Search Results (77)

Stevia rebaudiana Bertoni is a strategically important perennial crop because it is the main botanical source of steviol glycosides, a group of high-intensity, non-caloric sweeteners increasingly demanded by the global food and beverage industry. Despite the rapid expansion of stevia cultivation, commercial production remains strongly dependent on a narrow genetic base, particularly on clonally propagated cultivars such as ‘Morita II’, which has long served as the industrial benchmark because of its favourable rebaudioside A profile and processing consistency. This dependence has raised concerns about limited adaptive capacity, genetic erosion and restricted long-term breeding progress. In this review, we provide an integrated and critical synthesis of current knowledge on the genetic diversity of S. rebaudiana, the biosynthetic and regulatory architecture of steviol glycosides, and the conventional and emerging strategies available for crop improvement. Unlike previous reviews, this article explicitly connects domestication-driven genetic bottlenecks, wild germplasm mobilisation, metabolic pathway regulation, advanced analytical phenotyping and precision breeding into a single systems-oriented framework. We examine the roles of wild germplasm, somaclonal variation, polyploidy, molecular markers, omics-assisted approaches and transgene-free genome editing as complementary tools to broaden the stevia breeding base while preserving industrial quality standards. We finally propose an integrative roadmap for the sustainable genetic improvement of stevia, positioning ‘Morita II’ not as an endpoint, but as a benchmark within a broader diversification strategy. Full article

This review examines the potential impact of potato biofortification on boosting climate resilience and enhancing the nutritional content of potato tubers to combat hidden hunger. It also explores future possibilities for biofortified potatoes as a food source during space travel or colonization. Widespread mineral deficiencies are prevalent globally, particularly in developing countries. Additionally, climate change could adversely affect potato production and soil nutrient absorption. In this context, developing breeding methods to develop cultivars that respond better to biofortification amid climate change is essential. These cultivars may be physiologically efficient at absorbing and transporting minerals into tubers. The review covers various approaches, including identifying germplasm accessions with enhanced micronutrient storage, understanding mechanisms of micronutrient uptake and translocation, and pinpointing genes related to micronutrient, oligopeptide transport, and ligands. It also discusses in vitro selection and screening of calli with improved capacity for micronutrient absorption and transport. Full article

RNA-directed DNA methylation (RdDM), a new plant breeding technology, induces epigenetic modifications that can be inherited even after segregation of the responsible transgene. The transgene-free descendants (null segregants) are potentially exempt from the regulation of genetically modified plants. To evaluate the risks of potential unintended molecular changes in the null segregants of RdDM-positive plants, we produced null segregants (S44end2-null) from a transgenic tobacco line in which RdDM targeting the promoter of the transgene was introduced. Comprehensive multi-omics analyses, including transcriptomics, proteomics, and metabolomics, were conducted using S44end2-null and wild-type (WT) plants. Principal component analysis demonstrated clear separation of the transcriptomic and proteomic profiles of the two groups. The metabolomic profiles of S44end2-null plants exhibited considerable overlap with those of WT plants. Proteomic analysis of the null segregants of tobacco plants transformed with an empty vector demonstrated distinct cluster separation from WT plants. Because only sporadic DNA methylation on the tobacco genome was expected by the RdDM construct used in this study, the observed differences in omics profiles are considered to be significantly influenced by genetic variation accumulated during the transformation and regeneration processes (somaclonal variation). The safety assessment points for null segregants using RdDM technology are discussed. Full article

Secondary somatic embryogenesis (SSE) is a powerful tool in plant biotechnology, enabling the continuous production of embryos from primary somatic embryos (PSEs) and offering broad applications across agriculture, forestry, horticulture, and pharmaceutical industries. Depending on culture conditions, SSE may proceed directly from the surface of PSEs or indirectly via callus formation, with the outcome strongly influenced by exogenous plant growth regulators (PGRs). A key advantage of SSE is its cyclic nature, which offers a valuable strategy to maintain embryogenic potential over extended culture periods, generating true-to-type embryos without reliance on the original explant, while significantly increasing the multiplication rate, often making SSE more productive than PSE in many species. This review explores in detail the cellular origin and developmental pathways of secondary embryos, the maintenance of embryogenic competence through cyclic embryogenesis, as well as genetic and epigenetic aspects and the biotechnological applications of this process. Moreover, it addresses challenges regarding strong genotype dependence, variability in embryo quality and morphology, limitations in maturation and conversion potential, and the gradual decline of embryogenic competence with successive cycles, all of which need to be overcome to ensure the stability and reproducibility of SSE and maximize its impact. Full article

