TY - JOUR
T1 - Reduced glutamine synthetase activity plays a role in control of photosynthetic responses to high light in barley leaves
AU - Brestic, Marian
AU - Zivcak, Marek
AU - Olsovska, Katarina
AU - Shao, Hong Bo
AU - Kalaji, Hazem M.
AU - Allakhverdiev, Suleyman I.
N1 - Funding Information:
This work was supported by the European Community under the project no. 26220220180: “Construction of the “AgroBioTech” Research Centre”. SIA was supported by grants from the Russian Foundation for Basic Research (No: 13-04-91372 , 14-04-01549 , 14-04-92690 ) and by Molecular and Cell Biology Programs of the Russian Academy of Sciences .
Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 2014/8
Y1 - 2014/8
N2 - The chloroplastic glutamine synthetase (GS, EC 6.3.1.2) activity was previously shown to be the limiting step of photorespiratory pathway. In our experiment, we examined the photosynthetic high-light responses of the GS2-mutant of barley (Hordeum vulgare L.) with reduced GS activity, in comparison to wild type (WT). The biophysical methods based on slow and fast chlorophyll fluorescence induction, P700 absorbance, and gas exchange measurements were employed. Despite the GS2 plants had high basal fluorescence (F0) and low maximum quantum yield (Fv/Fm), the CO2 assimilation rate, the PSII and PSI actual quantum yields were normal. On the other hand, in high light conditions the GS2 had much higher non-photochemical quenching (NPQ), caused both by enhanced capacity of energy-dependent quenching and disconnection of PSII antennae from reaction centers (RC). GS2 leaves also maintained the PSII redox poise (QA-/QA total) at very low level; probably this was reason why the observed photoinhibitory damage was not significantly above WT. The analysis of fast chlorophyll fluorescence induction uncovered in GS2 leaves substantially lower RC to antenna ratio (RC/ABS), low PSII/PSI ratio (confirmed by P700 records) as well as low PSII excitonic connectivity.
AB - The chloroplastic glutamine synthetase (GS, EC 6.3.1.2) activity was previously shown to be the limiting step of photorespiratory pathway. In our experiment, we examined the photosynthetic high-light responses of the GS2-mutant of barley (Hordeum vulgare L.) with reduced GS activity, in comparison to wild type (WT). The biophysical methods based on slow and fast chlorophyll fluorescence induction, P700 absorbance, and gas exchange measurements were employed. Despite the GS2 plants had high basal fluorescence (F0) and low maximum quantum yield (Fv/Fm), the CO2 assimilation rate, the PSII and PSI actual quantum yields were normal. On the other hand, in high light conditions the GS2 had much higher non-photochemical quenching (NPQ), caused both by enhanced capacity of energy-dependent quenching and disconnection of PSII antennae from reaction centers (RC). GS2 leaves also maintained the PSII redox poise (QA-/QA total) at very low level; probably this was reason why the observed photoinhibitory damage was not significantly above WT. The analysis of fast chlorophyll fluorescence induction uncovered in GS2 leaves substantially lower RC to antenna ratio (RC/ABS), low PSII/PSI ratio (confirmed by P700 records) as well as low PSII excitonic connectivity.
KW - Barley
KW - Chlorophyll fluorescence
KW - Glutamine synthetase
KW - Non-photochemical quenching
KW - Photoinhibition
KW - Photorespiration
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U2 - 10.1016/j.plaphy.2014.01.002
DO - 10.1016/j.plaphy.2014.01.002
M3 - Article
C2 - 24491798
AN - SCOPUS:84904164293
SN - 0981-9428
VL - 81
SP - 74
EP - 83
JO - Plant Physiology and Biochemistry
JF - Plant Physiology and Biochemistry
ER -