Limits...
Somatic embryogenesis and enhanced shoot organogenesis in Metabriggsia ovalifolia W. T. Wang.

Ouyang Y, Chen Y, Lü J, Teixeira da Silva JA, Zhang X, Ma G - Sci Rep (2016)

Bottom Line: Thus, somatic embryogenesis in this plant needs a high cytokinin concentration (BA; TDZ), as evidenced by histology.Somatic embryos germinated easily when left on the same media, but formed adventitious roots in two weeks on MS supplemented with 0.5 μM NAA, 0.5 μM IBA and 0.1% activated charcoal.Over 93% of plantlets survived following acclimatization and transfer to a mixture of sand and vermiculite (1:1, v/v) in trays.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, the Chinese Academy of Sciences, Guangzhou, 510650, China.

ABSTRACT
An efficient protocol providing a dual regeneration pathway via direct shoot organogenesis and somatic embryogenesis for an endangered species, Metabriggsia ovalifolia W. T. Wang, was established from leaf explants. When applied at 2.5 μM, the cytokinins 6-benzyladenine (BA) or thidiazuron (TDZ) and the auxins indole-3-butyric acid (IBA), α-naphthaleneacetic acid (NAA) and indole-3-acetic acid (IAA) could induce shoots when on basal Murashige and Skoog (MS) medium. BA and TDZ could induce more adventitious shoots (19.1 and 31.2/explant, respectively) than NAA (4.6/explant), IBA (5.7/explant) or IAA (6.4/explant). BA and TDZ at 5-10 μM could induce both shoots and somatic embryos. A higher concentration of TDZ (25 μM) induced only somatic embryos (39.8/explant). The same concentration of BA induced both adventitious shoots (23.6/explant) and somatic embryos (9.7/explant). Thus, somatic embryogenesis in this plant needs a high cytokinin concentration (BA; TDZ), as evidenced by histology. Somatic embryos germinated easily when left on the same media, but formed adventitious roots in two weeks on MS supplemented with 0.5 μM NAA, 0.5 μM IBA and 0.1% activated charcoal. Over 93% of plantlets survived following acclimatization and transfer to a mixture of sand and vermiculite (1:1, v/v) in trays.

No MeSH data available.


Shoot organogenesis and somatic embryogenesis in Metabriggsia ovalifolia.(a) Adventitious shoots (white arrow) and somatic embryos (black arrow) induced from an immature leaf explant on induction medium containing 10 μM BA after culture for 5 weeks. (b) Adventitious shoot and some globular- and torpedo-shaped somatic embryos visible on the surface of a leaf explant on induction medium containing 10 μM BA after culture for 6 weeks. (c) Some yellow protuberances (black arrow) occurred on the leaf surface on induction medium containing 10 μM TDZ after culture for 4 weeks. (d) Some globular somatic embryos were visible on the surface of leaf explants on induction medium containing 10 μM TDZ after culture for 5 weeks. (e) Somatic embryos induced on a leaf explant on induction medium containing 25 μM TDZ after culture for 6 weeks. (f) Some somatic embryos germinated and developed epicotyl directly on induction medium containing higher concentration of TDZ (25 μM) after culture for 7 weeks. Bars = 2 mm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4835782&req=5

f2: Shoot organogenesis and somatic embryogenesis in Metabriggsia ovalifolia.(a) Adventitious shoots (white arrow) and somatic embryos (black arrow) induced from an immature leaf explant on induction medium containing 10 μM BA after culture for 5 weeks. (b) Adventitious shoot and some globular- and torpedo-shaped somatic embryos visible on the surface of a leaf explant on induction medium containing 10 μM BA after culture for 6 weeks. (c) Some yellow protuberances (black arrow) occurred on the leaf surface on induction medium containing 10 μM TDZ after culture for 4 weeks. (d) Some globular somatic embryos were visible on the surface of leaf explants on induction medium containing 10 μM TDZ after culture for 5 weeks. (e) Somatic embryos induced on a leaf explant on induction medium containing 25 μM TDZ after culture for 6 weeks. (f) Some somatic embryos germinated and developed epicotyl directly on induction medium containing higher concentration of TDZ (25 μM) after culture for 7 weeks. Bars = 2 mm.

