Background and Aims Wheat crops are exposed to a range of mechanical stimulations in their natural environment, yet we know very little about their response to such conditions. The aim of this study was to better understand the effect of mechanical stimulation on wheat growth and development, stem mechanical properties and grain measures. We focused on the following questions: (1) Does plant age affect the response to mechanical stimulation? (2) Is there a minimum threshold for the perception of mechanical stimuli? (3) Is the effect of manual brushing different to natural wind stimulation? Methods For age– and dose–response experiments, wheat plants were grown under controlled glasshouse conditions with brushing treatments applied using a purpose-built rig. The results of the controlled experiments are compared with those from an outside experiment where wheat plants were exposed to natural wind, with or without additional brushing. Detailed phenotypic measurements were conducted and treatment effects on grain characteristics were determined using micro-computed tomography imaging. Key Results Two-week-old wheat plants were particularly sensitive to mechanical stimulation by controlled brushing treatments. Amongst others, plants exhibited a large reduction in height and grain yield, and an increase in tillers, above-ground biomass and stiffness of stem segments. Plants responded significantly to doses as small as one daily brushstroke. Outdoor experiments by and large confirmed results from controlled environment experiments. Conclusions The morphological and developmental response to mechanical brushing treatment, in relation to vegetative above-ground biomass and grain yield, is dependent on plant age as well as the dose of the treatments. This study shows that mechanical stimulation of wheat impacts on a multitude of agriculturally relevant traits and provides a much needed advancement of our understanding of wheat thigmomorphogenesis and the potential applications of mechanical conditioning to control relevant traits.

中文翻译：

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小麦的机械刺激会触发生长、发育和谷物特征的年龄和剂量依赖性变化

背景和目标小麦作物在其自然环境中受到一系列机械刺激，但我们对它们对这些条件的反应知之甚少。本研究的目的是更好地了解机械刺激对小麦生长发育、茎的机械特性和籽粒措施的影响。我们关注以下问题：（1）植物年龄是否会影响对机械刺激的反应？(2) 对机械刺激的感知是否有最低阈值？（3）人工刷牙的效果和自然风刺激有区别吗？方法 对于年龄和剂量反应实验，小麦植物在受控温室条件下生长，并使用专用设备进行刷毛处理。将受控实验的结果与小麦植物暴露在自然风中的外部实验的结果进行比较，有或没有额外的刷牙。进行了详细的表型测量，并使用微型计算机断层扫描成像确定了处理对谷物特性的影响。主要结果 两周大的小麦植株对受控刷毛处理的机械刺激特别敏感。其中，植物表现出高度和谷物产量的大幅下降，以及分蘖、地上生物量和茎段刚度的增加。植物对小至每日一笔的剂量有显着反应。户外实验大体上证实了受控环境实验的结果。结论 机械刷毛处理的形态和发育反应与植物地上生物量和谷物产量有关，取决于植物年龄和处理剂量。这项研究表明，小麦的机械刺激会影响多种农业相关性状，并为我们对小麦 thigmomorphogenesis 的理解和机械调节控制相关性状的潜在应用提供了急需的进步。