Wang Qiang, Zhou Xijie, He Shengli, Wang Wenguo, Ma Danwei, Wang Yu, Zhang Hong
College of Life Science, Sichuan Normal University, Chengdu 610101, China.
Key Laboratory of Development and Application of Rural Renewable Energy, Biogas Institute of Ministry of Agriculture and Rural Affairs, Chengdu 610041, China.
Plants (Basel). 2023 Nov 9;12(22):3810. doi: 10.3390/plants12223810.
L. is an invasive plant native to the Neotropics that has seriously threatened the ecological security of China, and allelopathy is one of the mechanisms underlying its successful invasion. Maize ( L.) and soybean ( (L.) Merr.), as the main food crops, are usually affected by in their planting areas. The purpose of this study was to investigate the ultrastructure, autophagy, and release-related gene expression of receptor plant root border cells (RBCs) after exposure to volatile oil from and its main component α-terpene, which were studied using maize and soybean as receptor plants. The volatiles inhibited root growth and promoted a brief increase in the number of RBCs. As the volatile concentration increased, the organelles in RBCs were gradually destroyed, and intracellular autophagosomes were produced and continuously increased in number. Transcriptomic analysis revealed that genes involved in the synthesis of the plasma membrane and cell wall components in receptor root cells were significantly up-regulated, particularly those related to cell wall polysaccharide synthesis. Meanwhile, polygalacturonase and pectin methylesterases (PME) exhibited up-regulated expression, and PME activity also increased. The contribution of α-terpene to this allelopathic effect of volatile oil exceeded 70%. Based on these results, receptor plant root tips may increase the synthesis of cell wall substances while degrading the intercellular layer, accelerating the generation and release of RBCs. Meanwhile, their cells survived through autophagy of RBCs, indicating the key role of RBCs in alleviating allelopathic stress from volatiles.
假苍耳是一种原产于新热带地区的入侵植物，已严重威胁到中国的生态安全，化感作用是其成功入侵的机制之一。玉米（Zea mays L.）和大豆（Glycine max (L.) Merr.）作为主要粮食作物，在其种植区域常受假苍耳影响。本研究旨在以玉米和大豆作为受体植物，研究受体植物根边缘细胞（RBCs）在接触假苍耳挥发油及其主要成分α-萜品烯后的超微结构、自噬及释放相关基因表达。挥发物抑制根系生长并促使RBCs数量短暂增加。随着挥发物浓度升高，RBCs中的细胞器逐渐被破坏，细胞内产生自噬体且数量不断增加。转录组分析表明，受体根细胞中参与质膜和细胞壁成分合成的基因显著上调，尤其是与细胞壁多糖合成相关的基因。同时，多聚半乳糖醛酸酶和果胶甲酯酶（PME）表达上调，PME活性也增加。α-萜品烯对假苍耳挥发油这种化感作用的贡献超过70%。基于这些结果，受体植物根尖可能在降解细胞间层的同时增加细胞壁物质的合成，加速RBCs的产生和释放。同时，其细胞通过RBCs的自噬得以存活，这表明RBCs在缓解假苍耳挥发物的化感胁迫中起关键作用。
