Knowledge on the biosynthetic pathways of the monoterpene alkaloids is enormous, but little is kn... more Knowledge on the biosynthetic pathways of the monoterpene alkaloids is enormous, but little is known about their mechanism of transporting system from the plant cell. There is not concrete evidence confirming the role of ABC transporters in the secretion of monoterpene indole alkaloids (MIAs) in Catharanthus roseus. Therefore, in order to determine the role of different transporting systems involved in the MIAs translocation, we employed a pharmacological approach by using transport inhibitors such as, KCN, Na3VO4, quinidine and glibenclamide in hairy root cultures of C. roseus. It was found that the accumulation of ATP drastically decreased in the presence of KCN or 100 μM acetylsalicylic acid (ASA)/100 μM KCN. The treatment with the inhibitors KCN and glibenclamide in the presence of ASA significantly increased the ajmalicine secretion compared to the control. The secretion of serpentine was undetected during the first 24 h in all the samples. Treatment with the inhibitors quinidi...
Knowledge on the biosynthetic pathways of the monoterpene alkaloids is enormous, but little is kn... more Knowledge on the biosynthetic pathways of the monoterpene alkaloids is enormous, but little is known about their mechanism of transporting system from the plant cell. There is not concrete evidence confirming the role of ABC transporters in the secretion of monoterpene indole alkaloids (MIAs) in Catharanthus roseus. Therefore, in order to determine the role of different transporting systems involved in the MIAs translocation, we employed a pharmacological approach by using transport inhibitors such as, KCN, Na3VO4, quinidine and glibenclamide in hairy root cultures of C. roseus. It was found that the accumulation of ATP drastically decreased in the presence of KCN or 100 μM acetylsalicylic acid (ASA)/100 μM KCN. The treatment with the inhibitors KCN and glibenclamide in the presence of ASA significantly increased the ajmalicine secretion compared to the control. The secretion of serpentine was undetected during the first 24 h in all the samples. Treatment with the inhibitors quinidi...
Embryogenesis is the primary developmental program in plants. The mechanisms that underlie the re... more Embryogenesis is the primary developmental program in plants. The mechanisms that underlie the regulation of embryogenesis are an essential research subject given its potential contribution to mass in vitro propagation of profitable plant species. Somatic embryogenesis (SE) refers to the use of in vitro techniques to mimic the sexual reproduction program known as zygotic embryogenesis (ZE). In this review, we synthesize the current state of research on proteomic and metabolomic studies of SE and ZE in angiosperms (monocots and dicots) and gymnosperms. The most striking finding was the small number of studies addressing ZE. Meanwhile, the research effort focused on SE has been substantial but disjointed. Together, these research gaps may explain why the embryogenic induction stage and the maturation of the somatic embryo continue to be bottlenecks for efficient and large-scale regeneration of plants. Comprehensive and integrative studies of both SE and ZE are needed to provide the mo...
Auxin plays a central role in growth and plant development. To maintain auxin homeostasis, biolog... more Auxin plays a central role in growth and plant development. To maintain auxin homeostasis, biological processes such as biosynthesis, transport, degradation, and reversible conjugation are essential. The Gretchen Hagen 3 (GH3) family genes codify for the enzymes that esterify indole-3-acetic acid (IAA) to various amino acids, which is a key process in the induction of somatic embryogenesis (SE). The GH3 family is one of the principal families of early response to auxin genes, exhibiting IAA-amido synthetase activity to maintain optimal levels of free auxin in the cell. In this study, we carried out a systematic identification of the GH3 gene family in the genome of Coffea canephora, determining a total of 18 CcGH3 genes. Analysis of the genetic structures and phylogenetic relationships of CcGH3 genes with GH3 genes from other plant species revealed that they could be clustered in two major categories with groups 1 and 2 of the GH3 family of Arabidopsis. We analyzed the transcriptome...
