A PCR-based forward genetics screening, using expression domain-specific markers, identifies mutants in endosperm...

Area of Science:

• Plant genetics and molecular biology
• Maize (Zea mays) developmental biology
• Forward genetics and mutant screening

Background:

• Mutant collections are crucial for forward genetics but analyzing certain developmental stages or lethal mutations in maize is challenging.
• Physical inaccessibility and deleterious effects of mutations can hinder the characterization of specific maize kernel structures and processes.
• Early lethal mutations in maize may escape detection using traditional screening methods.

Purpose of the Study:

• To develop and validate an efficient molecular marker approach for characterizing maize seed mutants.
• To identify genes and affected tissue compartments in early developing maize kernels.
• To overcome limitations of traditional methods for analyzing maize mutants with early lethal phenotypes or complex developmental effects.

Main Methods:

• Screened 27,500 Mu-insertion maize lines to select 101 seed mutants.
• Utilized a streamlined combination of quantitative reverse transcription PCR (qRT-PCR) assays targeting genes in specific kernel tissue compartments.
• Performed morphological observations and immunolocalization experiments on selected mutant lines with significant variations in transfer cell-associated markers.

Main Results:

• Successfully pinpointed affected tissue compartments in maize kernel development for the selected mutants.
• Identified clusters of molecular markers co-affected by specific mutations, aiding in understanding gene function.
• Validated the molecular marker approach as an efficient tool for mutant description, enabling developmental comparisons with wild-type siblings.

Conclusions:

• The developed molecular marker strategy is an efficient method for describing maize seed mutants, particularly those with challenging phenotypes.
• This approach facilitates the identification of genes involved in early kernel development and specific tissue formation.
• The study validates the utility of qRT-PCR and marker-based analysis for advancing maize genetics research.