Analysis of the early-flowering mechanisms and generation of T-DNA tagging lines in Kitaake, a model rice cultivar

J Exp Bot. 2013 Nov;64(14):4169-82. doi: 10.1093/jxb/ert226. Epub 2013 Aug 21.

Abstract

As an extremely early flowering cultivar, rice cultivar Kitaake is a suitable model system for molecular studies. Expression analyses revealed that transcript levels of the flowering repressor Ghd7 were decreased while those of its downstream genes, Ehd1, Hd3a, and RFT1, were increased. Sequencing the known flowering-regulator genes revealed mutations in Ghd7 and OsPRR37 that cause early translation termination and amino acid substitutions, respectively. Genetic analysis of F2 progeny from a cross between cv. Kitaake and cv. Dongjin indicated that those mutations additively contribute to the early-flowering phenotype in cv. Kitaake. Because the short life cycle facilitates genetics research, this study generated 10 000 T-DNA tagging lines and deduced 6758 flanking sequence tags (FSTs), in which 3122 were genic and 3636 were intergenic. Among the genic lines, 367 (11.8%) were inserted into new genes that were not previously tagged. Because the lines were generated by T-DNA that contained the promoterless GUS reporter gene, which had an intron with triple splicing donors/acceptors in the right border region, a high efficiency of GUS expression was shown in various organs. Sequencing of the GUS-positive lines demonstrated that the third splicing donor and the first splicing acceptor of the vector were extensively used. The FST data have now been released into the public domain for seed distribution and facilitation of rice research.

Keywords: Flanking sequence database; GUS; Kitaake; T-DNA.; flowering time genes; splicing donor and acceptor.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chromosomes, Plant / genetics
  • Crosses, Genetic
  • DNA, Bacterial / genetics*
  • Flowers / genetics*
  • Flowers / physiology*
  • Gene Expression Profiling
  • Gene Expression Regulation, Plant
  • Genes, Reporter
  • Glucuronidase / genetics
  • Models, Biological*
  • Mutation / genetics
  • Oryza / genetics*
  • Oryza / growth & development
  • Oryza / physiology*
  • Plant Proteins / genetics
  • Plant Proteins / metabolism
  • RNA Splicing / genetics
  • Reproduction / genetics
  • Seedlings / genetics
  • Time Factors

Substances

  • DNA, Bacterial
  • Plant Proteins
  • T-DNA
  • Glucuronidase