Root anatomical phenes have important roles in soil resource capture and plant performance; however, their phenotypic plasticity and genetic architecture is poorly understood. We hypothesized that (a) the responses of root anatomical phenes to water deficit (stress plasticity) and different environmental conditions (environmental plasticity) are genetically controlled and (b) stress and environmental plasticity are associated with different genetic loci than those controlling the expression of phenes under water‐stress and well‐watered conditions. Root anatomy was phenotyped in a large maize (Zea mays L.) association panel in the field with and without water deficit stress in Arizona and without water deficit stress in South Africa. Anatomical phenes displayed stress and environmental plasticity; many phenotypic responses to water deficit were adaptive, and the magnitude of response varied by genotype. We identified 57 candidate genes associated with stress and environmental plasticity and 64 candidate genes associated with phenes under well‐watered and water‐stress conditions in Arizona and under well‐watered conditions in South Africa. Four candidate genes co‐localized between plasticity groups or for phenes expressed under each condition. The genetic architecture of phenotypic plasticity is highly quantitative, and many distinct genes control plasticity in response to water deficit and different environments, which poses a challenge for breeding programs.

中文翻译：

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玉米根部解剖可塑性的遗传控制

根系解剖酚在土壤资源捕获和植物生长中具有重要作用。然而，他们的表型可塑性和遗传结构了解甚少。我们假设（a）根部解剖酚对水分亏缺（应力可塑性）和不同环境条件（环境可塑性）的反应是遗传控制的（b）应力和环境可塑性与控制基因表达的基因位点相关处于水压力和浇水条件良好的地方。在大型玉米（玉米）中根系解剖表型。L.）在亚利桑那州有或没有缺水胁迫而在南非没有缺水胁迫的田间协会小组。解剖上的动物表现出压力和环境可塑性。许多对水分亏缺的表型反应都是适应性的，反应的强度因基因型而异。我们在亚利桑那州的干旱和干旱条件下以及南非的干旱条件下，鉴定了与压力和环境可塑性相关的57个候选基因和与苯酚相关的64个候选基因。四个候选基因共定位在可塑性组之间或在每种条件下表达的酚。表型可塑性的遗传结构是高度定量的，并且许多不同的基因响应缺水和不同环境而控制可塑性，