PJB-2013-119
OVER-EXPRESSION OF THE CODA GENE BY RD29A PROMOTER IMPROVES SALT TOLERANCE IN NICOTIANA TABACUM
JINGJIANG1,2+, HAIYING LI1,2+, GUIPING HE2+, YAFANG YIN3, MINGYING LIU1,2, BO LIU2, GUIRONG QIAO1,2, SHENG LIN1,2,4, LIHUA XIE1,2 AND RENYING ZHUO1,2*
Abstract
Soil-salinity is a serious problem that impedes food production and reforestation worldwide. In order to improve plant salt tolerance, many genes for abiotic stress have been over-expressed by genetic engineering. The codA gene encodes for the choline oxidase of the soil bacterium Arthrobacter globiformisa. We analyzed the effect of overexpression of CodA on stress tolerance in transgenic tobacco plants using the stress-inducible Rd29A promoter. Four transgenic Nicotiana tabacum plants were obtained. Southern blot analysis demonstrated that the codA gene had integrated into the genome of the tobacco. When exposed to NaCl salt stress, the chlorophyll content of the transgenic plants was not altered significantly. With prolonged stress (2-4 weeks), superoxide dismutase (SOD) activity increased by at least 50% relative to controls in all four transgenic lines. Malondialdehyde (MDA) accumulation was observed after 7 days of NaCl stress in all transgenic plants, but decreased during continued salt stress in some lines, indicative of salt stress tolerance. These results showed that the codA gene may enhance salt-tolerance by inhibiting lipid peroxidation through induction of stress response genes like SOD. These results offer additional support to the suggestion that CodA is involved in the modulation of plant gene activity in response to salt stress conditions and indicate that plants over-expressing codA could be engineered for agriculture in saline soils.
To Cite this article:
Download
