de Kroon Hans, Huber Heidrun, Stuefer Josef F, van Groenendael Jan M
Department of Ecology, Radboud University Nijmegen, Toernooiveld 1, 6525 ED Nijmegen, the Netherlands.
New Phytol. 2005 Apr;166(1):73-82. doi: 10.1111/j.1469-8137.2004.01310.x.
Based on empirical evidence from the literature we propose that, in nature, phenotypic plasticity in plants is usually expressed at a subindividual level. While reaction norms (i.e. the type and the degree of plant responses to environmental variation) are a property of genotypes, they are expressed at the level of modular subunits in most plants. We thus contend that phenotypic plasticity is not a whole-plant response, but a property of individual meristems, leaves, branches and roots, triggered by local environmental conditions. Communication and behavioural integration of interconnected modules can change the local responses in different ways: it may enhance or diminish local plastic effects, thereby increasing or decreasing the differences between integrated modules exposed to different conditions. Modular integration can also induce qualitatively different responses, which are not expressed if all modules experience the same conditions. We propose that the response of a plant to its environment is the sum of all modular responses to their local conditions plus all interaction effects that are due to integration. The local response rules to environmental variation, and the modular interaction rules may be seen as evolving traits targeted by natural selection. Following this notion, whole-plant reaction norms are an integrative by-product of modular plasticity, which has far-reaching methodological, ecological and evolutionary implications.
基于文献中的经验证据，我们提出，在自然界中，植物的表型可塑性通常在亚个体水平上表现出来。虽然反应规范（即植物对环境变化的反应类型和程度）是基因型的一种属性，但在大多数植物中，它们是在模块化亚单位水平上表现出来的。因此，我们认为表型可塑性不是一种全株反应，而是由局部环境条件触发的单个分生组织、叶片、枝条和根系的一种属性。相互连接的模块之间的通讯和行为整合可以以不同方式改变局部反应：它可能增强或减弱局部可塑性效应，从而增加或减少暴露于不同条件下的整合模块之间的差异。模块化整合还可以诱导出质上不同的反应，如果所有模块都经历相同的条件，这些反应就不会表现出来。我们提出，植物对其环境的反应是所有模块对其局部条件的反应之和，再加上由于整合而产生的所有相互作用效应。对环境变化的局部反应规则以及模块化相互作用规则可以被视为自然选择所针对的进化特征。按照这一概念，全株反应规范是模块化可塑性的一种综合副产品，这具有深远的方法学、生态学和进化意义。
