WRKY transcription factors WRKY12 and WRKY13 interact with SPL10 to modulate age-mediated flowering

Abstract

WRKY12 and WRKY13 are two WRKY transcription factors that play important roles in the control of flowering time under short-day (SD) conditions. The temporally regulated expression ofWRKY12andWRKY13indicates that they may be involved in the age-mediated flowering pathway. However, their roles in this pathway are poorly understood. Here, we show that the transcription ofWRKY12andWRKY13is directly regulated by SQUAMOSA PROMOTER BINDING-LIKE 10 (SPL10), a transcription factor downstream of the age pathway. Binding and activation analyses revealed that SPL10 functions as a positive regulator ofWRKY12and a negative regulator ofWRKY13. Further mechanistic investigation revealed that WRKY12 and WRKY13 physically interact with SPL10 and that both of them bind to the promoter ofmiR172b. Thus, the WRKY12-SPL10 and WRKY13-SPL10 interactions facilitate and inhibit SPL10 transcriptional function, respectively, to regulatemiR172bexpression. Together, our results show that WRKY12 and WRKY13 participate in the control of age-mediated flowering under SD conditions though physically interacting with SPLs and co-regulating the target genemiR172b.