Hypocotyl Explants Research Articles

Effects of spermine and putrescine polyamines on capsaicin accumulation in Capsicum annuum L. cell suspension cultures

This study examined the effects of different concentrations of spermine (Spm) and putrescine (Put) elicitors on capsaicin production at different times in cell suspension culture of peper (Capsicum annuum L‘Kahramanmaraş Hat-187’.), raised from pepper seeds. Callus was obtained from hypocotyl explants of pepper seedlings germinated in vitro conditions, and cell suspensions were prepared from calluses. Spm (0.1, 0.2 and 0.4 mg l-1) and Put (0.1, 0.2 and 0.4 mg l-1) elicitors were applied on cell suspensions, and control groups free from elicitor treatment were created. The amount of capsaicin in cells was found to be higher in the control groups and samples treated with Spm elicitors when compared to filtrates. The highest increase in the capsaicin amount in cells was determined on day 12 of elicitation with 0.2 mg l-1 Spm application. The highest capsaicin amount passing into the filtrate was determined as 0.1 mg l-1 Spm on day 8. The most effective Put concentration and time on capsaicin amount were found as 0.2 mg l-1 Put on day 12 in both cells and filtrates. The highest total capsaicin was also determined in the 0.2 mg l-1 Spm application on day 12with 312.747 ± 8.70 µg g-1 of culture. Exogenous treatment of Spm and Put elicitors affected capsaicin accumulation.

Micropropagation and Production of Health Promoting Lignans in Linum usitatissimum.

Linum usitatissimum commonly known as flax or linseed is an important medicinal plant, produces medicinally potent lignans, used in the treatment of several human diseases. Lignans limited production in the natural plants does not meet the increasing market demand. This study was conducted to establish an easy and rapid method for the in vitro micropropagation and production of potent lignans and antioxidant secondary metabolites in linseed. The results indicated that hypocotyl explants under the effects of thidiazuron (TDZ: 0.5 mg/L) + kinetin (Kn: 0.5 mg/L) in the basal growth media, resulted in the optimal shoot organogenesis parameters (shoot induction frequency: 86.87%, number of shoots: 6.3 ± 0.36 and shoots length: 6.5 ± 0.54 cm), in 4 weeks. Further, TDZ supplementation in the culture media efficiently activated the antioxidant system in the in vitro raised shoots, wherein maximum production of total phenolic content, TPC (34.33 ± 0.20 mg of GAE/g DW); total flavonoid content, TFC (8.99 ± 0.02 mg of QE/g DW); DPPH free radical scavenging activity (92.7 ± 1.32%); phenylalanine ammonia-lyase activity, PAL (8.99 ± 0.02 U/g FW); and superoxide dismutase expression, SOD (3.62 ± 0.01 nM/min/mg FW) were observed in the shoot cultures raised in presence of TDZ: 0.5 mg/L + Kn: 0.5 mg/L. Nonetheless, considerable levels of pharmacologically active lignans such as secoisolariciresinol (SECO: 23.13–37.10 mg/g DW), secoisolariciresinol diglucoside (SDG: 3.32–3.86 mg/g DW) and anhydrosecoisolariciresinol diglucoside (ANHSECO: 5.15–7.94 mg/g DW) were accumulated in the regenerated shoots. This protocol can be scaled up for the commercial production of linseed to meet the market demands for lignans.

Expression of cry1Aa gene in cabbage imparts resistance against diamondback moth (Plutella xylostella).

