Light and sugar regulation of the barley sucrose : fructan 6-fructosyltransferase promoter

Fructans are a class of major storage compounds in many plants including several economically important cereals. Earlier we characterized and cloned the sucrose : fructan 6-fructosyltransferase (6-SFT) of barley (Hordeum vulgare L.), a key enzyme for the synthesis of branched fructans (graminans) typical of many cereals and temperate forage grasses. Here, we describe the cloning of the barley 6-SFT promoter region, by PCR-based genome walking procedures. Using a promoter-reporter gene construct (uidA encoding β-glucuronidase) and microprojectile bombardment of excised barley leaves, we show that the cloned sequence contains the necessary cis acting elements conferring sucrose and light induction of 6-SFT transcription.