Involved in plant defense against Phytophtora sojae (PubMed:28082413). Contributes positively to soybean resistance against P.sojae (PubMed:28082413). Binds the P.sojae xyloglucanase XEG1 and inhibits its cell wall degrading enzyme activity and its contribution as P.sojae virulence factor (PubMed:28082413). XEG1 acts as an important virulence factor during P.sojae infection but also acts as a pathogen-associated molecular pattern (PAMP) in soybean and solanaceous species, where it can trigger defense responses including cell death (PubMed:26163574). (Microbial infection) Possesses stronger binding affinity with XLP1, a truncated paralog of P.sojae XEG1 which has no enzyme activity. Is impaired in its inhibitor activity towards the P.sojae xyloglucanase XEG1 when hijacked by XLP1 binding. Interacts with the Phytophtora sojae xyloglucanase XEG1 and xyloglucanase-like XLP1 (PubMed:28082413). Possesses stronger binding affinity with XLP1, a truncated paralog of P.sojae XEG1 which has no enzyme activity (PubMed:28082413). Plants silencing GIP1 display significantly increased susceptibility to infection by Phytophtora sojae, and plants over-expressing GIP1 show increased resistance. Belongs to the peptidase A1 family. Lure - Issue 218 of October 2019