it's also said aleurone

The aleurone layer is the outermost layer of the endosperm. Therefore it is also triploid and same as the ploidy of endosperm.

An aleurone is the protein content of the embryo, endosperm or perisperm of cereals.

Jonathan Charles Newman has written:

'Glyceride metabolism and gluconeogenesis in the barley aleurone layer'

Gibberellic acid is found in the embryo of the seed.

Starch is found in the endosperm.

Gibberellic acid activates genes in the DNA of cells in the aleurone layer which then causes amylase to be produced through transcription and translation.

At least I think that's right.