Figure 3.

Comparison of amino acid sequences of Suc/H⁺ symporters from dicotyledonous plants. The dendrogram was generated by comparison of the sequences by the PileUp program of the Genetics Computer Group sequence analysis software package. ara1, Arabidopsis (accession no. X75365); ara2, Arabidopsis (accession no. X75382); spi, spinach (accession no. X67125); bet, Beta vulgaris (accession no. X83850); pot, potato (accession no. X69165); tom, tomato (accession no. X82275); tob, tobacco (accession no. X82276); car2, DcSUT2 (accession no. Y16768); vif, fava bean (accession no. Z93774); pla2, P. major (accession no. X75764); pla1, P. major (accession no. X84379); car1, DcSUT1 (accession no. Y16766); and ric, castor bean (accession no. Z31561). The two carrot polypeptides are marked by asterisks. ara1 and pla1 have neutral pH optima, whereas all other transporters have maximal activities below pH 5.0.