Abstract
Arabidopsis SPL10 is a member of the SBP-box family that encodes a plant-specific transcription factor. SBPs have been shown to bind to AP1 promoter, but their biological function is unknown. To elucidate the function of SPL10, we produced transgenic plants. Expression of the chimeric SPL10 repressor (35S:SPL10-SRDX) caused multiple effects including reduced apical dominance, abnormal inflorescence, short floral organs and shrunk siliques. The silique phenotype was similar to that of ful mutant, and FUL expression was reduced. Expression of AP1, homologous gene of FUL, was not affected in 35S:SPL10-SRDX plants. Although ectopic expression of SPL10 (35S:SPL10) induced no apparent phenotype, overexpression of mSPL10, in which the target sequence of microRNA was mutated, resulted in cauline-like rosette leaves and an accumulation of FUL mRNA. Furthermore, transient assay suggested that SPL10 bind to the FUL promoter. These results indicate that SPL10 directly controls FUL expression and is regulated by microRNA.
