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>

丝状植物病原菌通过施加机械力穿透宿主体表并侵入宿主组织。毁灭性疫霉（Phytophthora）病原菌依托一种特化的侵入性顶端生长模式，以菌丝作为显微手术刀切割穿透植物体表。该切割过程需要尖锐的菌丝顶端，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迄今仍不明确。本研究在致病疫霉（Phytophthora infestans，缩写P. infestans）中发现了一套基于肌动蛋白（actin）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。当菌丝受到机械刺激时，会形成星状肌动蛋白结构，该结构可对局部应力做出快速、局部且定量的反馈响应。本研究证实，该结构可作为适应性机械支架，强化这一侵入性"武器"并防止其钝化。该机械稳态系统可将细胞膨压高效转化为实现宿主侵染所需的局部侵入压力。