SPATIALLY AND TEMPORALLY REGULATED EXPRESSION OF THE MADS-BOX GENE AGL2 IN WILD-TYPE AND MUTANT ARABIDOPSIS FLOWERS
SPATIALLY AND TEMPORALLY REGULATED EXPRESSION OF THE MADS-BOX GENE AGL2 IN WILD-TYPE AND MUTANT ARABIDOPSIS FLOWERS
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DOI：
10.1007/bf00013745
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发表时间：
1994-10-01
影响因子：
5.1
通讯作者：
MA, H
中科院分区：
文献类型：
--
作者：
FLANAGAN, CA;MA, H
AGL 2是基于同源异型基因AGAMOUS的序列相似性分离的几个拟南芥花MADS盒基因之一。为了研究其在花发育中可能的作用，我们已经详细描述了AGL 2在野生型和突变型花中的表达模式，使用RNA原位杂交。我们发现，AGL 2是花特异性的，它是不表达的花序分生组织。在花分生组织内，AGL 2首先在发育的非常早期表达，在花分生组织已经从花序分生组织出现之后但在任何器官原基出现之前。AGL 2转录物在整个花分生组织和所有四个花器官的原基中非常丰富和均匀：萼片，花瓣，雄蕊和心皮。因此，AGL 2代表了一类新的MADS盒基因，其在花的所有四个轮中表达。AGL 2转录本在形态分化期间在每个器官中保持丰富，但随着每个器官经历发育的最后成熟阶段而减少。AGL 2在发育中的胚珠中表达较高，受精后，在发育中的胚和种皮中表达较高，随着种子成熟而减弱。在花器官同一性突变体ag-1，ap 3 -3和ap 2 -2中，AGL 2的表达模式是器官和阶段依赖性的。这些结果表明，AGL 2可能在所有花器官，种子和胚胎的发育中发挥重要作用，AGL 2最终取决于器官身份基因的正确表达。
AGL2 is one of several Arabidopsis floral MADS-box genes that were isolated based on sequence similarity to the homeotic gene AGAMOUS. To investigate its possible role in flower development, we have characterized in detail the expression pattern of AGL2 in both wild-type and mutant flowers using RNA in situ hybridization. We find that AGL2 is floral-specific; it is not expressed in the inflorescence meristem. Within the floral meristem, AGL2 is first expressed very early in development, after the floral meristem has emerged from the inflorescence meristem but before any of the organ primordia emerge. The AGL2 transcript is very abundant and uniform throughout the floral meristem and in the primordia of all four floral organs: sepals, petals, stamens and carpels. Thus, AGL2 represents a new class of MADS-box genes which is expressed in all four whorls of the flower. The AGL2 transcript remains abundant in each organ during morphological differentiation, but diminishes as each organ undergoes the final maturation phase of development. AGL2 expression is high in developing ovules and, after fertilization, in developing embryos and seed coats, abating as seeds mature. In the floral organ identity mutants ag-1, ap3-3 and ap2-2, the AGL2 expression pattern is organ- and stage-dependent. These results indicate that AGL2 may play a fundamental role in the development of all floral organs, and of seeds and embryos, and that AGL2 ultimately depends upon the organ identity genes for proper expression.