Influence of Sulfur Deficiency on the Expression of Specific Sulfate Transporters and the Distribution of Sulfur, Selenium, and Molybdenum in Wheat

Abstract

Interactions between sulfur (S) nutritional status and sulfate transporter expression in field-grown wheat (Triticum aestivum) were investigated using Broadbalk +S and 2S treatments (S fertilizer withheld) at Rothamsted, United Kingdom. In 2008, S, sulfate, selenium (Se), and molybdenum (Mo) concentrations and sulfate transporter gene expression were analyzed throughout development. Total S concentrations were lower in all tissues of 2S plants, principally as a result of decreased sulfate pools. S, Se, and Mo concentrations increased in vegetative tissues until anthesis, and thereafter, with the exception of Mo, decreased until maturity. At maturity, most of the S and Se were localized in the grain, indicating efficient remobilization from vegetative tissues, whereas less Mo was remobilized. At maturity, Se and Mo were enhanced 7-and 3.7-fold, respectively, in 2S compared with +S grain, while grain total S was not significantly reduced. Enhanced expression of sulfate transporters, for example Sultr1;1 and Sultr4;1, in 2S plants explains the much increased accumulation of Se and Mo (7-and 3.7-fold compared with +S in grain, respectively). Sultr5;2 (mot1), thought to be involved in Mo accumulation in Arabidopsis (Arabidopsis thaliana), did not fully explain patterns of Mo distribution; it was expressed in all tissues, decreasing in leaf and increasing in roots under 2S conditions, and was expressed in florets at anthesis but not in grain at any other time. In conclusion, S fertilizer application has a marked impact on Mo and Se distribution and accumulation, which is at least partially a result of altered gene expression of the sulfate transporter family.

A Comparison of Sulfate and Selenium Accumulation in Relation to the Expression of Sulfate Transporter Genes in Astragalus Species

“…Selenate supply had little effect on transcript abundance, and S starvation only resulted in a slight increase in the expression of group 1 and group 4 transporters in root tissues. This is in contrast to observations with other species, where the expression of many sulfate transporters has been shown to be highly induced by sulfate starvation (Smith et al, 1995(Smith et al, , 1997Takahashi et al, 2000;Shibagaki et al, 2002;Yoshimoto et al, 2002Yoshimoto et al, , 2003Howarth et al, 2003;Buchner et al, 2004aBuchner et al, , 2004bHopkins et al, 2004Hopkins et al, , 2005Koralewska et al, 2008Koralewska et al, , 2009Rouached et al, 2008;Shinmachi et al, 2010). The expression of one group 1 isoform, Sultr1;1, and one group 2 isoform, Sultr2;1, has also been shown to be induced by increased Se supply (Takahashi et al, 2000).…”

“…Several studies have shown that a decrease in root sulfate availability results in a severalfold enhanced expression of sulfate transporter genes, which enhances the capacity for sulfate uptake and consequently enhances the uptake of Se (Hawkesford, 2000;Hawkesford et al, 2003;Shinmachi et al, 2010).…”

Enhanced Iron and Selenium Uptake in Plants by Volatile Emissions of Bacillus amyloliquefaciens (BF06)

“…Activating sulfate transporter is conducive to promoting Se uptake and translocation from roots to shoots in plants [51][52][53][54]. In this study, the data of RNA-Seq revealed that the release of VOCs released by BF06 induced the expression of sulfate transporter genes including SULRT1;1, SULRT1;2, SULTR2;1, SULTR2;2 and SULTR3;5, indicating that BF06 VOCs was likely involved in the regulation of Se uptake in Arabidopsis.…”

“…In addition, the transcription of several sulfate transporter genes was significantly increased in the VOCs-exposed plants compared with the controls (Table S4). These sulfate transporter genes have been demonstrated to play essential roles in Se assimilation in Arabidopsis plants [51][52][53][54]. Thus, the VOCs-induced expression of sulfate transporter genes might participate in the regulation of Se accumulation in plants.…”

Molybdate Alters Sulfate Assimilation and Induces Oxidative Stress in White Clover (Trifolium repens L.)

“…After absorption, Mo served as a substrate of the reaction catalyzed by ATPs, but there was no molybdenum-containing product from this reaction due to adenosine 5'-phosphomolybdate was either not formed or not stable (Reuveny, 1977). It has been speculated that Mo could compete with sulfate ion for sulfate transporter and ATPs enzyme resulting in a lower sulfate metabolism and wasteful use of ATP (Hale et al, 2001;Shinmachi et al, 2010). MOT1 was up-regulated in B. juncea plants supplied with Mo, and the increase of Mo transporter accompanied with an accumulation of Mo in both roots and leaves (Schiavon et al, 2012).…”