Embryogenic Callus Research Articles

MtWOX2 and MtWOX9-1 Effects on the Embryogenic Callus Transcriptome in Medicago truncatula.

WOX family transcription factors are well-known regulators of plant development, controlling cell proliferation and differentiation in diverse organs and tissues. Several WOX genes have been shown to participate in regeneration processes which take place in plant cell cultures in vitro, but the effects of most of them on tissue culture development have not been discovered yet. In this study, we evaluated the effects of MtWOX2 gene overexpression on the embryogenic callus development and transcriptomic state in Medicago truncatula. According to our results, overexpression of MtWOX2 leads to an increase in callus weight. Furthermore, transcriptomic changes in MtWOX2 overexpressing calli are, to a large extent, opposite to the changes caused by overexpression of MtWOX9-1, a somatic embryogenesis stimulator. These results add new information about the mechanisms of interaction between different WOX genes and can be useful for the search of new regeneration regulators.

Study on rapid multiplication of two hybrid Arabica coffee varieties F1 Centroamericano (H1) and Mundo Maya (H16) through somatic embryogenesis and Bioreactor technology

In this paper, the research focuses on determining some components and culture conditions in order to optimise the 4 main steps of somatic embryogenesis and embryo regeneration by Bioreactor of two Arabica F1 coffee varieties H1 and H16, including: (1) formation of embryogenic callus, (2) multiplication of embryogenic cells, (3) embryonic differentiation, and (4) regeneration of somatic embryo using the temporary immersion Bioreactor RITA 1L. The results showed that on the medium supplemented with Kinetin 2 mg/ll and Phytagel 4 g/l, the callus formation rate reached 94.2 and 92.1% for 2 varieties H1 and H16, respectively. Besides, the addition of Glycine 20 mg/l to the culture medium increased the embryogenic callus rate by 58.1% in both varieties. Adding Trichostatin A 0.03 mg/l in the embryo differentiation medium in the first 7 days of culture showed that the number of torpedo embryos was scored from 1g of initial callus up to 1287 in H1 and 1635 in H16. Finally, using Bioreactor 1L-RITA, soaking for 1 min every 6 hours, the regeneration efficiency reached 75.02% in H1 and 82.03% in H16.

Effect of Arabinogalactans on Induction of White-Opaque Somatic Embryos of Avocado (Persea americana Mill.) cv. Duke-7.

The development of somatic embryogenesis in avocado (Persea americana Mill.) has been hampered by different chronic problems. One such problem is the low level of induction of white-opaque somatic embryos (WOSEs) during the process of obtaining full avocado plants. We detected the induction of multiple WOSEs promoted after the placement of three or four small WOSEs over the embryogenic callus of Duke-7. Among the other possible chemical inductors of the Arabinogalactans (AGPs), we identified a family of extracellular plant proteoglycans implicated in many aspects of the in vitro induction of somatic embryos (SE). We extracted AGPs directly from embryogenic cultures of avocado. When the induction/proliferation medium of embryogenic avocado calli (MS-0.1 mg L-1 Picloram) was supplemented with 1-2 mg L-1 AGP, the induction rate of good-quality WOSEs from the embryogenic callus increased significantly (more than ten times that of the control without AGP) and this effect persisted for at least five subcultures after the initial treatment with AGP. AGP also modified the texture and quality of the callus. The effect of AGP extends to other cultivars and proliferation media. Our objectives were to improve the induction of WOSEs and study the effect of AGP in the somatic embryogenesis of avocado.

