Ascorbic Acid Controls Lethal Browning and Pluronic F-68 Promotes High-frequency Multiple Shoot Regeneration from Cotyldonary Node Explant of Okra (Abelmoschus esculentus L.)

Abstract

<jats:p>The regeneration frequency of okra (<jats:italic>Abelmoschus esculentus</jats:italic>) is greatly influenced by its genetic makeup and recalcitrant nature. Phenolic secretion, in particular, is a major problem in okra tissue culture. This study describes a reproducible, rapid, and more efficient in vitro regeneration method using cotyledonary node explants of okra. Explants were incubated on Murashige and Skoog (MS) medium containing different concentrations and combinations of various plant growth regulators (PGRs) [benzyladenine (BA), thidiazuron (TDZ), and α-naphthylacetic acid (NAA)], and regeneration enhancers [silver nitrate (AgNO<jats:sub>3</jats:sub>) and Pluronic F-68]. Cut ends of cotyledonary node segments rapidly turned brown and cultures failed to establish. Antibrowning additives, such as activated charcoal (AC), ascorbic acid (AA), and AgNO<jats:sub>3</jats:sub> at various concentrations in PGR-free MS basal medium were tested for their ability to control phenolic secretion from explants. Among these additives, 15 mg·L<jats:sup>−1</jats:sup> AA was found to be optimal for controlling phenolic secretion, resulting in healthy explants and culture establishment. The highest number of shoots (a mean of 9.3 ± 0.9 shoots per cotyledonary node explant) was obtained on MS media containing 0.5 mg·L<jats:sup>−1</jats:sup> NAA + 1 mg·L<jats:sup>−1</jats:sup> TDZ + 0.1% Pluronic F-68. Individual shoots were elongated on MS medium + 1 mg·L<jats:sup>−1</jats:sup> BA + 0.1 mg·L<jats:sup>−1</jats:sup> gibberellic acid (GA<jats:sub>3</jats:sub>) (shoot length 5.3 ± 0.2 cm) and rooted on ½ MS medium + 1 mg·L<jats:sup>−1</jats:sup> indole-3-butyric acid (IBA) and 200 mg·L<jats:sup>−1</jats:sup> AC (5.3 ± 0.2 roots per shoot). Rooted plantlets were acclimatized in plastic pots inside a plant growth chamber at 25 ± 2 °C and 70% relative humidity, with an 80% survival rate. This optimized protocol can be used for producing transgenic plants of commercial okra cultivars through genetic transformation.</jats:p>

Pluronic F-68 Improves Callus Proliferation of Recalcitrant Rice Cultivar via Enhanced Carbon and Nitrogen Metabolism and Nutrients Uptake

“…In this study, a high level of MDA was detected at a high concentration of PF-68, which signified oxidative damage in the cell membrane. This observation is able to prove the previous hypothesis made on high PF-68 concentration, whereby high PF-68 concentration induced detrimental and irreversible changes in the plasma membrane in plant cells (Curtis and Mirkov, 2012;Irshad et al, 2018).…”

Opportunities for Innovation in Genetic Transformation of Forest Trees

“…In vitro culture and selection conditions will strongly affect the value of DGs for promoting regeneration. For example, plant hormones added to culture media can mask or help to amplify DG effects, depending on the specific taxa, tissues, and hormone species and concentrations, and duration of treatments ( Hill and Schaller, 2013 ; Irshad et al, 2018 ; Kumar et al, 2018 ). With highly effective regeneration, use of selective agents such as antibiotics can be reduced or eliminated entirely, greatly reducing physiological stresses that retard regeneration ( Mookkan et al, 2017 ; Lowe et al, 2018 ).…”

Sucul bir bitki olan Pogostemon erectus (Dalzell) Kuntze’un In Vitro hızlı çoğaltımı

“…The correct choice of explant variety in tissue culture studies has an important effect on the success of the study. For this reason, researchers have experimented with different explant varieties such as shoot tip (Sasidharan and Jayachitra, 2017;Bourrain, 2018), node (Dobranszki et al, 2017;Irshad et al, 2018), internode (Thul and Kukreja, 2010;Zhang et al, 2017), leaf (Mahindrakar et al, 2018) and root (Sharma et al, 2017). In the present study, shoot tip and nodal explants of P. erectus were cultured in MS medium containing 0.10-0.80 mg/L TDZ + 0.10 mg/L 2,4-D for rapid and multiple production under in vitro conditions.…”