title: Expression of an Arabidopsis Ca2+/H+ antiporter CAX1 variant in petunia enhances cadmium tolerance and accumulation.
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 petunia 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 100μM CdCl(2) 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.
authors.affiliation: Department of Horticulture, Forestry and Recreation Resources, Kansas State University, Manhattan, KS 66506, USA.
authors.forename: Qingyu
authors.initials: Q
authors.lastname: Wu
authors.forename: Toshiro
authors.initials: T
authors.lastname: Shigaki
authors.forename: Kimberly A
authors.initials: KA
authors.lastname: Williams
authors.forename: Jeung-Sul
authors.initials: JS
authors.lastname: Han
authors.forename: Chang Kil
authors.initials: CK
authors.lastname: Kim
authors.forename: Kendal D
authors.initials: KD
authors.lastname: Hirschi
authors.forename: Sunghun
authors.initials: S
authors.lastname: Park
mesh_terms: D017920:Antiporters / Q000235:genetics / Q000378:metabolism*; D001673:Biodegradation, Environmental; D002104:Cadmium / Q000378:metabolism* / Q000633:toxicity*; D027682:Cation Transport Proteins / Q000235:genetics / Q000378:metabolism*; D032306:Petunia / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000187:drug effects / Q000235:genetics / Q000378:metabolism
chemical_list: D017920:Antiporters; D027682:Cation Transport Proteins; C027614:calcium-hydrogen antiporters; D002104:Cadmium