Brassica oleracea cv. Pride of India is one of the most promising vegetable cultivars commercially grown as cash crop in Himachal Pradesh, India. However, its overall production is severely hampered by diamondback moth (Plutella xylostella), a notorious pest. To avoid yield losses caused by this pest, cryIAa gene was introduced into cabbage cv. Pride of India using Agrobacterium-mediated transformation method. In an attempt to maximize the transformation frequency, critical determinant factors such as explant type, pre-incubation and co-cultivation period, and acetosyringone effect were successfully optimized. The highest transformation frequency (4.67% and 14.50%) in cotyledon and hypocotyl explant was achieved with a pre-incubation period of 72h and co-cultivation period of 48h. Furthermore, transformation frequency was enhanced in cotyledon (18.66%) and hypocotyl (32.00%) explants, when selective regeneration medium was fortified with 100µM acetosyringone, respectively. The transgene (cryIAa) integration and copy number were confirmed using PCR and Southern blotting. Reverse transcriptase PCR and quantitative real-time PCR analyses were performed that proved transcriptional expression of cryIAa gene in PCR-positive transgenic events. Transgenic cabbage-fed diamondback moth larvae showed significantly higher mortality, thereby proving transgene effectiveness against insect pest control.

An efficient protocol for clonal regeneration and excised root culture with enhanced alkaloid content in Thalictrum foliolosum DC.— an endemic and important medicinal plant of temperate Himalayan region

Thalictrum foliolosum DC. is an endemic herbaceous plant known for its various medicinal properties. Due to the presence of valuable alkaloids they are uprooted leading to a threat to their numbers and existence. In this study an efficient protocol has been developed for plant regeneration using hypocotyl explant. Hypocotyl explants formed multiple shoots via direct shoot organogenesis on Murashige and Skoog’s (MS) medium containing 0.25–2.0 mg l−1 BAP with NAA (0.1 mg l−1). Maximum shoot formation in hypocotyl regenerated shoots was achieved in BAP 1 mg l−1and NAA 0.1 mg l-1 with 0.3% activated charcoal and ascorbic acid 20 mg l−1. The regenerated shoots formed roots on MS medium (half strength) containing IBA (0.2 mg l−1). The rooted plantlets were established in the glasshouse after acclimatization and gave 72% survival. Genetic stability assessment of in vitro regenerated plants was done using simple sequence repeat (SSR) markers and no difference was observed when compared to the mother plants. Also, flow cytometric analysis confirmed that their ploidy level was similar to the mother plant. Additionally, establishment of excised root culture was also done and quantification by HPLC revealed that excised cultured roots were accumulated higher benzylisoquinoline alkaloids (BIAs).

Comparison of Profiling of Hairy Root of Two Tibetan Medicinal Plants Przewalskia tangutica Maxim. and Anisodus tanguticus Maxim.

Tropane Alkaloids (TAs) are important drugs for curing many diseases in the medical industry. To sustainably exploit TA resources in endangered traditional Tibetan herbs, the hairy root (HR) systems of Przewalskia tangutica Maxim. and Anisodus tanguticus Maxim. were compared under the same culture conditions. The results indicated that both the Agrobacterium rhizogenes strains and explants affected the HR induction frequency, MSU440, A4 and LBA9402 strains could induce hairy roots following infection of cotyledon and hypocotyl of A. tanguticus while LBA9402 could not induce HR on either explants of P. tangutica. The efficiency of LBA9402 was higher than A4 and MSU440 on A. tanguticus and A4 was better strain than MSU440 on P. tangutica. The hypocotyl explant was more suitable for P.tangutica and cotyledon explant was better for A.tangutica with a transformation frequency of 33.3% (P. tangutica) and 82.5% (A. tanguticus), respectively. In a flask reactor system, both the growth curves of HR for two species both appeared to be "S" curve; however, the HR of P. tangutica grew more rapidly than that of A. tanguticus, and the latter accumulated more biomass than the former. As the culture volume increased, the HR proliferation coefficient of both the species increased. HPLC analysis results showed that the content of TAs in the HR of P. tangutica was 257.24mg/100g·DW, which was more than that of A. tanguticus HR (251.08mg/100g·DW), and the anisodamine in the Pt- HR was significantly higher than that in At-HR. Moreover, tropane alkaloids in the HR of the two species were all significantly higher than that of the roots of aseptic seedlings. Our results suggest that HR of P. tangutica and A. tanguticus both could provide a useful platform for sustainable utilization of two Tibetan medicinal plants in the Qinghai-Tibetan Plateau in the future.

