On the mechanisms of development in monocot and eudicot leaves

First author: Phillip A. Conklin; Affiliations: Cornell University (康奈尔大学): Ithaca, USA

Corresponding author: Michael J. Scanlon

Comparisons of concepts in monocot and eudicot leaf development are presented, with attention to the morphologies and mechanisms separating these angiosperm lineages. Monocot and eudicot leaves are distinguished by the differential elaborations of upper and lower leaf zones, the formation of sheathing/nonsheathing leaf bases and vasculature (维管结构) patterning. We propose that monocot and eudicot leaves undergo expansion of mediolateral domains at different times in ontogeny (个体发生), directly impacting features such as venation (叶脉脉络) and leaf bases. Furthermore, lineage‐specific mechanisms in compound leaf development are discussed. Although models for the homologies of enigmatic tissues, such as ligules (叶舌) and stipules (托叶), are proposed, tests of these hypotheses are rare. Likewise, comparisons of stomatal development (气孔发育) are limited to Arabidopsis and a few grasses. Future studies may investigate correlations in the ontogenies of parallel venation (平行脉) and linear stomatal files (线性气孔) in monocots, and the reticulate patterning of veins (网状脉) and dispersed stoma (散生气孔) in eudicots. Although many fundamental mechanisms of leaf development are shared in eudicots and monocots, variations in the timing, degree and duration of these ontogenetic events may contribute to key differences in morphology. We anticipate that the incorporation of an ever‐expanding number of sequenced genomes will enrich our understanding of the developmental mechanisms generating eudicot and monocot leaves.

单、双子叶之间的叶片发育存在形态及分子机制之间的本质差异。单、双子叶植物的叶片差异主要表现在叶片的上、下部的精细结构、叶片基部鞘叶的形成与否及维管的模式建成。作者认为单、双子叶在个体发育不同时间中部侧面结构域的拓展直接影响了叶脉脉落及叶片基部的特性。此外，作者还在本文中讨论了复杂叶片发育中谱系特异性机制。尽管目前的研究已经提出了一些单、双子叶之间叶舌或托叶等叶片同源结构形成的模型，但对于这些模型的检验还很少。还有，对于叶片气孔发育的比较还仅限于拟南芥和少数几个禾本科植物之间。未来的一些研究可能会注重于单子叶平行脉和线性气孔分布与双子叶网状脉和散生气孔分布的个体发育之间的关系。尽管单、双子叶之间存在一些共同的基础性叶片发育机制，但在发挥作用的时间、程度及持续的时间等方面的差异可能就会导致单、双子叶叶片关键的形态差异。作者认为随着越来越多的植物基因组被测序，将会增加我们对于单、双子叶叶片之间发育机制差异的理解。

通讯：Michael J. Scanlon (http://scanlonlab.plantbio.cornell.edu/people/)

个人简介：爱荷华州立大学，遗传学博士；加利福尼亚大学伯克利分校，博士后。

研究方向：植物发育及形态演化。

doi: https://doi.org/10.1111/nph.15371

Journal: New Phytologist

Published date: 14 August, 2018

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