Inhibition of systemic onset of post‐transcriptional gene silencing by non‐toxic concentrations of cadmium

• Published in: The Plant journal : for cell and molecular biology Vol. 28; no. 3; pp. 283 - 291
• Main Authors: Ueki, Shoko, Citovsky, Vitaly
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01.11.2001; Blackwell Science
• Subjects: Biological and medical sciences; cadmium; Cadmium - pharmacology; Fundamental and applied biological sciences. Psychology; Gene expression; Gene Expression Regulation, Plant - drug effects; gene silencing; Gene Silencing - drug effects; heavy metal ions; Molecular and cellular biology; Molecular genetics; Mutation; Nicotiana - drug effects; Nicotiana - metabolism; Pathology. Damages, economic importance; Phytopathology. Animal pests. Plant and forest protection; Plant viruses and viroids; Plants - genetics; Plants - virology; Plants, Genetically Modified; post-transcriptional gene silencing; post‐transcriptional gene silencing (PTGS); RNA Processing, Post-Transcriptional; systemic spread; Tobamovirus; tobamoviruses; Cadmium; Plant pathogen; Induction; Biological transport; Stimulant plant; Tobamovirus; Nicotiana tabacum; Heavy metal; Dose activity relation; Posttranscriptional modification; Virus; Gene silencing; Regulation(control); Phytotoxicity; Dicotyledones; Angiospermae; Systemic disease; Poison; Spermatophyta; Solanaceae; Inhibition; Conductive tissue; Mechanism of action
• ISSN: 0960-7412; 1365-313X
• DOI: 10.1046/j.1365-313X.2001.01145.x

Summary Post‐transcriptional gene silencing (PTGS) is an important mechanism for regulation of plant gene expression and virus–plant interactions. To better understand this process, the heavy metal cadmium was identified as a specific inhibitor in two different PTGS systems, constitutive and inducible. The pattern of cadmium‐induced inhibition of PTGS allowed several insights into PTGS development. First, cadmium treatment prevented only systemic but not local onset of PTGS, uncoupling between these two modes of PTGS. Second, non‐toxic, but not toxic, levels of cadmium inhibited PTGS, suggesting induction of a pathway that interferes with PTGS. Third, cadmium effects on PTGS closely paralleled those on the movement of tobamoviruses, suggesting that both processes may share common steps in their systemic transport pathways. Interestingly, these effects of cadmium do not represent a general property of toxic metal ions because two other such elements, that is zinc and aluminum, did not interfere with PTGS and viral systemic movement.