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Sulfur in Brassica oleracea Gracie Gordon Michael Lorentsen James Helzberg

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Presentation on theme: "Sulfur in Brassica oleracea Gracie Gordon Michael Lorentsen James Helzberg"— Presentation transcript:

1 Sulfur in Brassica oleracea Gracie Gordon Michael Lorentsen James Helzberg pg

2 Why is Sulfur Important for Human Nutrition? Necessary for synthesis of the amino acids – Cystine – Methionine Detox functions – Toxic compounds – Free radicals – Reactive oxygen species (ROS) Glutathione (GSH) – Sulfur storage in the liver – Too little: impairs antioxidant functions – Too much: inhibits prostaglandin production (inflammation) Glucosinolates may help inhibit carcinogenesis Cystine (above) Methionine (below)

3 SO 4 2- in Soil H + /SO 4 2- co- transporter SULTR1;_ Genes (12) SO 4 2- in root cells SULTR2;_ Transporters distribute SO 4 2- (Also SULTR1;3) SO 4 2- in stem/leaves/etc. H + gradient established by PM proton ATPase Also named AST## or AT## genes. ie AST68 Uptake and Distribution of SO 4 2- Storage in vacuole Assimilation

4 Sulfate in Soil Root Uptake Transport in Xylem Vessels Important Destination=Leaves The Basics of Sulfur Transport Grossman, et al Smith, et al. 2000

5 Sulfur Transporter Structure

6 Sulfur Transporter Groups Group numberGeneral functionAssociated Genes Group 1Primary uptake of sulfate by the root Sultr1;1, Sultr1;2 - initial uptake Sultr1;3 - mediates redistribution of sulfate Group 2Mediates transport of sulfate within vascular tissues (xylem and phloem) Sultr2;1 - stem and leaf expression Sultr2;2 - root expression Group 3Not well characterizedSultr3;1, Sultr3;4 - stem expression Sultr3;2, Sultr3;5 -root expression Sultr3;3 - leaf and root expression, uptake into non vascular tissue Group 4May be responsible for sulfate efflux from vacuole Sultr4;1 Sultr4;2

7 Sultr gene comparison between Arabidopsis and B. oleracea

8 Organic Incorporation of Sulfur (assimilation) ●Reduction occurs in the plastids ○Two types of transporters have been identified ■SULTR4;1 ●Uses H + gradient ■Homologs of bacterial CysA/CysT genes ●ATPase

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10 Control of Sulfate Uptake in A. thaliana ● Sulfate uptake and sulfate accumulation are NOT coupled (Koprivova, et al.) ● Sulfate uptake is downregulated by sulfur containing compounds ○ Glutathione, Methionine ● Sulfate uptake is upregulated when Sulfur compounds are low in leaves ○ Sulfate in vacuole sequestered so cannot contribute to signaling ○ Sulfate uptake is upregulated when levels of OAS are high

11 Sulfur Related Pathway Genes Arabidopsis Gene IDFunction AT1G75270GSH-dependent dehydroascorbate reductase AT1G19570GSH-dependent dehydroascorbate reductase AT2G25080 AT3G24170Glutathione reductase, cytosolic AT1G02920Glutathione transferase AT3G43800 Glutathione transferase-like protein AT3G09270Putative glutathione transferase AT3G13110 AT3G59760 Cysteine synthase oasC AT3G03630O-acetylserine (thiol) lyase; cysteine synthase AT1G36370Putative serine hydroxymethyltransferase AT3G17390S-adenosylmethionine synthetase like AT4G01850S-adenosylmethionine synthetase 2 AT3G02470S-adenosylmethionine decarboxylase AT4G13940Adenosylhomocysteinase AT4G23100Gamma-glutamylcysteine synthetase AT5G10180 AT5G13550Sulfate transporter Sultr4;1

12 SULTR Genes (A. thaliana)

13 Our QTLs C09 19,664,943 C02 46,217,719 C01 33,168,082 A MBP A MBP A09 or A10could be near the end of 9 or the beginning of 10, possibly 2 copies?

14 References Nimni, M., Han, B., and Cordoba F Are we getting enough sulfur in our diet? Nutrition & Metabolism 4:24. Buchner, P., Stuiver, C., Westerman, S., Wirtz., Hell, R., Hawkesford, M., and De Kok, L Regulation of Sulfate Uptake and Expression of Sulfate Transporter Genes in Brassica oleracea as Affected by Atmospheric H2S and Pedospheric Sulfate Nutrition. Plant Physiology 136: Nikiforova, V., Freitag, J., Kempa, S., Adamik, M., Hesse, H., and Hoefgen, R Transcriptome analysis of sulfur depletion in arabidopsis thaliana: interlacing of biosyntheic pathways provides response specificity. The Plant Journal 33: Smith, F.W., Rae, A.L., and Hawkesford, M.J Molecular mechanisms of phosphate and sulphate transport in plants. Biochimica et Biophysica Acta 1465: Grossman, A., and Takahashi, H Macronutrient utilization by photosynthetic eukaryotes and the fabric of interactions. Annu. Rev. Plant Physiol. Plant Mol. Biol. 52: Hawkesford, M. J Plant responses to sulphur deficiency and the genetic manipulation of sulphate transporters to improve S-utilization efficiency. Journal of Experimental Botany. 51: Leustek, T., Martin, M.N., Bick, J., and Davies, J.P Pathways and Regulation of Sulfur Metabolism Revealed through Molecular and Genetic Studies. Annual Review of Plant Physiology and Plant Molecular Biology 51: Leustek, T Sulfate Metabolism. The Arabidopsis Book. Koprivova, A., Giovannetti, M., Baraniecka, P., Lee, B., Grondin, C., Loudet, O., and Kopriva, S Natural Variation in the ATPS1 Isoform of ATP Sulfurylase Contributes to the Control of Sulfate Levels in Arabidopsis. Plant Physiology 163: Takahashi, H., Yamizaki, M., Sasakuru, N., Watanabe, A., Leustek, T., Engler, J., Engler, G., Montagu, M.V., Saito, K Regulation of sulfur assimilation in higher plants; a sulfate transporter induced in sulfate-starved roots plays a central role in Arabidopsis thaliana. Plant Biology 94: Maruyama-Nakashita, A., Nakamura, Y., Yamaya, T., Takahashi, H A novel regulatory pathway of sulfate uptake in Arabidopsis roots: implication of CRE1/WOL/AHK4-mediated cytokinin-dependent regulation. The Plant Journal 38:


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