Header

UZH-Logo

Maintenance Infos

Altered patterns of senescence and ripening in gf, a stay-green mutant of tomato (Lycopersicon esculentum Mill.)


Akhtar, M S; Goldschmidt, E E; John, I; Rodoni, S; Matile, P; Grierson, D (1999). Altered patterns of senescence and ripening in gf, a stay-green mutant of tomato (Lycopersicon esculentum Mill.). Journal of Experimental Botany, 50(336):1115-1122.

Abstract

The gf tomato mutant, which retains chlorophyll during ripening, has been found to be affected in leaf senescence. The leaves of the gf mutant show an absolute stay-green phenotype. As leaf senescence and fruit ripening proceed, there is a marked difference in chlorophyll content between wild-type and gf. In both attached and detached leaf studies, or after treatment with ethylene, the leaves withered and abscised in gf with only slight loss of chlorophyll and carotenoids. Total protein content declined and free amino acids increased during leaf senescence in wild-type and gf, but Western analysis showed that LHCII polypeptides were retained at higher levels in gf. Expression of senescence-related mRNAs increased normally in gf whereas those for cab, rbcS and rbcL declined in both mutant and wild-type. The mutant possesses enzyme activity for chlorophyllase, the formation of phaeophorbide a by the action of Mg-dechelatase and the oxygenolytic opening of the porphyrin macrocycle. Analysis of chlorophyll breakdown products in fruit indicated that gf, like other stay-green mutants, accumulates chlorophyllides a and b, but phaeophorbide a does not accumulate in vivo. This may indicate that, in the mutant, in vivo the action of phaeophorbide a-oxygenase is somehow prevented, either by altered accessibility or transport of components required for thylakoid disassembly or the absence of another factor

Abstract

The gf tomato mutant, which retains chlorophyll during ripening, has been found to be affected in leaf senescence. The leaves of the gf mutant show an absolute stay-green phenotype. As leaf senescence and fruit ripening proceed, there is a marked difference in chlorophyll content between wild-type and gf. In both attached and detached leaf studies, or after treatment with ethylene, the leaves withered and abscised in gf with only slight loss of chlorophyll and carotenoids. Total protein content declined and free amino acids increased during leaf senescence in wild-type and gf, but Western analysis showed that LHCII polypeptides were retained at higher levels in gf. Expression of senescence-related mRNAs increased normally in gf whereas those for cab, rbcS and rbcL declined in both mutant and wild-type. The mutant possesses enzyme activity for chlorophyllase, the formation of phaeophorbide a by the action of Mg-dechelatase and the oxygenolytic opening of the porphyrin macrocycle. Analysis of chlorophyll breakdown products in fruit indicated that gf, like other stay-green mutants, accumulates chlorophyllides a and b, but phaeophorbide a does not accumulate in vivo. This may indicate that, in the mutant, in vivo the action of phaeophorbide a-oxygenase is somehow prevented, either by altered accessibility or transport of components required for thylakoid disassembly or the absence of another factor

Statistics

Citations

Dimensions.ai Metrics
54 citations in Web of Science®
66 citations in Scopus®
Google Scholar™

Altmetrics

Downloads

4 downloads since deposited on 16 Oct 2018
4 downloads since 12 months
Detailed statistics

Additional indexing

Item Type:Journal Article, refereed, original work
Communities & Collections:National licences > 142-005
Dewey Decimal Classification:Unspecified
Language:English
Date:1 July 1999
Deposited On:16 Oct 2018 16:16
Last Modified:24 Nov 2018 02:55
Publisher:Oxford University Press
ISSN:0022-0957
OA Status:Green
Free access at:Publisher DOI. An embargo period may apply.
Publisher DOI:https://doi.org/10.1093/jxb/50.336.1115
Related URLs:https://www.swissbib.ch/Search/Results?lookfor=nationallicenceoxford101093jxb503361115 (Library Catalogue)

Download

Download PDF  'Altered patterns of senescence and ripening in gf, a stay-green mutant of tomato (Lycopersicon esculentum Mill.)'.
Preview
Content: Published Version
Language: English
Filetype: PDF (Nationallizenz 142-005)
Size: 357kB
View at publisher