Genotypic variation in the sulfur assimilation and metabolism of onion (Allium cepa L.) I. Plant composition and transcript accumulation

Handle URI:
http://hdl.handle.net/10754/561786
Title:
Genotypic variation in the sulfur assimilation and metabolism of onion (Allium cepa L.) I. Plant composition and transcript accumulation
Authors:
McCallum, John A.; Thomas, Ludivine; Shaw, Martin L.; Pither-Joyce, Meeghan D.; Leung, Susanna; Cumming, Mathew; McManus, Michael T.
Abstract:
Organosulfur compounds are major sinks for assimilated sulfate in onion (Allium cepa L.) and accumulation varies widely due to plant genotype and sulfur nutrition. In order to better characterise sulfur metabolism phenotypes and identify potential control points we compared plant composition and transcript accumulation of the primary sulfur assimilation pathway in the high pungency genotype 'W202A' and the low pungency genotype 'Texas Grano 438' grown hydroponically under S deficient (S-) and S-sufficient (S+) conditions. Accumulation of total S and alk(en)yl cysteine sulfoxide flavour precursors was significantly higher under S+ conditions and in 'W202A' in agreement with previous studies. Leaf sulfate and cysteine levels were significantly higher in 'W202A' and under S+. Glutathione levels were reduced by S- treatment but were not affected by genotype, suggesting that thiol pool sizes are regulated differently in mild and pungent onions. The only significant treatment effect observed on transcript accumulation in leaves was an elevated accumulation of O-acetyl serine thiol-lyase under S-. By contrast, transcript accumulation of all genes in roots was influenced by one or more treatments. APS reductase transcript level was not affected by genotype but was strongly increased by S-. Significant genotype × S treatment effects were observed in a root high affinity-sulfur transporter and ferredoxin-sulfite reductase. ATP sulfurylase transcript levels were significantly higher under S+ and in 'W202A'. © 2011 Elsevier Ltd. All rights reserved.
KAUST Department:
Computational Bioscience Research Center (CBRC); Core Labs
Publisher:
Elsevier BV
Journal:
Phytochemistry
Issue Date:
Jun-2011
DOI:
10.1016/j.phytochem.2011.03.006
Type:
Article
ISSN:
00319422
Appears in Collections:
Articles; Computational Bioscience Research Center (CBRC)

Full metadata record

DC FieldValue Language
dc.contributor.authorMcCallum, John A.en
dc.contributor.authorThomas, Ludivineen
dc.contributor.authorShaw, Martin L.en
dc.contributor.authorPither-Joyce, Meeghan D.en
dc.contributor.authorLeung, Susannaen
dc.contributor.authorCumming, Mathewen
dc.contributor.authorMcManus, Michael T.en
dc.date.accessioned2015-08-03T09:04:35Zen
dc.date.available2015-08-03T09:04:35Zen
dc.date.issued2011-06en
dc.identifier.issn00319422en
dc.identifier.doi10.1016/j.phytochem.2011.03.006en
dc.identifier.urihttp://hdl.handle.net/10754/561786en
dc.description.abstractOrganosulfur compounds are major sinks for assimilated sulfate in onion (Allium cepa L.) and accumulation varies widely due to plant genotype and sulfur nutrition. In order to better characterise sulfur metabolism phenotypes and identify potential control points we compared plant composition and transcript accumulation of the primary sulfur assimilation pathway in the high pungency genotype 'W202A' and the low pungency genotype 'Texas Grano 438' grown hydroponically under S deficient (S-) and S-sufficient (S+) conditions. Accumulation of total S and alk(en)yl cysteine sulfoxide flavour precursors was significantly higher under S+ conditions and in 'W202A' in agreement with previous studies. Leaf sulfate and cysteine levels were significantly higher in 'W202A' and under S+. Glutathione levels were reduced by S- treatment but were not affected by genotype, suggesting that thiol pool sizes are regulated differently in mild and pungent onions. The only significant treatment effect observed on transcript accumulation in leaves was an elevated accumulation of O-acetyl serine thiol-lyase under S-. By contrast, transcript accumulation of all genes in roots was influenced by one or more treatments. APS reductase transcript level was not affected by genotype but was strongly increased by S-. Significant genotype × S treatment effects were observed in a root high affinity-sulfur transporter and ferredoxin-sulfite reductase. ATP sulfurylase transcript levels were significantly higher under S+ and in 'W202A'. © 2011 Elsevier Ltd. All rights reserved.en
dc.publisherElsevier BVen
dc.subjectAllium cepa L.en
dc.subjectChloroplastsen
dc.subjectEnzyme activityen
dc.subjectSulfur assimilationen
dc.subjectTranscript accumulationen
dc.titleGenotypic variation in the sulfur assimilation and metabolism of onion (Allium cepa L.) I. Plant composition and transcript accumulationen
dc.typeArticleen
dc.contributor.departmentComputational Bioscience Research Center (CBRC)en
dc.contributor.departmentCore Labsen
dc.identifier.journalPhytochemistryen
dc.contributor.institutionNew Zealand Institute for Plant and Food Research Ltd., Private Bag 4704, Christchurch, New Zealanden
dc.contributor.institutionInstitute of Molecular BioSciences, Massey University, Private Bag 11222, Palmerston North, New Zealanden
kaust.authorThomas, Ludivineen
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