ABSTRACT
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.
Subject(s)
Catalase/genetics , Isoenzymes/genetics , Phenotype , Zea mays/genetics , Blotting, Northern , Single-Strand Specific DNA and RNA Endonucleases , Transcription, Genetic , Zea mays/enzymologyABSTRACT
A 230-base-pair cDNA representing the 3' end of the Cat2 gene in maize was isolated and used to screen a lambda gt11 cDNA library made from scutellar poly(A)+ RNA. Several clones were subcloned into a pUC12 vector; one of the subclones, pCat2.1c, appears to represent a near-complete sequence of the Cat2 coding region. Immunological screening, hybridization-selection translation, and RNA blot analysis confirmed that pCat2.1c was derived from the Cat2 transcript. The DNA sequence of pCat2.1c was determined. The deduced amino acid sequence shows homology with catalase amino acid sequences from rat liver, bovine liver, human kidney, and yeast.