Mentions: When different concentrations of BA or TDZ were added to MS medium, some trends were observed. Firstly, a low concentration (1.0–2.5 μM) of BA or TDZ showed the results described in the above section, i.e., exclusive shoot organogenesis with five weeks of culture. Secondly, as BA concentration increased to 5–25 μM, some adventitious shoots and somatic embryos formed on the surface of the leaf explants, i.e., mixed organogenesis. Globular and torpedo-shaped somatic embryos were observed on the surface of leaf explants (Fig. 2a,b). As BA concentration increased, the frequency of somatic embryogenesis also increased (Table 2). Thirdly, as the TDZ concentration was increased to 5–25 μM, somatic embryos formed easily on leaf explants, and the frequency of somatic embryogenesis increased (Table 2). At first, some yellow protuberances formed within 2–3 weeks (Fig. 2c), and when cultures were transferred to light, these protuberances became green and globular (Fig. 2d). Prolonging the culture period resulted in an increasing number of globular and torpedo stage somatic embryos (Fig. 2e). After culture for seven weeks, some somatic embryos germinated directly and developed a shoot tip at the top of the somatic embryo (Fig. 2f). As the TDZ concentration increased to 25 μM, only somatic embryogenesis was induced and adventitious shoots were not visible (Fig. 2e,f) with a single leaf explant inducing as many as hundreds of somatic embryos (Fig. 3a,b). However, the total number of somatic embryos decreased (Table 2). Somatic embryos located on both sides of the leaf explants or in contact with the medium developed earlier than the middle parts. The former germinated early, forming a well-developed shoot tip while the somatic embryos in the middle part remained at the globular or torpedo-shaped stage (Fig. 3a,b).


Somatic embryogenesis and enhanced shoot organogenesis in Metabriggsia ovalifolia W. T. Wang.

Ouyang Y, Chen Y, Lü J, Teixeira da Silva JA, Zhang X, Ma G - Sci Rep (2016)

Shoot organogenesis and somatic embryogenesis in Metabriggsia ovalifolia.(a) Adventitious shoots (white arrow) and somatic embryos (black arrow) induced from an immature leaf explant on induction medium containing 10 μM BA after culture for 5 weeks. (b) Adventitious shoot and some globular- and torpedo-shaped somatic embryos visible on the surface of a leaf explant on induction medium containing 10 μM BA after culture for 6 weeks. (c) Some yellow protuberances (black arrow) occurred on the leaf surface on induction medium containing 10 μM TDZ after culture for 4 weeks. (d) Some globular somatic embryos were visible on the surface of leaf explants on induction medium containing 10 μM TDZ after culture for 5 weeks. (e) Somatic embryos induced on a leaf explant on induction medium containing 25 μM TDZ after culture for 6 weeks. (f) Some somatic embryos germinated and developed epicotyl directly on induction medium containing higher concentration of TDZ (25 μM) after culture for 7 weeks. Bars = 2 mm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4835782&req=5

