Molecular basis for the CAT-2 null phenotype in maize.

Previous reports have described several maize lines whose developmental patterns of catalase gene expression vary from the "typical" maize line, W64A. Among these variants are the lines A16 and A338, both found to be null for the CAT-2 protein. Identification of a third CAT-2 null line, designated A340, is described. RNA blots and S1 nuclease protection analysis indicate that all three CAT-2 null lines produce a similarly shortened Cat2 transcript. The molecular basis for this aberrant Cat2 transcript is discussed.