Combinations Of Phytohormones Research Articles

An Efficient System for Agrobacterium-Mediated Transformation of Elite Cultivars in Brassica juncea

Efficient genetic transformation approaches play pivotal roles in both gene function research and crop breeding. However, stable transformation in mustard, particularly for different horticultural types, has not been systematically studied and well-established so far. In this study, we optimized the key factors in the genetic transformation of mustard, including the optical density value of Agrobacterium suspension, the age of explants, and the combination of phytohormones at different concentrations. As a result, the optimal conditions for the genetic transformation of leaf and stem mustard included hypocotyl explants derived from 4-day-old seedlings, infection by 0.8 OD600nm Agrobacterium suspension, and then re-differentiation on a medium containing 4 mg/L trans-zeatin (tZ) and 0.1 mg/L indoleacetic acid (IAA) for leaf mustard, and for stem mustard, re-differentiation on a medium containing 2 mg/L tZ and 0.4 mg/L IAA, with positive rates of 4.74% and 5.26%, respectively. Those for root mustard were hypocotyl explants derived from 8-day-old seedlings, infection by 0.2 OD600nmAgrobacterium suspension, and a medium containing 2 mg/L tZ and 0.1 mg/L IAA, with a positive rate of 4.42%. Overall, this work provides an effective tool for both the theoretical study and genetic improvement of Brassica juncea.

Phytohormone-induced changes in growth, physiology, and biochemistry of Aurantiochytrium sp. for sustainable bioproduction

The study aimed to assess the effects of nine combinations of phytohormones, salicylic acid (SA), gibberellic acid (GA), and jasmonic acid (JA) on the growth, physiology, and biochemistry of Aurantiochytrium sp. Parameters like optical density (OD), biomass, protein content, hydrogen peroxide (H2O2), malondialdehyde (MDA), catalase activity (CAT), and gene expression (malic enzyme (ME) and acetyl-CoA carboxylase (ACCase)) were assessed at various cultivation stages (24, 48, 72, and 96 h). The research also analyzed fatty acid composition, unsaturated fatty acids (UFA), saturated fatty acids (SFA), and the UFA to SFA ratio (USS) to understand the biochemical changes induced by phytohormones. Results demonstrated that modifying phytohormone concentrations significantly affected the characteristics of the microalgae, particularly in correlation with different growth stages, emphasizing the necessity of precise control of phytohormone levels for optimizing cultivation conditions and enhancing bioactive compound production in Aurantiochytrium sp.

Direct Organogenesis of Citrus Cultivars from Shoot Tip Nodal Segments.

Citrus cultivar improvement via conventional breeding strategies is impeded by factors related to its reproductive biology. The orange is a hybrid between pomelo (Citrus maxima) and mandarin (Citrus reticulata). Among various orange cultivars, Valencia oranges have a bit of bitter tang mixed in with their sweetness, as Navel oranges are, the most widely cultivated citrus species, quite sweeter, and also don't contain any seeds. Tangelo mandarin orange cultivar is a hybrid of C. reticulata × C. maxima or × C. paradisi. The present study was undertaken to optimize the hormonal composition of the media with regard to plant growth regulators for in vitro propagation of sweet orange cultivars from nodal segment explants. The nodal segment explants were collected from three citrus cultivars, Washington Navel, Valencia and Tangelo. Murashige and Skoog (MS) medium supplemented with sucrose and different concentrations of growth regulators was used for shoot proliferation and root induction, and the optimum medium composition was assessed. The patent for Citrus Tissue Culture was obtained from the Office of Research Affairs, Haramaya University. The results indicate that the highest shoot response was recorded for Washington's navel with maximum shoot proliferation rate (99.75%), shoot number per explant (1.76), shoot length (10.70 cm), leaf number per explants (3.54) after three weeks of culture. In all experiments, no growth was observed for the basal MS medium. Phytohormone combinations of IAA (1.2 mg/L) and kinetin (2.0 mg/L) were found to be the best for shoot proliferation. Among the cultivars, there were significant differences for the highest rooting rate (81.255), root number (2.22), and root length (2.95 cm) variables for Washington Navel. The lowest rooting rate (48.45%), root number (1.47) and root length (2.26 cm) were observed for Valencia. The highest rooting rate (84.90%), root number per microshoot (2.22) and root length (3.05 cm) was on MS medium supplemented with 1.5 mg/L NAA. A comparison of different concentrations of IAA and NAA on root induction of microshoots from nodal segments of citrus cultivars demonstrated NAA was a more effective hormone than IAA.

