Transcriptional and Post-transcriptional Modulation of SQU and KEW Activities in the Control of Dorsal-Ventral Asymmetric Flower Development in Lotus japonicus

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• 作者：Zhiyong Xu¹ ; ² ; ³ ; ⁸ ; Kai Cheng¹ ; ⁸ ; Xin Li⁴ ; Jun Yang² ; Shilei Xu⁵ ; Xiangling Cao² ; Xiaohe Hu¹ ; Wei Xie¹ ; Ling Yuan⁶ ; Mike Ambrose⁷ ; Genyun Chen² ; Hualing Mi² ; Da Luo¹ ; ^{dluo@sibs.ac.cn" class="auth_mail" title="E-mail the corresponding author}
• 关键词：DV asymmetric flower development ; Lotus japonicus ; SQU ; KEW ; transcriptional activity ; post-transcriptional modification
• 刊名：Molecular Plant
• 出版年：2016
• 出版时间：2 May 2016
• 年：2016
• 卷：9
• 期：5
• 页码：722-736
• 全文大小：2174 K

文摘

In Papilionoideae legume, Lotus japonicus, 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 SQU and 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 collaboratively regulate their expression at the transcription level. Furthermore, we identified two types of post-transcriptional modifications, phosphorylation 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.