Journal
PLANT BIOLOGY
Volume 10, Issue 2, Pages 194-201Publisher
WILEY
DOI: 10.1111/j.1438-8677.2008.00032.x
Keywords
heat stress; light stress; net photosynthesis; paraheliotropism; photoprotection; Robinia pseudoacacia
Categories
Ask authors/readers for more resources
We assessed the contribution of leaf movements to PSII photoprotection against high light and temperature in Robinia pseudoacacia. Gas exchange and chlorophyll a fluorescence measurements were performed during the day at 10:00, 12:00, 15:00 and 18:00 hours on leaves where paraheliotropic movements were restrained (restrained leaves, RL) and on control unrestrained leaves (UL). RL showed a strong decrease of net photosynthesis (A(n)), stomatal conductance (g(sH2O)), quantum yield of electron transport (Phi(PSII)), percentage of photosynthesis inhibited by O-2 (IPO) and photochemical quenching (q(P)) in the course of the day, whereas, a significant increase in C-i/C-a and NPQ was observed. Contrary to RL, UL had higher photosynthetic performance that was maintained at elevated levels throughout the day. In the late afternoon, A(n), g(sH2O), Phi(PSII) and q(P) of RL showed a tendency to recovery, as compared to 15:00 hours, even if the values remained lower than those measured at 10:00 hours and in UL. In addition, contrary to UL, no recovery was found in F-v/F-m at the end of the study period in RL. Data presented suggest that in R. pseudoacacia, leaf movements, by reducing light interception, represent an efficient, fast and reversible strategy to overcome environmental stresses such as high light and temperature. Moreover, paraheliotropism was able to protect photosystems, avoiding photoinhibitory damage, leading to a carbon gain for the plant.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available