Functional diversification of the two C-class MADS box genes OSMADS3 and OSMADS58 in Oryza sativa
Functional diversification of the two C-class MADS box genes OSMADS3 and OSMADS58 in Oryza sativa
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DOI：
10.1105/tpc.105.037200
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发表时间：
2006-01-01
期刊：
影响因子：
11.6
通讯作者：
Hirano, HY
中科院分区：
文献类型：
--
作者：
Yamaguchi, T;Lee, DY;Hirano, HY
C 类 MADS 盒基因 AGAMOUS (AG) 通过调节雄蕊和心皮的器官特性、A 类基因的抑制和花分生组织的决定性，在拟南芥发育中发挥着至关重要的作用。为了研究单子叶植物中 C 类基因功能的保守性和多样性，我们分析了水稻 (Oryza sativa) 中的两个 C 类基因 OSMADS3 和 OSMADS58，它们可能是在水稻和玉米 (Zea mays) 分化之前由基因复制产生的。 OSMADS3 的敲除系，其中该基因被 T-DNA 插入破坏，显示雄蕊同源转化为浆片，并且在内稃附近的第二轮中浆片异位发育，其中浆片在野生型中不形成，但心皮几乎正常发育。相比之下，RNA沉默的OSMADS58品系会发育出令人惊讶的花，这些花重复了一组花器官，包括浆片、雄蕊和心皮样器官，这表明花分生组织的决定性受到严重影响。这些结果表明，这两个C类基因在水稻进化过程中已部分亚功能化（即AG调节的功能已部分划分为两个旁系同源基因OSMADS3和OSMADS58，它们是由植物进化中最近的基因复制事件产生的）。
The C-class MADS box gene AGAMOUS (AG) plays crucial roles in Arabidopsis thaliana development by regulating the organ identity of stamens and carpels, the repression of A-class genes, and floral meristem determinacy. To examine the conservation and diversification of C-class gene function in monocots, we analyzed two C-class genes in rice (Oryza sativa), OSMADS3 and OSMADS58, which may have arisen by gene duplication before divergence of rice and maize (Zea mays). A knockout line of OSMADS3, in which the gene is disrupted by T-DNA insertion, shows homeotic transformation of stamens into lodicules and ectopic development of lodicules in the second whorl near the palea where lodicules do not form in the wild type but carpels develop almost normally. By contrast, RNA-silenced lines of OSMADS58 develop astonishing flowers that reiterate a set of floral organs, including lodicules, stamens, and carpel-like organs, suggesting that determinacy of the floral meristem is severely affected. These results suggest that the two C-class genes have been partially subfunctionalized during rice evolution (i.e., the functions regulated by AG have been partially partitioned into two paralogous genes, OSMADS3 and OSMADS58, which were produced by a recent gene duplication event in plant evolution).