Introduction: Stevia rebaudiana Bertoni has recently gained significant attention due to the presence of intensely sweet yet low-calorie steviol glycosides (SGs) in its leaves, making it a promising natural sugar alternative with applications in the food, pharmaceutical, and cosmetics industries. The primary goal of this study was to determine whether generating somaclonal variation from plant material obtained by indirect regeneration results in further genetic changes identifiable using the SCoT marker (Start Codon Targeted). Methods: In the first stage, callus tissue was initiated from first-generation somaclones on MS medium supplemented with 4.0 mg/L 6-benzylaminopurine (BAP), 2.0 mg/L 1-naphthaleneacetic acid (NAA), and 2.0 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D). Their morphogenetic potential was analyzed on four media with different BAP and Kinetin concentrations. Donor plants, first and second generation somaclones, were also analyzed for genetic diversity using SCoT markers. Results: All first-generation somaclones demonstrated a very high callus initiation capacity, ranging from 95 to 100%. It was found that for most of the studied somaclones, the greatest number of shoots were developed by explants grown in a medium supplemented with 0.5 mg/L BAP and 0.25 mg/L Kin. The studied group of somaclones exhibits a high degree of polymorphism (55.2%). The analysis of genetic similarity of somaclones presented in the form of individual dendrograms indicates that in most cases, greater genetic diversity was revealed as a result of indirect regeneration in the first generation of somaclones compared to the second. Indirect organogenesis allows for the production of subsequent generations of genetically unstable somaclones, creating the potential for obtaining new phenotypic variants useful in plant breeding. Full article

Conventional propagation of the highly sought-after ornamental Philodendron erubescens ‘Pink Princess’ is constrained by slow multiplication rates, the risk of unstable variegation, and the limited availability of elite mother stock, making advanced in vitro techniques essential for large-scale production. This research aimed to establish an efficient micropropagation protocol by optimizing the shoot multiplication phase in a twin-flask Temporary Immersion Bioreactor (TIB) system (RITA-type) and subsequently assessing the genetic fidelity of the regenerated plants. Shoot induction was evaluated in a TIB system with an immersion frequency of 4 min every 8 h. Among the tested cytokinins, liquid Murashige and Skoog (MS) medium containing 1.0 mg/L 6-benzylaminopurine (BAP) provided the optimal conditions for shoot proliferation, accounting for approximately 21 shoots/explant. While the TIB system was highly effective for shoot multiplication, it proved suboptimal for root induction. Therefore, rooting was optimized on a semi-solid medium, where MS medium supplemented with 0.5 mg/L indole-3-acetic acid (IAA) was identified as the most effective treatment, yielding an average of 3.0 well-developed roots per explant (1.1 cm in length) within 30 days. For acclimatization, a substrate mix of peat moss, perlite, and vermiculite (2:1:1, v/v/v) ensured a 100% survival rate. Critically, genetic fidelity analysis using RAPD markers revealed monomorphic banding patterns between the micropropagated plantlets and the mother plant (100% similarity), confirming their genetic uniformity and true-to-type nature. The established protocol provides a robust and reliable method for the in vitro propagation of P. erubescens ‘Pink Princess’. This work offers a foundation for developing large-scale commercial production strategies and effectively overcomes many limitations of classical propagation techniques. Full article

Background: Tissue culture might be a method supplementing traditional plant propagation in various fields, like agriculture, medicine, industry, and the active conservation of plant species. For the purpose of plant restoration, it is important that the obtained progenies are identical with the mother plants to ensure the true-to-typeness of the future population. Methods: In the present study, the stability of Aldrovanda vesiculosa regenerants obtained in vitro through phenotypic and genetic analysis was estimated. Clones of aldrovanda plants were cultivated in tissue culture in the 1/10 MS liquid medium under the same conditions for over a year, with five weeks of subculturing. Results: It was observed that two clones formed plants that displayed atypical growth structures, the shoots were shorter with many lateral shoots, and they had a lower fresh weight. They also formed fewer and smaller snap-traps, which, in the case of carnivorous plants, determines the capability of catching prey. The 35 in vitro regenerated plants and 5 specimens obtained from the natural habitat were subjected to genetic analyses with two molecular markers: start codon targeted (SCoT) polymorphism and sequence-related amplified polymorphism (SRAP). Despite the visible morphological variants, the genetic stability of all the regenerants with the individuals from natural stands was confirmed. All of them were monomorphic except three bands that were obtained for reference, where individuals were amplified with SCoT28 and me12-em13 SRAP primers. Conclusions: As shown in the presented research, it might be recommended to use different methods to evaluate the stability of in vitro cultivated plants. Full article

