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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 on induction media supplemented with the same concentration (2.5 μM) of a single PGR from leaf explants of Metabriggsia ovalifolia after culture for 5 weeks (bars = 2 mm).Adventitious shoots and roots developed from an immature leaf explant on induction medium containing 2.5 μM IAA (a) or 2.5 μM NAA (b). Adventitious shoots developed from an immature leaf explant on induction medium containing 2.5 μM BA (c) or 2.5 μM TDZ (d).
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f1: Shoot organogenesis on induction media supplemented with the same concentration (2.5 μM) of a single PGR from leaf explants of Metabriggsia ovalifolia after culture for 5 weeks (bars = 2 mm).Adventitious shoots and roots developed from an immature leaf explant on induction medium containing 2.5 μM IAA (a) or 2.5 μM NAA (b). Adventitious shoots developed from an immature leaf explant on induction medium containing 2.5 μM BA (c) or 2.5 μM TDZ (d).

Mentions: Different PGRs, including auxins (2,4-D, IBA, IAA and NAA) and cytokinins (BA, KT, TDZ and ZEA), used at the same concentration (2.5 μM), were used to induce shoot organogenesis from leaf explants. The control consisted of no PGRs. This protocol, which was similar to the report by Ma et al.5, allowed for reproducibility to be tested, and also included ZEA as a novel factor. No growth was observed within the first 4 weeks from leaf explants on PGR-free medium. By the seventh week, a few small protuberances with limited callus formed on the leaf surface or on cut surfaces, some of these developing into adventitious shoots (Table 1). Callus, which was induced on the cut surface of leaf explants within 2–3 weeks on MS medium with 2.5 μM 2,4-D, could not develop shoots and became necrotic after browning. Leaf explants remained green for 2–3 weeks in the presence of 2.5 μM IAA, forming some protuberances and adventitious shoots directly on the leaf surface or on cut surfaces and adventitious roots 2 weeks later (Fig. 1a). Callus clusters and some adventitious roots could be induced in the presence of 2.5 μM NAA or 2.5 μM IBA within 2 weeks and adventitious shoots within 5 weeks (Fig. 1b). The use of 2.5 μM of KIN or ZEA caused leaf explants to turn yellow and necrotic, and no adventitious shoots formed. Initially (first 2 weeks), leaf explants were unresponsive to 2.5 μM BA, but by the fourth week, swollen explants formed protuberances on the leaf lamina with clearly formed adventitious shoots by the fifth week (Fig. 1c). Leaf explants were initially unresponsive to 2.5 μM TDZ, swelled within 2 weeks, and formed callus on cut surfaces and on the lamina, and by the fifth week, adventitious shoots were clearly visible (Fig. 1d). Among all PGRs supplied at the same concentration (2.5 μM), TDZ induced the most adventitious shoots, followed by BA (Table 1). Somatic embryogenesis was never observed in any of these media.


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 on induction media supplemented with the same concentration (2.5 μM) of a single PGR from leaf explants of Metabriggsia ovalifolia after culture for 5 weeks (bars = 2 mm).Adventitious shoots and roots developed from an immature leaf explant on induction medium containing 2.5 μM IAA (a) or 2.5 μM NAA (b). Adventitious shoots developed from an immature leaf explant on induction medium containing 2.5 μM BA (c) or 2.5 μM TDZ (d).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f1: Shoot organogenesis on induction media supplemented with the same concentration (2.5 μM) of a single PGR from leaf explants of Metabriggsia ovalifolia after culture for 5 weeks (bars = 2 mm).Adventitious shoots and roots developed from an immature leaf explant on induction medium containing 2.5 μM IAA (a) or 2.5 μM NAA (b). Adventitious shoots developed from an immature leaf explant on induction medium containing 2.5 μM BA (c) or 2.5 μM TDZ (d).
Mentions: Different PGRs, including auxins (2,4-D, IBA, IAA and NAA) and cytokinins (BA, KT, TDZ and ZEA), used at the same concentration (2.5 μM), were used to induce shoot organogenesis from leaf explants. The control consisted of no PGRs. This protocol, which was similar to the report by Ma et al.5, allowed for reproducibility to be tested, and also included ZEA as a novel factor. No growth was observed within the first 4 weeks from leaf explants on PGR-free medium. By the seventh week, a few small protuberances with limited callus formed on the leaf surface or on cut surfaces, some of these developing into adventitious shoots (Table 1). Callus, which was induced on the cut surface of leaf explants within 2–3 weeks on MS medium with 2.5 μM 2,4-D, could not develop shoots and became necrotic after browning. Leaf explants remained green for 2–3 weeks in the presence of 2.5 μM IAA, forming some protuberances and adventitious shoots directly on the leaf surface or on cut surfaces and adventitious roots 2 weeks later (Fig. 1a). Callus clusters and some adventitious roots could be induced in the presence of 2.5 μM NAA or 2.5 μM IBA within 2 weeks and adventitious shoots within 5 weeks (Fig. 1b). The use of 2.5 μM of KIN or ZEA caused leaf explants to turn yellow and necrotic, and no adventitious shoots formed. Initially (first 2 weeks), leaf explants were unresponsive to 2.5 μM BA, but by the fourth week, swollen explants formed protuberances on the leaf lamina with clearly formed adventitious shoots by the fifth week (Fig. 1c). Leaf explants were initially unresponsive to 2.5 μM TDZ, swelled within 2 weeks, and formed callus on cut surfaces and on the lamina, and by the fifth week, adventitious shoots were clearly visible (Fig. 1d). Among all PGRs supplied at the same concentration (2.5 μM), TDZ induced the most adventitious shoots, followed by BA (Table 1). Somatic embryogenesis was never observed in any of these media.

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.