Characterization of processes responsible for the distinct effect of herbicides DCMU and BNT on Photosystem II photoinactivation in cells of the cyanobacterium Synechococcus sp. PCC 7942 |
| |
Authors: | Komenda Josef Koblížek Michal Prášil Ondřej |
| |
Institution: | (1) Laboratory of Photosynthesis, Institute of Microbiology, Academy of Sciences, Opatovicky mlyn, 37901 Třeboň, Czech Republic;(2) Laboratory of Photosynthesis, Institute of Microbiology, Academy of Sciences, Opatovicky mlyn, 37901 Třeboň, Czech Republic |
| |
Abstract: | Light-induced modification of Photosystem II (PS II) complex was characterized in the cyanobacterium Synechococcus sp. PCC 7942 treated with either DCMU (a phenylurea PS II inhibitor) or BNT (a phenolic PS II inhibitor). The irradiance
response of photoinactivation of PS II oxygen evolution indicated a BNT-specific photoinhibition that saturated at relatively
low intensity of light. This BNT-specific process was slowed down under anaerobiosis, was accompanied by the oxygen-dependent
formation of a 39 kDa D1 protein adduct, and was not related to stable QA reduction or the ADRY effect. In the BNT-treated cells, the light-induced, oxygen-independent initial drop of PS II electron
flow was not affected by formate, an anion modifying properties of the PS II non-heme iron. For DCMU-treated cells, anaerobiosis
did not significantly affect PS II photoinactivation, the D1 adduct was not observed and addition of formate induced similar
initial decrease of PS II electron flow as in the BNT-treated cells. Our results indicate that reactive oxygen species (most
likely singlet oxygen) and modification of the PS II acceptor side are responsible for the fast BNT-induced photoinactivation
of PS II.
This revised version was published online in June 2006 with corrections to the Cover Date. |
| |
Keywords: | D1 protein photoinhibition PS II inhibitors Synechococcus PCC 7942 |
本文献已被 PubMed SpringerLink 等数据库收录! |
|