Screening for and genetic analysis on T-DNA-inserted mutant pool in rice

Area of Science:

• Plant genetics
• Molecular biology
• Agricultural science

Background:

• The T-DNA tagging technique is crucial for identifying novel plant genes.
• Discovering T-DNA-inserted mutants with altered phenotypes is key to this technique's success.

Purpose of the Study:

• To screen a large population of rice T-DNA tagged lines for morphological mutations.
• To identify T-DNA insertion mutants with potential roles in plant development and traits.
• To lay the groundwork for cloning genes associated with observed mutations.

Main Methods:

• Screening of 4,416 rice T1 tagged lines generated by an enhancer trap system.
• Analysis of mutation phenotypes across 14 different plant traits.
• Co-segregation analysis in T1 and T2 generations.
• Flanking sequence analysis using plasmid rescue or TAIL-PCR.

Main Results:

• Identified numerous lines with morphological mutations affecting traits such as plant height, heading date, leaf color, and male sterility.
• Observed high mutation frequencies for plant height, heading date, leaf color, and male sterility (>1%).
• Found that environmental factors significantly influenced the expression of heading date and male sterility.
• Identified 3 T-DNA insertion mutants exhibiting malformed panicles or spikelets.
• Successfully obtained flanking sequences for 14 T-DNA tagged lines, with T-DNA preferentially integrating into protein-coding regions.

Conclusions:

• The enhancer trap system effectively generated diverse rice mutants.
• Environmental influence on gene expression is significant for certain traits.
• Identified mutants provide valuable resources for cloning novel functional genes in rice.
• T-DNA insertion into protein-coding regions is a preferred integration site.