Enhancing petunia tissue culture efficiency with machine learning: A pathway to improved callogenesis.

The important feature of petunia in tissue culture is its unpredictable and genotype-dependent callogenesis, posing challenges for efficient regeneration and biotechnology applications. To address this issue, machine learning (ML) can be considered a powerful tool to analyze callogenesis data, extract key parameters, and predict optimal conditions for petunia callogenesis, facilitating more controlled and productive tissue culture processes. The study aimed to develop a predictive model for callogenesis in petunia using ML algorithms and to optimize the concentrations of phytohormones to enhance callus formation rate (CFR) and callus fresh weight (CFW). The inputs for the model were BAP, KIN, IBA, and NAA, while the outputs were CFR and CFW. Three ML algorithms, namely MLP, RBF, and GRNN, were compared, and the results revealed that GRNN (R2≥83) outperformed MLP and RBF in terms of accuracy. Furthermore, a sensitivity analysis was conducted to determine the relative importance of the four phytohormones. IBA exhibited the highest importance, followed by NAA, BAP, and KIN. Leveraging the superior performance of the GRNN model, a genetic algorithm (GA) was integrated to optimize the concentration of phytohormones for maximizing CFR and CFW. The genetic algorithm identified an optimized combination of phytohormones consisting of 1.31 mg/L BAP, 1.02 mg/L KIN, 1.44 mg/L NAA, and 1.70 mg/L IBA, resulting in 95.83% CFR. To validate the reliability of the predicted results, optimized combinations of phytohormones were tested in a laboratory experiment. The results of the validation experiment indicated no significant difference between the experimental and optimized results obtained through the GA. This study presents a novel approach combining ML, sensitivity analysis, and GA for modeling and predicting callogenesis in petunia. The findings offer valuable insights into the optimization of phytohormone concentrations, facilitating improved callus formation and potential applications in plant tissue culture and genetic engineering.

Enhancing drought resistance in Pogostemon cablin (Blanco) Benth. through overexpression of ACC deaminase gene using thin cell layer regeneration system.

Pogostemon cablin cultivation faces massive constraints because of its susceptability to drought stress that reduces patchouli propagation and oil yield. The present study has achieved an efficient and rapid direct regeneration system for the transgenic production of P. cablin using Agrobacterium-mediated genetic transformation. To establish an efficient regeneration protocol for fast in-vitro multiplication of patchouli plants, leaf, petiole, and transverse thin cell layer (tTCL) explants were used and inoculated on an MS medium supplemented with different combinations of phytohormones. A comparative study showed a maximum regeneration frequency of 93.30 ± 0.56% per explant was obtained from leaf segments on optimal MS medium fortified with 0.2mg/L BAP and 0.1mg/L NAA. Leaf and petiole explants took 25-35 days to regenerate while tTCL section showed regeneration in just 15-20 days on the same medium. Subsequently, productive genetic transformation protocol OD600 0.6, AS 200µM, 30mg/L kanamycin, and infection time 5 min. was standardized and best-suited explants were infected at optimum conditions from the Agrobacterium tumefaciens (LBA 4404) strain harboring ACC deaminase to generate transgenic P. cablin Benth. (CIM-Samarth) plants. The investigation suggested that the optimized protocol provides a maximum transformation frequency of 42 ± 1.9% in 15-20 days from tTCL. The transgenic plants were shifted to the greenhouse with a 52.0 ± 0.8% survival frequency. A molecular docking study confirmed significant binding affinity of ligand ACC with ACC deaminase at the catalytic site, and ligand interactions showed four H-bonds at the binding pocket with amino acids Cys-196, Val-198, Thr-199, and Gly-200 that validate gene relative expression in transgenic plants. Among all transgenic acclimatized greenhouse-grown patchouli plants, line PT4 showed improved drought resistance under severe water stress as its RWC was 71.7 ± 2.3% to 75.7 ± 2.1% which is greater than the RWC of the control plant, 58.30 ± 0.21%. Analysis of the other physiological indicators, H2O2, chlorophyll content, and ROS result support drought resistance ability. Our study concluded that the first report on P. cablin, tTCL direct regeneration, and standardized transformation protocol created a new opportunity for genetic manipulation to achieve drought-resistant patchouli plants for cultivation in all seasons at the commercial level.

