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The hybrid non-ethylene and ethylene ripening response in kiwifruit (Actinidia chinensis) is associated with differential regulation of MADS-box transcription factors.

McAtee PA, Richardson AC, Nieuwenhuizen NJ, Gunaseelan K, Hoong L, Chen X, Atkinson RG, Burdon JN, David KM, Schaffer RJ - BMC Plant Biol. (2015)

Bottom Line: The promoter of SEP4/RIN was shown to be transactivated by EIN3-like transcription factors, but unlike tomato, not by SEP4/RIN itself.Transient over-expression of SEP4/RIN in kiwifruit caused an increase in ethylene production.These results suggest that the non-ethylene/ethylene ripening response observed in kiwifruit is a hybrid of both the tomato and grape ripening progression, with Phase 1 being akin to the RIN/ethylene inhibitory response observed in grape and Phase 2 akin to the RIN-associated autocatalytic ethylene response observed in tomato.

View Article: PubMed Central - PubMed

Affiliation: The New Zealand Institute for Plant & Food Research Limited (PFR), Mt Albert Research Centre, Auckland, New Zealand. peter.mcatee@plantandfood.co.nz.

ABSTRACT

Background: Ripening in tomato is predominantly controlled by ethylene, whilst in fruit such as grape, it is predominantly controlled by other hormones. The ripening response of many kiwifruit (Actinidia) species is atypical. The majority of ripening-associated fruit starch hydrolysis, colour change and softening occurs in the apparent absence of ethylene production (Phase 1 ripening) whilst Phase 2 ripening requires autocatalytic ethylene production and is associated with further softening and an increase in aroma volatiles.

Results: To dissect the ripening response in the yellow-fleshed kiwifruit A. chinensis ('Hort16A'), a two dimensional developmental stage X ethylene response time study was undertaken. As fruit progressed through maturation and Phase 1 ripening, fruit were treated with different concentrations of propylene and ethylene. At the start of Phase 1 ripening, treated fruit responded to ethylene, and were capable of producing endogenous ethylene. As the fruit progressed through Phase 1 ripening, the fruit became less responsive to ethylene and endogeneous ethylene production was partially repressed. Towards the end of Phase 1 ripening the fruit were again able to produce high levels of ethylene. Progression through Phase 1 ripening coincided with a developmental increase in the expression of the ethylene-unresponsive MADS-box FRUITFUL-like gene (FUL1). The ability to respond to ethylene however coincided with a change in expression of another MADS-box gene SEPALLATA4/RIPENING INHIBITOR-like (SEP4/RIN). The promoter of SEP4/RIN was shown to be transactivated by EIN3-like transcription factors, but unlike tomato, not by SEP4/RIN itself. Transient over-expression of SEP4/RIN in kiwifruit caused an increase in ethylene production.

Conclusions: These results suggest that the non-ethylene/ethylene ripening response observed in kiwifruit is a hybrid of both the tomato and grape ripening progression, with Phase 1 being akin to the RIN/ethylene inhibitory response observed in grape and Phase 2 akin to the RIN-associated autocatalytic ethylene response observed in tomato.

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a The 2 kb region upstream of the transcriptional start of the SEP4/RIN gene showing potential EIN3 binding sites (including a putative PS1 binding site) and MADS box binding CaRG box consensus sequences. b Transient transactivation of a 3.2 kb RIN promoter fragment by RIN and EIN3-like transcription factors in tobacco (N. benthamiana) leaves with SEP4/RINgene (RIN) and three EIN3 like genes (EIL) compared to a 35S:GFP control (GFP). c Averages of Ethylene emission from three independent experiments of A. eriantha fruit transiently expressing a 35S:SEP4 (RIN) gene compared to untransformed Agrobacterium tumefaciens (Agro), water (control) and Agrobacterium containing a 35S:GFP gene (GFP)
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Fig8: a The 2 kb region upstream of the transcriptional start of the SEP4/RIN gene showing potential EIN3 binding sites (including a putative PS1 binding site) and MADS box binding CaRG box consensus sequences. b Transient transactivation of a 3.2 kb RIN promoter fragment by RIN and EIN3-like transcription factors in tobacco (N. benthamiana) leaves with SEP4/RINgene (RIN) and three EIN3 like genes (EIL) compared to a 35S:GFP control (GFP). c Averages of Ethylene emission from three independent experiments of A. eriantha fruit transiently expressing a 35S:SEP4 (RIN) gene compared to untransformed Agrobacterium tumefaciens (Agro), water (control) and Agrobacterium containing a 35S:GFP gene (GFP)

Mentions: A 3.2 kb region upstream of the transcriptional start, was firstly scanned for potential RIN-like CaRG sequences. In tomato the preference RIN binding site is CCA(A/T)(A/t)(A/T)ATAG, but RIN can also bind to a more general C(C/T)(A/T)6(A/G)G CaRG box [50]. In the kiwifruit genome sequence there were two CaRG sequences within the first 2 kb of the SEP4/RIN promoter. Also within this promoter is a potential EIN3 binding site (A(T/C)G(A/T)A(C/T)CT), as well as a PS1 sequence that EIN3 has been shown to bind to [51] (Fig. 8a). To test whether these sites are functional, the 3.2 kb fragment was inserted into a Luciferase reporter construct [52] and transiently co-injected into Nicotiana benthamiana leaves with the kiwifruit SEP4/RIN gene driven by a 35S promoter. It was found that SEP4/RIN was unable to transactivate the RIN promoter. When the 3.2 kb promoter fragment was co-infiltrated with three kiwifruit EIN3 transcription factors driven by a 35S promoter, it was shown that the ethylene associated EIN3-like genes could transactivate the promoter (Fig. 8b).Fig. 8


The hybrid non-ethylene and ethylene ripening response in kiwifruit (Actinidia chinensis) is associated with differential regulation of MADS-box transcription factors.

