English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Open

Presents the pdf analysis as premium feature

PDF Analysis

Insights

Presents the summarisation as premium feature

Summarisation

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

Drought stress can induce closure of stomata, thus leading to photoinhibition. The effects of prolonged severe drought under natural growing conditions on photosystem I (PSI), photosystem II (PSII) and cyclic electron flow (CEF) in drought-tolerant tree species are unclear. In spring 2010, southwestern China confronted severe drought that lasted several months. Using three dominant evergreen species,  Cleistanthus sumatranus  (Miq.) Muell. Arg. (Euphorbiaceae),  Celtis philippensis  Bl. (Ulmaceae) and  Pistacia weinmannifolia  J. Poisson ex Franch. (Anacardiaceae) that are native to a tropical limestone forest, we investigated the influence of this stress on PSI and PSII activities as well as light energy distribution in the PSII and P700 redox state. By the end of the drought period, predawn leaf water potential (Ψ pd ) largely declined in each species, especially in  C. sumatranus . Photosystem I activity strongly decreased in the three species, especially in  C. sumatranus  which showed a decrease of 65%. The maximum quantum yield of PSII after dark adaptation remained stable in  P. weinmannifolia  and  C. philippensis  but significantly decreased in  C. sumatranus . Light response curves indicated that both linear electron flow and non-photochemical quenching were severely inhibited in  C. sumatranus  along with disappearance of CEF, resulting in deleterious excess light energy in PSII. We conclude that PSI is more sensitive than PSII to prolonged severe drought in these three drought-tolerant species, and CEF is essential for photoprotection in them.

tree physiology

Differences in the responses of photosystem I and photosystem II of three tree species  Cleistanthus sumatranus ,  Celtis philippensis  and  Pistacia weinmannifolia  exposed to a prolonged drought in a tropical limestone forest