The SBP transcription factor SPL10 regulates leaf curvature by promoting REVOLUTA transcription in plants

The developmental functions of SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL) 10 have been extensively studied in Arabidopsis, but SPL10's role in regulating leaf curvature has not been well characterized. In this study, we observed an upward-curling leaf phenotype upon overexpression of a miR156/157-resistant version of SPL10 (rSPL10). DNA affinity purification sequencing (DAP-seq), RNA-seq, and transient transactivation assays revealed that SPL10 binds to the promoter of REVOLUTA (REV). Consistent with binding assays, overexpression of a miR165/166-resistant version of REV (rREV) in WT plants caused an upward-curling leaf phenotype. Conversely, overexpression of rSPL10 in a rev-6 mutant couldn't rescue the downward-curling leaf phenotype of rev-6. Notably, SPL10 physically interacts with REV, attenuating the upward-curling leaf phenotype of rREV mutants, suggesting a role as a molecular rheostat to prevent overamplification of REV transcripts. Furthermore, overexpression of the BrpREV-1 gene caused rosette leaves to change from flat to upward curving and accelerated heading in Chinese cabbage. Taken together, our findings identify the role of the SPL10-REV module in regulating leaf curvature in Arabidopsis and the crucial functions of BrpREV-1 in the heading of Chinese cabbage. DAP-seq to identify the dirctely target genes of SPL10.