Overexpression of tomato tAPX gene in tobacco improves tolerance to high or low temperature stress
In order to investigate the function of chloroplast ascorbate peroxidase under temperature stress, the thylakoid-bound ascorbate peroxidase gene from tomato leaf (TtAPX) was introduced into tobacco. Transformants were selected for their ability to grow on medium containing kanamycin. RNA gel blot analysis confirmed that TtAPX in tomato was induced by chilling or heat stress. Over-expression of TtAPX in tobacco improved seed germination under temperature stress. Two transgenic tobacco lines showed higher ascorbate peroxidase activity, accumulated less hydrogen peroxide and malondialdehyde than wild type plants under stress condition. The photochemical efficiency of photosystem 2 in the transgenic lines was distinctly higher than that of wild type plants under chilling and heat stresses. Results indicated that the over-expression of TtAPX enhanced tolerance to temperature stress in transgenic tobacco plants.
Additional key wordsLycopersicum esculentum malondialdehyde Nicotiana tabacum photosystem 2 thylakoid-bound ascorbate peroxidase transgenic tobacco
variable to maximum fluorescence ratio (maximum photochemical efficiency of PS 2)
net photosynthetic rate
- PS 2
relative electrolyte leakage
reactive oxygen species
sodium dodecyl sulfate
standard saline citrate
thylakoid-bound ascorbate peroxidase
tomato thylakoid-bound ascorbate peroxidase gene
wild type plant
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This research was supported by the State Key Basic Research and Development Plan of China (2009CB118500), the Natural Science Foundation of China (30871458) and Program for Changjiang Scholars and Innovative Research Team in University (Grant IRT0635).
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