ABSTRACT From bizarre palindromic repeats to a bacterial defense mechanism, to genome editing too... more ABSTRACT From bizarre palindromic repeats to a bacterial defense mechanism, to genome editing tool, and more, Clustered Regularly Interspaced Short Palindromic Repeats or CRISPR has significantly impacted the way we study genome modification in less than a decade. In this review, we would like to highlight some key players over 30 years of research and explain this biotechnological tool’s basic mechanisms. We also refer to the evolution of the CRISPR variants and some of the applications derived from them. The understanding and upgrading of this system will be a valuable tool in the years to come to solve some of the challenges in diverse fields from pharmaceuticals to therapeutics, from basic plant genetics to crop improvement, from metabolic engineering to waste management and industrial processing.
Auxins are plant growth regulators that participate in a variety of biological mechanisms during ... more Auxins are plant growth regulators that participate in a variety of biological mechanisms during the growth and development of plants. The most abundant natural auxin is indole-3-acetic acid (IAA). The physiological processes regulated by IAA depend on their temporal space accumulation in different tissues of a plant. This accumulation is regulated by its biosynthesis, conjugation, degradation, and transport. Therefore tools that allow us a qualitative and quantitative detection of IAA in plant tissues are very useful to understand the homeostasis of IAA during the life cycle of plants. In this protocol, the complete procedure for localization of IAA in different tissues of Coffea canephora is described using specific anti-IAA monoclonal antibodies.
Despite the existence of considerable research on somatic embryogenesis (SE), the molecular mecha... more Despite the existence of considerable research on somatic embryogenesis (SE), the molecular mechanism that regulates the biosynthesis of auxins during the SE induction process remains unknown. Indole-3-acetic acid (IAA) is an auxin that is synthesized in plants through five pathways. The biosynthetic pathway most frequently used in this synthesis is the conversion of tryptophan to indol-3-pyruvic acid (IPA) by tryptophan aminotransferase of Arabidopsis (TAA) followed by the conversion of IPA to IAA by enzymes encoded by YUCCA (YUC) genes of the flavin monooxygenase family; however, it is unclear whether YUC-mediated IAA biosynthesis is involved in SE induction. In this study, we report that the increase of IAA observed during SE pre-treatment (plants in MS medium supplemented with 1-naphthaleneacetic acid (NAA) 0.54 µM and kinetin (Kin) 2.32 µM for 14 days) was due to its de novo biosynthesis. By qRT-PCR, we demonstrated that YUC gene expression was consistent with the free IAA sign...
Somatic embryogenesis (SE) is a valuable model for understanding the mechanism of plant embryogen... more Somatic embryogenesis (SE) is a valuable model for understanding the mechanism of plant embryogenesis and a tool for the mass production of plants. However, establishing SE in avocado has been complicated due to the very low efficiency of embryo induction and plant regeneration. To understand the molecular foundation of the SE induction and development in avocado, we compared embryogenic (EC) and non-embryogenic (NEC) cultures of two avocado varieties using proteomic and metabolomic approaches. Although Criollo and Hass EC exhibited similarities in the proteome and metabolome profile, in general, we observed a more active phenylpropanoid pathway in EC than NEC. This pathway is associated with the tolerance of stress responses, probably through the reinforcement of the cell wall and flavonoid production. We could corroborate that particular polyphenolics compounds, including p-coumaric acid and t-ferulic acid, stimulated the production of somatic embryos in avocado. Exogen phenolic c...
Background Somatic embryogenesis (SE) is a useful biotechnological tool to study the morpho-physi... more Background Somatic embryogenesis (SE) is a useful biotechnological tool to study the morpho-physiological, biochemical and molecular processes during the development of Coffea canephora. Plant growth regulators (PGR) play a key role during cell differentiation in SE. The Auxin-response-factor (ARF) and Auxin/Indole-3-acetic acid (Aux/IAA) are fundamental components involved in the signaling of the IAA. The IAA signaling pathway activates or represses the expression of genes responsive to auxins during the embryogenic transition of the somatic cells. The growing development of new generation sequencing technologies (NGS), as well as bioinformatics tools, has allowed us to broaden the landscape of SE study of various plant species and identify the genes directly involved. Methods Analysis of transcriptome expression profiles of the C. canephora genome and the identification of a particular set of differentially expressed genes (DEG) during SE are described in this study. Results A tot...
