Title: Expression of an "Arabidopsis" Ca(2+)/H(+) antiporter CAX1 variant in petunia enhances cadmium tolerance and accumulation Authors
|Wu, Qingyu -|
|Shigaki, Toshiro -|
|Williams, Kimberly -|
|Han, Jeung-Sul -|
|Kim, Chang Kil -|
|Hirschi, Kendal -|
|Park, Sunghun -|
Submitted to: Journal of Plant Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 18, 2010
Publication Date: January 15, 2011
Citation: Wu, Q., Shigaki, T., Williams, K.A., Han, J., Kim, C., Hirschi, K.D., Park, S. 2011. Expression of an "Arabidopsis" Ca(2+)/H(+) antiporter CAX1 variant in petunia enhances cadmium tolerance and accumulation. Journal of Plant Physiology. 168(2):167-173. Interpretive Summary: Here we use an ornamental plant to remove toxic metals from soils. The use of plant to cleanse the environment is a process termed phytoremediation. We developed petunia plants that extract toxic metals such as cadmium for soils to cleanse the soil of the metal. The phytoremediation strategy we developed utilizes a plant transporter to extract the metal from the soil and "lock" the metal into the plant. The plant can then be cultivated and the metal removed from the environment. This work suggests that the process of phytoremediation can be done with a visually appealing ornamental plant.
Technical Abstract: Phytoremediation is a cost-effective and minimally invasive technology to cleanse soils contaminated with heavy metals. However, few plant species are suitable for phytoremediation of metals such as cadmium (Cd). Genetic engineering offers a powerful tool to generate plants that can hyperaccumulate Cd. An "Arabidopsis" CAX1 mutant (CAXcd), which confers enhanced Cd transport in yeast, was ectopically expressed in petunias to evaluate whether the CAXcd expression would enhance Cd tolerance and accumulation in "planta". The CAXcd-expressing petunia plants showed significantly greater Cd tolerance and accumulation than the controls. After being treated with either 50 or 100 microM CdCl for 6 weeks, the "CAXcd"-expressing plants showed more vigorous growth compared with controls, and the transgenic plants accumulated significantly more Cd (up to 2.5-fold) than controls. Moreover, the accumulation of Cd did not affect the development and morphology of the "CAXcd"-expressing petunia plants until the flowering and ultimately the maturing of seeds. Therefore, petunia has the potential to serve as a model species for developing herbaceous, ornamental plants for phytoremediation.