In order to elucidate the molecular and biochemical events occurring in embryogenesis in Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco), an essential gene expressed highly during early embryogenesis was identified, cloned and further characterized in this study. Douglas-fir LYR/LVR eDNA was obtained using RT-PCR with specific primers. followed by cloning and sequencing. Northern blot analysis showed higher amounts of LYR/LVR transcripts in early-cotyledonary embryonic stages and megagametophytes when compared with mid- and late-cotyledonary embryos. LYR/LVR transcript levels declined in seeds (mature embryos) and seedlings. Differential regulation of LYR/LVR gene expression with response to brassinosteroid treatment of Douglas-fir seeds was studied. LYR/LVR mRNA showed higher accumulation in seeds treated with different concentrations of brassinosteroids. Bioinformatic analysis showed that Douglas-fir LYR/LVR protein may be an essential inner mitochondrial protein, NADH oxidoreductase necessary for energy production. The phylogenetic tree analysis was used to investigate the evolutionary relationship of the newly identified Douglas-fir LYR/LVR protein with closely related proteins (LYR family) in different organisms. InterPro, UniProt and Pfam results showed the sequence similarity of Douglas-fir LYR/LVR protein with other related members in Arabidopsis thaliana and Oryza sativa, indicating that the LYR complex contains short stretches of closely related proteins that are essential for energy production. Amino acids 19-90 in the LYR/LVR protein were highly conserved and is likely the functional LYR motif necessary for oxidoreductase activity.
| Identifer | oai:union.ndltd.org:uvic.ca/oai:dspace.library.uvic.ca:1828/2258 |
| Date | 22 February 2010 |
| Creators | Ramachandran, Umesh |
| Contributors | Misra, Santosh |
| Source Sets | University of Victoria |
| Language | English, English |
| Detected Language | English |
| Type | Thesis |
| Rights | Available to the World Wide Web |
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