Auxin and polar auxin transport have been implicated in controlling zygotic embryo development, b... more Auxin and polar auxin transport have been implicated in controlling zygotic embryo development, but less is known about their role in the development of somatic embryos. The aim of this study was to determine if indole-3-acetic acid (IAA) and the PIN1 transporter participate in the induction of somatic embryogenesis (SE) and the development of somatic embryos. The results show that IAA levels gradually increase during pre-treatment and accumulate in the chloroplast. During pre-treatment and the globular stage of SE in C. canephora, auxin is distributed uniformly in all of the cells of the somatic embryo. During the subsequent stages of development, auxins are mobilized to the cells that will form the cotyledons and the root meristem. The location of the PIN transporters shifts from the plasmalemma of the protoderm cells during the globular stage to the plasmalemma of the cells that will give rise to the cotyledons and the vascular tissue in the late stages of somatic embryogenesis. ...
Methods in molecular biology (Clifton, N.J.), 2018
Plant tissue culture techniques are the most frequently used biotechnological tools for basic and... more Plant tissue culture techniques are the most frequently used biotechnological tools for basic and applied purposes ranging from investigation on plant developmental processes, functional gene studies, commercial plant micropropagation, generation of transgenic plants with specific industrial and agronomical traits, plant breeding and crop improvement, virus elimination from infected materials to render high-quality healthy plant material, preservation and conservation of germplasm of vegetative propagated plant crops, and rescue of threatened or endangered plant species. Additionally, plant cell and organ cultures are of interest for the production of secondary metabolites of industrial and pharmaceutical interest. New technologies, such as the genome editing ones combined with tissue culture and Agrobacterium tumefaciens infection, are currently promising alternatives for the highly specific genetic manipulation of interesting agronomical or industrial traits in crop plants. Applic...
Abstract The formation of chloroplasts during the greening of callus from a C 4 {Zea mays) and C ... more Abstract The formation of chloroplasts during the greening of callus from a C 4 {Zea mays) and C 3 (Canavalia ensiformis) plant was the object of our study. Benzylaminopurine (BAP) accelerated the synthesis of chlorophyll, the growth of callus and the development of the photochemical activity of both types of tissue grown under continuous light. However, the characteristics of the synthesis of chlorophyll and photochemical activities are different in Z. mays and C. ensiformis calli during greening. Chlorophyll a/b ratios were 3.2 for Z. mays ...
Somatic Embryogenesis: Fundamental Aspects and Applications, 2016
Somatic embryogenesis is one of the most powerful tools in plant biotechnology. It can be used to... more Somatic embryogenesis is one of the most powerful tools in plant biotechnology. It can be used to produce plants commercially, or to carry out basic studies of cell differentiation, gene expression, molecular genetics, and many others. We present here a compilation of the different chapters of this book.
Somatic Embryogenesis: Fundamental Aspects and Applications, 2016
Somatic embryogenesis is used currently as a powerful tool in biotechnology. It is also used to s... more Somatic embryogenesis is used currently as a powerful tool in biotechnology. It is also used to study the development of the embryo. Somatic embryogenesis is a natural phenomenon that was moved from nature to the laboratory by man. The history of the study of somatic embryogenesis is plenty of discoveries of very different natures: from the role of growth regulators, mainly auxins, to the function of the components of the media of culture. In this chapter, a revision of the major contribution to the advance of knowledge of somatic embryogenesis is made.
