Mutations in an AP2 transcription factor-like gene affect internode length and leaf shape in maize

Area of Science:

• Genetics
• Plant Biology
• Agronomy

Background:

• Plant height is a crucial agronomic trait influencing crop yield and stress tolerance.
• Understanding the genetic basis of plant height is key for maize development and breeding.

Purpose of the Study:

• To identify the genetic factors controlling plant height in maize.
• To characterize the developmental effects of mutations affecting plant height.

Main Methods:

• Isolation and characterization of ethyl methanesulfonate (EMS) induced semi-dwarf maize mutants (dil1).
• Cytological analysis of mutant plant tissues.
• Positional cloning and gene identification of the causative mutation.

Main Results:

• Two allelic semi-dwarf mutants (dil1) exhibited shorter internodes, altered leaf morphology (shorter, wider, wrinkled), and smaller leaf angles.
• Mutant plants showed irregular cell shapes and disrupted epidermal patterning in leaves and internodes.
• Positional cloning identified a candidate gene encoding an AP2 transcription factor-like protein, with mutations found near exon-intron junctions leading to mis-spliced transcripts.

Conclusions:

• An AP2 transcription factor-like gene regulating maize stalk and leaf development was identified.
• Mutations in this gene cause semi-dwarfism and altered leaf characteristics due to mis-spliced transcripts.