This study has investigated the involvement of photosynthetic electron transport chain on the regulation of gene expression of methionine sulfoxide reductase (UfMSR) in the marine macroalga Ulva fasciata Delile.UfMSRA is from copper stress and UfMSRB ir from hypersalinity stress. UfMSRA is similar to Arabidopsis AtMSRA4 and UfMSRB is similar to AtMSRB1. UfMSRA is specific to the MetSO S-enantiomer and UfMSRB catalytically reduces the MetSO R-enantiomer. Both enzymes are required, since in the cell oxidation of Met residues at the sulfur atom results in a racemic mixture of the two stereoisomers. UfMSRA and UfMSRB transcripts were increased by white light, blue light and red light with the maximum at 1 h following a decline, but kept constant in the dark. The magnitude of UfMSRA and UfMSRB transcript increase showed a positive linear correlation to increasing light intensity from 0-1200 u mole¡Pm-2¡Ps-1. The treatment with linear electron transport
chain inhibitors, hydroxylamine, 3-(3,4-dichlorophenyl) -1,1-dimethylurea (DCMU),
2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone (DBMIB) and stigmatellin,
effectively inhibited PS II activity under 300 u mole¡Pm-2¡Ps-1 irradiance. DBMIB and
stigmatellin can increase UfMSRA transcript that was reversed by
2,6-dichlorophenolindophenol (DCPIP), a PS I electron donor. It indicates that the
block of electron transport of the downstream of cytochrome b6f indeuces UfMSRA
gene expression. Hydroxylamine, DCMU and DBMIB decreased UfMSRB transcript
that was not reversed by DCPIP while stigmatellin increased UfMSRB mRNA level,
reflecting a role of reduced state with Qo site located at cytochrome b6f on the
induction of UfMSRB gene expression. The cyclic electron transport chain inhibitors,
antimycin A that inhibited photosynthetic electron transport, can inhibit the increase
of UfMSRA and UfMSRB transcripts by irradiance. UfMSRA and UfMSRB gene
expression were both modulated by cyclic electron transport chain and linear electron
transport chain. These results reveal that photosynthetic electron transport chain
modulates UfMSRA and UfMSRB gene expression by change its redox state.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-1120108-183121 |
| Date | 20 November 2008 |
| Creators | Hsu, Yuan-ting |
| Contributors | Zin-Huang Liu, Tse-Min Lee, Hsien-Jung Chen |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-1120108-183121 |
| Rights | campus_withheld, Copyright information available at source archive |
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