The Japan Radiation Research Society Annual Meeting Abstracts
The 48th Annual Meeting of The Japan Radiation Research Society
Session ID : P-A-058
Conference information

Radiation Biology - DNA damage, repair
UVB-induced cyclobutane pyrimidine dimer and photorepair in mitochondria of rice (Oryza sativa L)
*Masaaki TAKAHASHIJunji KAWASAKIJun HIDEMATadashi KUMAGAI
Author information
CONFERENCE PROCEEDINGS FREE ACCESS

Details
Abstract
UVB radiation can damage plants, decreasing growth and productivity. It also induces formation of pyrimidine dimers in DNA, which are the predominamt and biologically significiant UVB induced damages in DNA. Cyclobutane pyrimidine dimers (CPDs) constitute the major class of these damages (80%) with the remainder being mainly pyrimidine (6-4) pyrimidone dimers. Two major mechanisms of CPD repair are excision repair and photoreactivation. CPD photoreactivation is the major pathway in plants for repairing UV-induced DNA damage. Plant cell has different genome in each nuclei, chloroplasts, and mitochondria. CPD photoreactivation has been reported to be involved in nuclei, but not in the other two organelles. We previously found in rice that CPD photorepair was observed in nucleus-rich fraction, but not in chloroplast-rich fraction.
This study aimed to confirm whether or not CPD photorepair would be involved in mitochondrion. We measured UVB-induced CPDs and their photorepair in each organellar genome using intact leaves by Real-time quantitative PCR assay and Southern blot assay using CPD specific enzyme T4 endonuclease V. This enzyme cleaves the dimers quantitatively at CPD sites. Genes such as rbcS, cab, and, phr (nuclear genome-encoded genes), cox3, cob, and orf288 (mitochondrial genome-encoded genes) and atpB and rbcL (chloroplast’s genome-encoded genes) were targeted for analysis. As a result, we found that CPDs caused by UVB in mitochondria were photorepaired.
Content from these authors
© 2005 The Japan Radiation Research Society
Previous article Next article
feedback
Top