Somatic embryo production and GFP genetic transformation in elite Ugandan cassava genotypes

Friable embryogenic callus (FEC) production is a prerequisite for the genetic transformation of cassava (Manihot esculenta Crantz). This process necessitates the development of organized embryogenic structures (OES) as a precursor. However, the production of OES and FECs in cassava is dependent on the genotype. This study aimed to optimize somatic embryo production in elite Ugandan cassava genotypes (NASE13, NASE19, and NAROCASS1) and demonstrate genetic transformation using the enhanced green fluorescent protein (eGFP) gene. OES were induced by initiating leaf-lobe explants on Murashige and Skoog (MS) media at various concentrations of 24D and picloram followed by friable embryogenic callus (FEC) production and regeneration. There were highly significant differences among the different media compositions in the percentage response to OES formation (p < 0.001). NASE 13 exhibited the highest regeneration frequency of 38.4%; while NAROCASS1 had the lowest regeneration frequency of 10.5% recorded. The presence of GFP gene in NAROCASS1 was confirmed by polymerase chain reaction (PCR) analysis of the transformed lines. Compared to existing studies, this research pioneers genotype-specific optimization for somatic embryo production and successful genetic transformation in Ugandan cassava variaties. The utilization of these genotypes, already embraced by farmers, presents promising opportunities to enhance them with desirable traits, further augmenting cassava cultivation.

Somatic embryogenesis from mature sorghum seeds: An underutilized genome editing recipient system

Somatic embryogenesis is a process of cell totipotency in vitro, whereby an embryogenic cell develops from vegetative tissues rather than from zygotes after double fertilization. Sorghum is a recalcitrant crop in genetic transformation; previous recipient systems have usually been from immature zygotic embryos, which needed more time and labors to prepare. Here, an efficient 2,4-dichlorophenoxyacetic acid (2,4-D)-induced somatic embryogenesis system from mature sorghum seeds was introduced. 2,4-D can induce two types of calli from a plumular axis section. Low-concentration 2,4-D (e.g., 2 mg/L) induces white and loose non-embryogenic calli (type 1), while high-concentration 2,4-D (e.g., 8 mg/L) induces yellow and compact embryogenic calli (type 2), which can be clearly distinguished by Sudan red staining. Germinating seeds have a long 2-day window for SE induction. Somatic embryogenesis can be enhanced by HDAC inhibitor, trichostatin A (TSA), a histone deacetylase treatment, which shows more SE productivity and a bigger size. Importantly, this easily prepared protocol does not show obvious genotype dependency in sorghum hybrids. In this study, a high-concentration 2,4-D-induced SE system was established from mature sorghum seeds. This finding provides a technical option for the genome editing recipient in sorghum.

Machine Learning Analysis of the Impact of Silver Nitrate and Silver Nanoparticles on Wheat (Triticum aestivum L.): Callus Induction, Plant Regeneration, and DNA Methylation.

The objective of this study was to comprehend the efficiency of wheat regeneration, callus induction, and DNA methylation through the application of mathematical frameworks and artificial intelligence (AI)-based models. This research aimed to explore the impact of treatments with AgNO3 and Ag-NPs on various parameters. The study specifically concentrated on analyzing RAPD profiles and modeling regeneration parameters. The treatments and molecular findings served as input variables in the modeling process. It included the use of AgNO3 and Ag-NPs at different concentrations (0, 2, 4, 6, and 8 mg L-1). The in vitro and epigenetic characteristics were analyzed using several machine learning (ML) methods, including support vector machine (SVM), random forest (RF), extreme gradient boosting (XGBoost), k-nearest neighbor classifier (KNN), and Gaussian processes classifier (GP) methods. This study's results revealed that the highest values for callus induction (CI%) and embryogenic callus induction (EC%) occurred at a concentration of 2 mg L-1 of Ag-NPs. Additionally, the regeneration efficiency (RE) parameter reached its peak at a concentration of 8 mg L-1 of AgNO3. Taking an epigenetic approach, AgNO3 at a concentration of 2 mg L-1 demonstrated the highest levels of genomic template stability (GTS), at 79.3%. There was a positive correlation seen between increased levels of AgNO3 and DNA hypermethylation. Conversely, elevated levels of Ag-NPs were associated with DNA hypomethylation. The models were used to estimate the relationships between the input elements, including treatments, concentration, GTS rates, and Msp I and Hpa II polymorphism, and the in vitro output parameters. The findings suggested that the XGBoost model exhibited superior performance scores for callus induction (CI), as evidenced by an R2 score of 51.5%, which explained the variances. Additionally, the RF model explained 71.9% of the total variance and showed superior efficacy in terms of EC%. Furthermore, the GP model, which provided the most robust statistics for RE, yielded an R2 value of 52.5%, signifying its ability to account for a substantial portion of the total variance present in the data. This study exemplifies the application of various machine learning models in the cultivation of mature wheat embryos under the influence of treatments and concentrations involving AgNO3 and Ag-NPs.

