Heat emission as a protective mechanism against high-irradiance stress in sugar maple leaves

Title:

Heat emission as a protective mechanism against high-irradiance stress in sugar maple leaves

Creator:

Veeranjaneyulu, K. and Leblanc, R. M.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:b3a60ce8-d177-49ef-88cc-75e7d1d22350
uuid:b3a60ce8-d177-49ef-88cc-75e7d1d22350
issn:0300-3604
doi:10.1023/A:1006902621561

Subject:

Acer saccharum, fluorescence, photoacoustic spectroscopy, photoinhibition, photoprotection, and photosystems

Type:

model:article and TEXT

Format:

bez média and svazek

Description:

High-irradiance (HI) induced changes in heat emission, fluorescence, and photosynthetic energy storage (EST) of shade grown sugar maple (Acer saccharum Marsh.) saplings were followed using modulated photoacoustic and fluorescence spectroscopic techniques. HI-treatment at 900-4400 µmol m-2 s-1 for 15 min caused an increase in heat emission and a decrease in EST. In some leaves, HI-treatment of 900 µmol m-2 s-1 for 1 min induced a rapid increase in heat emission with a marginal decrease in EST. Parallel to the increase in heat emission, there was a decrease in fluorescence, and this phenomenon was reversible in darkness. Quenching of thermal energy dissipation and a recovery in EST were observed during the first 15 min after the HI-treatment. This down-regulation of photochemical activity and its recovery may be one of the photoprotective mechanisms in shade grown sugar maple plants. The increase in thermal energy dissipation was greater in the red absorbing long wavelength (640-700 nm) region than in the blue absorbing short wavelength region of photosynthetically active excitation radiation. The photochemical activity was affected more in short wavelengths (400-520 nm) than in the long wavelength region of the spectrum. This can be due to the migration of light-harvesting chlorophyll (Chl) a/b protein complex from photosystem (PS) 2 to PS1 and/or to the disconnection of carotenoid pool from Chls in the pigment bed of photosynthetic apparatus. and K. Veeranjaneyulu, R. M. Leblanc.

Language:

Multiple languages

Rights:

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

Coverage:

191-203

Source:

Photosynthetica | 1998 Volume:35 | Number:2

Harvested from:

CDK

Metadata only:

false