Chlamydomonas reinhardtii can utilize CO2 for autotrophic growth (HSM plus
5% CO2) or acetate for mixotrophic growth (TAP). This study was to elucidate the
differential regulation of methionine sulfoxide reductase (MSR) gene expression
between HSM plus 5% CO2 and TAP cultured cells, and also to determine the
difference of gene expression in response to high light (1,000 £gE m-2 s-1). The role of
photosynthetic electron transport (PET) in the regulation of MSR gene expression was
also examined by the use of PET inhibitors. High light inhibited PSII activity (Fv/Fm
and Fv'/Fm') of HSM plus 5% CO2 and TAP cultured cells., while the responses of
CrMSR gene expression in mixotrophically grown cells were different from
autotrophically grown cells, High light increased the expression of CrMSRA1,
CrMSRA2, CrMSRA3, CrMSRA5, CrMSRB1.2, and CrMSRB2.1, but inhibited the
expression of CrMSRA4 and CrMSRB2.2 in autotrophically grown cells. The
expression of CrMSRA3, CrMSRA5, and CrMSRB2.1 in mixotrophically grown cells
was increased by high light but that of CrMSRA1, CrMSRA4, and CrMSRB2.2 was
inhbited. The number of MSR isoform that was up-regulated by high light was greater
in autotrophically grown cell than that in mixotrophically grown cells. Using the PET
inhibitors (3-(3,4-dichlorophenyl)-1,1- dimethylurea (DCMU) and
2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone (DBMIB)), most of the CrMSRA
expression was regulated by reduced QA for autotrophically grown cells while
reduced PQ was the main site for mixotrophically grown cells by high light. The
expression of CrMSRB in autotrophically grown cells was mainy modulated by QA (-)
or Cytb6f (-), while that was not affected by PET, except a role of Cytb6f (-) on the
high light-induced CrMSRB2.2 expression. We fouind that CrMSRB gene expression
in autotrophically grown cells was highly affected by PET but not for micotrophically
grtown cells. The present result that H2O2 did not accumulate in autotrophically and
mixotrophically grown cells suggests that H2O2 may be not involved in the regulation
of high light regulation of CrMSR gene expression. The present study shows that the
mRNA expression of CrMSR isoforms in Chlamydomonas was diffrerentially
regulated between autotrophically and mixttrophically grown cells. The relationship
between the utilization of different C source and CrMSR gene expression will be
discussed.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0725111-142515 |
| Date | 25 July 2011 |
| Creators | Shie, Shu-Chiu |
| Contributors | Hsien-Jung Chen, Yi Ting Hsu, Tse-Min Lee |
| 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-0725111-142515 |
| Rights | campus_withheld, Copyright information available at source archive |
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