High-irradiance stress and photochemical activities of photosystems 1 and 2 in vivo

Title:

High-irradiance stress and photochemical activities of photosystems 1 and 2 in vivo

Creator:

Veeranjaneyulu, K., Charland, M., and Leblanc, R. M.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:57df0b36-b64a-4866-9cc8-6f58d47c45b9
uuid:57df0b36-b64a-4866-9cc8-6f58d47c45b9
issn:0300-3604
doi:10.1023/A:1006950504723

Subject:

Acer saccharum, light-harvesting complex 2, and photoacoustic spectroscopy

Type:

model:article and TEXT

Format:

bez média and svazek

Description:

High-irradiance (HI) stress induced changes in the photosynthetic energy storage (ES) of photosystems 1 (ESPS1) and 2 (ESPS2) were studied with 650 nm modulated radiation in intact sugar maple (Acer saccharum Marsh.) leaves. HI-treatment (420 W m-2, 1 h) caused an inhibition of about 40 % in ESPS2 and an enhancement of about 60 % in ESPS1. The rate of PS1 cyclic electron transport, measured with 705 nm modulated radiation, also increased in HI-treated leaves. There was a clear state 1- state 2 transition in HI-treated leaves. ESPS1 increased significantly and ESPS2 decreased drastically in leaves preadapted to state 1 after HI (600 W m-2, 30 min) treatment. Thus, the increase in PS1 activity observed immediately after HI-treatment in leaves preadapted to state 1 can be due to the coupling of LHC2 to PS1 during the HI-treatment. Further, the dissociation of LHC2 from PS2 during the HI-treatment resulted in apparently (about 15 %) greater inhibition than the "true" inhibition of PS2 activity. The presence of LHC2 with PS2 (state 1) at the time of HI-treatment caused no additional damage to PS2 or its coupling to PS1 offered no apparent HI-treatment. Further, the dissociation of LHC2 from PS2 during the HI-treatment resulted in apparently (about 15 %) greater inhibition than the "true" inhibition of PS2 activity. The presence of LHC2 with PS2 (state 1) at the time of HI-treatment caused no additional damage to PS2 or its coupling to PS1 offered no apparent protection to the photosynthetic apparatus. and K. Veeranjaneyulu, M. Charland, R. M. Leblanc.

Language:

Multiple languages

Rights:

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

Coverage:

177-190

Source:

Photosynthetica | 1998 Volume:35 | Number:2

Harvested from:

CDK

Metadata only:

false