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Negative effects of hydroxyl radical‐generating mists (simulated dew water) on the photosynthesis and growth of Japanese apricot seedlings ( Prunus mume )
Author(s) -
Yoon Johee,
AbeSuzuki Masayo,
Eko Pudjadi,
Tamai Hiroshi,
Hanamitsu Shigeichiro,
Nakane Kaneyuki
Publication year - 2006
Publication title -
ecological research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.628
H-Index - 68
eISSN - 1440-1703
pISSN - 0912-3814
DOI - 10.1007/s11284-005-0112-3
Subject(s) - dew , mist , chemistry , photosynthesis , horticulture , relative growth rate , hydroxyl radical , stomatal conductance , dry weight , relative humidity , botany , growth rate , radical , biology , biochemistry , physics , geometry , mathematics , meteorology , condensation , thermodynamics
The hydroxyl (OH) radical, which is generated in polluted dew water on leaf surfaces of the Japanese apricot ( Prunus mume ), is known to be a potent oxidant. In order to investigate the effects of the OH radical formed in polluted dew water on the photosynthesis and growth of 3‐year‐old seedlings of P. mume , OH radical‐generating solutions simulating polluted dew water were sprayed in the early morning as a mist throughout a growing season onto the leaf surfaces of seedlings growing in experimental greenhouses. Four OH radical‐generating solutions (0, 6, 18 and 54 μM H 2 O 2 with Fe(III) and an oxalate ion) were used in the mist treatment. Five months after the beginning of treatment, the leaves exposed to the mist containing 54 μM H 2 O 2 showed a significantly smaller maximum CO 2 assimilation rate ( A max ) and stomatal conductance ( g s ) as compared to the leaves exposed to the mist containing 0 μM H 2 O 2 . Exposure of P. mume seedlings to the OH radical‐generating mist had caused a reduction in the dry weight and relative growth rate (RGR) of the above‐ground parts (stem + branch) at the end of the growing season. A significant positive correlation was shown between RGR and A max . Thus, the effects of oxidants generated in polluted dew water on leaf surfaces can be considered to be a cause of the decrease in leaf photosynthesis and growth of P. mume .