Variation at the
ZmCALS5
promoter regulates maize pollen fertility by modulating
ZmABI4
binding affinity
Junyao Li, Tengyue Wang, Xi Wang, Zhen Tao, Chuanhong Wang, Yibing Zhao, Mingliang Cui, Liming Wang, Peijin Li Summary
Pollen fertility is a key factor affecting yield in maize (
Zea mays
), but the mechanism underlying this trait in natural accessions is poorly understood.
Here, we performed quantitative trait locus mapping and identified the candidate gene
ZmCALS5
encoding a callose synthase as controlling maize pollen fertility.
A single‐nucleotide polymorphism (SNP) within the
ZmCALS5
promoter (−756A/C) influenced the
ZmCALS5
expression level and the content of callose, a pollen component essential for maize pollen fertility. This SNP−756A/C lies within the binding site for the transcription factor ZmABI4, which directly binds and represses
ZmCALS5
expression. ZmABI4 is a negative regulator of callose accumulation and pollen fertility. The SNP−756C allele was found at high frequency in teosinte but rarely occurred in modern maize. Genetic diversity analysis demonstrated that
ZmCALS5
exhibits decreased nucleotide diversity, which might suggest a potential selection signature during maize domestication and improvement.
Collectively, this study establishes a new paradigm for the research of maize pollen development, revealing that ZmABI4 represses
ZmCALS5
expression, thereby negatively regulating callose accumulation and pollen fertility. These findings provide a new paradigm for maize pollen development and uncover a valuable natural allele variation for maize breeding.