Photoinhibition of photosynthesis in intact kiwifruit (Actinidia deliciosa) leaves: Changes in susceptibility to photoinhibition and recovery during the growth season

Planta ◽  
1992 ◽  
Vol 186 (3) ◽  
Author(s):  
D.H. Greer ◽  
W.A. Laing
1988 ◽  
Vol 15 (2) ◽  
pp. 195 ◽  
Author(s):  
DH Greer

Photoinhibition of photosynthesis was induced in intact leaves of kiwifruit (Actinidia deliciosa) grown in natural light not exceeding a photon irradiance (PI) of 300 �mol m-2 s-1 by exposing them to a PI of 1500 �mol m-2 s-1. The temperature was held constant during the high-light exposure between 5 and 35°C. Recovery was followed at temperatures between 10 and 35°C, after photoinhibition was induced by a 240 min exposure to high light. The kinetics of photoinhibition and recovery were followed by chlorophyll fluorescence at 692 nm and 77K. Photoinhibition occurred at all temperatures but was greatest at low temperatures. Temperature affected the severity of photoinhibitory damage but not the kinetics of photoinhibition. Recovery was also temperature-dependent with little or no recovery occurring below about 20°C and rapid recovery at 30-35°C. The extent of photoinhibition also affected the rates of recovery which were reduced as the severity of photoinhibition increased. An analysis of the rate constants for energy transfer within photosystem II indicated that kiwifruit leaves have some capacity to prevent photoinhibition by increasing the amount of non-radiative energy dissipation. However, the analysis also indicates that this protection mechanism was not wholly effective since the primary photochemical reactions apparently become inactivated during exposure of these leaves to high light.


1993 ◽  
Vol 20 (1) ◽  
pp. 33 ◽  
Author(s):  
DH Greer ◽  
WA Laing ◽  
DJ Woolley

Photoinhibition of photosynthesis in kiwifruit [Actinidia deliciosa (A. Chev.) C. F. Liang et A. R. Ferguson] leaves in high light and its subsequent recovery in low light was assessed in the presence of chloramphenicol (CAP), an inhibitor of chloroplast-encoded protein synthesis. Rooted cuttings were grown in a controlled environment at a photosynthetic irradiance of 700 μmol m-2 s-1 and a day/night temperature of 25/20�C. Time-courses of photoinhibition and recovery treatments were followed by measuring CO2 exchange and chlorophyll fluorescence at 77K and 692 nm. CAP both exacerbated photoinhibition and blocked recovery for at least 150 min, especially at high temperatures. The close conformation of these two effects affirm that photoinhibition and recovery occur concomitantly. There was no apparent effect of CAP on the xanthophyll cycle, either during photoinhibition or recovery, indicating that zeaxanthin-mediated non-radiative energy (thermal) dissipation was unaffected by CAP. Because the CAP-induced increase in photoinhibition was not matched by an increase in the ratio of zeaxanthin to violaxanthin and antheraxanthin, the capacity of this photoprotective mechanism was apparently saturated. The primary effect of CAP on chlorophyll fluorescence was to affect Fm, the maximum fluorescence. There was only a minor effect on the initial fluorescence, Fo, during the photoinhibition and recovery treatments. The calculation of the rate constants for non-radiative dissipation (kD) and photochemistry (kp) from the fluorescence measurements indicated that an increase in kD occurred during high-light exposures and this was stimulated by CAP. However, since zeaxanthin was not mediating this, an alternative quencher in kiwifruit leaves, perhaps damaged PSII centres, is proposed. This would be consistent with an increased inactivation of PSII, as indicated by the changes in kp.


Author(s):  
А.В. РЫНДИН ◽  
◽  
Ц.В. ТУТБЕРИДЗЕ ◽  
С.Н. ГРЕБЕНЮКОВ ◽  
В.А. ГРЯЗЕВ ◽  
...  
Keyword(s):  

2013 ◽  
Vol 42 (11) ◽  
pp. 1821-1828 ◽  
Author(s):  
Eunkyung Kim ◽  
Yoon Hyuk Chang ◽  
Jae Youn Ko ◽  
Yoonhwa Jeong

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