Mitochondrial alternative oxidase pathway acts as an electron sink during photosynthetic induction in Rumex K-1 leaves

Title:

Mitochondrial alternative oxidase pathway acts as an electron sink during photosynthetic induction in Rumex K-1 leaves

Creator:

Cheng, D.D. and Zhang, L.T.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:e2cbe0d3-a092-4d74-aa2a-65b6784ee66b
uuid:e2cbe0d3-a092-4d74-aa2a-65b6784ee66b
doi:10.32615/ps.2021.047

Subject:

alternative oxidase, photodamage, photosystem II photochemical efficiency, photosynthetic induction, and Rumex K-1

Type:

model:article and TEXT

Format:

počítač and online zdroj

Description:

Chloroplast PSII photochemical efficiency is upregulated more rapidly than CO2 assimilation during photosynthesis induction, suggesting the existence of other electron sinks than that of CO2 assimilation. We hypothesized that the mitochondrial alternative oxidase (AOX) pathway could be such a sink. Inhibition of the AOX restricted light activation of the malate-oxaloacetate shuttle and caused an excessive reduction of PSI acceptor side and substantial accumulation of QA-, hindering the photosynthetic linear electron transport rate (ETR) and leading to an imbalance between light energy absorption and exploitation during photosynthetic induction. ETR limitation also restricted the formation of thylakoid pH gradient, evidenced by a decreased de-epoxidation of the xanthophyll cycle, thus preventing nonphotochemical quenching. Delayed CO2 assimilation due to thylakoid pH gradient restriction was partially reversed by exogenous ATP application. The AOX pathway acts as a photosynthetic electron sink, protecting the photosynthetic apparatus against photoinhibition and accelerating the induction of CO2 assimilation during photosynthetic induction in Rumex K-1 leaves.

Language:

Multiple languages

Rights:

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

Coverage:

615-624

Source:

Photosynthetica | 2021 Volume:59 | Number:4

Harvested from:

CDK

Metadata only:

false