Somatic Embryogenesis: Fundamental Aspects and Applications, 2016
It is well known that auxins (Ax) and cytokinins (Ck) are key regulators of plant cell division a... more It is well known that auxins (Ax) and cytokinins (Ck) are key regulators of plant cell division and differentiation. These growth regulators can induce plant cell reprogramming. The balance between Ax and Ck during their application in the plant tissue culture determines the state of cell di- or dedifferentiation. Other plant growth regulators can also induce callus. However, Ax is the most widely used plant growth regulator to control organ regeneration, callus induction or somatic embryogenesis induction. Ax plays a central role in early and post-embryogenic plant development. Elegant studies have shown that temporal and spatial Ax distribution mediates important steps during the early embryo patterning formation of zygotic embryogenesis (ZE). The application of exogenous Ax into the culture medium can unbalance the endogenous of this growth regulator and modify the IAA metabolism inside the cell. In most of the cultures, it has been demonstrated that the removal of the exogenous Ax from of culture medium promotes the formation of embryogenic structures. The increment in the endogenous Ax regulates the expression of a great number of transcription factors, several of them related to stress. The other aspect about the homeostasis of Ax, which has an effect on the induction of somatic embryogenesis, is its transport. In this chapter, a revision and analysis about the role of Ax in different aspects of somatic embryogenesis is made.
Somatic Embryogenesis: Fundamental Aspects and Applications, 2016
Coffee is a very important commodity in the world. It is a perennial plant and as a consequence i... more Coffee is a very important commodity in the world. It is a perennial plant and as a consequence its genetic improvement had been difficult. The biotechnology, in particular somatic embryogenesis (SE) has helped to the propagation of commercial coffee cultivars. Along almost 50 years, different research groups around the world have developed uncountable SE processes to produce an efficient, reproducible, and reliable SE process. Many of the factors that affect the embryogenic response have been studied. It has been demonstrated that the genetic modification of coffee is possible. This transformation can lead to the improvement of varieties with very attractive agronomic traits, such as low caffeine content, resistant to diseases and pests.
Knowledge on the biosynthetic pathways of the monoterpene alkaloids is enormous, but little is kn... more Knowledge on the biosynthetic pathways of the monoterpene alkaloids is enormous, but little is known about their mechanism of transporting system from the plant cell. There is not concrete evidence confirming the role of ABC transporters in the secretion of monoterpene indole alkaloids (MIAs) in Catharanthus roseus. Therefore, in order to determine the role of different transporting systems involved in the MIAs translocation, we employed a pharmacological approach by using transport inhibitors such as, KCN, Na3VO4, quinidine and glibenclamide in hairy root cultures of C. roseus. It was found that the accumulation of ATP drastically decreased in the presence of KCN or 100 μM acetylsalicylic acid (ASA)/100 μM KCN. The treatment with the inhibitors KCN and glibenclamide in the presence of ASA significantly increased the ajmalicine secretion compared to the control. The secretion of serpentine was undetected during the first 24 h in all the samples. Treatment with the inhibitors quinidi...
Knowledge on the biosynthetic pathways of the monoterpene alkaloids is enormous, but little is kn... more Knowledge on the biosynthetic pathways of the monoterpene alkaloids is enormous, but little is known about their mechanism of transporting system from the plant cell. There is not concrete evidence confirming the role of ABC transporters in the secretion of monoterpene indole alkaloids (MIAs) in Catharanthus roseus. Therefore, in order to determine the role of different transporting systems involved in the MIAs translocation, we employed a pharmacological approach by using transport inhibitors such as, KCN, Na3VO4, quinidine and glibenclamide in hairy root cultures of C. roseus. It was found that the accumulation of ATP drastically decreased in the presence of KCN or 100 μM acetylsalicylic acid (ASA)/100 μM KCN. The treatment with the inhibitors KCN and glibenclamide in the presence of ASA significantly increased the ajmalicine secretion compared to the control. The secretion of serpentine was undetected during the first 24 h in all the samples. Treatment with the inhibitors quinidi...
