Enhanced accumulation of Cd2+ by a Mesorhizobium sp. transformed with a gene from Arabidopsis thaliana coding for phytochelatin synthase.

نویسندگان

  • Rutchadaporn Sriprang
  • Makoto Hayashi
  • Hisayo Ono
  • Masahiro Takagi
  • Kazumasa Hirata
  • Yoshikatsu Murooka
چکیده

We expressed the Arabidopsis thaliana gene for phytochelatin synthase (PCS(At)) in Mesorhizobium huakuii subsp. rengei B3, a microsymbiont of Astragalus sinicus, a legume used as manure. The PCS(At) gene was expressed under the control of the nifH promoter, which regulates the nodule-specific expression of the nifH gene. The expression of the PCS(At) gene was demonstrated in free-living cells under low-oxygen conditions. Phytochelatin synthase (PCS) was expressed and catalyzed the synthesis of phytochelatins [(gamma-Glu-Cys)(n)-Gly; PCs] in strain B3. A range of PCs, with values of n from 2 to 7, was synthesized by cells that expressed the PCS(At) gene, whereas no PCs were found in control cells that harbored the empty plasmid. The presence of CdCl(2) activated PCS and induced the synthesis of substantial amounts of PCs. Cells that contained PCs accumulated 36 nmol of Cd(2+)/mg (dry weight) of cells. The expression of the PCS(At) gene in M. huakuii subsp. rengei B3 increased the ability of cells to bind Cd(2+) approximately 9- to 19-fold. The PCS protein was detected by immunostaining bacteroids of mature nodules of A. sinicus containing the PCS(At) gene. When recombinant M. huakuii subsp. rengei B3 established the symbiotic relationship with A. sinicus, the symbionts increased Cd(2+) accumulation in nodules 1.5-fold.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Yeast Two Hybrid cDNA Screening of Arabidopsis thaliana for SETH4 Protein Interaction

SETH4 coding sequence with 2013 bp is a member of gene family expressed in gametophytic tissues of Arabidopsis thaliana. This fragment was PCR amplified using Kod Hi Fi DNA polymerase enzyme. This fragment was cloned into pGBKT7 bate vector and transformed E. coli DH5? cells containing vector were selected on LB medium containing Kanamycin. Finally, pGBKT7-SETH4 bate was transformed into yeast ...

متن کامل

AtPCS1, a phytochelatin synthase from Arabidopsis: isolation and in vitro reconstitution.

Phytochelatins, a class of posttranslationally synthesized peptides, play a pivotal role in heavy metal, primarily Cd2+, tolerance in plants and fungi by chelating these substances and decreasing their free concentrations. Derived from glutathione and related thiols by the action of gamma-glutamylcysteine dipeptidyl transpeptidases (phytochelatin synthases; EC 2.3.2.15), phytochelatins consist ...

متن کامل

Fission yeast HMT1 lowers seed cadmium through phytochelatin-dependent vacuolar sequestration in Arabidopsis.

Much of our dietary uptake of heavy metals is through the consumption of plants. A long-sought strategy to reduce chronic exposure to heavy metals is to develop plant varieties with reduced accumulation in edible tissues. Here, we describe that the fission yeast (Schizosaccharomyces pombe) phytochelatin (PC)-cadmium (Cd) transporter SpHMT1 produced in Arabidopsis (Arabidopsis thaliana) was loca...

متن کامل

Negative control of Strictisidine synthase like-7 gene on salt stress resistance in Arabidopsis thaliana

Strictosidine synthase-like (SSL) is a group of gene families in the Arabidopsis genome, which whose orthologues in other plants are key enzymes in mono-terpenoid indole-alkaloid biosynthesis pathway. The SSL7 is upregulated upon treatments of Arabidopsis plants with signaling molecules such as SA, methyl jasmonate and ethylene. To find the functional role of the gene, a T-DNA-mediated knockout...

متن کامل

Tolerance to toxic metals by a gene family of phytochelatin synthases from plants and yeast.

Phytochelatins play major roles in metal detoxification in plants and fungi. However, genes encoding phytochelatin synthases have not yet been identified. By screening for plant genes mediating metal tolerance we identified a wheat cDNA, TaPCS1, whose expression in Saccharomyces cerevisiae results in a dramatic increase in cadmium tolerance. TaPCS1 encodes a protein of approximately 55 kDa with...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Applied and environmental microbiology

دوره 69 3  شماره 

صفحات  -

تاریخ انتشار 2003