Transcriptomic Changes in Internode Explants of Stinging Nettle during Callogenesis

Callogenesis, the process during which explants derived from differentiated plant tissues are subjected to a trans-differentiation step characterized by the proliferation of a mass of cells, is fundamental to indirect organogenesis and the establishment of cell suspension cultures. Therefore, understanding how callogenesis takes place is helpful to plant tissue culture, as well as to plant biotechnology and bioprocess engineering. The common herbaceous plant stinging nettle (Urtica dioica L.) is a species producing cellulosic fibres (the bast fibres) and a whole array of phytochemicals for pharmacological, nutraceutical and cosmeceutical use. Thus, it is of interest as a potential multi-purpose plant. In this study, callogenesis in internode explants of a nettle fibre clone (clone 13) was studied using RNA-Seq to understand which gene ontologies predominate at different time points. Callogenesis was induced with the plant growth regulators α-napthaleneacetic acid (NAA) and 6-benzyl aminopurine (BAP) after having determined their optimal concentrations. The process was studied over a period of 34 days, a time point at which a well-visible callus mass developed on the explants. The bioinformatic analysis of the transcriptomic dataset revealed specific gene ontologies characterizing each of the four time points investigated (0, 1, 10 and 34 days). The results show that, while the advanced stage of callogenesis is characterized by the iron deficiency response triggered by the high levels of reactive oxygen species accumulated by the proliferating cell mass, the intermediate and early phases are dominated by ontologies related to the immune response and cell wall loosening, respectively.

Callus Induction and Shoot Formation for Mexican Red Bean (Phaseolus vulgaris L.) Pinto Cultivar in Vitro

The current study aimed to adopt a method for inducing callus cells and regenerating the important common red bean using different types of growth regulators such as N6-benzylaminopurine (BAP), Naphthalene acetic acid (NAA), and Thidiazuron (TDZ). Different types of common bean pinto cultivar explants, such as internodes, cotyledons and roots, were inoculated on Murashige and Skoog medium (MS) provided with different combinations of plant growth regulators, including 1- BAP (5 mg/l) 2-BAP (4.5 mg/l) NAA (0.5 mg/l), 3- BAP (4.5 mg/l), and TDZ (0.1mg/l). Callus was initiated on MS culture medium supplied with 5 mg/l BAP for all explants (internodes, cotyledons, and roots) at 50, 20, and 10% respectively, while adding NAA with 0.5mg/l showed a low percentage of callus (30%) only in the internode explants. Optimum results were obtained by growing the internodes on MS medium with 4.5 mg/l BA and either 0.5 mg/l NAA or 0.1 mg/l TDZ, transplanting the derived shoots into internodes and cotyledons with 70 and 10% respectively. This study concludes that the internodes as explants have the best growth results.

Optimization of core phases of biolistic transformation of potato

We have established the optimal exposure time for internodes and callus plant material of Aksor potato variety on the OSS osmotic medium before and after biolistics and the type of plant explant that is most suitable for that. The optimal objects were explants from internodes of test plants. The best time for exposure of plant material to the osmotic medium before bombardment is 24 hours, and after biolistics – 48 hours. Callus tissue developed on the MS medium with zeatin two weeks later in internodes that were cultivated before bombarding on the OSS for 24 hours and we observed an increase in the callus mass by the end of fourth week. Not a single callus was obtained with rhizogenesis on the R4 medium from internodes and potato calli that were on the osmotic medium within 24 and 72 hours after biolistics. The regenerative capacity of internodes after cultivation on an osmotic medium for 48 hours after bombarding was higher than that of calli. We obtained 12 regenerant plants out of 200 internode explants and 4 regenerant plants out of 150 calli that were used in the experiment.

Adventitious Shoot Organogenesis and Plant Regeneration from Internode Explants of Paederia foetida L.:A Valuable Medicinal Plant

ABSTRACT: A plant regeneration protocol via adventitious shoot organogenesis from internode explants of Paederia foetida (Skunk vine) is reported here for the first time. Three explants (leaf, mature internode and internode derived from axenic shoot cultures) were tested for shoot organogenesis. Leaf explants failed to induce adventitious shoots whereas axenic internode explant was found to be superior to mature internode explants for the induction of adventitious shoots. Axenic internode explants cultured on MS medium supplemented with 3.0 mg/l BAP showed maximum (86.7 %; 10.4 shoots per explant) adventitious shoot organogenesis. The regenerated shoots were best rooted (90 %; 14 roots per shoot) on half-strength MS medium. Eighty percent of the rooted shoots were successfully acclimatized in soil: sand (1:1) mixture. All these acclimatized plants were successfully transferred to larger pots containing garden soil and subsequently established in the field.

Indirect Organogenesis and Plant Regeneration in Common Sage (Salvia officinalis L.): An Important Medicinal Plant of Iran

Salvia species are an important resource for medicinal industry. This research was conducted to develop an indirect organogenesis regeneration protocol for Salvia officinalis L. via which callus was obtained from leaf and internode explants, among these explants internode explant gave best result on MS medium supplemented with 0.5 mg/l 6-Benzylaminopurine (BAP), 2.0 mg/l 1-Naphthaleneacetic acid (NAA). The maximum percentage (70%) of regeneration was obtained with 0.5 mg thidiazuron (TDZ) from internode explants. Shootlets were highly rooted on MS/2 medium added with 1.0 mg/l indole-3-butyric acid (IBA). In vitro rooted seedlings were successfully acclimatized. This in vitro regeneration system will facilitate further development of reliable procedures for this genus.

Effects of plant growth regulators on lentil (Lens culinaris Medik.) cultivars

Lentil (Lens culinaris Medik.) is an annual pulse legume crop of immense economic importance. This study reports use of 16 lentil cultivars' shoot tips, internode, hypocotyl, cotyledon and root explants cultured on MS medium containing 3 mg/l BAP-0.5 mg/l 2,4-D or 0.25 mg/l IBA for shoot regeneration. The results showed maximum shoot regeneration from cv. Yesil 21 on internode explants on 3mg/l BAP-0.5 mg/l 2,4-D. Best shoot regeneration on MS medium containing 0.25 mg/l IBA was noted on internode explants of cv. Seyran 96. In general shoot regeneration on 0.25 mg/l IBA was better compared to 3mg/l BAP and 0.5 mg/l 2,4-D. Well developed shoots from all cultivars regenerated on both types of culture media were rooted on MS medium containing 0.19 mg/l NAA. A system to regenerate lentil is established that will help in easy genetic transformation in future. DOI: http://dx.doi.org/10.3329/bjb.v44i1.22727 Bangladesh J. Bot. 44(1): 79-84, 2015 (March