Embryogenesis is the primary developmental program in plants. The mechanisms that underlie the re... more Embryogenesis is the primary developmental program in plants. The mechanisms that underlie the regulation of embryogenesis are an essential research subject given its potential contribution to mass in vitro propagation of profitable plant species. Somatic embryogenesis (SE) refers to the use of in vitro techniques to mimic the sexual reproduction program known as zygotic embryogenesis (ZE). In this review, we synthesize the current state of research on proteomic and metabolomic studies of SE and ZE in angiosperms (monocots and dicots) and gymnosperms. The most striking finding was the small number of studies addressing ZE. Meanwhile, the research effort focused on SE has been substantial but disjointed. Together, these research gaps may explain why the embryogenic induction stage and the maturation of the somatic embryo continue to be bottlenecks for efficient and large-scale regeneration of plants. Comprehensive and integrative studies of both SE and ZE are needed to provide the mo...
Auxin plays a central role in growth and plant development. To maintain auxin homeostasis, biolog... more Auxin plays a central role in growth and plant development. To maintain auxin homeostasis, biological processes such as biosynthesis, transport, degradation, and reversible conjugation are essential. The Gretchen Hagen 3 (GH3) family genes codify for the enzymes that esterify indole-3-acetic acid (IAA) to various amino acids, which is a key process in the induction of somatic embryogenesis (SE). The GH3 family is one of the principal families of early response to auxin genes, exhibiting IAA-amido synthetase activity to maintain optimal levels of free auxin in the cell. In this study, we carried out a systematic identification of the GH3 gene family in the genome of Coffea canephora, determining a total of 18 CcGH3 genes. Analysis of the genetic structures and phylogenetic relationships of CcGH3 genes with GH3 genes from other plant species revealed that they could be clustered in two major categories with groups 1 and 2 of the GH3 family of Arabidopsis. We analyzed the transcriptome...
ABSTRACT From bizarre palindromic repeats to a bacterial defense mechanism, to genome editing too... more ABSTRACT From bizarre palindromic repeats to a bacterial defense mechanism, to genome editing tool, and more, Clustered Regularly Interspaced Short Palindromic Repeats or CRISPR has significantly impacted the way we study genome modification in less than a decade. In this review, we would like to highlight some key players over 30 years of research and explain this biotechnological tool’s basic mechanisms. We also refer to the evolution of the CRISPR variants and some of the applications derived from them. The understanding and upgrading of this system will be a valuable tool in the years to come to solve some of the challenges in diverse fields from pharmaceuticals to therapeutics, from basic plant genetics to crop improvement, from metabolic engineering to waste management and industrial processing.
Auxins are plant growth regulators that participate in a variety of biological mechanisms during ... more Auxins are plant growth regulators that participate in a variety of biological mechanisms during the growth and development of plants. The most abundant natural auxin is indole-3-acetic acid (IAA). The physiological processes regulated by IAA depend on their temporal space accumulation in different tissues of a plant. This accumulation is regulated by its biosynthesis, conjugation, degradation, and transport. Therefore tools that allow us a qualitative and quantitative detection of IAA in plant tissues are very useful to understand the homeostasis of IAA during the life cycle of plants. In this protocol, the complete procedure for localization of IAA in different tissues of Coffea canephora is described using specific anti-IAA monoclonal antibodies.
Despite the existence of considerable research on somatic embryogenesis (SE), the molecular mecha... more Despite the existence of considerable research on somatic embryogenesis (SE), the molecular mechanism that regulates the biosynthesis of auxins during the SE induction process remains unknown. Indole-3-acetic acid (IAA) is an auxin that is synthesized in plants through five pathways. The biosynthetic pathway most frequently used in this synthesis is the conversion of tryptophan to indol-3-pyruvic acid (IPA) by tryptophan aminotransferase of Arabidopsis (TAA) followed by the conversion of IPA to IAA by enzymes encoded by YUCCA (YUC) genes of the flavin monooxygenase family; however, it is unclear whether YUC-mediated IAA biosynthesis is involved in SE induction. In this study, we report that the increase of IAA observed during SE pre-treatment (plants in MS medium supplemented with 1-naphthaleneacetic acid (NAA) 0.54 µM and kinetin (Kin) 2.32 µM for 14 days) was due to its de novo biosynthesis. By qRT-PCR, we demonstrated that YUC gene expression was consistent with the free IAA sign...