γ-tocopherol is an important antioxidant compound associated with anticancer activity in several plants. This study aimed to analyze the γ-TMT (γ-tocopherol methyltransferase) gene sequence and predict its protein structure in mutant rodent tuber (Typhonium flagelliforme Lodd.) plants. Degenerate primers were designed from homologous sequences in monocot species and used to amplify the γ-TMT gene. Amplification of the γ-TMT gene was observedin the mutant and the wild-type plants. The amplified region partially covers the γ-TMT gene, which has undergone mutations due to a combination of somaclonal variation and gamma irradiation. Sequence analysis revealed notable variations between mutant and wild-type lines, including base substitutions and deletions. Predicted protein structures based on the coding DNA sequence (CDS) revealed notable differences in helix and loop orientation, particularly in the C-terminal domain and central regions of the protein. These structural differences suggest potential links to increased tocopherol biosynthesis or biological activity; however, further experimental validation is required to confirm these functional implications. This study provides foundational insights into the link between the expression of the γ-TMT gene and tocopherol biosynthesis and supports the development of specific molecular markers in T. flagelliforme. Full article

Plant tissue culture has been recognized as an essential technology in plant science research. This process is widely used to regenerate and conserve phenotypically and genetically identical plant resources. The advancements in tissue culture methods have become a feasible option for the micropropagation of plants at the commercial level. The success of commercial micropropagation necessitates genetic stability among regenerated plants. Sometimes, in vitro-grown plants show genetic and epigenetic alterations due to stressful artificial culture conditions, media compositions, and explant types. As a result, it is essential to ensure genetic stability among tissue culture-derived plantlets at a very early stage. Somaclonal variations can be detected by phenotypic assessment, cytogenetic, DNA-based molecular markers, bisulfite sequencing, and RNA sequencing. This review aims to describe the causes behind somaclonal variation, the selection of somaclonal variants, and their uses in crop and plant improvement at the commercial level. This study discusses the optimization processes of undesirable genetic and epigenetic variation among micropropagated plants and their application in global horticulture, agriculture, and forestry. Full article

Micropropagation of blackberry (Rubus spp.) has emerged as a key technique for large-scale production of genetically uniform, disease-free plants. This review summarizes more than half a century of in vitro blackberry culture research, covering fundamental aspects such as establishment, proliferation, rooting, acclimation, genetic stability and conservation. Optimization of culture media, plant growth regulators and environmental conditions has significantly improved the efficiency of micropropagation. Recent advances, including bioreactors, cryopreservation and biostimulants, have further improved plant growth and stress tolerance. In addition, studies on bioactive compounds in micropropagated blackberries highlight their potential nutritional and pharmaceutical applications. Despite progress, challenges such as microbial contamination, somaclonal variation, and response variability among cultivars remain critical areas for future research. The integration of nanotechnology, alternative culture systems (i.e., bioreactors), synthetic seed technology should represent the future research trend of blackberry micropropagation, ensuring sustainable production and conservation of genetic resources. Full article

The use of in vitro cultures in plant breeding allows for obtaining cultivars with improved properties. In the case of Stevia rebaudiana Bert., genotypes with an appropriate rebaudioside A/stevioside ratio are desirable. The use of indirect organogenesis allows for the induction of somaclonal variation, which, consequently, results in obtaining variability within the regenerants. The Murashige and Skoog medium containing 4.0 mg × dm⁻³ 6-benzylaminopurine (BAP), 2.0 mg × dm⁻³ 1-naphthaleneacetic acid (NAA), and 2.0 mg × dm⁻³ 2,4-dichlorophenoxyacetic acid (2,4-D) resulted in obtaining plants that were biochemically and genetically diverse. The obtained regenerants were characterized by an increased content of rebaudioside A and a better rebaudioside A/stevioside ratio. Genetic analysis using SCoT (start-codon-targeted) markers showed their diversity at the molecular level. Moreover, this study showed that genotype multiplication through six subsequent re-cultures does not cause variability at the genotype level and does not affect the steviol glycoside profile. This study is the first report on obtaining genotypes with higher rebaudioside A content and a more attractive rebaudioside A to stevioside ratio through the use of in vitro cultures. The improved regenerants can be used as parents in hybridization programs or directly as valuable new genotypes. Full article

Somatic embryogenesis (SE) provides alternative methodologies for the propagation of grapevine (Vitis spp.) cultivars, conservation of their germplasm resources, and crop improvement. In this review, the current state of knowledge regarding grapevine SE as applied to these technologies is presented, with a focus on the benefits, challenges, and limitations of this method. The paper provides a comprehensive overview of the different steps involved in the grapevine SE process, including callus induction, maintenance of embryogenic cultures, and the production of plantlets. Additionally, the review explores the development of high-health plant material through SE; the molecular and biochemical mechanisms underlying SE, including the regulation of gene expression, hormone signaling pathways, and metabolic pathways; as well as its use in crop improvement programs. The review concludes by highlighting the future directions for grapevine SE research, including the development of new and improved protocols, the integration of SE with other plant tissue culture techniques, and the application of SE for the production of elite grapevine cultivars, for the conservation of endangered grapevine species as well as for cultivars with unique traits that are valuable for breeding programs. Full article

