Root-knot nematodes (RKNs; genus Meloidogyne) are a class of plant parasites that infect the roots of many plant species. It is believed that RKNs target certain signaling molecules derived from plants to locate their hosts; however, currently, no plant compound has been unambiguously identified as a universal RKN attractant. To address this question, we screened a chemical library of synthetic compounds for Meloidogyne incognita attractants. The breakdown product of aminopropylamino-anthraquinone, 1,3-diaminopropane, as well as its related compounds, putrescine and cadaverine, were found to attract M. incognita. After examining various polyamines, M. incognita were found to be attracted specifically by natural compounds that possess three to five methylene groups between two terminal amino groups. Using cryo-TOF-SIMS/SEM, cadaverine was indeed detected in soybean root cortex cells and the surrounding rhizosphere, establishing a chemical gradient. In addition to cadaverine, putrescine and 1,3-diaminopropane were also detected in root exudate by HPLC-MS/MS. Furthermore, exogenously applied cadaverine is sufficient to enhance M. incognita infection of Arabidopsis seedlings. These results suggest that M. incognita is likely attracted by polyamines to locate the appropriate host plants, and the naturally occurring polyamines have potential applications in agriculture in developing protection strategies for crops from RKN infection.

根结线虫（RKNs；根结线虫属）是一类植物寄生虫，可感染许多植物物种的根。据信RKNs靶向某些源自植物的信号传导分子以定位其宿主。然而，目前还没有任何植物化合物被明确确定为通用的RKN引诱剂。为了解决这个问题，我们筛选了Meloidogyne incognita引诱剂的合成化合物化学文库。发现氨基丙基氨基蒽醌，1,3-二氨基丙烷的分解产物及其相关化合物腐胺和尸胺吸引了隐孢子虫。在检查了各种多胺后，M。incognita被发现被两个末端氨基之间具有三到五个亚甲基的天然化合物特别吸引。使用cryo-TOF-SIMS / SEM，确实在大豆根皮层细胞和周围的根际中检测到了尸胺，建立了化学梯度。除尸胺外，还通过HPLC-MS / MS在根分泌物中检测到了腐胺和1,3-二氨基丙烷。此外，外用尸胺足以增强拟南芥幼苗的隐孢子虫感染。这些结果表明，M。incognita 可能被多胺吸引以定位合适的寄主植物，并且天然存在的多胺在农业中为开发针对RKN感染的作物的保护策略具有潜在的应用价值。