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Main enzymes (enzymatic and non-enzymatic systems) involved in metabolic pathways of Reactive Oxygen Species in plants. SOD superoxide dismutase, CAT catalase, APX ascorbate peroxidase, ASC ascorbate, GSH glutathione, H 2 O 2 hydrogen peroxide
Source publication
Plant somatic embryogenesis (PSE) provides several advantages when compared to other in vitro propagation methods of tissue culture. All factors affecting PSE are not known. Some prominent stress factors in tissue culture are serious injuries in explants, subcultures, unbalanced mineral composition of the culture medium and growth regulators, etc....
Similar publications
A simple and effective protocol was established for recurrent somatic embryogenesis and plant regeneration in Akebia trifoliata (Thunb.) Koidz. Somatic embryos directly formed from the root zone of the immature zygotic embryos cultured on MS medium devoid of plant growth regulator (PGR). The induction frequency of immature zygotic embryos was 52.5%...
Citations
... Finally, in addition to stress stimuli, reactive oxygen species (ROS) are thought to be ubiquitous in normal cells and act as cellular messengers that can induce gene expression leading to SE in plants [52,86]. In particular, hydrogen peroxide (H 2 O 2 ) has been implicated in SE in recent years [87]. In the MAPK signaling pathway, H 2 O 2 is perceived as an intracellular messenger and triggers a signal cascade. ...
Background
Rubber plant ( Hevea brasiliensis ) is one of the major sources of latex. Somatic embryogenesis (SE) is a promising alterative to its propagation by grafting and seed. Phytohormones have been shown to influence SE in different plant species. However, limited knowledge is available on the role of phytohormones in SE in Hevea. The anther cultures of two Hevea genotypes (Yunyan 73477-YT and Reken 628-RT) with contrasting SE rate were established and four stages i.e., anthers (h), anther induced callus (y), callus differentiation state (f), and somatic embryos (p) were studied. UPLC-ESI-MS/MS and transcriptome analyses were used to study phytohormone accumulation and related expression changes in biosynthesis and signaling genes.
Results
YT showed higher callus induction rate than RT. Of the two genotypes, only YT exhibited successful SE. Auxins, cytokinins (CKs), abscisic acid (ABA), jasmonic acid (JA), salicylic acid (SA), gibberellins (GAs), and ethylene (ETH) were detected in the two genotypes. Indole-3-acetic acid (IAA), CKs, ABA, and ETH had notable differences in the studied stages of the two genotypes. The differentially expressed genes identified in treatment comparisons were majorly enriched in MAPK and phytohormone signaling, biosynthesis of secondary metabolites, and metabolic pathways. The expression changes in IAA, CK, ABA, and ETH biosynthesis and signaling genes confirmed the differential accumulation of respective phytohormones in the two genotypes.
Conclusion
These results suggest potential roles of phytohormones in SE in Hevea .
... Some stress factors in PTC, like subcultures, unbalanced macroand micronutrients composition of the culture medium and PGR, may induce oxidative stress characterized by the accumulation of Reactive Oxygen Species (ROS). However, at proper concentrations, ROS may serve as signaling molecules, stimulating genes and transcription factors, causing defense responses and inducing somatic embryogenesis in plants [64,65]. ...
Somatic embryogenesis (SE) serves as a key biological model for studying cell totipotency and the ontogenic processes of zygotic embryogenesis in plants. The SE process, under in vitro conditions, can be induced from different sources of explant cultivated in a culture medium with plant growth regulators (PGR) or by subjecting tissues to abiotic stress treatments. Somatic embryogenesis, in plant tissue culture (PTC), is a multifactorial event. The use of PGR, particularly auxins, is an important factor during induction. However, in vitro abiotic stress treatments are physiologically, biochemically, and genetically relevant and should be further studied.
