APETALA3 and PISTILLATA homologs exhibit novel expression patterns in the unique perianth of Aristolochia (Aristolochiaceae)
APETALA3 and PISTILLATA homologs exhibit novel expression patterns in the unique perianth of Aristolochia (Aristolochiaceae)
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DOI：
10.1111/j.1525-142x.2004.04053.x
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发表时间：
2004-11-01
影响因子：
2.9
通讯作者：
Kramer, EM
中科院分区：
文献类型：
--
作者：
Jaramillo, MA;Kramer, EM
一些证据表明，不育花器官，统称为花被，在被子植物的进化过程中经历了多次进化。在马兜铃科中，马兜铃属的花被由两轮器官形成，但在其余的属中只有一轮，包括马兜铃属。虽然Saruma的形态在外观上类似于真双子叶植物的核心花被，具有叶状萼片和艳丽的彩色花瓣，但马兜铃属的单裂花被结合了花萼和花冠的形态学方面。为了研究在马兜铃属的新花被中起作用的器官身份程序，我们在Saruma和马兜铃属中鉴定了B类基因APETALA3（AP3）和PISTILLATA（PI）的同源物。这些基因在Saruma中的表达模式表明它们在第二轮瓣状器官和第三轮雄蕊的发育中起作用。然而，在马兜铃属中，在花被中的AP3和PI同源物的表达并不表明在器官身份中的作用，而是在促进细胞分化的后期方面。这些研究结果的花瓣性和B基因功能的演变的影响进行了讨论。
Several lines of evidence suggest that sterile floral organs, collectively known as the perianth, have evolved multiple times during the evolution of the angiosperms. In the family Aristolochiaceae, the perianth is formed by two whorls of organs in the genus Saruma but by only one whorl in the remaining genera, including Aristolochia. Although the morphology of Saruma is similar in appearance to the core eudicot perianth, with leaf-like sepals and showy colored petals, the unipartite perianth of Aristolochia combines morphological aspects of both calyx and corolla. To investigate the organ identity program functioning in the novel perianth of Aristolochia, we identified homologs of the B-class genes APETALA3 (AP3) and PISTILLATA (PI) in both Saruma and Aristolochia. The expression patterns of these genes in Saruma indicate they are functioning in the development of the second whorl petaloid organs and third whorl stamens. In Aristolochia, however, the expression of AP3 and PI homologs in the perianth does not suggest a role in organ identity but, rather, in promoting late aspects of cell differentiation. The implications of these findings for the evolution of both petaloidy and B gene function are discussed.