Effects of a New Plant Growth Regulator on Callus Induction from Immature Embryo Explants of Korean Pine (Pinus koraiensis)

Somatic embryogenesis is currently the most promising technique for the large-scale production and breeding of conifer species. Nonetheless, the low explant induction rate in this process hampers the development of improved materials. In this study, three immature Korean pine (Pinus koraiensis) embryos capable of induction were used as experimental materials. Various concentrations of brassinolide (BL), melatonin (Mel), salicylic acid (SA), glutathione (GSH), and ascorbic acid (AsA) were added to induce embryogenic callus tissue. The results show that BL had the most significant positive effect on promoting induction and increasing explant survival. Mel was also found to slightly increase the induction and survival rates of explants. When 1.00 mg·L−1 BL was added to the explants derived from stock tree I, which had strong self-induction ability, for 30 days, the callus induction rate rose to 400% compared to the control group. Following the addition of 25 mg·L−1 Mel to stock tree I for 30 days, the callus induction rate further increased to 450% of the control group. The effect of GSH on callus induction was insignificant. The addition of 0.10 g·L−1 to stock tree I for 30 days resulted in only a 150% higher induction rate compared to the control group. When 1.00 mg·L−1 BL was applied to explants with weak self-induction ability (stock tree III) for 15 days, the callus induction rate increased to 600% of that of the control group. The callus induction rate further increased to 800% of the control group after 50 mg·L−1 BL were added to stock tree III for 15 days. This study presents a method to improve the induction of embryogenic callus tissue in Korean pine.

Studies on Improving the Efficiency of Somatic Embryogenesis in Grapevine (Vitis vinifera L.) and Optimising Ethyl Methanesulfonate Treatment for Mutation Induction.

Somatic embryogenesis (SE) has many applications in grapevine biotechnology including micropropagation, eradicating viral infections from infected cultivars, mass production of hypocotyl explants for micrografting, as a continuous source for haploid and doubled haploid plants, and for germplasm conservation. It is so far the only pathway for the genetic modification of grapevines through transformation. The single-cell origin of somatic embryos makes them an ideal explant for mutation breeding as the resulting mutants will be chimera-free. In the present research, two combinations of plant growth regulators and different explants from flower buds at two stages of maturity were tested in regard to the efficiency of callusing and embryo formation from the callus produced in three white grape cultivars. Also, the treatment of somatic embryos with the chemical mutagen ethyl methanesulfonate (EMS) was optimised. Medium 2339 supplemented with β-naphthoxyacetic acid (5 μM) and 6-benzylaminopurine (BAP-9.0 μM) produced significantly more calluses than medium 2337 supplemented with 2,4-dichlorophenoxyacetic acid (4.5 µM) and BAP (8.9 µM) in all explants. The calluses produced on medium 2337 were harder and more granular and produced more SEs. Although the stage of the maturity of floral bud did not have a significant effect on the callusing of the explants, calluses produced from immature floral bud explants in the premeiotic stage produced significantly more SEs than those from more mature floral buds. Overall, immature ovaries and cut floral buds exposing the cut ends of filaments, style, etc., tested for the first time in grapevine SE, produced the highest percentage of embryogenic calluses. It is much more efficient to cut the floral bud and culture than previously reported explants such as anthers, ovaries, stigmas and styles during the short flowering period when the immature flower buds are available. When the somatic embryos of the three cultivars were incubated for one hour with 0.1% EMS, their germination was reduced by 50%; an ideal treatment considered to obtain a high frequency of mutations for screening. Our research findings will facilitate more efficient SE induction in grapevines and inducing mutations for improving individual traits without altering the genetic background of the cultivar.

CRISPR/Cas9 editing of Downy mildew resistant 6 (DMR6-1) in grapevine leads to reduced susceptibility to Plasmopara viticola.

