Genome-wide Identification of <i>Phloem Protein 2</i> Genes ( <i>PP2</i> s) and Characterization of <i>GhPP2</i> - <i>43</i> in <i>Verticillium wilt</i> Resistance of Cotton ( <i>Gossypium hirsutum</i> )

Phloem protein 2 (PP2) performs a vital function in plant stress response. <i>Verticillium wilt</i> is a destructive vascular disease that leads to significant reductions in cotton yield. However, limited systematic investigation has been conducted on the responsiveness of PP2 to <i>V. wilt</i> in cotton. Here, we identified a total of 46 <i>GhPP2</i>s from the genome of <i>Gossypium hirsutum</i>. Among them, 41 <i>GhPP2</i>s exhibited differentially expression during infection by <i>Verticillium dahliae</i>, with an <i>AtPP2</i>-<i>A1</i> homologue, <i>GhPP2-43</i> displaying a pronounced response, indicating their potential roles in <i>V. wilt</i> resistance. Furthermore, GhPP2-43 may interact with peroxidase GhPER24 and ribosomal protein L18 (GhRPL18), potentially serving as a key regulator for enhancing cotton's defense to <i>V. wilt</i> by improving a burst of reactive oxygen species (ROS) and its involvement in phytohormone signaling pathways. These findings offer valuable insights into <i>GhPP2</i>s and indicate potential molecular targets for improving resistance against <i>V. wilt</i> in cotton.