Comparative developmental anatomy of seedlings in nine species of podostemaceae (subfamily Podostemoideae).
Comparative developmental anatomy of seedlings in nine species of podostemaceae (subfamily Podostemoideae).
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DOI：
10.1093/aob/mcf109
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发表时间：
2002-06
期刊：
影响因子：
4.2
通讯作者：
Koji Suzuki;Y. Kita;Masahiro Kato
中科院分区：
文献类型：
--
作者：
Koji Suzuki;Y. Kita;Masahiro Kato
报道了Podostemideae亚科9个亚洲和澳大利亚种的幼苗的发育解剖学。下胚轴是不发育的(除了在Zeylandium olivaceum中)，并且在所检查的任何种中不形成初生根。不定根在6种植物的下胚轴中内源形成，具有带状或扁平的亚圆柱形根，在橄榄科植物中内源形成，具有叶状根。相反，它以外源形式形成于具有叶状根的水生植物和水生植物中。幼根变得扁平，背腹面，外源分枝(在柱花草、毛冬青和地衣草中)，并在内源产生新枝(在毛冬青、白毛香和地衣草中)。根分生组织结构简单，由表面均匀的内部细胞组成，所有种的根冠均无根冠。在亚裔澳大利亚的Podostemoideae中，幼苗根的分生组织形态可能是原始的。在培养期间没有形成根冠或保护组织，可能是由于发育迟缓，即使在7种具有盖状成根的物种中也是如此。在其他两个物种的个体发育过程中，它都不存在。子叶之间没有形成明显的顶端分生组织。在有内源不定根的树种中，有一到几片叶子占据顶端区域，而在有外源根的树种中，不形成叶片。这些差异表明在亚洲分支中的叶状根的经常性起源。讨论了拟南芥独特的幼苗形态和突变体表型之间的相似性。
The developmental anatomy is described for seedlings of nine Asian and Australian species of Podostemaceae, subfamily Podostemoideae. The hypocotyl is rudimentary (except in Zeylanidium olivaceum) and does not form a primary root in any of the species examined. An adventitious root forms endogenously in the hypocotyl of six species with ribbon-like or flattened subcylindrical roots, and in Z olivaceum with foliose roots. In contrast, it forms exogenously in Hydrobryum griffithii and Synstylis micranthera with foliose roots. The juvenile root becomes flattened and dorsiventral, branches exogenously (in Polypleurum stylosum, P. wallichii and Z. lichenoides) and produces shoots endogenously (in P. stylosum, P. wallichii, S. micranthera and Z. lichenoides). The root meristem is simple, composed of surface and uniform inner cells, and is devoid of root cap initials in all species. The reduced meristem morphology of seedling roots may be primitive in the Asian-Australian Podostemoideae. A root cap or protective tissue did not form during the culture period, even in the seven species with capped adult roots, probably due to its delayed development. It was absent throughout ontogeny in the other two species. No obvious shoot apical meristem forms between the cotyledons. One to several leaves occupy the shoot apical area in species with endogenous adventitious roots, while no leaves are formed in species with exogenous roots. These differences suggest recurrent origins of foliose roots in the Asian clade. Similarities between the unique seedling morphology and mutant Arabidopsis phenotypes are discussed.