Downy mildew of grapevine (Vitis vinifera), caused by the oomycete Plasmopara viticola, is an important disease that is present in cultivation areas worldwide, and using resistant varieties provides an environmentally friendly alternative to fungicides. DOWNY MILDEW RESISTANT 6 (DMR6) from Arabidopsis is a negative regulator of plant immunity and its loss of function confers resistance to downy mildew. In grapevine, DMR6 is present in two copies, named VvDMR6-1 and VvDMR6-2. Here, we describe the editing of VvDMR6-1 in embryogenic calli using CRISPR/Cas9 and the regeneration of the edited plants. All edited plants were found to be biallelic and chimeric, and whilst they all showed reduced growth compared with non-transformed control plants, they also had reduced susceptibility to P. viticola. Comparison between mock-inoculated genotypes showed that all edited lines presented higher levels of salicylic acid than controls, and lines subjected to transformation presented higher levels of cis-resveratrol than controls. Our results identify VvDMR6-1 as a promising target for breeding grapevine cultivars with improved resistance to downy mildew.

The search for inhibitors of somatic embryogenesis in Medicago truncatula

The success of protocols for the genetic transformation of legumes is limited by their low ability to regenerate. Plant regeneration can occur both along the path of shoot regeneration and their further rooting, and along the path of somatic embryogenesis (SE). SE is similar to zygotic embryogenesis (ZE). It is a method of asexual reproduction, in which the somatic cell, due to its totipotency, switches on the embryogenesis program.&#x0D; SE and ZE involve common participants in transcriptional, hormonal, and epigenetic control. Like many processes in the plant organism, SE is controlled by the activity of various stimulants or repressors.&#x0D; As a result of transcriptional analysis of embryogenic and non-embryogenic calli ofMedicago truncatulaat different stages of development, putative genes-inhibitors of SE were found. Using the Golden Gate system, we created vectors for agrobacterial transformation to overexpress genes of interest in embryogenic calli and evaluate their effect on SE. Overexpression of two genes encoding the transcription factors from WRKY and Homobox-WOX families had a significant inhibitory effect on SE (the average number of somatic embryos per callus decreased).&#x0D; TheMtCLE16,a previously found SE inhibitor from the CLE peptides group, was edited and heterozygous frameshift mutants were obtained. The impact of loss of its function on the SE capacity remains to be analyzed.&#x0D; This research was supported by the Sirius University of Science and Technology, project PBB-RND-2243.

English

Androgenesis is reported in a few tree crops such as citrus and papaya; however, there is little information available about guava. Different modified Chu (N6) media and cold pretreatments of floral buds were tested to induce embryogenic calli in the anthers of two white flesh guava cultivars, ‘Round’ and ‘Pyriform’. Four modified Chu (N6) media formulations, i.e., M1 (400 mgL-1 casein hydrolysate, 200 mgL-1 glutamine, 0.2 mgL-1NAA, 1.0 mgL-1 KIN, 0.5 mgL-1 6-BAP, 0.5 mgL-1 zeatin and 5% coconut water), M2 (400 mgL-1 casein hydrolysate, 200 mgL-1 glutamine, 0.2 mgL-1NAA, 1.0 mgL-1 KIN, 0.5 mgL-1 6-BAP), M10 (0.5 mgL-1 2,4-D), and M11 (0.5 mgL-1 2,4-D and 50 mgL-1 PVP) enhanced anther swelling and callus formation. Genotypic variability was found in pollen viability, phenolic exudation, and anther tissue browning after cold pretreatment for 0-72 hrs. intervals. Anthers of ‘Round’ showed more pollen viability across cold pretreatment intervals with less phenolic exudations and tissue browning than ‘Pyriform’. On both M10 and M11 media, anthers with uni-nucleate microspores developed embryogenic calli; however, anthers of ‘Pyriform’ resulted in more calli induction (69.58%) on M10 media, whereas anthers of ‘Round’ developed more calli (66.60%) on M11 media. The proliferating calli in white flesh ‘Round’ and ‘Pyriform’ cultivars and pink flesh ‘Round’ cultivar formed more embryogenic masses upon transfer to growth hormone-free Chu (N6) media under light conditions; however, embryos showed delayed maturity with limited germination. More genotypes shall be explored to enhance embryo germination, and embryogenic media shall be further fine-tuned. This study provides the foundation for the generation of homozygous lines in guava using androgenesis

The of Effects of Light and a Combination of Growth Regulators on the Induction of Somatic Embryogenesis in Orchid Rhynchostylis gigantea (LindI.) Ridl.

