A variant of a parent polypeptide wherein the variant has steviol glycoside transport mediating activity, wherein the variant comprises an amino acid sequence which, when aligned with the amino acid sequence set out in SEQ ID NO: 3, comprises at least one modification of an amino acid residue corresponding to any of amino acids, 15, 19, 26, 29, 31, 32, 33, 37, 46, 56, 59, 107,135, 136, 141, 145, 148, 150, 151, 153, 199, 200, 204, 206, 207, 210, 211, 255, 257, 258, 262, 267, 268, 272, 273, 276, 277, 278, 281, 282, 283, 284, 292, 294, 296, 297, 298, 299, 300, 302, 303, 306, 307, 309, 310, 311, 315, 318, 319, 320, 321, 322, 323, 324, 326, 328, 375, 376, 378, 379, 380, 382, 384, 386, 387, 389, 408, 410, 411, 413, 414, 415, 416, 417, 419, 420, 421, 422, 423, 424, 425, 427, 428, 429, 853, 854, 857, 859, 862, 864, 869, 890, 891, 892, 894, 903, 906, 968, 969, 972, 974, 977, 986, 996, 998, 999, 1001, 1003, 1004, 1010, 1012, 1016, 1017, 1018, 1019, 1020, 1021, 1059, 1060, 1061, 1062, 1063, 1075, 1076, 1107,1108, 1111, 1112, 1115, 1118, 1120, 1123, 1127, 1128, 1179, 1200, said positions being defined with reference to the amino acid sequence set out in SEQ ID NO: 3, wherein the variant polypeptide has at least 70% sequence identity with the amino acid sequence set out in SEQ ID NO: 3, and wherein when measured under the same conditions: a) the ratio between the molar concentration of rebaudioside M and the molar concentration of rebaudioside A produced by a recombinant cell expressing the variant is higher than the ratio between the molar concentration of rebaudioside M and the molar concentration of rebaudioside A produced by a reference cell; and/or b) the ratio between the molar concentration of rebaudioside M and the molar concentration of total steviol glycosides produced by a recombinant cell expressing the variant is higher than the ratio between the molar concentration of rebaudioside M and the molar concentration of total steviol glycosides produced by a reference cell; and wherein the reference cell is a recombinant cell expressing the parent polypeptide. 15, 19, 26, 29, 31, 32, 33, 37, 46, 56, 59, 107,135, 136, 141, 145, 148, 150, 151, 153, 199, 200, 204, 206, 207, 210, 211, 255, 257, 258, 262, 267, 268, 272, 273, 276, 277, 278, 281, 282, 283, 284, 292, 294, 296, 297, 298, 299, 300, 302, 303, 306, 307, 309, 310, 311, 315, 318, 319, 320, 321, 322, 323, 324, 326, 328, 375, 376, 378, 379, 380, 382, 384, 386, 387, 389, 408, 410, 411, 413, 414, 415, 416, 417, 419, 420, 421, 422, 423, 424, 425, 427, 428, 429, 853, 854, 857, 859, 862, 864, 869, 890, 891, 892, 894, 903, 906, 968, 969, 972, 974, 977, 986, 996, 998, 999, 1001, 1003, 1004, 1010, 1012, 1016, 1017, 1018, 1019, 1020, 1021, 1059, 1060, 1061, 1062, 1063, 1075, 1076, 1107,1108, 1111, 1112, 1115, 1118, 1120, 1123, 1127, 1128, 1179, 1200, said positions being defined with reference to the amino acid sequence set out in SEQ ID NO: 3, wherein the variant polypeptide has at least 70% sequence identity with the amino acid sequence set out in SEQ ID NO: 3, and wherein when measured under the same conditions: a) the ratio between the molar concentration of rebaudioside M and the molar concentration of rebaudioside A produced by a recombinant cell expressing the variant is higher than the ratio between the molar concentration of rebaudioside M and the molar concentration of rebaudioside A produced by a reference cell; and/or b) the ratio between the molar concentration of rebaudioside M and the molar concentration of total steviol glycosides produced by a recombinant cell expressing the variant is higher than the ratio between the molar concentration of rebaudioside M and the molar concentration of total steviol glycosides produced by a reference cell; and a) the ratio between the molar concentration of rebaudioside M and the molar concentration of rebaudioside A produced by a recombinant cell expressing the variant is higher than the ratio between the molar concentration of rebaudioside M and the molar concentration of rebaudioside A produced by a reference cell; and/or b) the ratio between the molar concentration of rebaudioside M and the molar concentration of total steviol glycosides produced by a recombinant cell expressing the variant is higher than the ratio between the molar concentration of rebaudioside M and the molar concentration of total steviol glycosides produced by a reference cell; and wherein the reference cell is a recombinant cell expressing the parent polypeptide.