... It has also been shown that oxidative stress-inducing compounds promote endogenous auxin accumulation during the early dedifferentiation stage of SE in many plant species. Hence, a particular stress gradient is established in the explants during the cell dedifferentiation stage, guided by antioxidant enzymes scavenging reactive oxygen species that arise throughout the process [49,50]. In such a context, the downregulation of SOD1a caused by the zma-miR528 might cause the localized accumulation of H 2 O 2 to promote specific expression programs and auxin accumulation that are crucial for embryogenic competence acquisition and maintenance during callus formation. ...
MicroRNAs (miRNAs) are small non-coding RNAs that regulate the accumulation and translation of their target mRNAs through sequence complementarity. miRNAs have emerged as crucial regulators during maize somatic embryogenesis (SE) and plant regeneration. A monocot-specific miRNA, mainly accumulated during maize SE, is zma-miR528. While several targets have been described for this miRNA, the regulation has not been experimentally confirmed for the SE process. Here, we explored the accumulation of zma-miR528 and several predicted targets during embryogenic callus induction, proliferation, and plantlet regeneration using the maize cultivar VS-535. We confirmed the cleavage site for all tested zma-miR528 targets; however, PLC1 showed very low levels of processing. The abundance of zma-miR528 slightly decreased in one month-induced callus compared to the immature embryo (IE) explant tissue. However, it displayed a significant increase in four-month sub-cultured callus, coincident with proliferation establishment. In callus-regenerated plantlets, zma-miR528 greatly decreased to levels below those observed in the initial explant. Three of the target transcripts (MATE, bHLH, and SOD1a) showed an inverse correlation with the miRNA abundance in total RNA samples at all stages. Using polysome fractionation, zma-miR528 was detected in the polysome fraction and exhibited an inverse distribution with the PLC1 target, which was not observed at total RNA. Accordingly, we conclude that zma-miR528 regulates multiple target mRNAs during the SE process by promoting their degradation, translation inhibition or both.
... Namely, accumulating evidence revealed that ROS (specifically H2O2) may function as signaling molecules that regulate plant growth and development, including cellular proliferation and differentiation [77,78]. As a cellular messenger, H2O2 in proper concentrations has the ability to induce gene expression and protein synthesis, hence triggering activation of embryogenic developmental program and formation of somatic embryos in different plant species [76]. On the other hand, excessive ROS could severely damage cellular proteins, DNA, and membrane lipids [78]. ...
... Three decades ago, Dudits et al. [72] suggested that the somatic embryo initiation in vitro was a stress response. Many reports since then underlined the importance of stress factors during SE induction in vitro [10,[73][74][75][76]. Cultured plant tissues experience a variety of stresses as a consequence of in vitro manipulations, including wounding, sterilization, mineral nutrient imbalance in the culture medium composition, PGRs, or subcultures. ...
... Namely, accumulating evidence revealed that ROS (specifically H 2 O 2 ) may function as signaling molecules that regulate plant growth and development, including cellular proliferation and differentiation [77,78]. As a cellular messenger, H 2 O 2 in proper concentrations has the ability to induce gene expression and protein synthesis, hence triggering activation of embryogenic developmental program and formation of somatic embryos in different plant species [76]. On the other hand, excessive ROS could severely damage cellular proteins, DNA, and membrane lipids [78]. ...
Centaurium erythraea (centaury) is a traditionally used medicinal plant, with a spectrum of secondary metabolites with confirmed healing properties. Centaury is an emerging model in plant developmental biology due to its vigorous regenerative potential and great developmental plasticity when cultured in vitro. Hereby, we review nearly two decades of research on somatic embryogenesis (SE) in centaury. During SE, somatic cells are induced by suitable culture conditions to express their totipotency, acquire embryogenic characteristics, and eventually give rise to somatic embryos. When SE is initiated from centaury root explants, the process occurs spontaneously (on hormone-free medium), directly (without the callusing phase), and the somatic embryos are of unicellular origin. SE from leaf explants has to be induced by plant growth regulators and is indirect (preceded by callusing). Histological observations and culture conditions are compared in these two systems. The changes in antioxidative enzymes were followed during SE from the leaf explants. Special focus is given to the role of arabinogalactan proteins during SE, which were analyzed using a variety of approaches. The newest and preliminary results, including centaury transcriptome, novel potential SE markers, and novel types of arabinogalactan proteins, are discussed as perspectives of centaury research.
