Rice OPEN BEAK is a negative regulator of class 1 knox genes and a positive regulator of class B floral homeotic gene
Rice OPEN BEAK is a negative regulator of class 1 knox genes and a positive regulator of class B floral homeotic gene
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DOI：
10.1111/j.1365-313x.2009.03823.x
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发表时间：
2009-06-01
期刊：
影响因子：
7.2
通讯作者：
Nagato, Yasuo
中科院分区：
文献类型：
--
作者：
Horigome, Ayako;Nagasawa, Nobuhiro;Nagato, Yasuo
许多基因参与植物发育的调控，包括调控花同源异型基因的基因，我们鉴定了两个隐性等位基因水稻突变体，开放喙-1(OPB-1)和OPB-2，它们在叶片形态发生、花序构型和花器官特性方面表现出多效性缺陷。在叶片和小穗中观察到异常的细胞增殖，并检测到几个1类KNOX基因的异位或过表达，因此，OPB突变体的细胞异常增殖可能是由1类KNOX基因的异位表达引起的。Opb突变体在花器官识别方面也存在缺陷，导致花叶器官的发育，包括具芒的鳞片、退化雄蕊和雌蕊。这些结果，再加上B类基因表达的降低，表明OPB正向调节B类基因的表达。基于图谱的克隆表明，OPB编码一个与拟南芥锯齿状基因同源的转录因子，在叶原基、花序分生组织、轴分生组织、花分生组织和花器官原基中表达。综上所述，我们的数据表明OPB基因通过调节第一类KNOX基因和花的同源异型基因来影响细胞增殖和花器官的特性。
Numerous genes are involved in the regulation of plant development, including those that regulate floral homeotic genes, We identified two recessive allelic rice mutants, open beak-1 (opb-1) and opb-2, which exhibited pleiotropic defects in leaf morphogenesis, inflorescence architecture, and floral organ identity. Abnormal cell proliferation was observed in the leaves and spikelets, and ectopic or overexpression of several class 1 knox genes was detected; thus, the abnormal cell proliferation in opb mutants is probably caused by ectopic class 1 knox gene expression. The opb mutants also had defects in floral organ identity, resulting in the development of mosaic organs, including gluminous lodicules, staminoid lodicules, and pistiloid stamens. These results, together with the reduced expression of a class B gene, indicate that OPB positively regulates the expression of class B genes. Map-based cloning revealed that OPB encodes a transcription factor that is orthologous to the Arabidopsis JAGGED gene and is expressed in leaf primordia, inflorescence meristem, rachis branch meristems, floral meristem, and floral organ primordia. Taken together, our data suggest that the OPB gene affects cellular proliferation and floral organ identity through the regulation of class 1 knox genes and floral homeotic genes.