Responses of photosystem 2 photochemistry and pigment compositíon in needles of Norway spruce saplings to increased radiation level

Title:

Responses of photosystem 2 photochemistry and pigment compositíon in needles of Norway spruce saplings to increased radiation level

Creator:

Špunda, V., Kalina, J., Nauš, J., Kuropatwa, R., Mašláň, M., and Marek, M.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:f89a99ff-7036-40f0-a3f1-27b6d0d3087c
uuid:f89a99ff-7036-40f0-a3f1-27b6d0d3087c
urnnbn:urn:nbn:cz:aba007-000fer

Type:

model:internalpart and TEXT

Format:

print

Description:

o reveal the dynamics of short-term photosynthetic acclimation to increased irradiance, the light response of photochemical (qp), non-photochemical (q^) and Fo (qo) quenchings of chlorophyll (Chl) fluorescence and Chl and carotenoids compositíon in Norway spruce needles were monitored within three days after transfer of saplings ffom low diffuse irradiance (maximum photosynthetic photon fluence density PPFD 50 pmol m'^ s'i) to direct sun radiation (maximum PPFD 2000 pmol m‘2 s'*). Irradiance responses of fluorescence quenching coefficients revealed the occurrence of substantíal changes in partítioning of excitation energy between photochemical reactions and radiatíonless dissipation within two days. The saturating irradiance for qj,j and the capacity of non-radiatíve dissipation processes was shifted from about 450 pmol m'^ s** to 1620 pmol m-2 s'L Whereas immediately after exposure to ťull sunlight was completely reduced at 1620 pmol m'^ s'*, two days later 40 % of was stíll present in oxidized form at this irradiance. A fast pigment photobleaching at noon prevented the over-reduction of and thus it was one of the possible short-term acclimation processes. No severe photoinhibition of photosystem 2 (PS 2) photochemistry occurred within the period of investigation as can be judged from the high F^/F^ value.

Language:

Multiple languages

Rights:

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

Coverage:

401-413 and 83-95

Source:

Photosynthetica | 1993 Volume:28 | Number:3

Harvested from:

CDK

Metadata only:

false