... Antioxidant enzymes play an important role in the development of somatic and zygotic embryos, partially due to their ability to remove reactive oxygen species produced by external damage in plants. Moderate stress can cause somatic cells to change their morphology and differentiate [41], but excessive stress can lead to a complete loss of totipotence and eventually cell death [42,43]. In our study, high levels of POD and CAT activity were found in NEC and E-L, while low levels of CAT were found in EC and NEC. ...
... In many plants, antioxidant enzymes have been shown to play an important role in somatic and zygotic embryogenesis [41]. However, little information is currently available about the role of redox metabolism in somatic embryogenesis. ...
Abstract
Korean pine broadleaf mixed forest is an important ecosystem for maintaining biodiversity in Northeast China. Korean pine is also an important species for the production of timber and nuts in the mountainous areas of Northeast China. In this study, we compared three types of Korean pine callus and found that embryogenic callus had high amounts of storage substances (protein, sugar and starch). Non-embryonic callus had high levels of polyphenols and polyphenol oxidation, while callus that lost somatic embryogenesis potential had lower levels of storage substances (protein, sugar and starch) and higher contents of peroxidase and catalase. These results indicate that high contents of storage substances (protein, sugar and starch), and low levels of polyphenols and polyphenol oxidase can be used as physiological markers of callus with somatic embryogenic potential. During the development process of Korean pine somatic embryos, fresh weight and dry weight gradually increased, while water content gradually decreased. Soluble protein, starch, soluble sugar and superoxide dismutase also increased during development, while peroxidase and catalase levels reduced over time. These results indicate that somatic embryogenesis involves energy storage, and antioxidant enzymes cooperate to regulate the occurrence and development of embryos. These results provide physiological markers for identification of embryogenic callus with somatic embryogenesis, to evaluate callus suitable for somatic embryogenesis, and provide basis for further research on the molecular mechanisms of somatic embryogenesis.
Keywords: Pinus koraiensis Sieb. et Zucc.; somatic embryogenesis; non-embryogenic callus; embryogenic callus; resistance oxidase activity
... H2O2 is the most stable ROS molecule as it diffuses through the cell membranes and functions as a signalling molecule. It also plays an important role in the transduction of the defence signal in plants and can induce gene expression [60,61] and protein synthesis, leading to somatic embryogenesis in some plant species [62,63]. For example, H2O2 may induce the expression of genes encoding APX in germinating rice embryos [64] as well as the expression of genes encoding a catalase in the embryos and leaves of maize after wounding [65]. ...
The effects of auxins 2,4-D (2,4-dichlorophenoxyacetic acid), NAA (1-naphthaleneacetic acid) or picloram (4-amino-3,5,6-trichloropicolinic acid; 9 µM) and cytokinin BA (benzyloadenine; 4.5 µM) applied in the early stages of somatic embryogenesis (SE) on specific stages of SE in Picea abies and P. omorika were investigated. The highest SE initiation frequency was obtained after 2,4-D application in P. omorika (22.00%) and picloram application in P. abies (10.48%). NAA treatment significantly promoted embryogenic tissue (ET) proliferation in P. abies, while 2,4-D treatment reduced it. This reduction was related to the oxidative stress level, which was lower with the presence of NAA in the proliferation medium and higher with the presence of 2,4-D. The reduced oxidative stress level after NAA treatment suggests that hydrogen peroxide (H2O2) acts as a signalling molecule and promotes ET proliferation. NAA and picloram in the proliferation medium decreased the further production and maturation of P. omorika somatic embryos compared with that under 2,4-D. The quality of the germinated P. abies embryos and their development into plantlets depended on the auxin type and were the highest in NAA-originated embryos. These results show that different auxin types can generate different physiological responses in plant materials during SE in both spruce species.
