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Ethylene resistance in flowering ornamental plants - improvements and future perspectives.

Olsen A, Lütken H, Hegelund JN, Müller R - Hortic Res (2015)

Bottom Line: This is primarily due to legislative issues, economic issues, difficulties of implementing this technology in some ornamental plants, as well as how these techniques are publically perceived, particularly in Europe.Recently, newer and more precise genome-editing techniques have become available and they are already being implemented in some crops.New breeding techniques may help change the current situation and pave the way toward a legal and public acceptance if products of these technologies are indistinguishable from plants obtained by conventional techniques.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Science, Department of Plant and Environmental Sciences, University of Copenhagen , Højbakkegård Alle 9-13, 2630 Taastrup, Denmark.

ABSTRACT
Various strategies of plant breeding have been attempted in order to improve the ethylene resistance of flowering ornamental plants. These approaches span from conventional techniques such as simple cross-pollination to new breeding techniques which modify the plants genetically such as precise genome-editing. The main strategies target the ethylene pathway directly; others focus on changing the ethylene pathway indirectly via pathways that are known to be antagonistic to the ethylene pathway, e.g. increasing cytokinin levels. Many of the known elements of the ethylene pathway have been addressed experimentally with the aim of modulating the overall response of the plant to ethylene. Elements of the ethylene pathway that appear particularly promising in this respect include ethylene receptors as ETR1, and transcription factors such as EIN3. Both direct and indirect approaches seem to be successful, nevertheless, although genetic transformation using recombinant DNA has the ability to save much time in the breeding process, they are not readily used by breeders yet. This is primarily due to legislative issues, economic issues, difficulties of implementing this technology in some ornamental plants, as well as how these techniques are publically perceived, particularly in Europe. Recently, newer and more precise genome-editing techniques have become available and they are already being implemented in some crops. New breeding techniques may help change the current situation and pave the way toward a legal and public acceptance if products of these technologies are indistinguishable from plants obtained by conventional techniques.

No MeSH data available.


Related in: MedlinePlus

Simplified ethylene pathway. (a) Basal production of ethylene in the flowers during development before senescence. (b) The ethylene pathway upon triggering. The stimulus is translated to elevated ethylene synthesis producing higher levels of ethylene which inactivates the receptors initiating the signaling cascade which changes gene expression and finally induces physiological processes in the flower which may include the initiation of an autocatalytic loop.14 (c) Simplified molecular events of the ethylene pathway. Methionine is enzymatically converted to S-adenosyl-l-methionine (SAM) by SAM synthase (SAS). SAM is partially converted back to methionine via several steps, but it also produces 1-aminocyclopropane-1-carboxylic acid (ACC) by ACC synthase (ACS). ACC is transformed to ethylene by ACC oxidase (ACO). Ethylene binds to receptors and stops their signal to CONSTITUTIVE TRIPLE RESPONSE1 (CTR1), which then stops its suppressing signal to ETHYLENE INSENSITIVE2 (EIN2). The released EIN2 is then cleaved and part of it is transported into the nucleus where activation of the ETHYLENE INSENSITIVE3/ETHYLENE INSENSITIVE3-LIKE (EIN3/EIL) transcription factor family occurs. This initiates a transcription cascade by activation of ETHYLENE RESPONSE FACTORs (ERFs) which eventually leads to differential gene expression and a physiological response.15
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fig1: Simplified ethylene pathway. (a) Basal production of ethylene in the flowers during development before senescence. (b) The ethylene pathway upon triggering. The stimulus is translated to elevated ethylene synthesis producing higher levels of ethylene which inactivates the receptors initiating the signaling cascade which changes gene expression and finally induces physiological processes in the flower which may include the initiation of an autocatalytic loop.14 (c) Simplified molecular events of the ethylene pathway. Methionine is enzymatically converted to S-adenosyl-l-methionine (SAM) by SAM synthase (SAS). SAM is partially converted back to methionine via several steps, but it also produces 1-aminocyclopropane-1-carboxylic acid (ACC) by ACC synthase (ACS). ACC is transformed to ethylene by ACC oxidase (ACO). Ethylene binds to receptors and stops their signal to CONSTITUTIVE TRIPLE RESPONSE1 (CTR1), which then stops its suppressing signal to ETHYLENE INSENSITIVE2 (EIN2). The released EIN2 is then cleaved and part of it is transported into the nucleus where activation of the ETHYLENE INSENSITIVE3/ETHYLENE INSENSITIVE3-LIKE (EIN3/EIL) transcription factor family occurs. This initiates a transcription cascade by activation of ETHYLENE RESPONSE FACTORs (ERFs) which eventually leads to differential gene expression and a physiological response.15

Mentions: The ethylene biosynthesis and signaling pathway can be presented in a linear model (Figure 1). Ethylene is essential for many processes in the plant and thus, there is a constant, low ethylene production (Figure 1a).14 Under certain conditions, however, ethylene biosynthesis and sensitivity increase in specific tissues and this triggers the ethylene signaling pathway (Figure 1b).15 This initially starts as an increase in expression of some of the enzymes responsible for ethylene biosynthesis16–18 which leads to higher ethylene production19 that may amplify itself in an autocatalytic fashion in some cases.20


Ethylene resistance in flowering ornamental plants - improvements and future perspectives.