The squirrel-tail orchid (Rhynchostylis gigantea) belongs to the Orchidaceae family. This orchid is indigenous to Southeast Asia and is scented and arranged in a bouquet of dangling stems. Its uniqueness makes it commercially desirable. In vitro culture has been utilized for orchid proliferation for a very long time to aid in the development of orchid seedlings. However, not all orchid species react the same way. Through somatic embryogenesis without gamete fusion, in vitro culture techniques can produce new plants during the entire embryonic phase. Endogenous and exogenous hormones, as well as light, influence the success of embryogenesis. Determining the optimal environmental parameters (light, combination and concentration of growth regulators, and their interaction) for inducing somatic embryogenesis from leaf explants in R. gigantea is the purpose of the present study. The leaves of R. gigantea clone 19 were utilized as explants in this investigation, utilizing a completely random factorial design. The first factor is a combination of growth regulator types and concentrations, and the second factor is light. Explants that are alive and growing at a rapid rate indicate that the in vitro culture is successful. Light and the combination of growth regulators significantly affected the percentage of viable explants, the beginning date of callus formation, and the number of embryogenic calluses produced. The interaction of two components (light and a combination of growth regulators) did not affect the three characteristics, with the exception of the proportion of somatic embryogenesis. Incubation in the dark is the optimal environment for initiating somatic embryogenesis in explants. The optimal combination of plant growth regulators for inducing somatic embryogenesis was 0.5 mgL-1 TDZ and 0.1 mgL-1 BAP. Bright light and a concentration of 1.0 mgL-1 TDZ + 0.1 mgL-1 BAP were the optimal interaction conditions for the induction of somatic embryogenesis in R. gigantea.

Histological studies on induction of somatic embryogenesis in mangabeira

The Hancornia speciosa Gomes (Apocynaceae), is a fruit tree known as mangabeira and officially listed as a genetic resource with food potential in Brazil. The aim of this investigation was to conduct histological studies on inducing maturation of somatic embryos from explants of Hancornia speciosa Gomes. For callus induction, leaf and nodal segments of the Terra Caída accession were cultured in media with different concentrations of putrescine (0, 250, 500, 750, and 1000 µM) in MS medium with 10 mg/L of 2,4D, 5 mg/L of BAP, 1 g/L of activated carbon, and 30 g/L of sucrose, and gelled with 3 g/L of Phytagel®. At 90 days of culture in multiplication medium, the embryogenic calluses were identified and selected for the maturation phase of somatic embryos in media composed of MS salts combined with two concentrations of BAP (10 and 15 mg/L) and two concentrations of polyethylene glycol – PEG 2000 (0% and 2%) with 30 g/L of sucrose, 1 g/L of activated carbon, and 4 g/L of Phytagel®. At 90 days of culture in multiplication medium (medium II) and at 60 days of culture in maturation medium (medium IV), the callus samples were fixed in FAA. After that, the samples were infiltrated in 100% ethanol + liquid resin (1:1) for 2 hours and then in activated resin = infiltration solution for 24 hours in the refrigerator. After drying, the slides were fixed with glass varnish and then evaluated in an optical microscope (Zeiss/Jenamed2), and photomicrographs (Axiocam software) were taken of the prepared slides. The results obtained in the different histological analyses of the Terra Caída accession of Hancornia speciosa Gomes are important to show the response of the nodal and leaf segments in inducing embryogenic calluses and possible maturation of somatic embryos, providing information that collaborates in validation of future protocols of somatic embryogenesis for this species.