Effect of exogenous phytohormone treatment on antioxidant activity, enzyme activity and phenolic content in wheat sprouts and identification of metabolites of control and treated samples by UHPLC-MS analysis

Phytohormones, Indole acetic acid, Salicylic acid and Gibberellic acid, either alone or in combination was applied on wheat sprouts to improve its nutritional status. The experiment included estimation of total phenolic, flavonoids, peroxidase activity and phenylalanine ammonium lyase activity. Antioxidant activity was determined by DPPH and FRAP assay. The results showed an increase in phenolic compounds, enzyme activity and antioxidant activity after treatment with the phytohormones. Phytohormone combinations were found to be more effective as compared to pure treatments. UHPLC-ESI-MS analysis was used to identify compounds in the control and treated samples. Phenolic acids, polyphenols, simple sugars, amino acids, dipeptides, lipids and fatty acids were detected. A multifold increase in the levels of phenolic compounds was observed in the phytohormone treated wheat sprouts.

The Eff ect of Precursors and Elicitors on the Production of Oleanolic Acid in Suspension Culture of Lantana camara

Oleanolic acid (OA) is an important pentacyclic triterpenoid. Traditionally used by Asian medicine, OA for anti-infl ammatory, anti-hyperlipidemic, and hepatoprotective. This study used triterpene precursors at 1 to 5 mg/L and elicitors in diff erent concentrations at 2, 5, 10 mg/L to enhance OA production in Lantana camara suspension cultures. Treated cells were evaluated for their OA contents by using HPLC and compared with the nontreated cells as a control. The results showed that FPP at 2 mg/L infl uenced the biomass and OA production more over the phytohormone combination, other precursors, and elicitors in Suspension cultures of L. camara.

Optimized Regeneration of Petunia Protoplast and Its Association with Tissue Identity Regulators

The popular ornamental plant Petunia is also a valuable model plant in tissue culture. Cellular conversions during differentiation and regeneration have been investigated using various combinations of phytohormones; however, studies on genes for reprogramming toward desired tissue identities have been limited. In this study, we isolated Petunia protoplasts and cultured them in the callus, rooting, or shooting stages, which were used to establish the optimal protoplast culture conditions and to identify genes that epigenetically function as tissue identifiers. The optimal conditions for plasmolysis and enzyme digestion to obtain healthy protoplasts were compared, in which combinations of Viscozyme, Celluclast, and Pectinex (VCP) enzymes were more efficient in isolating protoplasts when followed by 21 to 25% sucrose purification and washing processes. The filtered and washed protoplasts started to divide at 1 day and developed into colonies after 3 weeks of culture, which showed higher efficiency in the Murashige and Skoog (MS) salt culture media compared to that in the Kao and Michayluk (KM) salt media. The pluripotent colonies formed calli on the solid medium supplemented with 3% sucrose after 4 weeks, and were destined to the same cell mass, rooting, or shooting on the regeneration medium. Three epigenetic controllers, ATXR2, ATX4A, and ATX4B, were highly expressed in calli, shoots, and organs of shoots and roots, respectively, confirming that dedifferentiation and regeneration of tissue identity is plastic.

