Department of Plant Biology, University of Illinois, 191 Edward R. Madigan Laboratory, 1201 West Gregory Drive, Urbana, IL, 61801, USA.
Theor Appl Genet. 2009 Nov;119(8):1461-76. doi: 10.1007/s00122-009-1148-5. Epub 2009 Sep 29.
Owing to their sessile habits and trophic position within global ecosystems, higher plants display a sundry assortment of adaptations to the threat of predation. Unlike animals, nearly all higher plants can replace reproductive structures lost to predators by activating reserved growing points called axillary meristems. As the first step in a program aimed at defining the genetic architecture of the inflorescence replacement program (IRP) of Arabidopsis thaliana, we describe the results of a quantitative germplasm survey of developmental responses to loss of the primary reproductive axis. Eighty-five diverse accessions were grown in a replicated common garden and assessed for six life history traits and four IRP traits, including the number and lengths of axillary inflorescences present on the day that the first among them re-flowered after basal clipping of the primary inflorescence. Significant natural variation and high heritabilities were observed for all measured characters. Pairwise correlations among the 10 focal traits revealed a multi-dimensional phenotypic space sculpted by ontogenic and plastic allometries as well as apparent constraints and outliers of genetic interest. Cluster analysis of the IRP traits sorted the 85 accessions into 5 associations, a topology that establishes the boundaries within which the evolving Arabidopsis genome extends and restricts the species' IRP repertoire to that observable worldwide.
由于其固着的生活方式和在全球生态系统中的营养地位，高等植物表现出各种适应捕食威胁的特征。与动物不同，几乎所有的高等植物都可以通过激活称为腋芽分生组织的备用生长点来替代被捕食者破坏的生殖结构。作为旨在定义拟南芥花序替代计划（IRP）遗传结构的计划的第一步，我们描述了对初级生殖轴丧失的发育反应进行定量种质调查的结果。将 85 种不同的品系在重复的公共花园中生长，并评估了六个生活史特征和四个 IRP 特征，包括第一批腋生花序在基本剪去主花序后重新开花当天存在的腋生花序的数量和长度。所有测量的特征都观察到了显著的自然变异和高遗传力。10 个焦点特征之间的成对相关性揭示了一个由个体发生和塑性异速生长以及明显的遗传限制和感兴趣的异常值塑造的多维表型空间。对 IRP 特征的聚类分析将 85 个品系分为 5 个类群，该拓扑结构确定了进化中的拟南芥基因组扩展的边界，并将该物种的 IRP 库限制为全球范围内可观察到的。