Effect of the Combination of the Growth Regulators and Putrescine on the Somatic Embryogenesis of Wheat (Triticum Aestivum L.) on Some Types of Explants

Plant breeding programs need to be carried out in order to improve the genetics of wheat that is able to adapt to tropical environments through hybridization, mutation induction, tissue culture, and genetic transformation. In vitro culture through somatic embryogenesis pathways plays an important role in genetic improvement and its integration with other breeding programs can positively affect the improvement of wheat quality, quantity, and development in Indonesia. The purpose of this study was to obtain an embryogenic callus induction method from the Dewata variety using five different types of explants, namely mature Seeds, immature embryos, immature seeds, leaf, stem, and to obtain combination of plant growth regulators and putrescine on somatic embryogenesis of wheat. The experimental design was prepared based on a complete randomized design with a combination treatment of embryogenic callus induction media consisting of 9 levels, namely: 1 ppm 2.4- D, 1 ppm 2.4-D + 1 ppm Picloram, ppm 2.4-D + 1 mg / L Picloram, 1 ppm 2.4-D + 10-4 M Putrescine, 1 ppm 2.4-D + 1 ppm Picloram +10-4 M Putrescine, 2 ppm 2.4-D + 1 ppm Picloram + 10-4 M Putrescine, 1 ppm 2.4 D + 10-3 M Putrescine, 1 ppm 2.4 D + 1 ppm Picloram + 10-3 M Putrescine, 2 ppm 2.4 D + 1 ppm Picloram + 10-3 M Putrescine. The results showed that the media used was able to induce embryogenic callus using mature seed and immature embryo, but immature seed and leaf were not able to produce embryogenic callus. The best media that produced the highest percentage of embryogenic callus was 2 ppm 2.4-D + 1 ppm Picloram + 10-4 M Putrescine with as much as 85.9% in young embryo explants.

A Versatile Protocol for Efficient Transformation and Regeneration in Mega Indica Rice Cultivar MTU1010: Optimization through Hormonal Variables.

Rice is one of the apex food crops in terms of meeting the daily calorific and dietary requirement of the majority of the world population. However, rice productivity is severely limited by various biotic and abiotic attributes, causing a severe threat to global food security. In the use of functional genomics and genome editing for the generation of trait-enhanced genotypes, it is necessary to have an efficient genetic transformation and regeneration protocol. The recalcitrant nature and paucity of efficient and versatile genetic transformation and regeneration protocols for indica cultivars remains a constraint. In the present study, we have optimized a tissue culture method for MTU1010, a mega indica rice variety. We conducted a combinatorial analysis of different plant growth regulators on embryogenic callus induction efficiency, and it was observed that MSB5 medium supplemented with 2.5 mg/L 2-4D and 0.25 mg/L 6-BAP results in maximum embryogenic callus induction, i.e., 92%. The regeneration efficiency of a transformed callus can be enhanced by up to 50% with the supplementation of 1 mg/L kinetin alongside 2.5 mg/L BAP and 0.5 mg/L NAA in the shooting medium. Furthermore, our results unveiled that the pre-activation of Agrobacterium culture for 30 min with 150 µM acetosyringone significantly increased the transformation efficiency of calli. Additionally, descaling the salt concentration to half strength in resuspension and co-cultivation increased the efficiency of transformation up to 33%. Thus, the protocol developed in this study will be instrumental for the genome editing and genetic engineering of indica rice cultivars for functional genomics studies and crop improvement.

Time-Dependent Proteomic Signatures Associated with Embryogenic Callus Induction in Carica papaya L.