Phytochemical Profiling and Assessment of Anticancer Activity of Leptocarpha rivularis Extracts Obtained from In Vitro Cultures.

Plant cell culture is a source of plant material from which bioactive metabolites can be extracted. In this work, the in vitro propagation of Leptocarpha rivularis, an endemic Chilean shrub with anticancer activity, is described. Different media were tested and optimized for the introduction, propagation, and rooting steps of the micropropagation process. At the end of this process, 83% of plants were successfully acclimatized under greenhouse conditions. Callus induction from the internodal stem segment was performed using various combinations of phytohormones. Green-colored, friable, and non-organogenic callus was generated with a callus induction index higher than 90%. The chemical composition of extracts and callus, obtained from clonal plants, was assessed and the results indicate that the phytochemical profiles of extracts from micropropagated plants are like those found for plants collected from natural habitats, leptocarpine (LTC) being the major component. However, no LTC was detected in callus extract. HeLa and CoN cells, treated with LTC or extract of micropropagated plants, exhibit important diminution on cell viability and a drastic decrease in gene expression of IL-6 and mmp2, genes associated with carcinogenic activity. These effects are more important in cancer cells than in normal cells. Thus, micropropagated L. rivularis could be developed as a potential source of efficient antiproliferative agents.

The effects of sugars and growth regulators on embryo- and callusogenesis in isolated ovules culture of beetroot, Beta vulgaris L.

Haploid techniques have risen interest among researchers and breeders as they significantly reduce the time of creating pure lines in breeding programs, especially for biennial vegetable crops. The only way to produce doubled haploids used in representatives of the genus Beta is in vitro culture of non-pollinated ovules. This is a rather laborious method that requires manual labor to isolate beet ovules from flower buds, followed by their inoculation onto a culture medium. This method also has its drawback - the development of clones from the somatic tissues surrounding the embryo sac. At the same time, the yield of embryoids and subsequent regenerations is on average 12-14% of isolated ovules introduced into in vitro culture in the most responsive genotypes of sugar beet and 8% in beetroot. The selection of the optimal cultivation conditions for each genotype makes it possible to maximize the yield of regenerant plants in the culture of isolated ovules. This research is devoted to study the effect of various types of carbohydrates and growth regulators in the culture media on embryogenesis and callusogenesis in isolated ovules culture of five beetroot genotypes. We obtained embryoids and callus in isolated ovules culture of all studied genotypes using sucrose-based culture medium, while on a glucose- and fructose-based culture media or their combination, the number of callus and embryoids was much lower. Additionally, it has been shown that glucose has more negative effect on embryo- and callusogenesis than fructose. The addition of mannitol to the culture medium had a stimulatory effect on the ovules for one genotype only. The study of various combinations of phytohormones on 5 beetroot genotypes showed that gibberellic acid reduces the embryogenesis response of ovules in all genotypes.

In vitro Callus Culture of Cynara cardunculus subsp. scolymus: A Biosystem for Production of Caffeoylquinic Acid Derivatives, Sesquiterpene Lactones, and Flavonoids

In vitro culture of Cynara cardunculus subsp. scolymus was induced from bracts and leaves, using different phytohormone combinations. The most suitable one was 1-naphthaleneacetic acid: 6-benzylaminopurine (NAA-BAP), 3:1 mg/L. Modification of different phytohormone combinations altered the profile of C. cardunculus subsp. scolymus secondary metabolites as revealed by High Performance Liquid Chromatography. Rutin was recorded at 1.77 mg/g DW in leaf callus (not detected in leaves). After addition of 100 µM of methyl jasmonate (MeJA) as elicitor, 1.20 mg/g DW of cynarin was recorded in bract-derived callus and 1.18 mg/g DW in leaf-derived callus (not detected in leaves and bracts). Leaf callus enriched with NAA-BAP (3:1 mg/L) showed more elevated levels of rutin, cynarin, cynaropicrin, and pinoresinol (1.43, 1.2, 1.14, and 1.48 mg/g DW, respectively) as compared to the cultivated artichoke (0.0, 0.0, 0.40, and 0.0 mg/g DW, respectively). Moreover, elicitation of this callus by addition of 50 µM MeJA elevated luteolin, quercetin, cynarin, and chlorogenic acid levels relative to the initial callus. Higher Total Phenolics Content (TPC) was recorded in leaf and bract calluses (106 ± 2.69 and 55.19 ± 0.34 mg GAE/g DW, respectively) compared to leaves and bracts of cultivated plants (69.04 ± 0.05 and 19.42 ± 0.34 mg GAE/g DW, respectively).