McAtee PA, Richardson AC, Nieuwenhuizen NJ, Gunaseelan K, Hoong L, Chen X, Atkinson RG, Burdon JN, David KM, Schaffer RJ - BMC Plant Biol. (2015)

a The 2 kb region upstream of the transcriptional start of the SEP4/RIN gene showing potential EIN3 binding sites (including a putative PS1 binding site) and MADS box binding CaRG box consensus sequences. b Transient transactivation of a 3.2 kb RIN promoter fragment by RIN and EIN3-like transcription factors in tobacco (N. benthamiana) leaves with SEP4/RINgene (RIN) and three EIN3 like genes (EIL) compared to a 35S:GFP control (GFP). c Averages of Ethylene emission from three independent experiments of A. eriantha fruit transiently expressing a 35S:SEP4 (RIN) gene compared to untransformed Agrobacterium tumefaciens (Agro), water (control) and Agrobacterium containing a 35S:GFP gene (GFP)
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4696264&req=5

Fig8: a The 2 kb region upstream of the transcriptional start of the SEP4/RIN gene showing potential EIN3 binding sites (including a putative PS1 binding site) and MADS box binding CaRG box consensus sequences. b Transient transactivation of a 3.2 kb RIN promoter fragment by RIN and EIN3-like transcription factors in tobacco (N. benthamiana) leaves with SEP4/RINgene (RIN) and three EIN3 like genes (EIL) compared to a 35S:GFP control (GFP). c Averages of Ethylene emission from three independent experiments of A. eriantha fruit transiently expressing a 35S:SEP4 (RIN) gene compared to untransformed Agrobacterium tumefaciens (Agro), water (control) and Agrobacterium containing a 35S:GFP gene (GFP)
Mentions: A 3.2 kb region upstream of the transcriptional start, was firstly scanned for potential RIN-like CaRG sequences. In tomato the preference RIN binding site is CCA(A/T)(A/t)(A/T)ATAG, but RIN can also bind to a more general C(C/T)(A/T)6(A/G)G CaRG box [50]. In the kiwifruit genome sequence there were two CaRG sequences within the first 2 kb of the SEP4/RIN promoter. Also within this promoter is a potential EIN3 binding site (A(T/C)G(A/T)A(C/T)CT), as well as a PS1 sequence that EIN3 has been shown to bind to [51] (Fig. 8a). To test whether these sites are functional, the 3.2 kb fragment was inserted into a Luciferase reporter construct [52] and transiently co-injected into Nicotiana benthamiana leaves with the kiwifruit SEP4/RIN gene driven by a 35S promoter. It was found that SEP4/RIN was unable to transactivate the RIN promoter. When the 3.2 kb promoter fragment was co-infiltrated with three kiwifruit EIN3 transcription factors driven by a 35S promoter, it was shown that the ethylene associated EIN3-like genes could transactivate the promoter (Fig. 8b).Fig. 8

Bottom Line: The promoter of SEP4/RIN was shown to be transactivated by EIN3-like transcription factors, but unlike tomato, not by SEP4/RIN itself.Transient over-expression of SEP4/RIN in kiwifruit caused an increase in ethylene production.These results suggest that the non-ethylene/ethylene ripening response observed in kiwifruit is a hybrid of both the tomato and grape ripening progression, with Phase 1 being akin to the RIN/ethylene inhibitory response observed in grape and Phase 2 akin to the RIN-associated autocatalytic ethylene response observed in tomato.

View Article: PubMed Central - PubMed

Affiliation: The New Zealand Institute for Plant & Food Research Limited (PFR), Mt Albert Research Centre, Auckland, New Zealand. peter.mcatee@plantandfood.co.nz.

ABSTRACT

Background: Ripening in tomato is predominantly controlled by ethylene, whilst in fruit such as grape, it is predominantly controlled by other hormones. The ripening response of many kiwifruit (Actinidia) species is atypical. The majority of ripening-associated fruit starch hydrolysis, colour change and softening occurs in the apparent absence of ethylene production (Phase 1 ripening) whilst Phase 2 ripening requires autocatalytic ethylene production and is associated with further softening and an increase in aroma volatiles.

Results: To dissect the ripening response in the yellow-fleshed kiwifruit A. chinensis ('Hort16A'), a two dimensional developmental stage X ethylene response time study was undertaken. As fruit progressed through maturation and Phase 1 ripening, fruit were treated with different concentrations of propylene and ethylene. At the start of Phase 1 ripening, treated fruit responded to ethylene, and were capable of producing endogenous ethylene. As the fruit progressed through Phase 1 ripening, the fruit became less responsive to ethylene and endogeneous ethylene production was partially repressed. Towards the end of Phase 1 ripening the fruit were again able to produce high levels of ethylene. Progression through Phase 1 ripening coincided with a developmental increase in the expression of the ethylene-unresponsive MADS-box FRUITFUL-like gene (FUL1). The ability to respond to ethylene however coincided with a change in expression of another MADS-box gene SEPALLATA4/RIPENING INHIBITOR-like (SEP4/RIN). The promoter of SEP4/RIN was shown to be transactivated by EIN3-like transcription factors, but unlike tomato, not by SEP4/RIN itself. Transient over-expression of SEP4/RIN in kiwifruit caused an increase in ethylene production.

Conclusions: These results suggest that the non-ethylene/ethylene ripening response observed in kiwifruit is a hybrid of both the tomato and grape ripening progression, with Phase 1 being akin to the RIN/ethylene inhibitory response observed in grape and Phase 2 akin to the RIN-associated autocatalytic ethylene response observed in tomato.

Show MeSH
Related in: MedlinePlus