Department of Soil Microbiology and Symbiotic Systems, Estación Experimental del Zaidín (CSIC), Granada, Spain.
Dipartimento di Biologia e Biotecnologie C. Darwin, Sapienza Università di Roma, Rome, Italy.
Plant Cell Environ. 2021 Jan;44(1):275-289. doi: 10.1111/pce.13917. Epub 2020 Nov 3.
Oligogalacturonides (OGs) are fragments of pectin released from the plant cell wall during insect or pathogen attack. They can be perceived by the plant as damage signals, triggering local and systemic defence responses. Here, we analyse the dynamics of local and systemic responses to OG perception in tomato roots or shoots, exploring their impact across the plant and their relevance in pathogen resistance. Targeted and untargeted metabolomics and gene expression analysis in plants treated with purified OGs revealed that local responses were transient, while distal responses were stronger and more sustained. Remarkably, changes were more conspicuous in roots, even upon foliar application of the OGs. The treatments differentially activated the synthesis of defence-related hormones and secondary metabolites including flavonoids, alkaloids and lignans, some of them exclusively synthetized in roots. Finally, the biological relevance of the systemic defence responses activated upon OG perception was confirmed, as the treatment induced systemic resistance to Botrytis cinerea. Overall, this study shows the differential regulation of tomato defences upon OGs perception in roots and shoots and reveals the key role of roots in the coordination of the plant responses to damage sensing.
寡糖（OGs）是果胶的片段，在昆虫或病原体攻击时从植物细胞壁中释放出来。它们可以被植物感知为损伤信号，触发局部和系统防御反应。在这里，我们分析了番茄根系或地上部对 OG 感知的局部和系统反应的动态，探索了它们在植物中的影响及其在抗病性中的相关性。用纯化的 OGs 处理的植物的靶向和非靶向代谢组学和基因表达分析表明，局部反应是短暂的，而远端反应更强且更持久。值得注意的是，即使在叶片施用 OGs 的情况下，根中的变化也更加明显。处理还会差异激活与防御相关的激素和次生代谢物（包括类黄酮、生物碱和木脂素）的合成，其中一些仅在根中合成。最后，证实了 OG 感知引发的系统防御反应的生物学相关性，因为处理诱导了对灰葡萄孢的系统抗性。总的来说，这项研究表明，在根和地上部对 OG 感知的过程中，番茄防御反应的差异调节，并揭示了根在协调植物对损伤感应的反应中的关键作用。