Volatile organic compound and endogenous phytohormone characteristics during callus browning in Aquilaria sinensis

Callus browning, a common feature in plant cell cultures, has hardly been explored in Aquilaria sinensis. Here, the volatile organic compounds (VOCs) were characterized during the browning of A. sinensis cells using Gas Chromatography-Mass Spectrometry (GC–MS), and total sesquiterpene accumulation was significantly induced and peaked during A. sinensis callus browning, after 60 days of callus growth. Additionally, 14 types of sesquiterpenes were detected in the browning A. sinensis callus, with greater sesquiterpene diversity than in the ones treated with methyl jasmonate and salicylic acid (SA) in a previous study. To further evaluate the mechanism of regulation of agarwood sesquiterpenes during cell browning in A. sinensis, changes on phytohormone concentrations were explored using ultra-performance liquid chromatography-electrospray tandem mass spectrometry system (UPLC-ESI-MS/MS). Both endogenous jasmonic acid and SA, key plant defense hormones, increased during A. sinensis callus browning. 1-aminocyclopropanecarboxylic acid, an ethylene (ET) precursor, decreased significantly after A. sinensis callus browning. Conversely, two primary growth hormones, auxin and cytokinin, exhibited opposite trends, suggesting that they also play roles in agarwood sesquiterpene accumulation. Our results potentially offer novel insights that could facilitate the production valuable phytochemical compounds such as agarwood sesquiterpenes, using plant cell cultures treated with appropriate phytohormone combinations.

From genes to networks: The genetic control of leaf development.

Substantial diversity exists for both the size and shape of the leaf, the main photosynthetic organ of flowering plants. The two major forms of leaf are simple leaves, in which the leaf blade is undivided, and compound leaves, which comprise several leaflets. Leaves form at the shoot apical meristem from a group of undifferentiated cells, which first establish polarity, then grow and differentiate. Each of these processes is controlled by a combination of transcriptional regulators, microRNAs and phytohormones. The present review documents recent advances in our understanding of how these various factors modulate the development of both simple leaves (focusing mainly on the model plant Arabidopsis thaliana) and compound leaves (focusing mainly on the model legume species Medicago truncatula).

Adjustment of culture media to optimize in vitro rhizogenesis of domestic plums of various origins

This paper presents the results of the adjustment of 18 modifications of culture medium based on MS medium composition – Murashige and Skoog (1962) for in vitro rhizogenesis of 10 varieties of domestic plum. There were used 4 nutrient media with a full amount of macro- and microelements – MS1 with a different combination of phytohormones, 1 medium without hormones – MSc, 13 media – MS2 with half the amount of macronutrients, differing in hormonal composition. It was found that the maximum number of rooted microshoots from 21.2 to 52.2 % was on MS2–8 medium, from 11.2 to 43.1 % on MS2–5. The analysis showed that into the medium increases the percentage of microplants by 12-17 % comparing with the medium MS2–5 and MS2–7 without FA. The distinctiveness of nutrient media by the type of auxin (IAA, NAA, IBA) made it possible to clarify that IBA is the most optimal of the auxins, and the concentration of 1.7 mg/l is borderline for the growth reactions of plum varieties. It was revealed that in vitro root formation depends not only on the compositions of growth substances in the nutrient medium, but also on the genotype of the variety.

