
%0 Journal Article
%A Lu, Congming 
%A Zhang, Jianhua 
%T Thermostability of photosystem II is increased in salt-stressed sorghum
%J Functional Plant Biology
%D 1998/05/21
%V 25
%N 3
%P 317-324
%K chlorophyll fluorescence, heat stress, photosystem II, salt stress, sorghum (Sorghum bicolor L.), thermostability of photosystem II.
%R https://doi.org/10.1071/PP97138
%U https://www.publish.csiro.au/paper/PP97138 
%X Modulated chlorophyll fluorescence and rapid fluorescence induction kinetics were used to evaluate the functions of photosystem II (PSII) photochemsitry in sorghum leaves exposed to salinity (0&#8211;100 mM NaCl) and/or high temperature stress (30&#8211;50&#176;C). No differences were detected in the steady- state fluorescence parameters and rapid fluorescence induction kinetics in salt-stressed leaves, indicating that PSII was highly resistant to salinity stress alone. However, salinity stress modified the responses of PSII to high temperature. When the temperature was above 45&#176;C, the thermostability of PSII was strongly enhanced in salt-stressed leaves, which was reflected in a smaller decrease in maximum efficiency of PSII photochemistry, coefficients of photochemical and non-photochemical quenching, and efficiency of excitation capture by open PSII reaction centres, and in a smaller increase in the proportion of the QB-non-reducing PSII centres in salt-stressed leaves than in control leaves. This increased thermostability in salt-stressed leaves exposed to high temperature seemed to be independent of the imposed salt concentration since there were no significant variations in the above fluorescence parameters among the salt-stressed plants treated with different salt concentrations. The results are discussed in terms of the physiological significance of such increased resistance of PSII to high temperature. 
