MADS-box encoding gene Tunicate1 positively controls maize yield by increasing leaf number above the ear

Area of Science:

• Plant genetics
• Crop science
• Maize breeding

Background:

• The number of leaves above the ear in maize is crucial for carbohydrate supply during grain filling.
• Increasing this leaf number is a key but challenging goal in modern maize breeding for enhanced yield.

Purpose of the Study:

• To clone the gene responsible for the quantitative trait locus (QTL) affecting the number of leaves above the ear in maize.
• To investigate the mechanism by which this gene influences leaf development and maize yield.

Main Methods:

• Gene cloning of the quantitative trait locus (QTL) associated with leaf number.
• Analysis of the Tunicate1 (Tu1) gene and its upstream regulatory elements.
• Field trials to assess the impact of a specific Tu1 allele on grain yield.

Main Results:

• The causative gene for increased leaves above the ear was identified as Tunicate1 (Tu1).
• A 5-base pair insertion upstream of Tu1, originating from a popcorn landrace, enhances its transcription and increases leaf number.
• This specific Tu1 allele led to yield increases of 11.4% and 9.5% under regular and dense planting, respectively.

Conclusions:

• The Tunicate1 (Tu1) gene, particularly a landrace-derived allele, can significantly increase maize leaf number and grain yield.
• Maize landraces are a valuable genetic resource for improving high-yield breeding strategies.
• Understanding and utilizing favorable alleles like the Tu1 insertion can advance maize breeding efforts.