Effect of 1-naphthylacetic and indol-3-acetics acid on the intensity of callusogenesis and organogenesis of Linum usitatissimum L. in vitro

Aim. Investigate the effect of auxins of exogenous origin in nutrient medium in vitro on the germination and organogenesis intensity in Linum usitatissimum L. convar. elongatum (‘Hlinum’ variety) at the constant concentration of 6-benzylaminopurine (BAP). Methods. Hypocotyl segments were cultured on Murashige and Skoog nutrient medium supplemented with sucrose (30 g/l) and phytohormones at various concentrations. Other conditions: photoperiod 16 hours, relative humidity 60–80%, air temperature 22–24°C. Results. Common flax has a great capacity to form callus and shoots under the effect of the following factors: 1) only auxins, 2) only cytokines, 3) combinations of auxins and cytokines. Somatic embryogenesis is also possible on a nonhormonal nutrient medium. Conclusions. For somatic embryogenesis in vitro, the optimal concentrations of BAP can be expressed as 1.0 ≤ BAP ≤ 1.75, the optimal concentrations of BAP for the medium supplemented with 1-naphthylacetic (NAA, 0.05 mg/l) 0.5 ≤ BAP ≤ 2.0, the optimal concentration of NAA for the medium supplemented with BAP (1.0 mg/l) 0.025 ≤ NAA ≤ 0.150, and the optimal concentrations of indol-3-acetics acid (IAA) for the medium supplemented with BAP (1.0 mg/l) 0.05 ≤ IAA ≤ 0.50. Keywords: Linum usitatissimum L., in vitro, phytohormones, callus, organogenesis.

Induction of calusogenesis in a technical (industrial) hemp in in vitro

Separate elements of a technique for introducing hemp into an in vitro culture have been developed. The best option for inducing calusogenesis in technical (industrial) hemp among the studied genotypes in vitro is Murashige and Skoog medium with the addition of 0,5 or 0,3 mg/l 2,4-D, 0,3 mg/l KIN, 0,5 mg/l GA3, vitamins B1, B6, C and 30 g/l sucrose. In this embodiment, the frequency of calusogenesis was 88,5–100%, the formation of green callus with meristematic zones was observed in 73,1–76,5% of the hypocotyl segments, and in some cases organogenesis (shoot formation) also occurred.

Induction of callus and adventitious shoots on epicotyl and hypocotyl segments of cumaru (Dipteryx odorata)

Somatic embryogenesis from callus induced in epicotyl and hypocotyl segments can be viable native species in order to better -benefit ratio costs, and rates of clonal multiplication. In this sense, two trials were established to induce callus and adventitious buds on hypocotyl and epicotyl segments of cumaru bean seedlings germinated in vitro in different concentrations and combinations of growth regulators. At first, we used the MS medium supplementwith ANA (0.0, 1.5 mg.L-1) and TDZ (0.0, 4.0 and 8.0 mg.L-1) distributed in factorial 2 x 3 x 2 (x auxin cytokinin x explant) with eight replications. In the second, it was used the WPM medium supplemented with BAP (2.0 mg L-1) and plus 2,4-D (2.0 and 4.0 mg L-1) in a factorial 2 x 2 (auxin x explant) with 15 repetitions each. They were evaluating callus formation and the average number of adventitious shoots during the period of 90 days. The results indicated that the highest average for callus formation was observed when the explants were subjected to concentrations of 8.0 mg L-1 TDZ combined with 1.5 mg L-1 ANA in MS medium. For the formation of buds, the WPM medium plus 2.0 mg L-1 2,4-D in the second experiment, induced higher number of shoots, being significant the use of auxin, and its interaction with the type of explant.

Efficient In Vitro Callus Induction and Plant Regeneration Protocol for Different Polish Tomato Cultivars

The major goal of this research was to establish a stable regeneration system for tomato cultivars in order to lay the foundations for the future genetic transformation of the tomato. The regeneration ability of two kinds of explants (cotyledons and hypocotyl segments) was compared for three Polish cultivars of the tomato (Solanum lycopersicum). Explants were cultured on 10 different regeneration media (basal mediums MS or B5, and with a combination of 6-benzylaminopurine (BAP) and indole-3-acetic acid (IAA). It was found that the ability to regenerate was substantially dependent on the cultivars, as well as on the kind of explant. The best explants for inducing shoot regeneration were cotyledons, followed by hypocotyls. It was noticed that the best formulation of the medium for this regeneration from the two types of explants used in this study, is MS with 2 mg/L BA and 0.1 mg/L IAA. Tomato shoots were transferred to a ½ MS medium and ½ MS complemented with 0.1 mg/L IAA for rooting and all of them responded positively to the rooting medium.

Improvement of Flax Drought Tolerance Using Gene Transfer

Attempt was made to produce transgenic cell lines of flax cv. Blanka tolerant to drought stress. Genetic transformation systems were used to incorporate the DREB2A gene, as the specific gene for drought stress tolerance. In biolistic transformation, hypocotyl segments were bombarded with DREB2A and GFP genes at particle flight distance of 9 cm and rupture disc pressure of 1300 psi. The expression of the gene was observed under a light microscope after 24 and 48 hrs. In Agrobacterium?mediated transformation, the hypocotyl segments were incubated overnight with Agrobacterium culture at five optical density OD600 i.e. 0.2, 0.4, 0.6, 0.8 and 1 for 30 min with occasional stirring. Later, the explants were transferred to a selection regeneration medium supplemented with 50 mg/dm3 hygromycin and 300 mg/dm3 cefotaxime and subcultured every two weeks on a new selection medium. Molecular analysis confirmed the expression of the target DREB2A gene in flax genome.Plant Tissue Cult. & Biotech. 26(2): 197-207, 2016 (December

Influence of lead on auxin-induced cell elongation

The influence of lead chloride on plant tissue growth is described. Lead reduced elongation of etiolated wheat coleoptile segments, green pea epicotyl fragments and etiolated and green sunflower hypocotyls. Green tissues were more susceptible to lead than etiolated ones. PbCl₂ in a 10^-4 M concentration significantly reduced plastic and elastic extensibility of the wheat coleoptile cell walls and diminished the hydration of sunflower hypocotyl segments. Auxin (indolyl-3-acetic acid - IAA) applied in concentration optimal for growth of the particular tissues partly attenuated the inhibitory action of lead on elongation, plastic and elastic extensibility and water absorption. Auxin applied in supraoptimal concentrations did not abolish the inhibitory action of lead on tissue growth.