摘要
In Papilionoideae legume, Lotusjaponicus, the development of dorsal-ventral （DV） asymmetric flowers is mainly controlled by two TB1/CYCLOIDEA/PCF （TCP） genes, SQUARED STANDARD （SQU） and KEELED WINGS IN LOTUS （KEW）, which determine dorsal and lateral identities, respectively. However, the molecular basis of how these two highly homologous genes orchestrate their diverse functions remains unclear. Here, we analyzed their expression levels, and investigated the transcriptional activities of SQUand KEW. We demonstrated that SQU possesses both activation and repression activities, while KEW acts only as an activator. They form homo- and heterodimers, and then collaboraUvely regulate their expression at the transcription level. Furthermore, we identified two types of post-transcriptional modifications, phosphor- ylation and ATP/GTP binding, both of which could affect their transcriptional activities. Mutations in ATP/ GTP binding motifs of SQU and KEW lead to failure of phosphorylation, and transgenic plants bearing the mutant proteins display defective DV asymmetric flower development, indicating that the two conjugate modifications are essential for their diverse functions. Altogether, SQU and KEW activities are precisely modulated at both transcription and post-transcription levels, which might link DV asymmetric flower development to different physiological status and/or signaling pathways.
In Papilionoideae legume, Lotusjaponicus, the development of dorsal-ventral （DV） asymmetric flowers is mainly controlled by two TB1/CYCLOIDEA/PCF （TCP） genes, SQUARED STANDARD （SQU） and KEELED WINGS IN LOTUS （KEW）, which determine dorsal and lateral identities, respectively. However, the molecular basis of how these two highly homologous genes orchestrate their diverse functions remains unclear. Here, we analyzed their expression levels, and investigated the transcriptional activities of SQUand KEW. We demonstrated that SQU possesses both activation and repression activities, while KEW acts only as an activator. They form homo- and heterodimers, and then collaboraUvely regulate their expression at the transcription level. Furthermore, we identified two types of post-transcriptional modifications, phosphor- ylation and ATP/GTP binding, both of which could affect their transcriptional activities. Mutations in ATP/ GTP binding motifs of SQU and KEW lead to failure of phosphorylation, and transgenic plants bearing the mutant proteins display defective DV asymmetric flower development, indicating that the two conjugate modifications are essential for their diverse functions. Altogether, SQU and KEW activities are precisely modulated at both transcription and post-transcription levels, which might link DV asymmetric flower development to different physiological status and/or signaling pathways.
基金
This work was supported by National Natural Science Foundation of China （Grant Noa. 30930009） and Science and Technology Planning Project of Guangdong Province, China （Grant Nos, 2011A020201008）.
