title: Remediation of cadmium toxicity in field peas (Pisum sativum L.) through exogenous silicon.
abstract: Cadmium (Cd) is an important phytotoxic element causing health hazards. This work investigates whether and how silicon (Si) influences the alleviation of Cd toxicity in field peas at biochemical and molecular level. The addition of Si in Cd-stressed plants noticeably increased growth and development as well as total protein and membrane stability of Cd-stressed plants, suggesting that Si does have critical roles in Cd detoxification in peas. Furthermore, Si supplementation in Cd-stressed plants showed simultaneous significant increase and decrease of Cd and Fe in roots and shoots, respectively, compared with Cd-stressed plants. At molecular level, GSH1 (phytochelatin precursor) and MTA(metallothionein) transcripts predominantly expressed in roots and strongly induced due to Si supplementation in Cd-stressed plants compared with Cd-free conditions, suggesting that these chelating agents may bind to Cd leading to vacuolar sequestration in roots. Furthermore, pea Fe transporter (RIT1) showed downregulation in shoots when plants were treated with Si along with Cd compared with Cd-treated conditions. It is consistent with the physiological observations and supports the conclusion that alleviation of Cd toxicity in pea plants might be associated with Cd sequestration in roots and reduced Cd translocation in shoots through the regulation of Fe transport. Furthermore, increased CAT, POD, SOD and GR activity along with elevated S-metabolites (cysteine, methionine, glutathione) implies the active involvement of ROS scavenging and plays, at least in part, to the Si-mediated alleviation of Cd toxicity in pea. The study provides first mechanistic evidence on the beneficial effect of Si on Cd toxicity in pea plants.
authors.affiliation: Department of Botany, University of Rajshahi, Rajshahi 6205, Bangladesh.
authors.forename: Mohammad Farhadur
authors.initials: MF
authors.lastname: Rahman
authors.affiliation: Department of Biology, Massachusetts Institute of Technology (MIT), MA 02139, United States.
authors.forename: Anubrata
authors.initials: A
authors.lastname: Ghosal
authors.affiliation: Department of Botany, University of Rajshahi, Rajshahi 6205, Bangladesh.
authors.forename: Mohammad Firoz
authors.initials: MF
authors.lastname: Alam
authors.affiliation: Department of Botany, University of Rajshahi, Rajshahi 6205, Bangladesh. Electronic address: ahmad.kabifigr@ru.ac.bd.
authors.forename: Ahmad Humayan
authors.initials: AH
authors.lastname: Kabir
mesh_terms: D002104:Cadmium / Q000378:metabolism* / Q000633:toxicity; D002374:Catalase / Q000378:metabolism; D003545:Cysteine / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D007501:Iron / Q000378:metabolism; D008668:Metallothionein / Q000235:genetics / Q000378:metabolism; D008715:Methionine / Q000378:metabolism; D018532:Pisum sativum / Q000187:drug effects* / Q000254:growth & development; D009195:Peroxidase / Q000378:metabolism; D054811:Phytochelatins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects* / Q000378:metabolism; D018520:Plant Shoots / Q000187:drug effects / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D012825:Silicon / Q000494:pharmacology*; D013312:Stress, Physiological / Q000187:drug effects*; D013482:Superoxide Dismutase / Q000378:metabolism; D014131:Trace Elements / Q000494:pharmacology*
chemical_list: D017382:Reactive Oxygen Species; D014131:Trace Elements; D002104:Cadmium; D008668:Metallothionein; D054811:Phytochelatins; D008715:Methionine; D007501:Iron; D002374:Catalase; D009195:Peroxidase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase; D005978:Glutathione; D003545:Cysteine; D012825:Silicon
keywords: Antioxidant defense; Cd sequestration; Fe translocation; Field peas; RIT1