EFFECT OF SULFUR LEVELS ON TRANSGENIC DOUBLE-LOW BRASSICA-NAPUS PLANTS EXPRESSING A SEED-SPECIFIC GENE ENCODING A METHIONINE-RICH 2S ALBUMIN

The effects of supplying varying levels of sulphur to transgenic Brass ica napus plants expressing the Brazil nut 2S albumin in their seeds w ere studied in the field. The aim was to determine if transgenic plant s responded differently to such stress, and whether expression of the transgene would be effected. The transgenic plants were similar to nor mal plants in their response to sulphur stress. Increases in sulphur c oncentration were correlated with an increase in fresh and dry matter quantities as well as an increase in the carbon, nitrogen and sulphur levels in the vegetative parts of the plants. No effect on yield param eters was observed. Increasing sulphur levels resulted in an increase in the glucosinolate content, and shifts in fatty acid composition wer e observed. None of these changes could be correlated with the respons e of the transgene. The expression of the latter was altered at neithe r the mRNA nor the protein levels, presumably because the promoter use d does not respond directly to sulphur level changes. The procedures u sed to create the transgenic plants in this work appear not to result in plants that respond to sulphur stress differently from normal plant s in the ranges studied.