“…Plant carbonic anlhydrase is thought to be only wveaklx affected, if at all, by sulfonamides (5,9) although the literature shows s,ome variability (1,11,13,19,24). It has been found by some workers that free sulfhydryl groups are necessarv for expression of the plant enzyme or for its enhancement (1,23) but variability in this regard has ailso been reported (15,24).…”