Data underlying the publication: Phytophthora pathogens exploit slicing action for host invasion

Host entry requires plant pathogens to breach the protective surface of the plant. <i>Phytophthora </i>species, classified as oomycetes, are among the most destructive filamentous plant pathogens worldwide and pose a substantial threat to food security. Little is known about the biomechanics of host invasion in oomycetes, yet this understanding is crucial to combat these pathogens more effectively. Here we unveil how <i>Phytophthora</i> spp. invade elastic surfaces by pressure application at an oblique angle without appressorium formation. This ‘slicing’ action, coined the <i>naifu</i>-mechanism, facilitates crack initiation by concentrating stresses towards the surface enabling host entry through the crack void. This contrasts the ‘brute’ force approach found in fungal filamentous plant pathogens capable of producing a melanized appressorium that generates tremendous turgor pressures. Measurements of surface deformations during invasion reveal an asymmetric geometry of decoupled adherence and indentation sites that is quantitatively described with a mathematical model. Moreover, we establish how polarized growth, surface adherence and turgor generation are each essential to accomplish host entry by this approach. The naifu-mechanism enables <i>Phytophthora </i>pathogens to penetrate their hosts without necessitating specialized pressure organs and vast turgor pressures. <b></b>

宿主侵染过程要求植物病原微生物突破植物的保护性表层。疫霉属（*Phytophthora*）物种隶属于卵菌，是全球范围内破坏力最强的丝状植物病原物之一，对粮食安全构成严重威胁。目前学界对卵菌宿主侵染的生物力学机制知之甚少，但该领域的研究对于更高效地防控此类病原物至关重要。本研究揭示了疫霉属（*Phytophthora*）物种如何无需附着胞（appressorium）形成，通过斜向施加压力的方式侵入植物弹性表层。这种被命名为‘naifu机制’的‘切割’动作，通过将应力集中于表层以引发裂纹，借助裂纹空隙完成宿主侵染。这与丝状真菌病原物的‘蛮力’侵染方式截然不同：后者可产生黑色素化附着胞，借助巨大膨压完成侵染。对侵染过程中表层变形的测量结果显示，病原物的附着位点与压入位点呈现解耦的不对称几何形态，该形态可通过数学模型进行定量描述。此外，本研究明确了极性生长、表层附着与膨压产生这三个要素，对于通过该机制完成宿主侵染均不可或缺。naifu机制使得疫霉属病原物无需特化压力器官与极高膨压，即可完成宿主侵入。