Expression profiling of metabolic genes in response to methyl jasmonate reveals regulation of genes of primary and secondary sulfur-related pathways in Arabidopsis thaliana

Abstract

The treatment of Arabidopsis thaliana with methyl jasmonate was used to investigate the reaction of 2467 selected genes of primary and secondary metabolism by macroarray hybridization. Hierarchical cluster analysis allowed distinctions to be made between diurnally and methyl jasmonate regulated genes in a time course from 30 min to 24 h. 97 and 64 genes were identified that were up- or down-regulated more than 2-fold by methyl jasmonate, respectively. These genes belong to 18 functional categories of which sulfur-related genes were by far strongest affected. Gene expression and metabolite patterns of sulfur metabolism were analysed in detail, since numerous defense compounds contain oxidized or reduced sulfur. Genes encoding key reactions of sulfate reduction as well as of cysteine, methionine and glutathione synthesis were rapidly up-regulated, but none of the known sulfur-deficiency induced sulfate transporter genes. In addition, increased expression of genes of sulfur-rich defense proteins and of enzymes involved in glucosinolate metabolism was observed. In contrast, profiling of primary and secondary sulfur metabolites revealed only an increase in the indole glucosinolate glucobrassicin upon methyl jasmonate treatment. The observed rapid mRNA changes were thus regulated by a signal independent of the known sulfur deficiency response. These results document for the first time how comprehensively the regulation of sulfur-related genes and plant defense are connected. This interaction is discussed as a new approach to differentiate between supply- and demand-driven regulation of the sulfate assimilation pathway.

Chloroplastic Phosphoadenosine Phosphosulfate Metabolism Regulates Basal Levels of the Prohormone Jasmonic Acid in Arabidopsis Leaves

“…JA application strongly activates the expression of several genes of the S-reduction pathway in Arabidopsis (Jost et al, 2005;Sasaki-Sekimoto et al, 2005). Likewise, plants undergoing S-starvation responses show enhanced expression of JA-related genes (Hirai et al, 2003;Maruyama-Nakashita et al, 2003;Nikiforova et al, 2003).…”

“…Other evidence links both S reduction and oxidized S (SO 4 22 ) metabolism and JA responses. For example, treatment with exogenous jasmonate strongly up-regulates the expression of a number of genes involved in S reduction and in Cys, Met, and glutathione (GSH) synthesis (Jost et al, 2005;Sasaki-Sekimoto et al, 2005). A more recent study has greatly extended knowledge of how oxidized S metabolism may impinge on jasmonate responses in plants.…”

Molecular Mechanisms of Selenium Tolerance and Hyperaccumulation in Stanleya pinnata

“…We hypothesized that the positive effects of these hormones on Se tolerance may be due to up-regulation of S uptake and assimilation. MeJA has been shown to up-regulate genes involved in primary and secondary S-related pathways (Jost et al, 2005). After selenite treatment, genes encoding key reactions of sulfate assimilation and glutathione synthesis were indeed up-regulated in Arabidopsis (Tamaoki et al, 2008b).…”

Mitochondrial Serine Acetyltransferase Functions as a Pacemaker of Cysteine Synthesis in Plant Cells

“…Thus, the 4-fold lowered OAS and doubled thiol steady-state levels in amiSAT3 lines may, independently or in combination, act as signals for the repression of Apr2 in amiSAT3 lines. MJ has been shown to modulate expression levels of sulfate assimilation-related genes (Jost et al, 2005;Sasaki-Sekimoto et al, 2005). According to microarray analysis of the amiSAT3 line 5 ST2a, a hydroxyjasmonate sulfotransferase, which is supposed to inactivate jasmonic acid signals (Gidda et al, 2003), is one of the strongest responding genes.…”