Loading...
Please wait, while we are loading the content...
Similar Documents
Identification and molecular characterization of a mutant that shows Chlamydomonas reinhardtii a light intensity dependent progressive chlorophyll deficiency
| Content Provider | Semantic Scholar |
|---|---|
| Author | Grovenstein, Phillip B. Wilson, Darryel A. Lankford, Kathryn D. Gaston, Kelsey A. Perera, Surangi Mitra, Mautusi |
| Copyright Year | 2014 |
| Abstract | The green micro-alga is an elegant model Chlamydomonas reinhardtii organism to study oxygenic photosynthesis. Chlorophyll (Chl) and heme are major tetrapyrroles that play an essential role in photosynthesis and respiration. These tetrapyrroles are synthesized via a common branched pathway that involves mainly enzymes, encoded by nuclear genes. One of the enzymes in the pathway is Mg chelatase (MgChel). MgChel catalyzes insertion of Mg into 2+ protoporphyrin IX (PPIX, proto) to form Magnesium-protoporphyrin IX (MgPPIX, Mgproto), the first biosynthetic intermediate in the Chl branch. The GUN4 (genomes uncoupled 4) protein is not essential for the MgChel activity but has been shown to significantly stimulate its activity. We have isolated a light sensitive mutant, , by random DNA insertional mutagenesis. cannot 6F14 6F14 tolerate light intensities higher than 90-100 μmol photons m s . It shows a -2 -1 light intensity dependent progressive photo-bleaching. is incapable of 6F14 photo-autotrophic growth under light intensity higher than 100 μmol photons m s . PCR based analyses show that in the insertion of the plasmid -2 -1 6F14 outside the locus has resulted in a genetic rearrangement of the GUN4 GUN4 gene and possible deletions in the genomic region flanking the gene. GUN4 Our mutant has a Chl content very similar to that in the wild type in the gun4 dark and is very sensitive to fluctuations in the light intensity in the environment unlike the earlier identified mutant. Complementation Chlamydomonas gun4 with a functional copy of the gene restored light tolerance, Chl GUN4 biosynthesis and photo-autotrophic growth under high light intensities in . 6F14 is the second mutant to be identified in . Additionally, 6F14 gun4 C. reinhardtii we show that our two complements over-express the GUN4 protein and gun4 show a higher Chl content per cell compared to that in the wild type strain. Referees |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://f1000researchdata.s3.amazonaws.com/manuscripts/1957/0561811e-43c1-497a-87ad-46906fa808f8_1517%20-%20mitra%20-%202-142_v2.pdf?doi=10.12688/f1000research.2-142.v2 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
