RRC ID 3988
Author Tamaoki M, Freeman JL, Pilon-Smits EA.
Title Cooperative ethylene and jasmonic acid signaling regulates selenite resistance in Arabidopsis.
Journal Plant Physiol
Abstract Selenium (Se) is an essential element for many organisms, but excess Se is toxic. To better understand plant Se toxicity and resistance mechanisms, we compared the physiological and molecular responses of two Arabidopsis (Arabidopsis thaliana) accessions, Columbia (Col)-0 and Wassilewskija (Ws)-2, to selenite treatment. Measurement of root length Se tolerance index demonstrated a clear difference between selenite-resistant Col-0 and selenite-sensitive Ws-2. Macroarray analysis showed more pronounced selenite-induced increases in mRNA levels of ethylene- or jasmonic acid (JA)-biosynthesis and -inducible genes in Col-0 than in Ws-2. Indeed, Col-0 exhibited higher levels of ethylene and JA. The selenite-sensitive phenotype of Ws-2 was attenuated by treatment with ethylene precursor or methyl jasmonate (MeJA). Conversely, the selenite resistance of Col-0 was reduced in mutants impaired in ethylene or JA biosynthesis or signaling. Genes encoding sulfur (S) transporters and S assimilation enzymes were up-regulated by selenite in Col-0 but not Ws-2. Accordingly, Col-0 contained higher levels of total S and Se and of nonprotein thiols than Ws-2. Glutathione redox status was reduced by selenite in Ws-2 but not in Col-0. Furthermore, the generation of reactive oxygen species by selenite was higher in Col-0 than in Ws-2. Together, these results indicate that JA and ethylene play important roles in Se resistance in Arabidopsis. Reactive oxygen species may also have a signaling role, and the resistance mechanism appears to involve enhanced S uptake and reduction.
Volume 146(3)
Pages 1219-30
Published 2008-3-1
DOI 10.1104/pp.107.110742
PII pp.107.110742
PMID 18178671
PMC PMC2259059
MeSH Adaptation, Biological / genetics* Arabidopsis / genetics Arabidopsis / metabolism* Cyclopentanes / metabolism* Ethylenes / metabolism* Gene Expression Oxylipins / metabolism* Reactive Oxygen Species / metabolism Signal Transduction / physiology Sodium Selenite / metabolism* Sulfur / metabolism Up-Regulation
IF 6.902
Times Cited 104
Arabidopsis / Cultured plant cells, genes pda