Studies On ATP Sulfurylase In Sedum Alfredii Leaves With It's Cadmium Hyperaccumulate

Phytoremediation is difined as the use of plants to decontaminate and/or remove pollutants from the environment.It has emerged as an altermative technique for removing toxic metals from soil and offers the benefits of being in situ,cost effective and environmentally sustainable plants with high metal uptake and accumulation capacity have been termed as hyperaccumulator species.Sedum Alfredii Hance(S.Alfredii) was found in an old Pb/Zn mined area,Southern China and was originally identified as a new Zn/Cd co-hyperaccumulating plant,it was probably mutants from the non-hyperaccumulating ecotypes of S.Alfredii after a considerably long period(more than one thousand years)of inhabitation the highly heavy metal polluted environments.It has an extraordinary ability to tolerate and accumulate high concentration of environmental Zn and Cd,and with the characteristics of large biomass,fast growth speed, asexual propagation and perennial.Therefore,it is an ideal plant for studying mechanisms which are responsible for hyperaccumulation and phytoremediation practice.In the early study,we found that the ATP sulfurylase in hyperaccumulate ecotype have difference with other ecotypes,and there have closely relationship between ATP sulfurylase and hyperaccumulation,so it is necessary to research the ATP sulfurylase in Sedum Alfredii.This study was conducted on cadmium accumulation and ATP sulfurylase activity in two ecotypes(hyperaccumulating ecotype HE and non-hyperaccumulating ecotype NHE)of sedum alfredii hance under different concentration cadmium and different treatment;in addition,part of the ATPS gene was cloned.The major results were summarized as follows:The results showed that the NHE ecotype root cadmium accumulation quantity is higher than the HE ecotype in each contrast experiment,but in the stem and leaf,the cadmium accumulates then is lower than the HE ecotype by far.ATPS activity in HE is higher than it in NHE in all treatments.Under the short time Cd treatment,two ecotypes of sedum alfredii hance leaf ATPS activity change tendency is similar besides the HE ecotype under 10μM cadmium,all is rises first drops again;But when the treatment time increases to 168h,NHE ecotype ATPS activity drops obviously,but the HE ecotype ATPS activity then rises obviously.Through a variety of PCR methods,part of ATPS DNA sequence and actin gene were cloned,blast results showed that:DNA sequences obtained from Tail-PCR have some similarity with ATPS protein sequence in other species;ATPS DNA sequence cloned from NHE have a significant difference compared to HE,actin gene obtained from HE and NHE have high similarity to other species actin.