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Coronatine Enhances Chilling Tolerance in Cucumber ( Cucumis sativus L.) Seedlings by Improving the Antioxidative Defence System
Author(s) -
Wang L.,
Chen W. J.,
Wang Q.,
Eneji A. E.,
Li Z. H.,
Duan L. S.
Publication year - 2009
Publication title -
journal of agronomy and crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.095
H-Index - 74
eISSN - 1439-037X
pISSN - 0931-2250
DOI - 10.1111/j.1439-037x.2009.00378.x
Subject(s) - cucumis , malondialdehyde , apx , coronatine , catalase , chemistry , superoxide dismutase , horticulture , peroxidase , antioxidant , shoot , botany , biology , enzyme , biochemistry , arabidopsis , gene , mutant
Coronatine (COR) is a new plant growth regulator that mimics the biological activities of methyl jasmonate. We determined whether COR enhanced chilling tolerance of cucumber ( Cucumis sativus L. cv. Jinchun 4) seedlings and if such tolerance was correlated with changes in the activity of antioxidant enzymes. COR was applied to seedlings at two‐leaf stage at 0 (Control), 0.1, 1, 10, and 100 n m . Seedlings were then subjected to chilling stress at 5 ± 1 °C for 4 days. Seedlings treated with COR showed significant higher tolerance to chilling stress and the optimal concentration was 1–10 n m . Compared with control, the chilling injury index (CII) of the seedlings treated with COR at 1 and 10 n m was decreased by 44.9 % and 24.5 %, respectively, while the membrane chilling stability (MCS) expressed as the change of relative conductance was increased by 37.2 % and 17.0 %, respectively. The malondialdehyde (MDA) content in leaves treated with COR at 1 n m was decreased by 39.7 %, and the O 2 − production rate and H 2 O 2 content reduced by 28.6 % and 8.5 %, respectively. Treatment with COR at 1 n m increased the activities of superoxide dismutase (SOD) in leaves by 34.4 %, catalase (CAT) by 58.7 % and ascorbate peroxidase (APX) by 23.0 % under low temperature. The 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical scavenging activities were also significantly improved by 28.9 % and 21.3 % following treatment with COR at 1 and 10 n m , respectively. The overall results suggest that COR enhanced chilling tolerance in cucumber seedlings by improving the antioxidative defence system.