Changes in chlorophyll fluorescence during the course of photoperiod and in response to drought in Casuarina equisetifolia Forst. and Forst.

Title:

Changes in chlorophyll fluorescence during the course of photoperiod and in response to drought in Casuarina equisetifolia Forst. and Forst.

Creator:

Martínez-Carrasco, R., Sánchez-Rodriguez, J., and Pérez, P.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:bc5573ff-023f-455b-95bc-53538996b18b
uuid:bc5573ff-023f-455b-95bc-53538996b18b
issn:0300-3604
doi:10.1023/A:1022618823538

Subject:

energy dissipation, photochemical and non-photochemical quenching, photosystem 2, quantum yield, and water stress

Type:

model:article and TEXT

Format:

bez média and svazek

Description:

The effects of drought and the diurnal changes in photosynthetic electron transport were studied in non-nodulated plants of Casuarina equisetifolia. The induction of fluorescence showed a slightly higher I step in water-stressed than control plants, and the time from the start of irradiation to the P step of induction was significantly shortened by drought. The quantum efficiency of photosystem 2 (PS2) in the dark-adapted state (Fv/Fm) was generally not affected by drought, whereas it decreased during the central hours of the day. The decrease in quantum yield of PS2 electron transport (Φ2) in water-stressed plants was associated with decreases in the photochemical efficiency of open (oxidised) PS2 centres (Fv'/Fm') and increases in non-photochemical quenching (qN) rather than with increased closure of PS2 centres (lowered photochemical quenching, qP). In contrast, the changes in quantum yield of electron transport during the day were related to changes in qP rather than in Fv'/Fm'. When chlorophyll fluorescence was measured at the same irradiance during the day, a greater qN was observed at the end of the drying cycle than after watering, and early and late in the photoperiod than in the central hours of the day. The greater qN at the beginning and end of the day did not prevent an increase in energy not used photochemically nor dissipated non-photochemically. Drought did not affect this excess of photon energy. and R. Martínez-Carrasco, J. Sánchez-Rodriguez, P. Pérez.

Language:

Multiple languages

Rights:

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

Coverage:

363-368

Source:

Photosynthetica | 2002 Volume:40 | Number:3

Harvested from:

CDK

Metadata only:

false