[Effects of exogenous salicylic acid on membrane lipid peroxidation and photosynthetic characteristics of Cucumis sativus seedlings under drought stress].
To approach the related mechanisms of exogenous salicylic acid (SA) in improving plant drought-resistance, this paper studied the effects of applying exogenous SA to the rhizosphere on the plant growth, membrane lipid peroxidation, proline accumulation, water use efficiency, net photosynthetic rate (Pn), and chlorophyll fluorescence parameters of cucumber (Cucumis sativus) seedlings under drought stresses (60% and 50% of saturated water capacity). Applying SA relieved the inhibitory effects of drought stress on plant growth, Pn, and water use efficiency, decreased membrane lipid peroxidation, and promoted proline accumulation. Meanwhile, the SA decreased the decrements of the maximum photochemical efficiency of PS II, actual photochemical efficiency of PS II, potential activity of PS II, effective photochemical efficiency of PS II, and photochemical quenching coefficient under drought stress significantly, and limited the increase of non-photochemical quenching coefficient. All the results suggested that applying exogenous SA could alleviate the oxidation damage of cell membrane resulted from the drought-caused membrane lipid peroxidation, improve the Pn by increasing PS II activity to benefit water utilization, enhance the regulation capability of osmosis to decrease water loss and increase water use efficiency, and thereby, improve the plant drought-resistance.
Ministry of Agriculture Key Laboratory of Horticultural Crop Biology and Germplasm Innovation, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China. haojinghongzj@yahoo.com.cn
Jing-Hong
JH
Hao
Yang
Y
Yi
Qing-Mao
QM
Shang
Chun-Juan
CJ
Dong
Zhi-Gang
ZG
Zhang
D018553:Cucumis sativus / Q000378:metabolism / Q000502:physiology*; D055864:Droughts; D015227:Lipid Peroxidation / Q000187:drug effects*; D008563:Membrane Lipids / Q000378:metabolism; D010788:Photosynthesis / Q000502:physiology*; D020156:Salicylic Acid / Q000494:pharmacology*; D036226:Seedlings / Q000378:metabolism / Q000502:physiology; D013312:Stress, Physiological / Q000187:drug effects
D008563:Membrane Lipids; D020156:Salicylic Acid