The Study Of F9C22.6on Heavy Metal Cadmium Stress Response

There is an increasing threat of heavy metal cadmium pollution for human health recently. Phytoremediation is a management method that has aroused wide public concern due to more safety and more eco-friendly as well as more economy. In order to improve possibility of actual apply, researchers have been focused on how the plant respond to cadmium stress, thus comprehending deeply and constantly underlying mechanism of the plant resisting cadmium stress. With the development of study, a host of genes related to cadmium stress have been reported. These genes were mainly involved in coding plasmalemma transporter and chelation protein. It has been found that NO is also related to cadmium stress recently. The study, in order to further understand mechanism, screened cadmium sensitive mutant from Arabidopsis mutant pool, cloning a new cadmium response gene F9C22.6which encodes peptidyl-prolyl cis/trans isomerases (PPIases) that accelerate energetically unfavorable cis/trans isomerization of the peptide bond preceding proline production, thus helping protein fold accurately. The results showed that F9C22.6expression was response to cadmium stress, and expression of some genes coding plasma member protein which related to cadmium transport and some genes which were responsible for cadmium chelation were also changed in wide type, while these variations were not appeared in f9c22.6mutant. Additionally, according to contacting cadmium stress to H2S gas-transmitter, we founded that the genes related to H2S emission were increased in wide type when facing cadmium stress, while these variations were also not be indentified in f9c22.6mutant. Consequently, contrasting expression style of genes related to cadmium stress and H2S emission between wide type and f9c22.6mutant, it is supposed that H2S take part in cadmium stress process, and has relationship with cadmium sensitive phenotype of f9c22.6mutant. According to the deduction, we founded that H2S could regulate expression of some cadmium related gene and, to some extent, recover cadmium sensitive phenotype of f9c22.6mutant by using exogenous H2S dealing with both wide type and f9c22.6mutant. Finally, one possible suggestion was given:down-regulation of f9c22.6, depending on H2S gas-transmitter, not only weakened Cd2+chelation but also reduced Cd2+transportation into vacuole as well as enhancing the Cd2+assimilation, thus rendering f9c22.6mutant sensitive to cadmium stress.