Yamawo Akira, Hagiwara Tomika, Yoshida Satomi, Ohno Misuzu, Nakajima Riku, Mori Yusuke, Hayashi Tamayo, Yamagishi Hiroki, Shiojiri Kaori
Department of Biology, Faculty of Agriculture and Life Science Hirosaki University Hirosaki Japan.
Center for Ecological Research Kyoto University Otsu, Shiga Japan.
Ecol Evol. 2025 Jan 17;15(1):e70876. doi: 10.1002/ece3.70876. eCollection 2025 Jan.
Plants evolve diverse communication systems in adapting to complex and variable environments. Here, we examined the relationship between plant architecture, population density and inter-plant communication within tree species. We tested the hypothesis that trees of species with complex architecture or high population density (high population density: HPD) communicate among conspecifics via volatiles. In addition, we hypothesize that states of mycorrhizal symbiosis (arbuscular mycorrhizal or ectomycorrhiza) which relation to population density can predict the development of interplant communication in trees. We tested induced defense as an indicator of communication in saplings of nine tree species with various complexities of architecture (number of leaves per shoot) and either low (low population density: LPD) or HPD, either exposed for 10 days to volatiles from a damaged conspecific or not exposed. We evaluated the number of insect-damaged leaves and the area of leaf damage on these trees after 1 and 2 months in the field. Most exposed HPD trees had less leaf damage than controls. However, LPD trees did not differ in leaf damage between treatments. These results are partially supported by plant hormone analysis. In addition, the presence of inter-plant communication was positively correlated with both the number of leaves per shoot (complexity of plant architecture) and population density. The analysis which combined results of previous studies suggests that states of mycorrhizal symbiosis predict the development of interplant communication; interplant communication is common in ectomycorrhiza species. These results suggest the importance of plant architecture and population density as well as state of mycorrhizal symbiosis in the development of interplant communications within tree species.
植物在适应复杂多变的环境过程中进化出了多样的通讯系统。在此，我们研究了树种内部植物结构、种群密度与植株间通讯之间的关系。我们检验了这样一个假设：具有复杂结构或高种群密度（高种群密度：HPD）的树种会通过挥发性物质在同种个体间进行通讯。此外，我们假设与种群密度相关的菌根共生状态（丛枝菌根或外生菌根）可以预测树木中植株间通讯的发展。我们以诱导防御作为通讯的指标，对9种具有不同结构复杂性（每枝的叶片数量）且处于低（低种群密度：LPD）或高种群密度的树苗进行了测试，这些树苗要么暴露于受损同种个体的挥发性物质中10天，要么未暴露。我们在野外1个月和2个月后评估了这些树上昆虫损伤叶片的数量和叶片损伤面积。大多数暴露于挥发性物质的高种群密度树木的叶片损伤比对照少。然而，低种群密度树木在不同处理间的叶片损伤没有差异。这些结果得到了植物激素分析的部分支持。此外，植株间通讯的存在与每枝的叶片数量（植物结构的复杂性）和种群密度均呈正相关。结合先前研究结果的分析表明，菌根共生状态可预测植株间通讯的发展；植株间通讯在外生菌根树种中很常见。这些结果表明了植物结构、种群密度以及菌根共生状态在树种内部植株间通讯发展中的重要性。