Growth Dynamics and Cell Viability in Tomato Suspension Cultures Derived from Different Types of Calli

To establish a dynamic and fine suspension culture, four different methods of tomato cell suspension culture were compared. Hypocotyl explants of the tomato cultivar Jina were used for callus induction on Murashige and Skoog (MS) Medium supplemented with three different phytohormone combinations. Then, one gram of each type of calli was transferred to 50 mL of liquid MS medium with four combinations of auxins and cytokinins to produce cell suspensions. The growth rate, judged by cell turbidity, cell fresh weight, and cell viability was evaluated. The best suspension culture was obtained by using friable calli formed on MS medium containing 1 mg L-1 NAA and 0.1 mg L-1 kinetin, transferred to the liquid MS supplemented with 2 mg L-1 NAA, 0.2 mg L-1 2, 4-D and 0.2 mg L-1 zeatin.

Rapid delivery of Cas9 gene into the tomato cv. ‘Heinz 1706’ through an optimized Agrobacterium-mediated transformation procedure

Solanum lycopersicum ‘Heinz 1706’ is a pioneer model cultivar for tomato research, whose whole genome sequence valuable for genomics studies is available. Nevertheless, a genetic transformation procedure for this cultivar has not yet been reported. Meanwhile, various genome editing technologies such as transfection of clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) ribonucleoprotein complexes into cells are in the limelight. Utilizing the Cas9-expressing genotype possessing a reference genome can simplify the verification of an off-target effect, resolve the economic cost of Cas9 endonuclease preparation, and avoid the complex assembly process together with single-guide RNA (sgRNA) in the transfection approach. Thus, this study was designed to generate Cas9-expressing ‘Heinz 1706’ lines by establishing an Agrobacterium tumefaciens-mediated transformation (ATMT) procedure. Here, we report a rapid and reproducible transformation procedure for ‘Heinz 1706’ by finetuning various factors: A. tumefaciens strain, pre-culture and co-culture durations, a proper combination of phytohormones at each step, supplementation of acetosyringone, and shooting/rooting method. Particularly, through eluding subculture and simultaneously inducing shoot elongation and rooting from leaf cluster, we achieved a short duration of three months for recovering the transgenic plants expressing Cas9. The presence of the Cas9 gene and its stable expression were confirmed by PCR and qRT-PCR analyses, and the Cas9 gene integrated into the T0 plant genome was stably transmitted to T1 progeny. Therefore, we anticipate that our procedure appears to ease the conventional ATMT in ‘Heinz 1706’, and the created Cas9-expressing ‘Heinz 1706’ lines are ultimately useful in gene editing via unilateral transfection of sgRNA into the protoplasts.

THE EFFECT OF PHYTOHORMONES AND LIGHT ON THE GERMINATION OF APPLE POLLEN WITH REDUCED VIABILITY

Background. Studying the effect of phytohormones and light on the germination of apple pollen with reduced viability on an artificial nutrient medium is of importance, because it may facilitate an increase in the germination percentage among plant samples promising for breeding after their long-term preservation under low temperatures.Materials and methods. Pollen viability of the apple-tree cultivar ‘Krasnolistnaya’ was measured by germinating it on an artificial nutrient medium containing 10% sucrose solution and 0.8% agar. Drops of a distilled water suspension of pollen with added phytohormones were applied to the surface of the nutrient medium. Pollen was germinated in the dark (24 hours in a thermostat at 21°C) and under light (in an artificial light chamber at 21°C with a photoperiod of 16 hours of light / 8 hours of darkness). Results. Pollen of cv. ‘Krasnolistnaya’ with reduced viability most effectively germinated with the use of gibberellin at a concentration of 1 mg/l and 10 mg/l: the germination percentage was 22.3±0.8% and 21.8±1.3% respectively (сf. 10.9±1.5% in the reference). The most effective combination of phytohormones was gibberellin 10 mg/l + kinetin 10 mg/l – the percentage of germination was 22.8±6.3%; kinetin 1 mg/l + indolylbutyric acid 1 mg/l – the percentage of germination was 17.5±5.9% vs. 10.9±1.5% in the reference.Conclusion. Phytohormones were observed to have a significant effect on the germination of apple pollen with reduced viability. Effective concentrations and combinations of phytohormones that promote the germination of pollen with reduced viability have been identified. Light does not affect the germination of pollen with reduced viability.

