Catalase activity and hydrogen peroxide levels are inversely correlated in maize scutella during seed germination.
Temporal patterns of hydrogen peroxide (H2O2) levels and total catalase activity are presented for post-imbibition scutella from six maize inbred lines expressing variable catalase activity. In all lines examined, H2O2 levels were highest during the initial days post-imbibition (1-2 dpi) and decreased thereafter, while total catalase activity was lowest during early dpi (1-2 dpi) and reached maximal activity at 4-6 dpi. In three of the six lines tested, a simple inverse correlation between catalase activity and H2O2 level was significant by Spearman's rank (P < 0.01). In addition to the general decline in H2O2 level throughout the dpi period, a reproducible increase in H2O2 level was observed at 4-5 dpi in five of six lines examined. Mutant lines lacking CAT-3 activity demonstrated a temporal shift in the occurrence of this increase. The role of total catalase (and individual isozymes) in controlling H2O2 levels during germination and the role of H2O2 as a potential regulator of catalase expression during germination are discussed.
Hite
D R
DR
Department of Genetics, North Carolina State University, Raleigh 27695-7614, USA.
Auh
C
C
Scandalios
J G
JG
D002374:Catalase / Q000378:metabolism*; D018525:Germination; D006861:Hydrogen Peroxide / Q000378:metabolism*; D012639:Seeds / Q000502:physiology; D003313:Zea mays / Q000378:metabolism*
D006861:Hydrogen Peroxide; D002374:Catalase