Somatic embryogenesis (SE) is a valuable model for understanding the mechanism of plant embryogen... more Somatic embryogenesis (SE) is a valuable model for understanding the mechanism of plant embryogenesis and a tool for the mass production of plants. However, establishing SE in avocado has been complicated due to the very low efficiency of embryo induction and plant regeneration. To understand the molecular foundation of the SE induction and development in avocado, we compared embryogenic (EC) and non-embryogenic (NEC) cultures of two avocado varieties using proteomic and metabolomic approaches. Although Criollo and Hass EC exhibited similarities in the proteome and metabolome profile, in general, we observed a more active phenylpropanoid pathway in EC than NEC. This pathway is associated with the tolerance of stress responses, probably through the reinforcement of the cell wall and flavonoid production. We could corroborate that particular polyphenolics compounds, including p-coumaric acid and t-ferulic acid, stimulated the production of somatic embryos in avocado. Exogen phenolic c...
Background Somatic embryogenesis (SE) is a useful biotechnological tool to study the morpho-physi... more Background Somatic embryogenesis (SE) is a useful biotechnological tool to study the morpho-physiological, biochemical and molecular processes during the development of Coffea canephora. Plant growth regulators (PGR) play a key role during cell differentiation in SE. The Auxin-response-factor (ARF) and Auxin/Indole-3-acetic acid (Aux/IAA) are fundamental components involved in the signaling of the IAA. The IAA signaling pathway activates or represses the expression of genes responsive to auxins during the embryogenic transition of the somatic cells. The growing development of new generation sequencing technologies (NGS), as well as bioinformatics tools, has allowed us to broaden the landscape of SE study of various plant species and identify the genes directly involved. Methods Analysis of transcriptome expression profiles of the C. canephora genome and the identification of a particular set of differentially expressed genes (DEG) during SE are described in this study. Results A tot...
Auxin and polar auxin transport have been implicated in controlling zygotic embryo development, b... more Auxin and polar auxin transport have been implicated in controlling zygotic embryo development, but less is known about their role in the development of somatic embryos. The aim of this study was to determine if indole-3-acetic acid (IAA) and the PIN1 transporter participate in the induction of somatic embryogenesis (SE) and the development of somatic embryos. The results show that IAA levels gradually increase during pre-treatment and accumulate in the chloroplast. During pre-treatment and the globular stage of SE in C. canephora, auxin is distributed uniformly in all of the cells of the somatic embryo. During the subsequent stages of development, auxins are mobilized to the cells that will form the cotyledons and the root meristem. The location of the PIN transporters shifts from the plasmalemma of the protoderm cells during the globular stage to the plasmalemma of the cells that will give rise to the cotyledons and the vascular tissue in the late stages of somatic embryogenesis. ...
Methods in molecular biology (Clifton, N.J.), 2018
Plant tissue culture techniques are the most frequently used biotechnological tools for basic and... more Plant tissue culture techniques are the most frequently used biotechnological tools for basic and applied purposes ranging from investigation on plant developmental processes, functional gene studies, commercial plant micropropagation, generation of transgenic plants with specific industrial and agronomical traits, plant breeding and crop improvement, virus elimination from infected materials to render high-quality healthy plant material, preservation and conservation of germplasm of vegetative propagated plant crops, and rescue of threatened or endangered plant species. Additionally, plant cell and organ cultures are of interest for the production of secondary metabolites of industrial and pharmaceutical interest. New technologies, such as the genome editing ones combined with tissue culture and Agrobacterium tumefaciens infection, are currently promising alternatives for the highly specific genetic manipulation of interesting agronomical or industrial traits in crop plants. Applic...