Studies on Pellitorine Production and Antioxidant Activity of Explant Specific Calli of Anacyclus pyrethrum

Anacyclus pyrethrum is a perennial and procumbent herb of immense medicinal value, largely due to the presence of an array of therapeutically active alkaloids such as Pellitorine. In this study, cotyledon, hypocotyl and root explants of A. pyrethrum were tested for their callogenic response and subsequent pellitorine accumulation on MS medium supplemented with 2, 4-D. At elevated concentrations of 2,4-D cotyledonary explants showed higher callogenic response than root and hypocotyl but at lower concentrations of 2,4-D, the results were observed the opposite. The calli of all the treatments were harvested after 30, 45, 60 and 75 days of inoculation. In this study, it was observed that a linear increase in the fresh and dry weight of the callus was recorded towards the end of the treatment. The calli of all the three explants were tested for pellitorine content after 30d, 45d, 60d, and 75d of the culture. The results showed that there was a significant increase in the accumulation of pellitorine from 30d to 75d of harvesting. Interestingly, calli of cotyledons harvested at 75d of inoculation accumulated maximum pellitorine content of 94.50 μg/g dry weight indicating that the old callus is harvested for maximum economic benefit and large scale production of pellitorine. Antioxidant activity of calli raised from different explants and harvested after different time intervals were examined using DPPH (2,2-diphenyl-1-picrylhydrazyl) method. Thus, this study reports an efficient and reproducible protocol for successful callus induction from various explants of A. pyrethrum for large scale production of pellitorine and evaluation of antioxidant activities.

Initiation of callus from different genotypes of Sorghum bicolor L. Moench

The study aimed to examine three genotypes of sorghum for their response in tissue culture using Murashige and Skoog (MS) medium supplemented with auxins (2,4-dichlorophenoxy acetic acid (2,4-D), naphthalene acetic acid (NAA)) and cytokinins (Kinetin, 6-benzyle amino purine (BAP)) at different concentrations. The cultures were initiated from different explants (seed, embryo and hypocotyl). The response of explants varied with the genotype. Callus culture were initiated successfully on MS medium supplemented with 2 mg/l 2,4-D and 0.5 mg/l Kinetin from G4 (L58) seedling and embryo explants. G2 (94) hypocotyl explants gave callus on media supplemented with 2,4-D only. G5 (2) explants failed to initiate callus but bulging from the embryo explants was observed on MS medium supplemented with 2 mg/l 2,4-D and 0.5 mg/l Kinetin. The initiated calluses differed morphologically and in their growth rates. Key words: Sorghum bicolor, callus formation, embryo, Kinetin, 2,4-dichlorophenoxy acetic acid (2,4-D).

Influence of plant growth regulators on plant regeneration from epicotyl and hypocotyl explants of Caesalpinia bonduc (L.) Roxb – an ethnomedical plant

Influence of plant growth regulators on plant regeneration from epicotyl and hypocotyl explants of Caesalpinia bonduc (L.) Roxb – an ethnomedical plant

Callus induction and browning suppression in tree peony Paeonia ostii ‘Fengdan’

