[Formation of α-amylase isozymes during germination of barley]

The α-amylase formed in germinating barley has been separated into six isozymes by means of polyacrylamide gel electrophoresis. These isozymes do not appear from the beginning of germination but are formed gradually so that after six days all six α-amylase isozymes are present.When gibberellic acid is added to the culture medium the production of the α-amylase isozymes is accelerated considerably, whereas the addition of kinetin has no influence at all on the formation of the α-amylase isozymes.The α-amylase induced by gibberellic acid in the aleurone layers of isolated barley endosperms apparently consists of five isozymes, a number that does not change upon further incubation.The action of phytohormones such as gibberellic acid and kinetin on the formation of α-amylase and its isozymes during the germination of barley is discussed.