Improving Phenolic Total Content and Monoterpene in Mentha x piperita by Using Salicylic Acid or Methyl Jasmonate Combined with Rhizobacteria Inoculation.

The effects of plant inoculation with plant growth-promoting rhizobacteria (PGPR) and those resulting from the exogenous application of salicylic acid (SA) or methyl jasmonte (MeJA) on total phenolic content (TPC) and monoterpenes in Mentha x piperita plants were investigated. Although the PGPR inoculation response has been studied for many plant species, the combination of PGPR and exogenous phytohormones has not been investigated in aromatic plant species. The exogenous application of SA produced an increase in TPC that, in general, was of a similar level when applied alone as when combined with PGPR. This increase in TPC was correlated with an increase in the activity of the enzyme phenylalanine ammonia lyase (PAL). Also, the application of MeJA at different concentrations in combination with inoculation with PGPR produced an increase in TPC, which was more relevant at 4 mM, with a synergism effect being observed. With respect to the main monoterpene concentrations present in peppermint essential oil (EO), it was observed that SA or MeJA application produced a significant increase similar to that of the combination with rhizobacteria. However, when plants were exposed to 2 mM MeJA and inoculated, an important increase was produced in the concentration on menthol, pulegone, linalool, limonene, and menthone concentrations. Rhizobacteria inoculation, the treatment with SA and MeJA, and the combination of both were found to affect the amount of the main monoterpenes present in the EO of M. piperita. For this reason, the expressions of genes related to the biosynthesis of monoterpene were evaluated, with this expression being positively affected by MeJA application and PGPR inoculation, but was not modified by SA application. Our results demonstrate that MeJA or SA application combined with inoculation with PGPR constitutes an advantageous management practice for improving the production of secondary metabolites from M. piperita.

Exogenous addition of indole acetic acid and kinetin under nitrogen-limited medium enhances lipid yield and expression of glycerol-3-phosphate acyltransferase & diacylglycerol acyltransferase genes in indigenous microalgae: A potential approach for biodiesel production

In the present study, a combination of phytohormones (indole acetic acid and kinetin) was augmented in nitrogen-limited medium to achieve higher biomass and lipid yield in Graesiella emersonii NC-M1 and Chlorophyta sp. NC-M5. This condition was recorded with a 2.3- and 2.5-fold increase in biomass and lipid yield for Graesiella emersonii NC-M1 compared to the nitrogen-limited condition. Also, this condition showed a 1.6- and 1.08-fold increase in lipid yield and neutral lipid compared to the standard condition. Phytohormones addition also reduced oxidative damage caused by nitrogen-limitation and enhanced monounsaturated fatty acid content. Further, a 5.2- and 3.17-fold enhance in expression level of GPAT and DGAT genes were noticed under nitrogen-limited medium supplemented with phytohormones compared to control.

Effect of Explant Source, Culture Media, and Growth Regulators on Callogenesis and Expression of Secondary Metabolites of Curcuma Longa

ABSTRACTThe effects of explant source, medium composition, and growth regulators were examined in callus lines of Curcuma longa. Callus cultures were induced from leaf sheath, leaf lamina, leaf base, apical buds, and lateral buds. The growth potential of established callus lines varied with a combination of phytohormones and culture medium. The greatest callus induction (79%) after 21 d was observed with MS medium supplemented with 3 mg L−1 2,4-D and 0.8 mg mL−1 kinetin. Phytochemical and chromatographic analysis of callus extract after 6th sub-culture revealed the presence of 53.6 mg g−1 of total polyphenols and 36.1 mg g−1 curcumin dry wt. with higher in-vitro anti-oxidant activity compared to turmeric rhizome extract. The lateral bud callus of C. longa may be used as a starting material for the synthesis of secondary metabolites of pharmaceutical interest.