Callus induction is an important stage in micropropagation. In this study, embryos, cotyledons, and hypocotyls of tree peony (Paeonia ostii ‘Fengdan’) were used as explants to induce callus formation. Callus induction was largely influenced by the medium, plant growth regulator, and explant. All combinations of the medium and plant growth regulator were conducive to callus induction from zygotic embryos, where the ratio of explants with callus induction was very high in all of the combinations. The greatest ratio of explants with callus induction from the cotyledon explants was found on Woody Plant Medium (WPM) or Murashige and Skoog (MS) medium supplemented with both 0.5 mg L−1 thidiazuron (TDZ) and either 0.5 mg L−1 2,4-dichlorophenoxyacetic acid (2,4-D) or 0.5 mg L−1 1-naphthaleneacetic acid (NAA), and on the WPM containing 0.5 mg L−1 NAA and 0.5 mg L−1 6-benzylaminopurine (BA). The ratio of explants with callus induced from the hypocotyl explants was the greatest on either MS medium or WPM supplemented with both 0.5 mg L−1 2,4-D and 0.5 mg L−1 TDZ. In contrast, a combination of 0.5 mg L−1 2,4-D and 0.5 mg L−1 TDZ, or 0.5 mg L−1 NAA and 0.5 mg L−1 TDZ was highly likely to cause a browning problem during culture. For browning suppression, calcium chloride (CaCl2), polyvinyl pyrrolidone (PVP), gallic acid, and caffeic acid were much more effective than other reagents. The efficacy on browning suppression was concentration-dependent, and the best results were obtained at a concentration of 4.0 mg L−1 CaCl2, 1.0–2.0 g L−1 PVP, 0.5–1.0 mg L−1 gallic acid, and 0.5–1.0 mg L−1 caffeic acid, respectively. In summary, callus formation was successfully induced from the zygotic embryo, cotyledon, and hypocotyl explants, and callus browning was effectively suppressed by caffeic acid (0.5–1.0 mg L−1), gallic acid (1.0 mg L−1), CaCl2 (4.0 mg L−1), and PVP (1.0 g L−1).

Micropropagation of Cleome dendroides (Cleomaceae), an endemic Brazilian species, as a source of glucosinolates

This is the first study related to micropropagation and phytochemical analyses of Cleome dendroides, an endemic species of the Brazilian Atlantic Forest, a biome affected by human activity. Among the classes of substances produced by the genus Cleome, the glucosinolates are used as chemotaxonomic markers. They have a wide structural diversity, which affords, for example, antineoplastic bioactivity. The micropropagation was established using explants from two sources: seedlings and in vitro plants. The morphogenic response was evaluated on Murashige-Skoog (MS) medium with different concentrations of benzyladenine (BA). Hypocotyl explants from seedlings and stem explants from in vitro plants showed higher capacity of shoot regeneration (56.3-100%). Shoot proliferation (75-100%) was maintained when hypocotyl explant-derived shoots and stem explant-derived shoots were subcultured three times a month. Hypocotyl explant-derived shoots maintained on MS + 2.0 mgL−1 BA induced the highest shoot production along the subcultures. Shoots were elongated and rooted on growth regulator-free MS medium. Plantlet establishment was successful in the hardening medium composed of Plantmax® substrate, reaching 85%survival. The phytochemical studies indicated two glucosinolate derivatives, highlighting the presence of 5,6-dimethyltetrahydro-1,3-oxazine-2-thione, identified for the first time in plants. This work demonstrates an efficient method for in-vitro production of C. dendroides plants, which can be used as a source of glucosinolates.

High frequency regeneration of plants via callus-mediated organogenesis from cotyledon and hypocotyl cultures in a multipurpose tropical tree (Neolamarkia Cadamba)

In this works, a simple, efficient and repeatable protocol was developed for in vitro regeneration via callus-mediated organogenesis of Neolamarkia Cadamba using cotyledonary petioles and hypocotyls. Effects of basal medium, plant growth regulators, the types and age of explant on the formation of adventitious buds/shoots were studied. Meanwhile, histological analysis for early ontogenic stages and genetic stability assessment by flow cytometry were investigated. Our investigation demonstrated that, compared with 6-benzyladenine (BA), N6-(2-isopentenyl) adenine (2-ip), Thidiazuron (TDZ) was the optimal cytokinin for buds/shoots induction on cotyledon and hypocotyl explants. Douglas-fir and sugar pine medium (DCR) supplemented with 22.7 μM TDZ and 0.27 μM α-naphthalene acetic acid (NAA) was most effective on bud induction, with the highest bud-induction rate and numbers of buds on cotyledon and hypocotyl explants. The available shoot per explant hit 35.2 when the induced callus sub-cultured to a medium without TDZ. It was found that TDZ could promote induction of the callus and the buds, however, continuous exposure beyond 4 weeks of supplemented high concentration (exceed 11.35 μM), TDZ was harmful to the proliferation and growth of buds/shoots. DCR appeared more efficiency than Murashige and Skoog medium (MS), Woody Plant medium (WPM), anther culture of cereal crops medium (N6) on bud induction. Age of cotyledon and hypocotyl explants in 20-day to 25-day was most beneficial to adventitious buds/shoots formation. Histological investigation confirmed that the buds originated from the wounded incisions of cotyledonary petiole and hypocotyl fragments, with callus formation. The regeneration plantlets were successfully acclimatized in greenhouse, yielded above 95% survival rate in field, exhibited normal morphology and growth characteristics. The analysis of flow cytometry on N. cadamba indicated no variation in the ploidy levels between the regenerated plantlets and the donor trees. The developed procedure can be used for mass production, germplasm exchange and transgenic studies to improve the resistance of the species via Agrobacterium-mediated.

