A single spot (no. 5) identified as cytosolic malate dehydrogenase (MDH) was characteristic for PHS resistant phenotype, together with not well functionally characterized protein (spot no. 6) showing partial homology to rubber elongation factor from distant species of Hevea brasiliensis. Two other molecular forms of this protein (spots no. 19 and 23) were present in higher amount in PHS resistant lines, similarly to proteins with sequence homology to dimeric alpha-amylase inhibitor (spot no. 21) and 14-3-3-like protein B (spot no. 16). Here, MDH1 is linked to Pallister-Hall syndrome.