Background
Rubber plant (Hevea brasiliensis) is one of the major sources of latex. Somatic embryogenesis (SE) is a promising alterative to its propagation by grafting and seed. Phytohormones have been shown to influence SE in different plant species. However, limited knowledge is available on the role of phytohormones in SE in Hevea. The anther cultures of two Hevea genotypes (Yunyan 73477-YT) and Reken 628-RT) with contrasting SE rate were established and four stages i.e., anthers (h), anther induced callus (y), callus differentiation state (f), and somatic embryos (p) were studied. UPLC-ESI-MS/MS and transcriptome analyses were used to study phytohormone accumulation and related expression changes in biosynthesis and signaling genes.
Results
YT showed higher callus induction rate than RT. Of the two genotypes, only YT exhibited successful SE. We detected auxins, cytokinins (CKs), abscisic acid (ABA), jasmonic acid (JA), salicylic acid (SA), gibberellins (GAs), and ethylene (ETH) in the two genotypes. Indole-3-acetic acid (IAA), CKs, ABA, and ETH had notable differences in the studied stages of the two genotypes. The DEGs identified in treatment comparisons were majorly enriched in MAPK and phytohormone signaling, biosynthesis of secondary metabolites, and metabolic pathways. The expression changes in IAA, CK, ABA, and ETH biosynthesis and singling genes confirmed the differential accumulation of respective phytohormones in the two genotypes.
Conclusion
These results suggest potential roles of phytohormones in SE in Hevea.
Melissa officinalis L., popularly known as lemon balm, is an aromatic plant widely used in medicine, cosmetics, and pharmaceutical industries for its essential oil rich in phenylpropanoids, terpenes, and phenolics. This study aimed to assess the effect of growth regulators on the development and physiological and biochemical metabolism of M. officinalis cultured in vitro. Seeds were inoculated in Murashige and Skoog medium and added with the regulators 6-benzylaminopurine (BAP) and 1-naphthaleneacetic acid (NAA) according to six different treatments. After 90 days of culture, plants were evaluated for growth and biochemical and physiological parameters (flavonoids, anthocyanins, and chlorophyll). The balance between regulators interfered with plant growth, which increased in the presence of 0.2 mg L⁻¹ BAP. In this treatment, the plants had greater growth with more leaves, and the biomass production of shoots and roots was higher than the control. Growth regulators did not influence nitrogen assimilation or flavonoid production; however, total chlorophyll and anthocyanin indexes were enhanced by treatment with BAP at concentrations ranging from 0.2 to 0.5 mg L⁻¹. Auxin treatment did not improve root production or growth but favored callus formation when combined with 0.5–3.0 mg L⁻¹ BAP. The results indicate that high BAP concentrations (above 1.0 mg L⁻¹) should not be used in in vitro production of lemon balm.
Keywords:
Anthocyanins; Chlorophyll; Lamiaceae; Micropropagation
Exogenous glutathione (GSH) promotes the proliferation of embryogenic callus (EC) cells in Korean pine in the course of somatic embryogenesis, and reactive oxygen species (ROS) may play an important role in regulating the proliferation of EC cells by exogenous GSH. However, the concrete metabolic response of ROS is unclear. In this study, two cell lines of Korean pine with high proliferative potential 001#-001 (F, Fast proliferative potential cell line is abbreviated as F) and low proliferative potential 001#-010 (S, Slow proliferative potential cell line is abbreviated as S) were used as test materials. The responses of ROS-related enzymes and substances to exogenous GSH and L-Buthionine-sulfoximine (BSO) were investigated in EC cells. The results showed that the exogenous addition of GSH increased the number of early somatic embryogenesis (SEs) in EC cells of both F and S cell lines, decreased the amount of cell death in both cell lines. Exogenous addition of GSH promoted cell division in both cell lines, increased intracellular superoxide dismutase (SOD) and catalase (CAT) activities, inhibited intracellular hydrogen peroxide (H2O2), malondialdehyde (MDA) and nitric oxide (NO) production, and increased NO/ROS ratio. In conclusion, the exogenous GSH promoting the proliferation of Korean pine EC cells, the activity of intracellular antioxidant enzymes was enhanced, the ROS level was reduced, and the resistance of cells to stress was enhanced.
