The bacterium Xanthomonas citri subsp. citri (Xcc) mobilizes sugars from plant cell walls by activating the fruit ripening program through the type III effector PthA4.1 PthA4 activates the plant regulator CsLOB1, which induces approximately 100 genes, many of which encode cell wall degrading enzymes.[1] CsLOB1 activation also promotes Xanthomonas growth in the non-fruiting plant Nicotiana benthamiana, showing that its effect is not strictly tied to the fruit ripening program.[1] Transcriptomics and reporter assays have demonstrated PthA4-dependent activation of a bacterial xylan CUT system that is triggered by host xylose.This CUT system involves type II-secreted xylanases that bacterial enzymes secrete into the environment to degrade xylan.[1] In a manner in which PthA4 remodulates the plant cell wall and the released sugars then activate bacterial xylan utilization, a feedback (feedforward) mechanism is established between type III and type II effectors that promotes Xcc proliferation[1].