In vitro regeneration of castor (Ricinus communis L.)

Standardization of a reliable regeneration protocol is important in castor to develop transgenics conferringresistance to biotic and abiotic stresses. An attempt has been made to developan in vitro regeneration protocol using the hypocotyl explants derived from seedlings obtained from decoated seeds. Out of 60 different hormonal combinations tried, three combinations showed better shoot induction and the rooting was better with IBA 1.0 mg/L.

Somatic embryogenesis of hypocotyl derived calli from an eggplant cultivar

Optimization of tissue culture and regeneration conditions of eggplant is necessary for achieving different goals such as gene transformation and the development of somaclonal variations. In this study, hypocotyl explants ware used to produce callus in a medium containing different concentrations of NAA and BAP. Moreover, the concentration of the elements Ca, Mn, Mg, Fe and K were measured and analysed between embryogenic and non-embryogenic calli. For shoot elongation, embryogenic calli were transferred to a new culture medium containing 3.5, 4 and 4.5 mg l-1 BAP plus 2 mg l-1 GA3. Finally, produced shoots were rooted in a culture medium containing 1, 1.5 and 2 mg l-1 NAA. Results showed that the best treatment for the embryogenic callus induction was MS medium containing 0.5 mg l-1 BAP plus 0.25 mg l-1 NAA. Two elements, Fe and K, had the highest amount in non-embryogenic calli compare to the embryogenic one. For plant regeneration, MS medium containing 4.5 mg l-1 BAP plus 2 mg l-1 GA3 and 2 mg l-1 NAA were the best treatments for shooting and rooting, respectively. In this study, the best treatments for plant regeneration produced 35 shoots from an explant with 92 % shooting. This regeneration protocol could be useful for gene transformation and micro-propagation studies.

The interaction of reactive oxygen species and antioxidants at the metabolic interface in salicylic acid-induced adventitious root formation in mung bean [Vigna radiata (L.) R. Wilczek

Implications of the role of antioxidant buffering in reactive oxygen species (ROS)-antioxidant interactions and associated redox regulation during adventitious root formation (ARF) were assessed in redox-manipulated salicylic acid (SA)-treated hypocotyl explants of mung bean [Vigna radiata (L.) R. Wilczek]. Application of pro-oxidant H2O2 (500 μM) followed by SA (600 μM) was shown to stimulate ARF, whereas treatments combining 600 μM SA and 10 × 10−4 M DPI (diphenyleneiodonium, an inhibitor of NADPH-oxidase) and 600 μM and SA 10 × 10−4 M (dimethylthiourea, a free radical scavenger) were found to prevent ARF. The redox status of the experimental explants monitored under such treatment conditions (in terms of accumulation of pro-oxidants, in situ localization of O2- and H2O2, radical scavenging property and total thiol content) revealed significant changes in ROS-antioxidant interactions at the metabolic interface, causing alterations in the pattern of ARF. Further, the assessment of activities and transcript abundance of the enzymes of the H2O2 turnover pathway (mainly the ascorbate-glutathione system) supported the transcriptional regulation of genes such as vrrboh, vrAPX, vrGR, vrSOD, and vrCAT and the activities of the relevant enzymes necessary for the generation of endogenous redox cues during ARF. The present work provides an inventory in support of the importance of antioxidant buffering associated with redox regulation for the origin of the metabolic redox cue (redox signal) necessary for SA-induced ARF in mung bean.

