Bollier N, Sicard A, Gonzalez N, Chevalier C, Hernould M, Delmas F
a UMR1332 BFP, INRA , University of Bordeaux , Bordeaux , France.
Plant Signal Behav. 2018;13(6):e1473687. doi: 10.1080/15592324.2018.1473687. Epub 2018 Jun 26.
The INHIBITOR OF MERISTEM ACTIVITY in tomato (SlIMA) and MINI ZINC FINGER 2 in Arabidopsis (AtMIF2), two members of the MINI ZINC FINGER family (MIF), are involved in the regulation of flower and ovule development. MIF proteins possess a unique non-canonical zinc-finger domain that confers the capacity to interact with other protein partners. The characterization of SlIMA and AtMIF2 gain- and loss-of-function transgenic lines in Solanum lycopersicum and Arabidopsis thaliana respectively, allowed the demonstration of their conserved functional role in the termination of floral stem cell maintenance. During early floral development, the expression of SlIMA and AtMIF2 is induced by the MADS-Box transcription factor AGAMOUS (AG). Then, SlIMA or AtMIF2 protein recruits the CH zinc finger KNUCKLES (KNU), in a transcriptional repressor complex together with TOPLESS (TPL) and HISTONE DEACETYLASE19 (HDA19). This complex binds to the WUSCHEL (WUS) locus leading to its repression. To further characterize the role of these interactions in flower development, we have investigated the effects of a dominant negative form of SlIMA, SlIMA that leads to spectacular phenotypes, including ovule conversion into a floral meristem.
番茄中的分生组织活性抑制剂（SlIMA）和拟南芥中的小锌指蛋白2（AtMIF2）是小锌指蛋白家族（MIF）的两个成员，它们参与花和胚珠发育的调控。MIF蛋白拥有一个独特的非典型锌指结构域，赋予其与其他蛋白质伙伴相互作用的能力。分别对番茄和拟南芥中SlIMA和AtMIF2功能获得和功能缺失转基因株系的特性进行研究，证实了它们在终止花干细胞维持方面具有保守的功能作用。在花发育早期，SlIMA和AtMIF2的表达由MADS盒转录因子AGAMOUS（AG）诱导。然后，SlIMA或AtMIF2蛋白与TOPLESS（TPL）和组蛋白去乙酰化酶19（HDA19）一起，在一个转录抑制复合物中招募CH锌指蛋白KNUCKLES（KNU）。该复合物与WUSCHEL（WUS）基因座结合，导致其受到抑制。为了进一步阐明这些相互作用在花发育中的作用，我们研究了一种显性负型SlIMA（导致包括胚珠转变为花分生组织等显著表型的SlIMA）的影响。