Soybean’s lengthy protocols for transgenic plant production are a bottleneck in the transgenic breeding of this crop. Explants cultured on a medium for an extended duration exhibit unanticipated modifications. Stress-induced somaclonal variations and in vitro contaminations also cause substantial losses of transgenic plants. This effect could potentially be mitigated by direct shoot regeneration without solid media or in-planta transformation. The current study focused primarily on developing a rapid and effective media-free in-planta transformation technique for three soybean genotypes (Wm82) and our newly developed two hybrids, designated as ZX-16 and ZX-3. The whole procedure for a transgenic plant takes the same time as a stable grown seedling. Multiple axillary shoots were regenerated on stable-grown soybean seedlings without the ectopic expression of developmental regulatory genes. An approximate amount of 200 µL medium with a growth regulator was employed for shoot organogenesis and growth. The maximal shoot regeneration percentages in the Wm82 and ZX-3 genotypes were 87.1% and 84.5%, respectively. The stable transformation ranged from 3% to 8.0%, with an average of 5.5%. This approach seems to be the opposite of the hairy root transformation method, which allowed transgenic shoots to be regenerated on normal roots. Further improvement regarding an increase in the transformation efficiency and of this technique for a broad range of soybean genotypes and other dicot species would be extremely beneficial in achieving increased stable transformation. Full article

The fresh fruits of ‘Grande Naine’ (Cavendish AAA—Musa spp.) dominate the world market, especially in countries with a population in a situation of social vulnerability. However, Fusarium wilt, caused by the fungus Fusarium oxysporum f.sp. cubense race 4 Subtropical (Foc ST4), emerges as a serious threat to banana production, requiring the development of resistant cultivars based on biotechnological strategies, such as the induction of mutation in tissue culture. This study aimed to identify and characterize genetic variation in somaclones resistant to Fusarium oxysporum f.sp. cubense subtropical race 4 (Foc ST4), derived from ‘Grand Naine’ bananas, by molecular markers based on retrotransposons IRAP (Inter-retrotransposon Amplified Polymorphism) and REMAP (Retrotransposon-Microsatellite Amplified Polymorphism). Nine combinations of IRAP and six combinations of REMAP primers were used. The low number of polymorphic bands did not allow for genetic diversity studies; however, ten polymorphic bands between the somaclones and control were sequenced. Of these, three presented good base calling and were aligned, namely, 1AF, 2AF, and 3AF bands. Only the 1AF band presented function related to stress response with homology to a calcium-binding protein. These proteins act early in plant infection as secondary messengers activated by pathogen-associated molecular patterns (PAMPs), initiating the cascade of plant defense signals. The fact that this band is present in all somaclones reinforces previous assessments of their resistance to Foc ST4. The use of markers IRAP and REMAP produced polymorphic bands that can, through future primer design and field validations, accelerate the identification of resistant banana genotypes for use in banana genetic breeding programs. Full article

Fusarium wilt, caused by the fungus Fusarium oxysporum f. sp. cubense (Foc), is one of the most devastating diseases affecting banana cultivation worldwide. Although Foc tropical race 4 (TR4) has not yet been identified in Brazilian production areas, the damage caused by races 1 and subtropical 4 is the main cause of production losses, especially affecting cultivars of the Prata subgroup. Thus, the induction of somaclonal variation is a promising strategy in biotechnology to generate genetic variability and develop resistant varieties. This study aimed to induce somaclonal variation in the Prata Catarina cultivar (AAB genome) using successive subcultures in Murashige and Skoog (MS) medium enriched with the plant regulator Thiadizuron (TDZ) at two concentrations: 1 and 2 mg/L. After evaluating the symptoms, we selected 13 resistant somaclones that were not infected by the fungus. Histochemical and histological analyses of the somaclones indicated possible defense mechanisms that prevented colonization and/or infection by Foc, such as intense production of phenolic compounds and the presence of cellulose and callose in the roots. Some somaclones showed no pathogen structures in the xylem-conducting vessels, indicating possible pre-penetration resistance. Furthermore, molecular studies indicated that the genetic alterations in the somaclones may have induced resistance to Foc without compromising the agronomic characteristics of the commercial genotype. Full article