The Sulfate Transporter Family in Wheat: Tissue-Specific Gene Expression in Relation to Nutrition

Sulfate uptake and distribution in plants are managed by the differential expression of a family of transporters, developmentally, spatially, and in response to sulfur nutrition. Elucidation of the signaling pathways involved requires a knowledge of the component parts and their interactions. Here, the expression patterns of the full complement of sulfate transporters in wheat, as influenced by development and sulfur nutrition, are described. The 10 wheat sulfate transporters characterized here are compared to the gene families for both rice and Brachypodium, for whom full genome information is available. Expression is reported in young seedlings with a focus on roles in uptake from nutrient solution and differential expression in relation to sulfate deprivation. In addition, patterns of expression in all organs at the grain filling stage are reported and indicate differential responses to nutritional signals of the individual transporters in specific tissues and an overall coordination of uptake, storage, and remobilization to deliver sulfur to the developing grain.