T-DNA insertional mutagenesis for functional genomics in rice.

Area of Science:

• Plant Molecular Biology
• Genomics
• Agricultural Science

Background:

• Large-scale insertional mutagenesis is crucial for rice functional genomics.
• T-DNA tagging offers a robust method for generating mutants and identifying novel genes.

Purpose of the Study:

• To create a comprehensive T-DNA insertion mutant population in rice.
• To characterize the T-DNA insertion patterns and gene trapping efficiency.
• To assess the utility of the generated lines for gene discovery.

Main Methods:

• Production of over 22,000 primary transgenic rice plants via T-DNA insertion.
• Genomic DNA analysis (gel-blot, PCR) to determine T-DNA copy number and loci.
• Hygromycin resistance assays to quantify insert loci.
• Histochemical GUS assays for gene expression analysis in various plant organs.

Main Results:

• Generated 18,358 fertile rice lines from 22,090 primary transgenic plants.
• Approximately 65% of lines contained multiple T-DNA inserts, averaging 1.4 loci per line.
• Gene trapping identified GUS expression in 1.6-2.1% of tested organs, showing diverse expression patterns.

Conclusions:

• The large T-DNA tagged rice population is a valuable resource for insertional mutagenesis.
• This resource facilitates the identification of novel rice genes and their functions.
• The gene trap vector effectively enables the discovery of gene fusions and expression patterns.