Changes in photosynthetic pigments and in vivo chlorophyll fluorescence parameters under photoinhibitory growth conditions

Title:

Changes in photosynthetic pigments and in vivo chlorophyll fluorescence parameters under photoinhibitory growth conditions

Creator:

Lichtenthaler, H. K., Burkart, S., Schindler, C., and Stober, F.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:7fa4b671-2906-4763-850a-7fb7bbbabd36
uuid:7fa4b671-2906-4763-850a-7fb7bbbabd36
urnnbn:urn:nbn:cz:aba007-000fbl

Type:

model:internalpart and TEXT

Format:

print

Description:

Changes in the chlorophyll (Chl) and carotenoid (Car) contents and photosynthetic activity of leaves of three-year-old maple trees were studied under an extremely high irradiance (HI) (5 000 and 7 000 pmol m-2 s‘*) and subsequent low irradiance (LI) (10 pmol m-2 s‘*). Speciál attention was paid to a possible linear correlation between zeaxanthin (z) accumulation and the decrease in variable Chl fluorescence (ratio Fy/FnO during photoinhibitory treatment. Hl-induced violaxanthin (v) transformation into z was a fast one-step response proceeding within 2-5 min. Changes in the Chl a and b contents or in non-xanthophyll cycle Car were either not observed (30 min at 5 000 pmol m*2 s‘i) or a slight decline of the Chl a, lutein, 3-carotene and z contents only occurred at prolonged exposure (60 min at 7 000 pmol m'^ s'i)- Photosynthetic activity measured via the ratios (Fy/F^, Fy/F^, Rfj 690, Rfj 735) sank during this treatment to a much higher extent at 7 000 than at 5 000 pmol m'^ s'*. Ratios Fy/F<„ Rfd 690 and Rfj 735 proved to be better indicators of photoinhibition with a larger amplitudě ťhan the ratio Fy/F,„. Unlike literatuře reports, no linear correlation was found between Hl-induced decrease of fluorescence ratios and the z accumulation. Decrease of the fluorescence ratios appears to be biphasic in nátuře: fast initial fall which parallels the z formation is followed by a phase when ratios Fy/F^,, Fy/F^,, Rj^ 690 and Rf^ 735 sink further without any changes in the z pool. Regeneration of photosynthetic activity under LI also proceeded in two steps; a relatively fast increase in ratios with little or no changes in the z pool followed by a slow many hours' restoring of the former fluorescence ratios, paralleled by the z transformation into v. The back-reaction of z to v under LI was increasingly retarded with higher irradiance. Z formation and decrease in the fluorescence ratios are thus probably two Hl-induced processes which may be mutually independent.

Language:

Multiple languages

Rights:

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

Coverage:

343-353 and 79-89

Source:

Photosynthetica | 1992 Volume:27 | Number:3

Harvested from:

CDK

Metadata only:

false