Photochemical activities in wheat chloroplasts incubated under irradiation and possible photoprotection by zeaxanthin

Title:

Photochemical activities in wheat chloroplasts incubated under irradiation and possible photoprotection by zeaxanthin

Creator:

Choudhury, N.K., Aslam, M., and Huffaker, R.C.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:f854642a-d72e-4473-8d92-a827510b7f87
uuid:f854642a-d72e-4473-8d92-a827510b7f87
urnnbn:urn:nbn:cz:aba007-000fld

Type:

model:internalpart and TEXT

Format:

print

Description:

Chloroplasts isolated from the primary leaves of wheat seedlings lost 22 % of their chlorophyll and 35 % of the carotenoids after 4 h of incubation under a medium irradiance (MI) (400 pmol m'^ s'*, PAR). After a 3 h MI exposure, the photosystem (PS) 2 activity was completely lost while photosystem 1 (PSI) activity was reduced to 32 % of that, found initially. Chloroplasts isolated from the leaves of seedlings exposed to a high irradiance (1500 pmol m-^ s"') contained a higher concentiation of zeaxanthin (z) and lost pigments and photochemical activities at a relatively slower rate. When the z concentration in chloroplasts incubated under MI was enhanced several times by ascorbate (Asc), the losses of pigment contents and photosystem activities were significantly reduced. However, when the Asc-induced synthesis of z was inhibited by dithiothreitol, protection of the pigment contents and photochemical activities disappeared. Thus, z can photoprotect the chloroplasts during incubation under irradiation.

Language:

Multiple languages

Rights:

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

Coverage:

397-405 and 79-87

Source:

Photosynthetica | 1994 Volume:30 | Number:3

Harvested from:

CDK

Metadata only:

false