Plant Defender Targeted by Bacterial Trick

Plants rely on surface sensors to spot invading bacteria. One key sensor is called FLS2. The cell keeps the right amount of this protein on its surface by using an internal transport system. A plant protein named PRA1. F3 helps FLS2 reach the surface. When PRA1. F3 works well, many FLS2 molecules appear on the membrane and the plant can fight off attackers. A bacterium called Shigella uses a tool named VirA to break this system. VirA sticks to PRA1. F3 inside the cell and marks it for destruction by the protein‑degradation machine. With PRA1. F3 gone, FLS2 cannot accumulate on the surface. The plant’s first line of defense weakens.VirA needs two abilities to work: it must be able to attach to membranes and it must turn on a GTPase that speeds up PRA1. F3 breakdown. If either function is missing, the bacterium can’t suppress immunity. Another plant protein, PRA1. F4, behaves differently. It actually reduces FLS2 levels but does not get destroyed by VirA. This shows that the bacterium has chosen a specific target in the plant’s transport network. The study highlights how a single bacterial protein can hijack a plant’s internal routing to avoid detection. It also shows that PRA1. F3 is essential for keeping defense sensors in place.