Phenotypic measurements of STERILE APETALA mutants in Mimulus verbenaceus

In Mimulus verbenaceus, we identified three mutants with abnormal corolla development and significantly reduced nectar volume through EMS mutagenesis screening, designated as MV00081, MV00017, and NJ00356-1. BSA sequencing revealed that MV00081 corresponds to the homolog of the Arabidopsis STERILE APETALA. These mutants were named sap-1, sap-2, and sap-3, respectively. Among them, sap-1, caused by a premature termination mutation, exhibited the most pronounced phenotypic defects compared to the other two mutants. We measured leaf, flower, and nectar sugar content in sap-1 and found that it significantly inhibited leaf and petal development, reduced nectar production, and decreased the fructose and glucose content in nectar.