Optimization of Plant Regeneration in Different Pepper (Capsicum annuum L.) Lines

Development of an efficient plant regeneration protocol is essential for vegetable crop advancement by biotechnological methods. In this study, regeneration protocols of four pepper lines of different pepper types were optimized. Different protocols for organogenesis were investigated in regeneration experiments. Optimum plant regeneration was obtained in different combinations of 6-Benzylaminopurine (BAP) and Indole-3-acetic acid (IAA) in organogenesis assays. In organogenesis experiment, the highest shoot development was determined as 80% from hypocotyl explant of Demre pepper in 4 mg L-1 BA+0.5 mg L-1 IAA, 80% from hypocotyl explant of Charleston pepper in 3 mg L-1 BA+0.5 mg L-1 IAA, 80% from hypocotyl explant of capia pepper in 5 mg L-1 BA+0.5 mg L-1 and 84% from hypocotyl explant of bell pepper in 5 mg L-1 BA+0.5 mg L-1 IAA. Afterward, shoots were rooted and whole plants were obtained.

Antioxidant activity of in vitro plantlets and callus cultures of Randia echinocarpa, a medicinal plant from northwestern Mexico

Randia echinocarpa, an endemic plant to Northwest Mexico, is used as food and in traditional medicine, and several of its biological activities have been demonstrated (antioxidant, antimutagenic, antidiabetic, and immunomodulatory). Plant tissue culture is a safe and scalable system for plant propagation and production of bioactive compounds. Therefore, this study aims to establish protocols for seed germination and callus culture of R. echinocarpa and to evaluate the antioxidant activity of methanol extracts (ME) of plantlets and calli via the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) methods. Seeds were cultured in media with different concentrations of Murashige and Skoog (MS) salts and sucrose, and a higher germination rate and plantlet growth was observed in half-strength MS medium with 15 g L−1 of sucrose. Calli were obtained from cotyledon and hypocotyl explants cultured in MS media with different concentrations of benzyl aminopurine (BAP) and indole-3-acetic acid (IAA). All treatments induced callus formation in 100% of explants; however, the medium containing 1 mg L−1 BAP + 1 mg L−1 IAA was selected because it produced calli with higher biomass and friable texture. The ME of cotyledons showed the highest antioxidant activity values (μmol Trolox per 100 g dry weight) in DPPH (345.5) and ABTS (1166.4) assays, whereas the ME of calli from hypocotyls showed a higher antioxidant activity than the ME of calli from cotyledons in both antioxidant assays. The tissue culture protocols established here will be useful for R. echinocarpa germplasm conservation and propagation, as well as for the production of bioactive compounds.

Optimization of in vitro conditions favourable for effective regeneration in Pusa Meghna Indian cauliflower

Establishment of an efficient in vitro regeneration system is a pre-requisite for genetic modification of plants. The present study reports a high efficiency regeneration protocol for cauliflower cv. Pusa Meghna using cotyledon and hypocotyl explants cultured on different growth media with varying combinations of plant growth regulators. Maximum shoot regeneration response from hypocotyl (95.76%) and cotyledon (83.01%) was obtained on MS medium containing 1mg/L BAP and 1 mg/L BAP+0.1 mg/L NAA+0.5 mg/L AgNO3+0.1 mg/L GA3, respectively. Further optimization of rooting media for development of full grown plants showed maximum root regeneration of 92.20% and 94.86% from hypocotyl and cotyledon explants grown on MS medium containing 0.5 mg/L IBA and 0.2 mg/L IBA, respectively. Utilization of the present established regeneration protocol would serve as a valuable tool for various crop improvement studies in cauliflower.