Sex segregation increases the cost of Carica papaya production through seed-based propagation. Therefore, in vitro techniques are an attractive option for clonal propagation, especially of hermaphroditic plants. Here, we performed a temporal analysis of the proteome of C. papaya calli aiming to identify the key players involved in embryogenic callus formation. Mature zygotic embryos used as explants were treated with 20 μM 2,4-dichlorophenoxyacetic acid to induce embryogenic callus. Total proteins were extracted from explants at 0 (zygotic embryo) and after 7, 14, and 21 days of induction. A total of 1407 proteins were identified using a bottom-up proteomic approach. The clustering analysis revealed four distinct patterns of protein accumulation throughout callus induction. Proteins related to seed maturation and storage are abundant in the explant before induction, decreasing as callus formation progresses. Carbohydrate and amino acid metabolisms, aerobic respiration, and protein catabolic processes were enriched throughout days of callus induction. Protein kinases associated with auxin responses, such as SKP1-like proteins 1B, accumulated in response to callus induction. Additionally, regulatory proteins, including histone deacetylase (HD2C) and argonaute 1 (AGO1), were more abundant at 7 days, suggesting their role in the acquisition of embryogenic competence. Predicted protein-protein networks revealed the regulatory role of proteins 14-3-3 accumulated during callus induction and the association of proteins involved in oxidative phosphorylation and hormone response. Our findings emphasize the modulation of the proteome during embryogenic callus initiation and identify regulatory proteins that might be involved in the activation of this process.

Modeling Callus Induction and Regeneration in Hypocotyl Explant of Fodder Pea (Pisum sativum var. arvense L.) Using Machine Learning Algorithm Method

A comprehensive understanding of genetic diversity and the categorization of germplasm is important to effectively identify appropriate parental candidates for the goal of breeding. It is necessary to have a technique of tissue culture that is both effective and reproducible to perform genetic engineering on fodder pea genotypes (Pisum sativum var. arvense L.). In this investigation, the genetic diversity of forty-two fodder pea genotypes was assessed based on their ability of callus induction (CI), the percentage of embryogenic callus by explant number (ECNEP), the percentage of responding embryogenic calluses by explant number (RECNEP), the number of somatic embryogenesis (NSE), the number of responding somatic embryogenesis (RSE), the regeneration efficiency (RE), and the number of regenerated plantlets (NRP). The findings of the ANOVA showed that there were significant differences (p &lt; 0.001) between the genotypes for all in vitro parameters. The method of principal component analysis (PCA) was used to study the correlations that exist between the factors associated with tissue culture. While RE and NRP variables were most strongly associated with Doğruyol, Ovaçevirme-4, Doşeli-1, Yolgeçmez, and Incili-3 genotypes, RECNEP, NSE, RDE, and RECNEP variables were strongly associated with Avcılar, Ovaçevirme-3, and Ardahan Merkez-2 genotypes. The in vitro process is a complex multivariate process and more robust analyses are needed for linear and nonlinear parameters. Within the scope of this study, artificial neural network (ANN), random forest (RF), and multivariate adaptive regression spline (MARS) algorithms were used for RE estimation, and these algorithms were also compared. The results that we acquired from our research led us to the conclusion that the employed ANN-multilayer perceptron (ANN-MLP) model (R2 = 0.941) performs better than the RF model (R2 = 0.754) and the MARS model (R2 = 0.214). Despite this, it has been shown that the RF model is capable of accurately predicting RE in the early stages of the in vitro process. The current work is an inquiry regarding the use of RF, MARS, and ANN models in plant tissue culture, and it indicates the possibilities of application in a variety of economically important fodder peas.

Molecular mechanism of somatic embryogenesis in paeonia ostii ‘Fengdan’ based on transcriptome analysis combined histomorphological observation and metabolite determination

BackgroundTree peony (Paeonia sect. Moutan DC.) is a famous flower native to China with high ornamental, medicinal, and oil value. However, the low regeneration rate of callus is one of the main constraints for the establishment of a genetic transformation system in tree peony. By histomorphological observation, transcriptomic analysis and metabolite determination, we investigated the molecular mechanism of somatic embryogenesis after the establishment of a culture system and the induction of somatic embryo(SE) formation.ResultsWe found that SE formation was successfully induced when cotyledons were used as explants. A total of 3185 differentially expressed genes were screened by comparative transcriptomic analysis of embryogenic callus (EC), SE, and non-embryogenic callus (NEC). Compared to NEC, the auxin synthesis-related genes GH3.6 and PCO2 were up-regulated, whereas cytokinin dehydrogenase (CKX6) and CYP450 family genes were down-regulated in somatic embryogenesis. In SE, the auxin content was significantly higher than the cytokinin content. The methyltransferase-related gene S-adenosylmethionine synthase (SAMS) and the flavonoid biosynthesis-related gene (ANS and F3’5’H) were down-regulated in somatic embryogenesis. The determination of flavonoids showed that rhoifolin and hyperoside had the highest content in SE. The results of transcriptome analysis were consistent with the relative expression of 8 candidate genes by quantitative polymerase chain reaction analysis.ConclusionThe results revealed that auxin and cytokinin may play a key role in ‘Fengdan’ somatic embryogenesis. The genes related to somatic embryogenesis were revealed, which has partly elucidated the molecular mechanism of somatic embryogenesis in ‘Fengdan’.

