Expression of the Ced-9 (Cell Death abnormal-9) gene in transgenic Chrysanthemum morifolium can enhance drought and salt tolerances

Abstract

Abstract Salt and drought are important abiotic stresses of Chrysanthemum morifolium(Asteraceae). Limited information is available with regard to molecular management strategies for salt and drought. Ced-9 (Cell Death abnormal-9) is already known to enhance the tolerance of plants to abiotic stresses. Asteraceae plants overexpressing Ced-9 have showed improved tolerance to stresses - they kept freshness for longer time, and were fast to grow, and had higher tolerance to salt. Additional analyses revealed that transgenic plants generally show lower transpiration rate and higher chlorophyll content when subjected to salt and drought stresses. These results suggest that Ced-9 inhibits the activity of a cysteine protease with caspase-like activity and that Ced-9 also enhances salt and drought tolerances by maintaining intracellular ion balance by apparently inhibiting the external efflux of K+ induced by salt stress. Ced-9 has been proved to improve the low temperature tolerance of asteraceae plants by controlling 2,4-D signal and other pathways responding to stresses.