Genetic and molecular interactions between BELL1 and MADS box factors support ovule development in Arabidopsis
Genetic and molecular interactions between BELL1 and MADS box factors support ovule development in Arabidopsis
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DOI：
10.1105/tpc.107.051797
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发表时间：
2007-08-01
期刊：
影响因子：
11.6
通讯作者：
Colombo, Lucia
中科院分区：
文献类型：
--
作者：
Brambilla, Vittoria;Battaglia, Raffaella;Colombo, Lucia
在拟南芥和许多其他植物物种中，胚珠作为新的分生组织形成于心皮组织。增殖胚珠原基中的细胞命运由特定的胚珠身份因子指定，例如同源结构域因子BELL1（BEL1）和MADS盒家族成员SEEDSTICK（STK）、SHATTERPROOF1（SHP1）、SHP2和AGAMOUS。在bel1突变体和stk shp1 shp2三重突变体中，珠被都转化为心皮状结构。将这些突变体组合在bel1 stk shp1 shp2四重突变体中，我们发现bel1表型显著增强。我们还表明，胚珠分化需要调节的干细胞维持基因WUSCHEL，镇压主要是维持由BEL1胚珠发育过程中。基于酵母三杂交试验和遗传数据，我们表明，当BEL 1与SEPALLATA蛋白二聚化时，BEL 1与胚珠身份MADS盒因子相互作用。我们提出了一个胚珠发育模型，解释了如何建立一个MADS盒同源结构域蛋白复合物的心皮身份活动和胚珠身份活动之间的平衡。
In Arabidopsis thaliana and many other plant species, ovules arise from carpel tissue as new meristematic formations. Cell fate in proliferating ovule primordia is specified by particular ovule identity factors, such as the homeodomain factor BELL1 (BEL1) and MADS box family members SEEDSTICK (STK), SHATTERPROOF1 (SHP1), SHP2, and AGAMOUS. Both in the bel1 mutant and the stk shp1 shp2 triple mutant, integuments are transformed into carpelloid structures. Combining these mutants in a bel1 stk shp1 shp2 quadruple mutant, we showed that the bel1 phenotype is significantly enhanced. We also demonstrate that ovule differentiation requires the regulation of the stem cell maintenance gene WUSCHEL, repression of which is predominantly maintained by BEL1 during ovule development. Based on yeast three-hybrid assays and genetic data, we show that BEL1 interacts with the ovule identity MADS box factors when they dimerize with SEPALLATA proteins. We propose a model for ovule development that explains how the balance between carpel identity activity and ovule identity activity is established by a MADS box homeodomain protein complex.