OsMADS60 Controls Rice Yield Through Auxin Transport

Rice grain yield is significantly influenced by tillering, yet the underlying molecular mechanisms remain poorly understood. A study published in The Plant Journal reveals that the transcription factor OsMADS60 plays a crucial role in suppressing rice tillering and grain yield by enhancing the expression of the auxin transporter OsPIN5b, thus altering auxin distribution.

Natural variation within the OsMADS60 promoter region was observed, with its expression levels showing a negative correlation with tiller number and a positive response to auxin. Overexpression of OsMADS60 resulted in decreased tillering and yield, while CRISPR-mediated knockout of OsMADS60 led to increased tillering and yield. Furthermore, OsMADS60 and OsPIN5b overexpression lines exhibited increased auxin content in various tissues compared to wild-type ZH11, whereas mutant lines showed the opposite trend. Genetic analysis confirmed that OsPIN5b functions downstream of OsMADS60, jointly regulating hormone pathway genes.

The findings establish that OsMADS60 modulates auxin distribution via OsPIN5b, thereby controlling rice tillering. This regulatory pathway presents a valuable target for genetically enhancing rice architecture and grain yield.