Different responses of Norway spruce needles from shaded and exposed crown layers to the prolonged exposure to elevated CO2 studied by various chlorophyll a fluorescence techniques

Title:

Different responses of Norway spruce needles from shaded and exposed crown layers to the prolonged exposure to elevated CO2 studied by various chlorophyll a fluorescence techniques

Creator:

Kalina, J., Urban, O., Čajánek, M., Kurasová, I., Špunda, V., and Marek, M. V.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:418a6020-9136-4de8-874a-c143ad7fdbc8
uuid:418a6020-9136-4de8-874a-c143ad7fdbc8
issn:0300-3604
doi:10.1023/A:1015126225775

Subject:

carotenoids, irradiance, net photosynthetic rate, photosystem 2, and Picea abies

Type:

model:article and TEXT

Format:

bez média and svazek

Description:

The acclimation depression of capacity of photon utilisation in photochemical reactions of photosystem 2 (PS2) can develop already after three months of cultivation of the Norway spruces (Picea abies [L.] Karst.) under elevated concentrations of CO2 (i.e., ambient, AC, + 350 µmol(CO2) mol-1 = EC) in glass domes with adjustable windows. To examine the role that duration of EC plays in acclimation response, we determined pigment contents, rate of photosynthesis, and parameters of chlorophyll a fluorescence for sun and shade needles after three seasons of EC exposure. We found responses of shaded and exposed needles to EC. Whereas the shaded needles still profited from the EC and revealed stimulated electron transport, for the exposed needles the stimulation of both electron transport activity and irradiance saturated rate of CO2 assimilation (PNmax) under EC already disappeared. No signs of the PS2 impairment were observed as judged from high values of potential quantum yield of PS2 photochemistry (FV/FM) and uniform kinetics of QA reoxidation for all variants. Therefore, the long-term acclimation of the sun-exposed needles to EC is not necessarily accompanied with the damage to the PS2 reaction centres. The eco-physiological significance of the reported differentiation between the responses of shaded and sun exposed needles to prolonged EC may be in changed contribution of the upper and lower crown layers to the production activity of the tree. Whereas for the AC spruces, PNmax of shaded needles was only less than 25 % compared to exposed ones, for the EC spruces the PNmax of shaded needles reached nearly 40 % of that estimated for the exposed ones. Thus, the lower shaded part of the crown may become an effective consumer of CO2. and J. Kalina ... [et al.].

Language:

Multiple languages

Rights:

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

Coverage:

369-376

Source:

Photosynthetica | 2001 Volume:39 | Number:3

Harvested from:

CDK

Metadata only:

false