Quantitative assessment of the high-light tolerance in plants with an impaired photosystem II donor side.

This study shows that through the use of PSII donor-side inhibitors, such as UV-B and Cd2+, there is a steeper gradient of photoinactivation in the systems with a weakened donor side, independent of the level of NPQ attained. This is coupled with a concomitant decline in the light tolerance of PSII. The native light tolerance is partially restored upon use of 1,5-diphenylcarbazide (DPC), a PSII electron donor, allowing for the balance between the inhibitory pathways to be sensitively quantified. Thus, this study confirms that the impact of donor-side inhibition can be detected alongside acceptor-side photoinhibition using the qPd parameter, and confirms qPd as a valid, sensitive and unambiguous parameter to sensitively quantify the onset of photoinhibition through both acceptor- or donor-side mechanisms.
PMID: 31036714 [PubMed - as supplied by publisher]

Source: The Biochemical Journal - April 28, 2019 Category: Biochemistry Authors: Wilson S, Ruban AV Tags: Biochem J Source Type: research