Involved in resistance to abiotic stress. Homodimer and heterodimers (PubMed:29272523). Binds weakly to CYSTM4, CYSTM6 and CYSTM7 (PubMed:29272523). Mostly expressed in roots, flowers and siliques and, to a lower extent, in stems and leaves. Induced by salt in shoots. Belongs to the CYSTM1 family.