Photosynthetic electron flow during leaf senescence: evidence for a preferential maintenance of photosystem I activity and increased cyclic electron flow

Title:

Photosynthetic electron flow during leaf senescence: evidence for a preferential maintenance of photosystem I activity and increased cyclic electron flow

Creator:

Kotakis, C., Kyzeridou, A., and Manetas, Y.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:67f56805-b8aa-4c74-8d1d-8d5842db0715
uuid:67f56805-b8aa-4c74-8d1d-8d5842db0715
issn:0300-3604
doi:10.1007/s11099-014-0046-5

Subject:

fotosyntéza, chloroplasty, photosynthesis, chloroplasts, alternative routes, electron flow, chlorophyll fluorescence, senescence regulation, Euphorbia dendroides, Morus alba, 2, and 581

Type:

model:article and TEXT

Format:

print, bez média, and svazek

Description:

Limitations in photosystem function and photosynthetic electron flow were investigated during leaf senescence in two field-grown plants, i.e., Euphorbia dendroides L. and Morus alba L., a summer- and winter-deciduous, shrub and tree, respectively. Analysis of fast chlorophyll (Chl) a fluorescence transients and post-illumination fluorescence yield increase were used to assess photosynthetic properties at various stages of senescence, the latter judged from the extent of Chl loss. In both plants, the yield of primary photochemistry of PSII and the content of PSI remained quite stable up to the last stages of senescence, when leaves were almost yellow. However, the potential for linear electron flow along PSII was limited much earlier, especially in E. dendroides, by an apparent inactivation of the oxygen-evolving complex and a lower efficiency of electron transfer to intermediate carriers. On the contrary, the corresponding efficiency of electron transfer from intermediate carriers to final acceptors of PSI was increased. In addition, cyclic electron flow around PSI was accelerated with the progress of senescence in E. dendroides, while a corresponding trend in M. alba was not statistically significant. However, there was no decrease in PSI activity even at the last stages of senescence. We argue that a switch to cyclic electron flow around PSI during leaf senescence may have the dual role of replenishing the ATP and maintaining a satisfactory nonphotochemical energy quenching, since both are limited by hindered linear electron transfer., C. Kotakis, A. Kyzeridou, Y. Manetas., and Obsahuje bibliografii

Language:

Multiple languages

Rights:

http://creativecommons.org/licenses/by-nc-sa/4.0/
policy:public

Coverage:

413-420

Source:

Photosynthetica | 2014 Volume:52 | Number:3

Harvested from:

CDK

Metadata only:

false