Data from the paper An actin mechanostat ensures hyphal tip sharpness in Phytophthora infestans to facilitate host entry.

Filamentous plant pathogens apply mechanical forces to pierce their hosts surface and penetrate its tissues. Devastating Phytophthora pathogens harness a specialized form of invasive tip growth to slice through the plant surface, wielding their hypha as a microscopic knife. Slicing requires a sharp hyphal tip that is not blunted at the site of the mechanical interaction. How tip shape is controlled, however, is unknown. We uncover an actin-based mechanostat in P. infestans that controls tip sharpness during penetration. Mechanical stimulation of the hypha leads to the emergence of an aster-like actin structure, which shows fast, local and quantitative feedback to the local stress. We evidence that this functions as an adaptive mechanical scaffold that sharpens the invasive weapon and prevents it from blunting. The hyphal tip mechanostat enables the efficient conversion of turgor into localized invasive pressures that are required to achieve host penetration. <br>

丝状植物病原体可通过施加机械力刺穿宿主表面并侵入其组织。极具破坏性的疫霉（Phytophthora）病原菌借助一种特化的侵入性顶端生长方式切割植物表面，将菌丝作为微观利刃加以运用。该切割过程需要保持菌丝顶端尖锐，且在机械互作位点不会发生钝化。然而，菌丝顶端形状的调控机制至今仍未阐明。我们在致病疫霉（Phytophthora infestans）中发现了一套基于肌动蛋白的机械稳态系统（mechanostat），可在侵染过程中调控菌丝顶端的尖锐程度。对菌丝施加机械刺激会诱导出星状肌动蛋白结构，该结构可对局部应力产生快速、局部且定量的反馈响应。我们证实，该结构可作为适应性机械支架，强化这一侵入性"利刃"并避免其发生钝化。菌丝顶端的机械稳态系统可将膨压高效转化为宿主侵染所需的局域侵入压力。