Analysis of qualitative contribution of assimilatory and non-assimilatory de-excitation processes to adaptation of photosynthetic apparatus of barley plants to high irradiance

Title:

Analysis of qualitative contribution of assimilatory and non-assimilatory de-excitation processes to adaptation of photosynthetic apparatus of barley plants to high irradiance

Creator:

Kurasová, I., Čajánek, M., Kalina, J., and Špunda, V.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:e2f42062-35ed-4f9c-a174-e7a6e9ce3a3a
uuid:e2f42062-35ed-4f9c-a174-e7a6e9ce3a3a
issn:0300-3604
doi:10.1023/A:1012401221669

Subject:

chlorophyll fluorescence, Hordeum vulgare, non-radiative dissipation, non-assimilatory electron transports, and photosynthetic oxygen evolution

Type:

model:article and TEXT

Format:

bez média and svazek

Description:

The adaptation of barley (Hordeum vulgare L. cv. Akcent) plants to low (LI, 50 µmol m-2 s-1) and high (HI, 1000 µmol m-2 s-1) growth irradiances was studied using the simultaneous measurements of the photosynthetic oxygen evolution and chlorophyll a (Chl a) fluorescence at room temperature. If measured under ambient CO2 concentration, neither increase of the oxygen evolution rate (P) nor enhancement of non-radiative dissipation of the absorbed excitation energy within photosystem 2 (PS2) (determined as non-photochemical quenching of Chl a fluorescence, NPQ) were observed for HI plants compared with LI plants. Nevertheless, the HI plants exhibited a significantly higher proportion of QA in oxidised state (estimated from photochemical quenching of Chl a fluorescence, qP), by 49-102 % at irradiances above 200 µmol m-2 s-1 and an about 1.5 fold increase of irradiance-saturated PS2 electron transport rate (ETR) as compared to LI plants. At high CO2 concentration the degree of P stimulation was approximately three times higher for HI than for LI plants, and the irradiance-saturated P values at irradiances of 2 440 and 2 900 µmol m-2 s-1 were by 130 and 150 % higher for HI plants than for LI plants. We suggest that non-assimilatory electron transport dominates in the adaptation of the photosynthetic apparatus of barley grown at high irradiances under ambient CO2 rather than an increased NPQ or an enhancement of irradiance-saturated photosynthesis. and I. Kurasová ... [et al.].

Language:

Multiple languages

Rights:

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

Coverage:

513-519

Source:

Photosynthetica | 2000 Volume:38 | Number:4

Harvested from:

CDK

Metadata only:

false