Association of a specific cationic peroxidase isozyme with maize stress and disease resistance responses, genetic identification, and identification of a cDNA coding for the isozyme.
The presence of a pI 9.0 cationic peroxidase isozyme from milk stage pericarp of six susceptible and five resistant inbreds was correlated significantly with previously reported field data on percentage infection by Aspergillus flavus in the inbreds and their hybrids. The isozyme was constitutively expressed in some additional maize tissues and lines examined, and frequently induced by mechanical damage, heat shock, Fusarium proliferatum, and/or Bacillus subtilis in other lines tested. Native/IEF two-dimensional electrophoresis identified the isozyme as the previously genetically identified px5. A cDNA clone expressed in black Mexican sweet (BMS) maize cell cultures produced the pI 9.0 isozyme. In addition to potential use in marker-assisted breeding, enhanced expression of this cationic peroxidase through breeding or genetic engineering may lead to enhanced disease or insect resistance.
Dowd
Patrick F
PF
National Center for Agricultural Utilization Research, Agricultural Research Service, U.S. Department of Agriculture, 1815 North University Street, Peoria, Illinois 61604, USA. dowdpf@ncaur.usda.gov
Johnson
Eric T
ET
D001231:Aspergillus flavus; D001947:Breeding; D002412:Cations; D018076:DNA, Complementary; D015870:Gene Expression; D017343:Genes, Plant; D007526:Isoelectric Point; D007527:Isoenzymes / Q000032:analysis / Q000235:genetics; D009195:Peroxidase / Q000032:analysis* / Q000737:chemistry / Q000235:genetics*; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology; D003313:Zea mays / Q000201:enzymology*
D002412:Cations; D018076:DNA, Complementary; D007527:Isoenzymes; D009195:Peroxidase