Plant regeneration from embryogenic callus-derived from immature leaves of Momordica charantia L

Bitter melon (Momordica charantia L.), a widely cultivated food and medicinal plant native to the world's subtropics and tropics, is a Cucurbitaceae rich in carotenoids. However, the low seed germination frequency and progeny variability associated with the production of this plant have a substantial impact on its growth and yield. These constraints affect the availability and exploitation of this crop, especially the fruits, which are rich in secondary metabolites such as β-carotene and α-carotene. In vitro regeneration would help overcome the obstacle linked to the germination of this plant and increase its yield and utilization. A reproducible in vitro organogenesis protocol was established using bitter melon embryogenic callus derived from immature leaf explants of in vivo grown seedlings and in vitro plantlets. Regeneration via callus was conducted on MSB5 media augmented with different plant growth regulator concentrations. The maximum frequency of callus formation (95.09 %) was produced in MSB5 media incorporated with 1.2 mg L−1 NAA augmented with 0.5 mg L−1 TDZ. MSB5 medium with no growth regulators was observed to be the most suitable for the shoot and root formation from the callus, producing a significantly high shoot percentage of 90.91 % and 21.53 shoots per explants, and the highest rooting frequency and root number of 88.92 % and 6.23 roots per explant, respectively, from leaf-derived callus of in vitro plantlets. The elongated plantlets had grown to a significantly higher average height of 12.20 cm on media added with 0.75 mg L−1 GA3. This reproducible method for regenerating bitter melon plantlets could facilitate mass multiplication, conservation, and commercial field production.

Agrobacterium-Mediated Genetic Transformation of Withania coagulans (Dunal) with rol A Genes and Its Antioxidant Potential.

In ancient times, Withania coagulans Dunal was used as a therapeutic plant for the treatment of several diseases. This report aims to examine the effect of Agrobacterium tumefactions-mediated transformation of W. coagulans with the rolA gene to enhance secondary metabolite production, antioxidant activity, and anticancer activity of transformed tissues. Before transgenic plant production, the authors designed an efficient methodology for in vitro transformation. In this study, leaf explants were cultured on Murashage and Skoog (MS) media containing different amounts of naphthalene acetic acid (NAA) and benzyl adenine (BA). The best performance for inducing embryogenic callus was in MS medium containing 4 μM NAA and 6.0 μM BA, while the best results for shooting (100%) were obtained at 8 μM benzyl adenine. On the other hand, direct shooting was attained by subculturing leaves on MS medium supplemented with 8 μM benzyl adenine. Prolonged shoots showed excellent in vitro rooting results (80%) with 12 μM indole-3-butyric acid (IBA). The samples were precultivated for 3 days and were followed by 48 h infection with A. tumefaciens strain GV3101 having pCV002. Then, a vector expressed the rol A gene of strain Agrobacterium rhizogenes. Furthermore, three independent transgenic shoot lines and one callus line (T2) were produced and exhibited stable integration of transgene rol A genes, as revealed by PCR analysis. Transgenic strains showed a significant increase in antioxidant potential as compared to untransformed plants. Additionally, LC-MS analysis showed that the transformed strains have a higher withanolide content as compared to untransformed ones. Moreover, the reduced proliferation of prostate cancer cells was observed after treatment with extracts of transgenic plants. Furthermore, these transformed plants exhibited superior antioxidant capability and higher withanolide content than untransformed ones. In conclusion, the reported data can be used to select withanolide-rich germplasm from transformed cell cultures.