[Plant sulfate assimilation and regulation of the activity of related enzymes under cadmium stress].
The complexation and sequestration of heavy metal ions (e.g. Cd) by the cysteine-rich polypeptides known as phytochelatins (PC) are thought to confer heavy metal hyperaccumulation and tolerance in some plant species. PC is synthesized enzymatically from glutathione. The tripeptide glutathione is a product of primary sulfur metabolism. A variety of enzymes or proteins are involved in sulfur assimilation including sulfate transporters (STs), ATP sulfurylase (ATPS), APS reductase (APSR), sulfite reductase (SiR), glutathione synthetase (GS) and phytochelatin synthesis (PCS). These enzymes or proteins are upstream-regulated by Cd at either the metabolic or the genetic level under metal stress. Increasing evidence shows that enhancement of sulfate uptake and reduction occurs with the production of PC in plants under heavy metal stress. In this article, the key aspects of our recent understanding of regulatory mechanisms involved in the relation between the sulfate assimilation and phytochelatin synthesis are described.
Sun
Xue-Mei
XM
Department of Biochemistry and Molecular Biology, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China.
Yang
Zhi-Min
ZM
D001729:Bismuth; D002104:Cadmium / Q000494:pharmacology*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D009942:Organometallic Compounds; D050862:Oxidoreductases Acting on Sulfur Group Donors / Q000378:metabolism; D054811:Phytochelatins / Q000096:biosynthesis*; D010944:Plants / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D012459:Salicylates; D013430:Sulfate Adenylyltransferase / Q000378:metabolism; D013431:Sulfates / Q000378:metabolism*
D009942:Organometallic Compounds; D012459:Salicylates; D013431:Sulfates; D002104:Cadmium; C015715:bismuth subsalicylate; D054811:Phytochelatins; D050862:Oxidoreductases Acting on Sulfur Group Donors; C019618:adenylylsulfate reductase; D013430:Sulfate Adenylyltransferase; D001729:Bismuth