The small GTP-binding protein GhARAC3 is involved in cotton resistance to Verticillium dahliae by regulating lignin metabolism

Plant Rac/Rop GTPases are important signaling regulators involved in various biological processes, including responses to pathogen infection. Cotton (Gossypium hirsutum L.) GhARAC3 encodes a Rho/ROP GTPase. This study demonstrated GhARAC3 contributed positively to cotton resistance to Verticillium dahliae, as overexpressing the gene in cotton and Arabidopsis enhanced resistance against V. dahliae, and knockdown the gene increased the susceptibility of cotton to V. dahliae. These findings demonstrated a role of ubiquitination in regulating the function of GhARAC3 and linked Rho/ROP GTPase to lignin metabolism in cotton resistance against V. dahliae.