Abstract The formation of chloroplasts during the greening of callus from a C 4 {Zea mays) and C ... more Abstract The formation of chloroplasts during the greening of callus from a C 4 {Zea mays) and C 3 (Canavalia ensiformis) plant was the object of our study. Benzylaminopurine (BAP) accelerated the synthesis of chlorophyll, the growth of callus and the development of the photochemical activity of both types of tissue grown under continuous light. However, the characteristics of the synthesis of chlorophyll and photochemical activities are different in Z. mays and C. ensiformis calli during greening. Chlorophyll a/b ratios were 3.2 for Z. mays ...
Somatic Embryogenesis: Fundamental Aspects and Applications, 2016
Somatic embryogenesis is one of the most powerful tools in plant biotechnology. It can be used to... more Somatic embryogenesis is one of the most powerful tools in plant biotechnology. It can be used to produce plants commercially, or to carry out basic studies of cell differentiation, gene expression, molecular genetics, and many others. We present here a compilation of the different chapters of this book.
Somatic Embryogenesis: Fundamental Aspects and Applications, 2016
Somatic embryogenesis is used currently as a powerful tool in biotechnology. It is also used to s... more Somatic embryogenesis is used currently as a powerful tool in biotechnology. It is also used to study the development of the embryo. Somatic embryogenesis is a natural phenomenon that was moved from nature to the laboratory by man. The history of the study of somatic embryogenesis is plenty of discoveries of very different natures: from the role of growth regulators, mainly auxins, to the function of the components of the media of culture. In this chapter, a revision of the major contribution to the advance of knowledge of somatic embryogenesis is made.
Somatic Embryogenesis: Fundamental Aspects and Applications, 2016
It is well known that auxins (Ax) and cytokinins (Ck) are key regulators of plant cell division a... more It is well known that auxins (Ax) and cytokinins (Ck) are key regulators of plant cell division and differentiation. These growth regulators can induce plant cell reprogramming. The balance between Ax and Ck during their application in the plant tissue culture determines the state of cell di- or dedifferentiation. Other plant growth regulators can also induce callus. However, Ax is the most widely used plant growth regulator to control organ regeneration, callus induction or somatic embryogenesis induction. Ax plays a central role in early and post-embryogenic plant development. Elegant studies have shown that temporal and spatial Ax distribution mediates important steps during the early embryo patterning formation of zygotic embryogenesis (ZE). The application of exogenous Ax into the culture medium can unbalance the endogenous of this growth regulator and modify the IAA metabolism inside the cell. In most of the cultures, it has been demonstrated that the removal of the exogenous Ax from of culture medium promotes the formation of embryogenic structures. The increment in the endogenous Ax regulates the expression of a great number of transcription factors, several of them related to stress. The other aspect about the homeostasis of Ax, which has an effect on the induction of somatic embryogenesis, is its transport. In this chapter, a revision and analysis about the role of Ax in different aspects of somatic embryogenesis is made.
Somatic Embryogenesis: Fundamental Aspects and Applications, 2016
Coffee is a very important commodity in the world. It is a perennial plant and as a consequence i... more Coffee is a very important commodity in the world. It is a perennial plant and as a consequence its genetic improvement had been difficult. The biotechnology, in particular somatic embryogenesis (SE) has helped to the propagation of commercial coffee cultivars. Along almost 50 years, different research groups around the world have developed uncountable SE processes to produce an efficient, reproducible, and reliable SE process. Many of the factors that affect the embryogenic response have been studied. It has been demonstrated that the genetic modification of coffee is possible. This transformation can lead to the improvement of varieties with very attractive agronomic traits, such as low caffeine content, resistant to diseases and pests.
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