih was due mainly though nol entirely to inorj^auic rather than organic con.stitttenls in the extract. In the isolation of Rrowth factors from plant tissues and other sources inorj '̂anic salts are fre(|uently carried along with fhe organic fraclioits. When tissue cultures are used for bioassays, therefore, il is necessary lo lake into account increases in growth which may result from nutrient elements or other known constituents of the medium which may he present in the te.st materials. To minimize interference trom rontaminaitis of this type, an altempt has heen made to de\\eh)p a nieditmi with such adequate supplies of all re(iuired tnineral nutrients and cotntnott orgattic cottslitueitls that no apprecial»le change in growth rate or yield will result from the inlroduclion of additional amounts in the range ordinarily expected to be present in tnaterials to be assayed. As a point of referetice for this work some of the culture media in mc)st common current use will he cotisidered briefly. For ease of comparis4)n Iheir mineral compositions are listed in Tables 1 and 2. White's nutrient .solution, designed originally for excised root cultures, was based on Uspeuski and Uspetiskaia's medium for algae and Trelease and Trelease's micronutrieni solution. This medium also was employed successfully in the original cttltivation of callus from the tobacco Iiybrid Nicotiana gtauca x A', tanijadorffii, atitl as further modified by White in 194̂ ^ and by others it has been used for the
63,098 citations
01 Jan 1962
16,251 citations
"Somatic embryogenesis and plant reg..." refers background or methods in this paper
...Callus induction medium was MS medium (Murashige and Skoog, 1962) containing 4....
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...Callus induction medium was MS medium (Murashige and Skoog, 1962) containing 4.4 g l−1 MS basal medium powder, 30 g l−1 sucrose, and 3 g l−1 Phytagel, supplemented with 2,4-...
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TL;DR: It is suggested that while typical bipolar embryos are generally not formed, plant regeneration nevertheless takes place through embryogenesis and the precocious germination of the embryoids, which are considered modifications of the scutellum, a definitive part of the cereal embryo.
Abstract: Tissue cultures ofTriticum aestivum L. (wheat) initiated from young inflorescences and immature embryos possessed the potential for regeneration of whole plants. Both a friable and a compact type of callus were produced on Murashige and Skoog's medium with 2 mg/l 2,4-dichlorophenoxyacetic acid. The friable callus contained meristematic centers in which the peripheral cells ceased dividing, elongated, and could be easily separated. Roots were frequently formed in this type of callus. The compact, yellowish, and nodular callus arose from the epithelial and sub-epithelial cells of the embryo scutellum, and the rachis and glumes of the young inflorescence. Such callus had a smooth surface and characteristic chlorophyllous areas. Plants were regenerated only from the compact callus. The first sign of differentiation in the compact callus was the formation of a cleft or notch on the smooth surface, followed by the appearance of trichomes and the direct development of leafy structures which were not associated initially with any shoot meristems. Multiple shoots subsequently arose at the bases of the leafy structures, which are considered modifications of the scutellum, a definitive part of the cereal embryo. Accordingly, we suggest that while typical bipolar embryos are generally not formed, plant regeneration nevertheless takes place through embryogenesis and the precocious germination of the embryoids. Plants regenerated from immature embryo and inflorescence cultures were grown to maturity in soil, and were shown to have the normal chromosome number of 2n=6x=42.
315 citations
"Somatic embryogenesis and plant reg..." refers background or result in this paper
...All of these characters were very similar to the somatic embryogenesis reported in wheat (Ozias-Akins and Vasil, 1982, 1983), pearl millet (Vasil and Vasil, 1982) and maize (Vasil et al., 1984), and previously reported in bermudagrass (see above), indicating a similar in vitro developmental pathway…...
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...The scutellum-like structures also had a leafy nature (Ozias-Akins and Vasil, 1982) as indicated by the development of trichomes on their surface which became obvious when the calli were transferred to the regeneration medium (Figure 2D)....
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...The embryogenic nature of the compact callus structure, similar to that reported in cereals and other grasses (Ozias-Akins and Vasil, 1982, 1983; Vasil and Vasil, 1982), was confirmed by SEM examination....
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TL;DR: The development of a white, nodulated embryogenic callus in somatic embryogenesis and the formation of green buds during organogenesis suggest divergent modes of plastid differentiation during morphogenesis.
Abstract: This review examines the literature on successful establishment of regenerable cell cultures in the economically important cereal crops. Some of the major trends and strategies for the establishment of in vitro cultures that express totipotency are discussed as well as current approaches. It is apparent that in cereal tissue culture, not all cells express totipotency. Generally the auxin 2,4-dichlorophenoxyacetic acid (2,4-D) is critical for the production of regenerable callus; however, the addition of cytokinin can be significant. Meristematic cells from immature tissues are the targets for plant growth regulator action. Some genotypes produce embryogenic cultures, while others are recalcitrant to in vitro manipulation. Regeneration occurs either by somatic embryogenesis or adventitious bud and shoot development with subsequent rooting. In these meristematic tissues, plastids are at the undifferentiated proplastid stage of development. The development of a white, nodulated embryogenic callus in somatic embryogenesis and the formation of green buds during organogenesis suggest divergent modes of plastid differentiation during morphogenesis. Plant growth regulators may be involved with inducing or directing different pathways of plastid differentiation. Genotypic differences in morphogenesis may be due to differences in endogenous hormone levels. Technical Article no. 24703 from the Texas Agric. Exp. Stn.
269 citations
"Somatic embryogenesis and plant reg..." refers background in this paper
...The requirement of exogenous plant growth regulators probably depends on the specific endogenous hormone levels (Bhaskaran and Smith, 1990)....
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...Improved regeneration rates by including low levels of BA in combination with certain auxin in callus induction media have been reported in other grass species (Bhaskaran and Smith, 1990; Zhong et al., 1991; Griffin and Dibble, 1995; Van der Valk et al., 1995)....
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...regeneration rates by including low levels of BA in combination with certain auxin in callus induction media have been reported in other grass species (Bhaskaran and Smith, 1990; Zhong et al., 1991; Griffin and Dibble, 1995; Van der Valk et al., 1995)....
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TL;DR: Suspensions composed of small, richly cytoplasmic starch-containing cells (embryogenic cells) and elongated thick-walled cells with large vacuoles were established from cultured inflorescence segments of pearl millet in Murashige and Skoog's medium supplemented with 2,4-D/l + 5% coconut milk and developed into green plants when transferred to medium + ABA.
Abstract: Suspensions composed of small, richly cytoplasmic starch-containing cells (embryogenic cells) and elongated thick-walled cells with large vacuoles were established from cultured inflorescence segments of pearl millet in Murashige and Skoog's medium supplemented with 2.5 mg 2,4-D/l + 5% coconut milk. When 2- to 3-wk-old suspensions were transferred to agar with reduced 2,4-D levels, hundreds of globular and early cotyledonary embryoids were produced which developed into green plants when transferred to medium + ABA. Atypical embryoids, some containing many shoot meristems and a leafy scutellum were also observed
141 citations
"Somatic embryogenesis and plant reg..." refers background or result in this paper
...All of these characters were very similar to the somatic embryogenesis reported in wheat (Ozias-Akins and Vasil, 1982, 1983), pearl millet (Vasil and Vasil, 1982) and maize (Vasil et al., 1984), and previously reported in bermudagrass (see above), indicating a similar in vitro developmental pathway…...
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...The embryogenic nature of the compact callus structure, similar to that reported in cereals and other grasses (Ozias-Akins and Vasil, 1982, 1983; Vasil and Vasil, 1982), was confirmed by SEM examination....
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