f2: Shoot organogenesis and somatic embryogenesis in Metabriggsia ovalifolia.(a) Adventitious shoots (white arrow) and somatic embryos (black arrow) induced from an immature leaf explant on induction medium containing 10 μM BA after culture for 5 weeks. (b) Adventitious shoot and some globular- and torpedo-shaped somatic embryos visible on the surface of a leaf explant on induction medium containing 10 μM BA after culture for 6 weeks. (c) Some yellow protuberances (black arrow) occurred on the leaf surface on induction medium containing 10 μM TDZ after culture for 4 weeks. (d) Some globular somatic embryos were visible on the surface of leaf explants on induction medium containing 10 μM TDZ after culture for 5 weeks. (e) Somatic embryos induced on a leaf explant on induction medium containing 25 μM TDZ after culture for 6 weeks. (f) Some somatic embryos germinated and developed epicotyl directly on induction medium containing higher concentration of TDZ (25 μM) after culture for 7 weeks. Bars = 2 mm.
Mentions: When different concentrations of BA or TDZ were added to MS medium, some trends were observed. Firstly, a low concentration (1.0–2.5 μM) of BA or TDZ showed the results described in the above section, i.e., exclusive shoot organogenesis with five weeks of culture. Secondly, as BA concentration increased to 5–25 μM, some adventitious shoots and somatic embryos formed on the surface of the leaf explants, i.e., mixed organogenesis. Globular and torpedo-shaped somatic embryos were observed on the surface of leaf explants (Fig. 2a,b). As BA concentration increased, the frequency of somatic embryogenesis also increased (Table 2). Thirdly, as the TDZ concentration was increased to 5–25 μM, somatic embryos formed easily on leaf explants, and the frequency of somatic embryogenesis increased (Table 2). At first, some yellow protuberances formed within 2–3 weeks (Fig. 2c), and when cultures were transferred to light, these protuberances became green and globular (Fig. 2d). Prolonging the culture period resulted in an increasing number of globular and torpedo stage somatic embryos (Fig. 2e). After culture for seven weeks, some somatic embryos germinated directly and developed a shoot tip at the top of the somatic embryo (Fig. 2f). As the TDZ concentration increased to 25 μM, only somatic embryogenesis was induced and adventitious shoots were not visible (Fig. 2e,f) with a single leaf explant inducing as many as hundreds of somatic embryos (Fig. 3a,b). However, the total number of somatic embryos decreased (Table 2). Somatic embryos located on both sides of the leaf explants or in contact with the medium developed earlier than the middle parts. The former germinated early, forming a well-developed shoot tip while the somatic embryos in the middle part remained at the globular or torpedo-shaped stage (Fig. 3a,b).

Bottom Line: Thus, somatic embryogenesis in this plant needs a high cytokinin concentration (BA; TDZ), as evidenced by histology.Somatic embryos germinated easily when left on the same media, but formed adventitious roots in two weeks on MS supplemented with 0.5 μM NAA, 0.5 μM IBA and 0.1% activated charcoal.Over 93% of plantlets survived following acclimatization and transfer to a mixture of sand and vermiculite (1:1, v/v) in trays.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, the Chinese Academy of Sciences, Guangzhou, 510650, China.

ABSTRACT
An efficient protocol providing a dual regeneration pathway via direct shoot organogenesis and somatic embryogenesis for an endangered species, Metabriggsia ovalifolia W. T. Wang, was established from leaf explants. When applied at 2.5 μM, the cytokinins 6-benzyladenine (BA) or thidiazuron (TDZ) and the auxins indole-3-butyric acid (IBA), α-naphthaleneacetic acid (NAA) and indole-3-acetic acid (IAA) could induce shoots when on basal Murashige and Skoog (MS) medium. BA and TDZ could induce more adventitious shoots (19.1 and 31.2/explant, respectively) than NAA (4.6/explant), IBA (5.7/explant) or IAA (6.4/explant). BA and TDZ at 5-10 μM could induce both shoots and somatic embryos. A higher concentration of TDZ (25 μM) induced only somatic embryos (39.8/explant). The same concentration of BA induced both adventitious shoots (23.6/explant) and somatic embryos (9.7/explant). Thus, somatic embryogenesis in this plant needs a high cytokinin concentration (BA; TDZ), as evidenced by histology. Somatic embryos germinated easily when left on the same media, but formed adventitious roots in two weeks on MS supplemented with 0.5 μM NAA, 0.5 μM IBA and 0.1% activated charcoal. Over 93% of plantlets survived following acclimatization and transfer to a mixture of sand and vermiculite (1:1, v/v) in trays.

No MeSH data available.