In silico assessment of gene function involved in cysteine biosynthesis in Arabidopsis: expression analysis of multiple isoforms of serine acetyltransferase

Noji, Masaaki; Kawashima, Cintia Goulart; Obayashi, Takeshi; Saito, Kazuki

doi:10.1007/s00726-005-0253-2

Cited by 8 publications

(5 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Mutation of ATPS1 resulted in reduction of flux in both organs, particularly during sulfate starvation. Reduction in ATPS4 expression led to similar effects on the flux, however, under normal sulfate supply, the reduction of flux in leaves was not statistically significant, which agrees with predominant expression of this isoform in the roots (Noji et al. , 2006).…”

Section: Resultsmentioning

confidence: 56%

Interplay of SLIM1 and miR395 in the regulation of sulfate assimilation in Arabidopsis

et al. 2011

View full text Add to dashboard Cite

SUMMARYMicroRNAs play a key role in the control of plant development and response to adverse environmental conditions. For example, microRNA395 (miR395), which targets three out of four isoforms of ATP sulfurylase, the first enzyme of sulfate assimilation, as well as a low-affinity sulfate transporter, SULTR2;1, is strongly induced by sulfate deficiency. However, other components of sulfate assimilation are induced by sulfate starvation, so that the role of miR395 is counterintuitive. Here, we describe the regulation of miR395 and its targets by sulfate starvation. We show that miR395 is important for the increased translocation of sulfate to the shoots during sulfate starvation. MiR395 together with the SULFUR LIMITATION 1 transcription factor maintain optimal levels of ATP sulfurylase transcripts to enable increased flux through the sulfate assimilation pathway in sulfate-deficient plants. Reduced expression of ATP sulfurylase (ATPS) alone affects both sulfate translocation and flux, but SULTR2;1 is important for the full rate of sulfate translocation to the shoots. Thus, miR395 is an integral part of the regulatory circuit controlling plant sulfate assimilation with a complex mechanism of action.

show abstract

Section: Resultsmentioning

confidence: 56%

Interplay of SLIM1 and miR395 in the regulation of sulfate assimilation in Arabidopsis

et al. 2011

View full text Add to dashboard Cite

show abstract

“…A similar reduction of levels of APS4 , but not the other two targets, could be observed in B. napus WT roots grown under sulfur starvation (figure 6B). These results indicate that APS4 mRNA might be a target of miR395 in roots, and interestingly, this mRNA has previously been shown to exhibit root-specific expression [40]. The observation that the other miR395 target SULTR2;1 was up- and not down-regulated under -S conditions (figure 6A and 6B, [39]) was earlier explained by the spatially differential expression of SULTR2;1 and miR395 in xylem parenchyma and companion cells, respectively [39].…”

Section: Resultsmentioning

confidence: 71%

Phloem small RNAs, nutrient stress responses, and systemic mobility

et al. 2010

View full text Add to dashboard Cite

BackgroundNutrient availabilities and needs have to be tightly coordinated between organs to ensure a balance between uptake and consumption for metabolism, growth, and defense reactions. Since plants often have to grow in environments with sub-optimal nutrient availability, a fine tuning is vital. To achieve this, information has to flow cell-to-cell and over long-distance via xylem and phloem. Recently, specific miRNAs emerged as a new type of regulating molecules during stress and nutrient deficiency responses, and miR399 was suggested to be a phloem-mobile long-distance signal involved in the phosphate starvation response.ResultsWe used miRNA microarrays containing all known plant miRNAs and a set of unknown small (s) RNAs earlier cloned from Brassica phloem sap [1], to comprehensively analyze the phloem response to nutrient deficiency by removing sulfate, copper or iron, respectively, from the growth medium. We show that phloem sap contains a specific set of sRNAs that is distinct from leaves and roots, and that the phloem also responds specifically to stress. Upon S and Cu deficiencies phloem sap reacts with an increase of the same miRNAs that were earlier characterized in other tissues, while no clear positive response to -Fe was observed. However, -Fe led to a reduction of Cu- and P-responsive miRNAs. We further demonstrate that under nutrient starvation miR399 and miR395 can be translocated through graft unions from wild type scions to rootstocks of the miRNA processing hen1-1 mutant. In contrast, miR171 was not transported. Translocation of miR395 led to a down-regulation of one of its targets in rootstocks, suggesting that this transport is of functional relevance, and that miR395, in addition to the well characterized miR399, could potentially act as a long-distance information transmitter.ConclusionsPhloem sap contains a specific set of sRNAs, of which some specifically accumulate in response to nutrient deprivation. From the observation that miR395 and miR399 are phloem-mobile in grafting experiments we conclude that translocatable miRNAs might be candidates for information-transmitting molecules, but that grafting experiments alone are not sufficient to convincingly assign a signaling function.

show abstract

“…1B) and the number of ESTs in The Arabidopsis Information Resource (TAIR; http://www. arabidopsis.org; Noji et al, 2006; Fig. 1C).…”

Section: Expression Analysis Indicates That Four Bsas Genes Are Presumentioning

confidence: 99%

Physiological Roles of the β-Substituted Alanine Synthase Gene Family in Arabidopsis

Watanabe

Kusano²,

Oikawa³

et al. 2007

Plant Physiology

161

164

View full text Add to dashboard Cite

The b-substituted alanine (Ala) synthase (Bsas) family in the large superfamily of pyridoxal 5#-phosphate-dependent enzymes comprises cysteine (Cys) synthase (CSase) [O-acetyl-serine (thiol) lyase] and b-cyano-Ala synthase (CASase) in plants. Nine genomic sequences encode putative Bsas proteins in Arabidopsis thaliana. The physiological roles of these Bsas isoforms in vivo were investigated by the characterization of T-DNA insertion mutants. Analyses of gene expression, activities of CSase and CASase, and levels of Cys and glutathione in the bsas mutants indicated that cytosolic Bsas1;1, plastidic Bsas2;1, and mitochondrial Bsas2;2 play major roles in Cys biosynthesis. Cytosolic Bsas1;1 has the most dominant contribution both in leaf and root, and mitochondrial Bsas2;2 plays a significant role in root. Mitochondrial Bsas3;1 is a genuine CASase. Nontargeted metabolome analyses of knockout mutants were carried out by a combination of gas chromatography time-offlight mass spectrometry and capillary electrophoresis time-of-flight mass spectrometry. The level of g-glutamyl-b-cyano-Ala decreased in the mutant bsas3;1, indicating the crucial role of Bsas3;1 in b-cyano-Ala metabolism in vivo.

show abstract

In silico assessment of gene function involved in cysteine biosynthesis in Arabidopsis: expression analysis of multiple isoforms of serine acetyltransferase

Cited by 8 publications

References 40 publications

Interplay of SLIM1 and miR395 in the regulation of sulfate assimilation in Arabidopsis

Interplay of SLIM1 and miR395 in the regulation of sulfate assimilation in Arabidopsis

Phloem small RNAs, nutrient stress responses, and systemic mobility

Physiological Roles of the β-Substituted Alanine Synthase Gene Family in Arabidopsis

Contact Info

Product

Resources

About