RYE CHROMOSOME ARM 3RS ENCODES A HOMODIMERIC INHIBITOR OF INSECT ALPHA-AMYLASE

A new inhibitor of insect alpha-amylase, designated RDAI-1, has been p urified from rye (Secale cereale L.) endosperm. RDAI-1 is homologous t o wheat homodimeric inhibitors. This homology is supported by their si milar N-terminal amino-acid sequences, inhibitory activities towards a mylases from Tenebrio molitor (Coleoptera) and human saliva, and aggre gative properties in gel-filtration chromatography. The gene encoding RDAI-1, IdhaR1, is located on the short arm of chromosome 3R, which is homoeologous with wheat chromosome arms 3BS and 3DS, where the genes for homodimeric inhibitors have been previously mapped.