Brassicaceae INDEHISCENT genes specify valve margin cell fate and repress replum formation
Brassicaceae INDEHISCENT genes specify valve margin cell fate and repress replum formation
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DOI：
10.1111/j.1365-313x.2010.04244.x
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发表时间：
2010-07-01
期刊：
影响因子：
7.2
通讯作者：
Ostergaard, Lars
中科院分区：
文献类型：
--
作者：
Girin, Thomas;Stephenson, Pauline;Ostergaard, Lars
Brassicaceae家族的成员，包括拟南芥（Arabidopsis thaliana）和油菜（Brassica napus），在成熟时沿着一种叫做瓣缘的特殊组织产生干燥的果实。拟南芥瓣缘的正常发育依赖于INDEHISCENT （IND）基因，该基因在遗传和激素调节中的作用已经得到了充分的研究。在这里，我们对拟南芥和芸苔中的IND基因进行了系统发育比较，以确定负责阀缘特定表达的保守调控序列。此外，我们还采用比较开发的方法证明了芥蓝和甘蓝的BraA.IND.a和BolC.IND.a基因与拟南芥IND具有相同的功能，因为甲基硫乙基（EMS）突变等位基因和沉默转基因系具有阀缘缺陷。此外，我们表明，这些缺陷的程度可以微调作物改良。野生型拟南芥在果实的中部产生一个由大约6个细胞锉组成的外管，而芸苔果实则没有这个组织。一个功能严重丧失的braA.ind.a突变体除了瓣膜边缘发育缺陷外，还获得了外复组织。在拟南芥ind突变体中还观察到复瓣大小的增大，这表明芸苔科ind基因在阻止阀缘细胞采用复瓣特性方面发挥了普遍作用。
P>Members of the Brassicaceae family, including Arabidopsis thaliana and oilseed rape (Brassica napus), produce dry fruits that open upon maturity along a specialised tissue called the valve margin. Proper development of the valve margin in Arabidopsis is dependent on the INDEHISCENT (IND) gene, the role of which in genetic and hormonal regulation has been thoroughly characterised. Here we perform phylogenetic comparison of IND genes in Arabidopsis and Brassica to identify conserved regulatory sequences that are responsible for specific expression at the valve margin. In addition we have taken a comparative development approach to demonstrate that the BraA.IND.a and BolC.IND.a genes from B. rapa and B. oleracea share identical function with Arabidopsis IND since ethyl methanesulphonate (EMS) mutant alleles and silenced transgenic lines have valve margin defects. Furthermore we show that the degree of these defects can be fine-tuned for crop improvement. Wild-type Arabidopsis produces an outer replum composed of about six cell files at the medial region of the fruits, whereas Brassica fruits lack this tissue. A strong loss-of-function braA.ind.a mutant gained outer replum tissue in addition to its defect in valve margin development. An enlargement of replum size was also observed in the Arabidopsis ind mutant suggesting a general role of Brassicaceae IND genes in preventing valve margin cells from adopting replum identity.