| Project/Area Number |
03660001
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Breeding science
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| Research Institution | Hirosaki University |
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Principal Investigator |
HARADA Takeo Hirosaki University, Faculty of Agriculture Associate Professor, 農学部, 助教授 (10228645)
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| Project Period (FY) |
1991 – 1992
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| Project Status |
Completed (Fiscal Year 1992)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1992: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1991: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | Rice / Anther culture / Albino / Chloroplast DNA / Plastid DNA / Linear DNA / Hairpin telomere / Vector / ベクター |
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| Research Abstract |
Albino rice plants derived from pollen contain plastid genomes that have suffered large-scale deletions. From the roots of albino plants, we obtained several calli containing homogeneous plastid DNA differing in the size and position of the deletion. Southern blotting and pulsed field gel electrophoresis experiments revealed that the DNAs were linear molecules having a hairpin structure at both termini, existing as monomers (19 kb) or dimers, trimers and tetramers liked to form head-to-head and tail-to-tail multimers. This characteristic form is similar to that of the vaccinia virus, in which the replication origin is thought to lie at or near the hairpin termini. Farthermore, polymerase chain reaction experiments revealed complete loss of the ribosomal RNA genes of the plastid DNA. The results suggest that plant cells can grow without translation occurring in plastids. All of the deleted plastid DNAs commonly retained the region containing the tRNA^<Glu> gene(trnE), which is essential for biosynthesis of porphyrin. As porphyrin is the precursor of heme for mitochondria and other organelles, it is considered that trnE on the remnant plastid genome may be transcribed by an RNA polymerase encoded on nuclear DNA.
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