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Suppression of Ku70/80 or Lig4 leads to decreased stable transformation and enhanced homologous recombination in rice
Article first published online: 10 OCT 2012
© 2012 The Authors. New Phytologist © 2012 New Phytologist Trust
Volume 196, Issue 4, pages 1048–1059, December 2012
How to Cite
Nishizawa-Yokoi, A., Nonaka, S., Saika, H., Kwon, Y.-I., Osakabe, K. and Toki, S. (2012), Suppression of Ku70/80 or Lig4 leads to decreased stable transformation and enhanced homologous recombination in rice. New Phytologist, 196: 1048–1059. doi: 10.1111/j.1469-8137.2012.04350.x
- Issue published online: 5 NOV 2012
- Article first published online: 10 OCT 2012
- Manuscript Accepted: 23 AUG 2012
- Manuscript Received: 3 JUL 2012
- Ministry of Agriculture, Forestry and Fisheries of Japan. Grant Number: GMC-0001
- KAKENHI. Grant Numbers: 23658012, 23310142
- DNA double-strand breaks (DSBs);
- DNA ligase 4 (Lig4);
- homologous recombination (HR);
- Ku70 ;
- Ku80 ;
- nonhomologous end joining (NHEJ);
- Oryza sativa (rice);
- transferred DNA (T-DNA)
Evidence for the involvement of the nonhomologous end joining (NHEJ) pathway in Agrobacterium-mediated transferred DNA (T-DNA) integration into the genome of the model plant Arabidopsis remains inconclusive.
Having established a rapid and highly efficient Agrobacterium-mediated transformation system in rice (Oryza sativa) using scutellum-derived calli, we examined here the involvement of the NHEJ pathway in Agrobacterium-mediated stable transformation in rice. Rice calli from OsKu70, OsKu80 and OsLig4 knockdown (KD) plants were infected with Agrobacterium harboring a sensitive emerald luciferase (LUC) reporter construct to evaluate stable expression and a green fluorescent protein (GFP) construct to monitor transient expression of T-DNA.
Transient expression was not suppressed, but stable expression was reduced significantly, in KD plants. Furthermore, KD-Ku70 and KD-Lig4 calli exhibited an increase in the frequency of homologous recombination (HR) compared with control calli. In addition, suppression of OsKu70, OsKu80 and OsLig4 induced the expression of HR-related genes on treatment with DNA-damaging agents.
Our findings suggest strongly that NHEJ is involved in Agrobacterium-mediated stable transformation in rice, and that there is a competitive and complementary relationship between the NHEJ and HR pathways for DNA double-strand break repair in rice.