The effect of silicon on the leaf proteome of rice (Oryza sativa L.) plants under cadmium-stress.
The best known silicon (Si)-accumulating plant, rice (Oryza sativa L.), stores most of its Si in leaves, but the importance of Si has been limited to a mechanical role. Our initial studies showed that Si-induced cadmium (Cd) tolerance is mediated by the enhancement of instantaneous water-use-efficiency, carboxylation efficiency of ribulose-1,5-bisphosphate carboxylase oxygenase (RuBisCO), and light-use-efficiency in leaves of rice plants. In this study, we investigated changes in the rice leaf proteome in order to identify molecular mechanisms involved in Si-induced Cd tolerance. Our study identified 60 protein spots that were differentially regulated due to Cd and/or Si treatments. Among them, 50 were significantly regulated by Si, including proteins associated with photosynthesis, redox homeostasis, regulation/protein synthesis, pathogen response and chaperone activity. Interestingly, we observed a Si-induced up-regulation of a class III peroxidase and a thaumatin-like protein irrespective of Cd treatment, in addition to a Cd-induced up-regulation of protein disulfide isomerase, a HSP70 homologue, a NADH-ubiquinone oxidoreductase, and a putative phosphogluconate dehydrogenase, especially in the presence of Si. Taken together, our study sheds light on molecular mechanisms involved in Si-induced Cd tolerance in rice leaves and suggests a more active involvement of Si in plant physiological processes than previously proposed.
Department of Microbiology, Miami University, Oxford, Ohio 45056, USA. nwugocc@muohio.edu
Chika C
CC
Nwugo
Alfredo J
AJ
Huerta
D002104:Cadmium / Q000494:pharmacology*; D053858:Metabolic Networks and Pathways / Q000187:drug effects; D012275:Oryza / Q000187:drug effects* / Q000378:metabolism; D018515:Plant Leaves / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D010940:Plant Proteins / Q000032:analysis* / Q000378:metabolism; D020543:Proteome / Q000032:analysis / Q000378:metabolism*; D040901:Proteomics; D015398:Signal Transduction / Q000187:drug effects; D012825:Silicon / Q000494:pharmacology*; D013312:Stress, Physiological / Q000187:drug effects
D010940:Plant Proteins; D020543:Proteome; D002104:Cadmium; D012825:Silicon