Catalyzes xyloglucan endohydrolysis (XEH) (By similarity). Cleaves and religates xyloglucan polymers, an essential constituent of the primary cell wall, and thereby participates in cell wall construction of growing tissues (PubMed:23585673). Involved in cell proliferation in the tissue reunion process of wounded inflorescence stems. Maybe a downstream target of NAC071 as a consequence of auxin action in wounded stems (PubMed:25182467). breaks a beta-(1->4) bond in the backbone of a xyloglucan and transfers the xyloglucanyl segment on to O-4 of the non-reducing terminal glucose residue of an acceptor, which can be a xyloglucan or an oligosaccharide of xyloglucan. Root specific. Contains at least one intrachain disulfide bond essential for its enzymatic activity. Belongs to the glycosyl hydrolase 16 family. XTH group 2 subfamily.