Olsen A, Lütken H, Hegelund JN, Müller R - Hortic Res (2015)

Simplified ethylene pathway. (a) Basal production of ethylene in the flowers during development before senescence. (b) The ethylene pathway upon triggering. The stimulus is translated to elevated ethylene synthesis producing higher levels of ethylene which inactivates the receptors initiating the signaling cascade which changes gene expression and finally induces physiological processes in the flower which may include the initiation of an autocatalytic loop.14 (c) Simplified molecular events of the ethylene pathway. Methionine is enzymatically converted to S-adenosyl-l-methionine (SAM) by SAM synthase (SAS). SAM is partially converted back to methionine via several steps, but it also produces 1-aminocyclopropane-1-carboxylic acid (ACC) by ACC synthase (ACS). ACC is transformed to ethylene by ACC oxidase (ACO). Ethylene binds to receptors and stops their signal to CONSTITUTIVE TRIPLE RESPONSE1 (CTR1), which then stops its suppressing signal to ETHYLENE INSENSITIVE2 (EIN2). The released EIN2 is then cleaved and part of it is transported into the nucleus where activation of the ETHYLENE INSENSITIVE3/ETHYLENE INSENSITIVE3-LIKE (EIN3/EIL) transcription factor family occurs. This initiates a transcription cascade by activation of ETHYLENE RESPONSE FACTORs (ERFs) which eventually leads to differential gene expression and a physiological response.15
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4591681&req=5

fig1: Simplified ethylene pathway. (a) Basal production of ethylene in the flowers during development before senescence. (b) The ethylene pathway upon triggering. The stimulus is translated to elevated ethylene synthesis producing higher levels of ethylene which inactivates the receptors initiating the signaling cascade which changes gene expression and finally induces physiological processes in the flower which may include the initiation of an autocatalytic loop.14 (c) Simplified molecular events of the ethylene pathway. Methionine is enzymatically converted to S-adenosyl-l-methionine (SAM) by SAM synthase (SAS). SAM is partially converted back to methionine via several steps, but it also produces 1-aminocyclopropane-1-carboxylic acid (ACC) by ACC synthase (ACS). ACC is transformed to ethylene by ACC oxidase (ACO). Ethylene binds to receptors and stops their signal to CONSTITUTIVE TRIPLE RESPONSE1 (CTR1), which then stops its suppressing signal to ETHYLENE INSENSITIVE2 (EIN2). The released EIN2 is then cleaved and part of it is transported into the nucleus where activation of the ETHYLENE INSENSITIVE3/ETHYLENE INSENSITIVE3-LIKE (EIN3/EIL) transcription factor family occurs. This initiates a transcription cascade by activation of ETHYLENE RESPONSE FACTORs (ERFs) which eventually leads to differential gene expression and a physiological response.15
Mentions: The ethylene biosynthesis and signaling pathway can be presented in a linear model (Figure 1). Ethylene is essential for many processes in the plant and thus, there is a constant, low ethylene production (Figure 1a).14 Under certain conditions, however, ethylene biosynthesis and sensitivity increase in specific tissues and this triggers the ethylene signaling pathway (Figure 1b).15 This initially starts as an increase in expression of some of the enzymes responsible for ethylene biosynthesis16–18 which leads to higher ethylene production19 that may amplify itself in an autocatalytic fashion in some cases.20

Bottom Line: This is primarily due to legislative issues, economic issues, difficulties of implementing this technology in some ornamental plants, as well as how these techniques are publically perceived, particularly in Europe.Recently, newer and more precise genome-editing techniques have become available and they are already being implemented in some crops.New breeding techniques may help change the current situation and pave the way toward a legal and public acceptance if products of these technologies are indistinguishable from plants obtained by conventional techniques.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Science, Department of Plant and Environmental Sciences, University of Copenhagen , Højbakkegård Alle 9-13, 2630 Taastrup, Denmark.

ABSTRACT
Various strategies of plant breeding have been attempted in order to improve the ethylene resistance of flowering ornamental plants. These approaches span from conventional techniques such as simple cross-pollination to new breeding techniques which modify the plants genetically such as precise genome-editing. The main strategies target the ethylene pathway directly; others focus on changing the ethylene pathway indirectly via pathways that are known to be antagonistic to the ethylene pathway, e.g. increasing cytokinin levels. Many of the known elements of the ethylene pathway have been addressed experimentally with the aim of modulating the overall response of the plant to ethylene. Elements of the ethylene pathway that appear particularly promising in this respect include ethylene receptors as ETR1, and transcription factors such as EIN3. Both direct and indirect approaches seem to be successful, nevertheless, although genetic transformation using recombinant DNA has the ability to save much time in the breeding process, they are not readily used by breeders yet. This is primarily due to legislative issues, economic issues, difficulties of implementing this technology in some ornamental plants, as well as how these techniques are publically perceived, particularly in Europe. Recently, newer and more precise genome-editing techniques have become available and they are already being implemented in some crops. New breeding techniques may help change the current situation and pave the way toward a legal and public acceptance if products of these technologies are indistinguishable from plants obtained by conventional techniques.

No MeSH data available.


Related in: MedlinePlus