May be involved in aluminium (Al) tolerance (PubMed:12805622). Involved in resistance to abiotic stress (PubMed:29272523). Heterodimers (PubMed:29272523). Binds weakly to CYSTM7 and WIH1/CYSTM13 (PubMed:29272523). Mostly expressed in roots, flowers and siliques and, to a lower extent, in stems and leaves. Induced by drought and oxidation stress. Belongs to the CYSTM1 family.