Enhanced Somatic Embryo Induction of a Tree Peony, Paeonia ostii 'Fengdan', by a Combination of 6-benzylaminopurine (BA) and 1-naphthylacetic Acid (NAA).

Somatic embryogenesis is a preferred method for vegetative propagation due to its high propagation efficiency. In this study, zygotic embryos, cotyledons, and hypocotyls of Paeonia ostii ‘Fengdan’ were used as the explant to induce somatic embryogenesis. The results showed that a combination of 0.5 mg·L−1 thidiazuron (TDZ) and 0.5 mg·L−1 2,4-dichlorophenoxyacetic acid (2,4-D) was effective in inducing somatic embryos from the zygotic embryo and cotyledon explants. Hypocotyls only formed somatic embryos on Murashige and Skoog (MS) medium supplemented with both 0.5 mg·L−1 TDZ and 0.5 mg·L−1 1-naphthylacetic acid (NAA). Moreover, the compact callus was effectively produced from zygotic embryo, cotyledon, and hypocotyl explants in medium supplemented with a combination of 3.0 mg·L−1 6-benzylaminopurine (BA) and 1.0 mg·L−1 NAA, and then converted into somatic embryos in the same medium, and the ratio of the explants with embryo induction and number of embryos induced per explant were much higher than those induced by 0.5 mg·L−1 TDZ and either 0.5 mg·L−1 2,4-D or 0.5 mg·L−1 NAA. The MS medium was better than the woody plant medium (WPM) for inducing somatic embryos from zygotic embryo and hypocotyl explants, whereas the WPM was better than the MS medium for somatic embryogenesis induction from cotyledon explants. All of the somatic embryos developed well into mature embryos on their respective media supplemented with both 3.0 mg·L−1 BA and 1.0 mg·L−1 NAA. Overall, the protocols for indirect somatic embryogenesis from zygotic embryo, cotyledon, and hypocotyl of P. ostii ‘Fengdan’ were successfully established, which can greatly facilitate their propagation and breeding processes.

Peculiarities of induction of callusogenesis and morphogenesis in fennel depending on the age of seedlings

The influence of the age of seedlings (of which hypocotyl explants were isolated) and the composition of the culture medium on the callusogenesis and morphogenesis induction of fennel cultivars ‘Mertsishor’ and ‘Oksamit Kryma’ were studied. It was established that with the use of younger seedlings (7-day of age) callus induction began in a larger number of explants for a week of cultivation earlier compared to 14 and 21-day seedlings. The frequency of somatic embryogenesis in the callus obtained from 7-day seedling hypocotyl was almost twice higher than that of the callus from more mature seedling. It was revealed that the cultivar ‘Mertsishor’ had a higher morphogenetic potential compared to ‘Oksamit Kryma’. Improved methods of embryogenic callus induction and plant regeneration can be used for obtaining the initial breeding material of fennel.

Stimulation of adventitious root formation by the oligosaccharin OSRG at the transcriptome level

ABSTRACTOligosaccharins, which are biologically active oligosaccharide fragments of cell wall polysaccharides, may regulate the processes of growth and development as well as the response to stress factors. We characterized the effect of the oligosaccharin that stimulates rhizogenesis (OSRG) on the gene expression profile in the course of IAA-induced formation of adventitious roots in hypocotyl explants of buckwheat (Fagopyrum esculentum Moench.). The transcriptomes at two stages of IAA-induced root primordium formation (6 h and 24 h after induction) were compared after either treatment with auxin alone or joint treatment with auxin and OSRG. The set of differentially expressed genes indicated the special importance of oligosaccharin at the early stage of auxin-induced adventitious root formation. The list of genes with altered mRNA abundance in the presence of oligosaccharin included those, which Arabidopsis homologs encode proteins directly involved in the response to auxin as well as proteins that contribute to redox regulation, detoxification of various compounds, vesicle trafficking, and cell wall modification. The obtained results contribute to understanding the mechanism of adventitious root formation and demonstrate that OSRG is involved in fine-tuning of ROS and auxin regulatory modes involved in root development.