Selective sensation of sound by the plant Arabidopsis thaliana may enable the timely upregulation of defensive compounds to protect against caterpillars of the plant’s primary insect herbivore. Vibration of leaf trichomes has been shown to occur over frequency ranges that are appropriate for responding to these caterpillars, but the distribution of trichome shapes and sizes over a leaf means that a range of sounds could possibly be transduced. To assess how the diversity of trichomes on a leaf may affect sound transduction, we characterized the distribution of trichome sizes on a mature plant of A. thaliana and calculated the ensemble responses of entire leaves. Trichome sizes followed a normal distribution. Modal peaks in single trichome response spectra were at lower frequencies those of larger trichomes, roughly consistent with an inverse relationship between modal frequencies and trichome size. Ensemble response spectra for entire leaves showed frequency bands of responsiveness separated by defined band gaps, suggesting a possible mechanism for collective identification of the sounds of specific caterpillars.

拟南芥植物对声音的选择性感觉可以及时上调防御性化合物，以防止植物主要昆虫食草动物的毛虫。叶毛状体的振动已被证明会在适合对这些毛虫做出反应的频率范围内发生，但毛状体形状和大小在叶子上的分布意味着可能会转换一系列声音。为了评估叶子上毛状体的多样性如何影响声音转导，我们表征了拟南芥成熟植物上毛状体大小的分布并计算了整片叶子的整体响应。毛状体大小服从正态分布。单个毛状体响应谱中的模态峰位于较大毛状体的较低频率，大致符合模态频率和毛状体大小之间的反比关系。整个叶子的集合响应谱显示了由定义的带隙分隔的响应频带，这表明集体识别特定毛虫声音的可能机制。